This document discusses disease mitigation measures that have been proposed to lessen the impact of an influenza pandemic, including isolation, quarantine, social distancing, and other actions. It reviews the limited evidence on the effectiveness of such measures from past pandemics and studies. While models provide some guidance, they have significant limitations and cannot predict real-world behavioral or economic impacts. Most mitigation measures would be extremely difficult to implement on a large scale for the months-long duration of a pandemic. Decision-makers must consider not just epidemiological impacts but also logistical feasibility, social consequences, and potential unintended economic and political effects of different response strategies.
There are several key reasons why infectious disease outbreaks have been increasing globally in recent decades. Increased travel, trade, and urbanization have made it easier for pathogens to spread to new areas. Climate change is also enabling some disease-carrying mosquitoes and other animals to thrive in new environments. However, public health organizations have gotten better at detecting and responding to outbreaks early, meaning fewer cases per outbreak overall. Still, underfunding of disease surveillance programs in some areas has allowed certain illnesses to resurge. Continued challenges include poverty, conflict, and environmental degradation. Proper isolation of infectious patients also remains important for control.
The role of influenza in the epidemiology of pneumoniaJoshua Berus
1. The document examines the role of influenza in pneumonia epidemiology using longitudinal influenza and pneumonia incidence data from different time periods and locations in the US.
2. Using a transmission model and likelihood-based inference framework, the analysis found that influenza infection increases an individual's risk of developing pneumonia by around 100-fold, supporting the hypothesis that influenza enhances susceptibility to pneumonia.
3. However, the analysis found no evidence that influenza infection affects the transmission or severity of pneumonia. The consistency of these findings across different datasets and the model's ability to predict pneumonia incidence increases confidence in the conclusion that influenza substantially increases risk of pneumonia for a short period.
Imperial college-covid19-npi-modelling-16-03-2020Wouter de Heij
- The document presents the results of epidemiological modelling to assess the potential impact of non-pharmaceutical interventions (NPIs) aimed at reducing COVID-19 transmission in the UK and US.
- Two fundamental strategies are evaluated: mitigation, which focuses on slowing spread to protect healthcare systems, and suppression, which aims to reverse epidemic growth and maintain low case numbers indefinitely until a vaccine is available.
- Modelling suggests that while mitigation may halve deaths and reduce the healthcare demand peak, hundreds of thousands could still die and healthcare systems would be overwhelmed. Suppression is the preferred option if possible, requiring a combination of social distancing, case isolation and household quarantine.
Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. There are several key methods used in epidemiology including observational studies like cross-sectional studies, case-control studies, and cohort studies which examine disease occurrence without intervention. Experimental studies like randomized controlled trials can also be used to study the effects of interventions on disease.
Dynamics and Control of Infectious Diseases (2007) - Alexander Glaser Wouter de Heij
See also:
- https://food4innovations.blog/2020/03/26/montecarlo-simulaties-tonen-aan-wat-de-onzekerheid-is-en-dat-we-minimaal-1600-maar-misschien-wel-2000-2500-ic-plaatsen-nodig-hebben/
This document discusses the use of subtractive genomics to identify potential drug targets for pathogenic organisms. Subtractive genomics involves subtracting the sequences between a host and pathogen's proteome to identify proteins essential to the pathogen but not present in the host. This approach has been applied to identify drug targets for multi-drug resistant pathogens like Salmonella typhi and Listeria monocytogenes, as well as pathogens with no existing effective drugs like Leishmania donovani and Clostridium botulinum. Identifying novel drug targets through subtractive genomics can help develop new defenses against antibiotic-resistant pathogens and treat diseases currently lacking effective treatments.
This document discusses epidemiology and various definitions of epidemiology from different sources. It discusses how epidemiology has evolved over time to include concerns about infectious diseases, non-infectious diseases, and the ecology of health and disease. Various organizations conducting epidemiological work in the Philippines are mentioned, along with some of their research studies and goals. Additional health-related information about the Philippines is also provided.
Introduction to Epidemiology
At the end of this session the participants will be able to:
Discuss the historical evolution of epidemiology
Explain the usage of epidemiology
List the core epidemiological functions
Explain types of epidemiological studies
There are several key reasons why infectious disease outbreaks have been increasing globally in recent decades. Increased travel, trade, and urbanization have made it easier for pathogens to spread to new areas. Climate change is also enabling some disease-carrying mosquitoes and other animals to thrive in new environments. However, public health organizations have gotten better at detecting and responding to outbreaks early, meaning fewer cases per outbreak overall. Still, underfunding of disease surveillance programs in some areas has allowed certain illnesses to resurge. Continued challenges include poverty, conflict, and environmental degradation. Proper isolation of infectious patients also remains important for control.
The role of influenza in the epidemiology of pneumoniaJoshua Berus
1. The document examines the role of influenza in pneumonia epidemiology using longitudinal influenza and pneumonia incidence data from different time periods and locations in the US.
2. Using a transmission model and likelihood-based inference framework, the analysis found that influenza infection increases an individual's risk of developing pneumonia by around 100-fold, supporting the hypothesis that influenza enhances susceptibility to pneumonia.
3. However, the analysis found no evidence that influenza infection affects the transmission or severity of pneumonia. The consistency of these findings across different datasets and the model's ability to predict pneumonia incidence increases confidence in the conclusion that influenza substantially increases risk of pneumonia for a short period.
Imperial college-covid19-npi-modelling-16-03-2020Wouter de Heij
- The document presents the results of epidemiological modelling to assess the potential impact of non-pharmaceutical interventions (NPIs) aimed at reducing COVID-19 transmission in the UK and US.
- Two fundamental strategies are evaluated: mitigation, which focuses on slowing spread to protect healthcare systems, and suppression, which aims to reverse epidemic growth and maintain low case numbers indefinitely until a vaccine is available.
- Modelling suggests that while mitigation may halve deaths and reduce the healthcare demand peak, hundreds of thousands could still die and healthcare systems would be overwhelmed. Suppression is the preferred option if possible, requiring a combination of social distancing, case isolation and household quarantine.
Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. There are several key methods used in epidemiology including observational studies like cross-sectional studies, case-control studies, and cohort studies which examine disease occurrence without intervention. Experimental studies like randomized controlled trials can also be used to study the effects of interventions on disease.
Dynamics and Control of Infectious Diseases (2007) - Alexander Glaser Wouter de Heij
See also:
- https://food4innovations.blog/2020/03/26/montecarlo-simulaties-tonen-aan-wat-de-onzekerheid-is-en-dat-we-minimaal-1600-maar-misschien-wel-2000-2500-ic-plaatsen-nodig-hebben/
This document discusses the use of subtractive genomics to identify potential drug targets for pathogenic organisms. Subtractive genomics involves subtracting the sequences between a host and pathogen's proteome to identify proteins essential to the pathogen but not present in the host. This approach has been applied to identify drug targets for multi-drug resistant pathogens like Salmonella typhi and Listeria monocytogenes, as well as pathogens with no existing effective drugs like Leishmania donovani and Clostridium botulinum. Identifying novel drug targets through subtractive genomics can help develop new defenses against antibiotic-resistant pathogens and treat diseases currently lacking effective treatments.
This document discusses epidemiology and various definitions of epidemiology from different sources. It discusses how epidemiology has evolved over time to include concerns about infectious diseases, non-infectious diseases, and the ecology of health and disease. Various organizations conducting epidemiological work in the Philippines are mentioned, along with some of their research studies and goals. Additional health-related information about the Philippines is also provided.
Introduction to Epidemiology
At the end of this session the participants will be able to:
Discuss the historical evolution of epidemiology
Explain the usage of epidemiology
List the core epidemiological functions
Explain types of epidemiological studies
Epidemiology and mortality,morbidity slideshare maglinanusha
This document defines epidemiology and describes its approaches and uses. It discusses descriptive and analytical epidemiology and how epidemiology is used to study disease distribution, risk factors, and implement prevention measures. It also outlines key epidemiological terms like incidence, prevalence, and mortality rates and how they are used to measure disease burden and assess community health.
The document discusses key concepts in epidemiology. It begins by defining epidemiology and its objectives, which include studying disease patterns and determinants in populations to aid health planning. It then covers epidemiological terms like incidence, prevalence, reservoirs, modes of transmission and susceptible hosts. Different theories of disease causation are presented, including the germ theory that pathogens cause disease, and the epidemiological triad model showing the interaction between an external agent, host factors and the environment. The document provides an overview of fundamental epidemiological concepts.
Epidemiology is the study of the distribution and determinants of health and disease in populations. It has evolved rapidly in recent decades from focusing only on disease distribution and causation to also examining health events, treatment modalities, and health services. Modern epidemiology identifies risk factors for chronic diseases and evaluates prevention and treatment options to improve population health.
Pandemic Response in the Era of Big Data (Prier, 2015)Kyle Prier
This document discusses pandemic response in the era of big data by exploring global influenza surveillance and information overload. It summarizes how during the 2009 H1N1 pandemic, WHO officials became overwhelmed by the rapid increase in data coming in and resorted to only qualitative indicators from country officials due to insufficient time to analyze the data. This information overload negatively impacted decision making and response efforts. The document then discusses the concepts of information overload, big data, and emerging novel syndromic surveillance systems using social media data like Twitter to monitor influenza trends.
Epidemiology is the study of disease occurrence and distribution in populations. It derives from Greek words meaning "upon people." Key concepts in epidemiology include disease frequency (prevalence and incidence), distribution (who, where, when disease occurs), and determinants (causes and spread). The epidemiological triad of host, agent, and environment, along with their interactions in a disease cycle, help explain how diseases manifest and spread. Understanding epidemiology allows public health efforts to better control health problems.
This document discusses the classification and determinants of disease. It identifies three main ways to classify determinants: primary vs secondary, intrinsic vs extrinsic, and those associated with the host, agent, or environment. Primary determinants have a major effect in inducing disease, while secondary determinants are predisposing or enabling factors. Intrinsic determinants are internal to the host, while extrinsic determinants are external. Virulence refers to an agent's ability to cause disease severity, while pathogenicity is an agent's ability to induce disease. Pathogenicity and virulence can be conditioned intrinsically by an agent's characteristics or extrinsically by environmental factors.
Epidemiology is a scientific discipline that studies the causes and spread of infectious diseases in human populations. It aims to apply knowledge about infectious disease processes to fight against, restrict, and eventually eradicate diseases. The epidemiological method involves observation, description, comparison, statistical analysis, and diagnostic methods to characterize disease processes and evaluate prevention and control measures. Descriptive epidemiology collects data on disease incidence, risk factors, and impact to form hypotheses for prevention, while analytical epidemiology discovers causal relationships between diseases and risk factors. Experimental and mathematical modeling methods are also used.
The document discusses the threat of pandemic influenza and the need for healthcare systems to prepare for disease outbreaks. It notes that recent outbreaks of avian influenza A(H5N1) are a reminder that a human pandemic could occur at any time, causing major suffering and economic losses. Past pandemics like the 1918 Spanish flu prompted authorities to plan for preparedness, but structured planning is still lacking in many healthcare systems. The ability of influenza viruses to mutate and reassort means a new pandemic strain could emerge.
Epidemiology is the study and analysis of the patterns, causes, and effects of health and disease conditions in defined populations. It is the cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences
This document discusses epidemiology and screening. It defines epidemiology as the study of distribution and determinants of health-related states or events in populations. The history and scope of epidemiology are described, including key figures like John Snow. The aims and approaches of epidemiology, like asking questions and making comparisons, are outlined. Concepts around disease causation and the natural history of disease are explained. Finally, the document defines screening as searching for unrecognized disease in healthy individuals and discusses the aims, uses, and types of screening.
The document models the potential impact of non-pharmaceutical interventions on the COVID-19 epidemic in the UK. It finds that without interventions, there could be 23 million cases and 350,000 deaths by December 2021. Individual interventions like school closures or physical distancing may lower transmission rates but may not be enough. A combination of interventions is more effective but lockdown measures that substantially limit contacts outside the home are needed to reduce transmission to sustainable levels and prevent overwhelming health services. Intensive lockdown periods may need to continue for much of the year to control the epidemic.
The document summarizes the problems with pursuing a "community infection approach" or widespread community spread of COVID-19 in Switzerland. It argues that this approach would cause widespread damage to health, society, and the economy for several key reasons: (1) It is unclear if and how long infection leads to lasting immunity; (2) It would lead to a massive health toll in terms of deaths and severe disease; and (3) Containing the spread until effective vaccines are available is more beneficial and in line with protecting public health.
This document discusses self hygiene in epidemic areas. It begins with definitions of key terms like self hygiene, personal hygiene, self care, and epidemic. It then describes major factors that allow viruses to cause epidemics, like human behavior, changes in insect/reservoir populations, weather, technology, and changes in viruses. It discusses challenges of new epidemics and outlines personal hygiene practices, properties of self care, and actual simple self care that can be done in epidemic areas. It concludes with potential nursing diagnoses, interventions, and care related to hygiene.
This document discusses lessons that can be learned from past influenza pandemics and applied to understanding the future course of the COVID-19 pandemic. It outlines three possible scenarios for the future trajectory of COVID-19 based on patterns seen in influenza. Scenario 1 involves repetitive smaller waves over 1-2 years as immunity gradually increases. Scenario 2 consists of a large second peak in cases around 6 months after the first. Scenario 3 follows a seasonal pattern with peaks in winter. The pandemic may last 18-24 months until 60-70% of the population is immune through natural infection or vaccination.
This document discusses epidemiology and communicable disease control in public health nursing. It provides historical context on epidemiology dating back to Hippocrates and outlines key terms and concepts. The document also describes methods of epidemiological investigation and sources of epidemiological information. It examines global and national trends in communicable disease control and prevention as well as major communicable diseases in the US and emerging infectious diseases globally.
The document discusses the history and evolution of theories of disease causation and treatment from ancient Greece to modern times. It describes how theories have progressed from associating disease with humors and elements, to ideas of contagion and miasmas, to the germ theory of disease established by Pasteur and Koch. It also outlines the development of veterinary medicine and changing roles of veterinarians from a focus on individual animal treatment to herd health management, food safety, and animal welfare.
This document evaluates the surveillance components of national and state pandemic preparedness plans based on criteria from the WHO Checklist for Influenza Pandemic Preparedness Planning. Thirty-six national and forty-nine state plans were reviewed. While some plans were more thorough than others, the evaluation found that all plans could benefit from additional surveillance planning. Surveillance will play a key role in pandemic response by identifying cases, characterizing viruses, tracking spread, and monitoring health impacts.
This document discusses community health nursing, epidemiology, communicable disease control, and environmental health. It defines key concepts in epidemiology like causality, risk, and rate of occurrence. It compares the community health nursing and epidemiological processes. It describes modes of transmission for communicable diseases and strategies for prevention. It also outlines major areas related to environmental health like living patterns, work risks, atmospheric quality, water quality, housing, food quality, waste control, and radiation risks.
This document provides an introduction to the course MPH 5101: Epidemiology. It defines epidemiology as the study of the distribution and determinants of health-related states or events in human populations. The document summarizes the historical evolution of epidemiology, from Hippocrates to John Snow. It also lists the key features and uses of descriptive and analytic epidemiology, and components of the epidemiologic triad.
Epidemiology is defined as the study of the distribution and determinants of health-related states or events in populations and the application of this study to control health problems. The key components of an epidemiological model are the agent, host, and environment. Agents can be biological, nutritional, physical, chemical, mechanical, or social. Host factors include demographic, biological, socioeconomic, and lifestyle characteristics. Environments encompass physical, biological, and psychosocial factors. Descriptive epidemiology studies measure disease frequency, distribution over time, place and person. Analytical studies test etiological hypotheses and identify risk factors. Experimental studies manipulate suspected causes to confirm relationships.
Imperial college-covid19-npi-modelling-16-03-2020Mumbaikar Le
This document summarizes the results of epidemiological modelling to assess the potential impact of non-pharmaceutical interventions (NPIs) aimed at reducing COVID-19 transmission in the UK and US. It finds that while mitigation strategies could reduce healthcare demand and deaths, hundreds of thousands may still die and healthcare systems would be overwhelmed. Suppression, including social distancing and case isolation, is the preferred option but would need to be maintained until a vaccine is available, around 18 months. Intermittent distancing may allow temporary relaxation but cases would likely rebound without continuous measures. Experience in China and South Korea shows suppression is possible short-term, but long-term feasibility and economic costs require further analysis.
On July 1, 1665, the lordmayor and aldermen of thecity of Lo.docxvannagoforth
On July 1, 1665, the lordmayor and aldermen of the
city of London put into place a set
of orders “concerning the infec-
tion of the plague,” which was
then sweeping through the popula-
tion. He intended that these
actions would be “very expedient
for preventing and avoiding of
infection of sickness” (1).
At that time, London faced a
public health crisis, with an inade-
quate scientific base in that the
role of rats and their fleas in dis-
ease transmission was unknown.
Nonetheless, this crisis was faced
with good intentions by the top
medical and political figures of
the community.
Daniel Defoe made an observation that could apply to
many public health interventions then and today, “This
shutting up of houses was at first counted a very cruel and
unchristian method… but it was a public good that justi-
fied a private mischief” (1). Then, just as today, a complex
relationship existed between the science of public health
and the practice of public health and politics. We address
the relationship between science, public health, and poli-
tics, with a particular emphasis on infectious diseases.
Science, public health, and politics are not only com-
patible, but all three are necessary to improve the public’s
health. The progress of each area of public health is relat-
ed to the strength of the other areas. The effect of politics
in public health becomes dangerous when policy is dictat-
ed by ideology. Policy is also threatened when it is solely
determined by science, devoid of considerations of social
condition, culture, economics, and public will.
When using the word “politics,” we refer not simply to
partisan politics but to the broader set of policies and sys-
tems. Although ideology is used in many different ways, in
this case, it refers to individual systems of belief that may
color a person’s attitudes and actions and that are not nec-
essarily based on scientific evidence (2).
Public Health Achievements
Science influences public health decisions and conclu-
sions, and politics delivers its programs and messages.
This pattern is obvious in many of public health’s greatest
triumphs of the 20th century, 10 of which were chronicled
in 1999 by the Centers for Disease Control and Prevention
(CDC) as great public health achievements, and several of
which are presented below as examples of policy affecting
successes (3). These achievements remind us of what can
be accomplished when innovation, persistence, and luck
converge, along with political will and public policy.
Vaccination
Childhood vaccinations have largely eliminated once-
common, terrible diseases, such as polio, diphtheria,
measles, mumps, and pertussis (4). Polio is being eradicat-
ed worldwide. The current collaboration between the
World Health Organization, the United Nations Children’s
Fund, CDC, and Rotary International is a political as well
as biological “tour de force,” and eradication of polio in
Nigeria has been threatened by local political struggles and
decisions. ...
Epidemiology and mortality,morbidity slideshare maglinanusha
This document defines epidemiology and describes its approaches and uses. It discusses descriptive and analytical epidemiology and how epidemiology is used to study disease distribution, risk factors, and implement prevention measures. It also outlines key epidemiological terms like incidence, prevalence, and mortality rates and how they are used to measure disease burden and assess community health.
The document discusses key concepts in epidemiology. It begins by defining epidemiology and its objectives, which include studying disease patterns and determinants in populations to aid health planning. It then covers epidemiological terms like incidence, prevalence, reservoirs, modes of transmission and susceptible hosts. Different theories of disease causation are presented, including the germ theory that pathogens cause disease, and the epidemiological triad model showing the interaction between an external agent, host factors and the environment. The document provides an overview of fundamental epidemiological concepts.
Epidemiology is the study of the distribution and determinants of health and disease in populations. It has evolved rapidly in recent decades from focusing only on disease distribution and causation to also examining health events, treatment modalities, and health services. Modern epidemiology identifies risk factors for chronic diseases and evaluates prevention and treatment options to improve population health.
Pandemic Response in the Era of Big Data (Prier, 2015)Kyle Prier
This document discusses pandemic response in the era of big data by exploring global influenza surveillance and information overload. It summarizes how during the 2009 H1N1 pandemic, WHO officials became overwhelmed by the rapid increase in data coming in and resorted to only qualitative indicators from country officials due to insufficient time to analyze the data. This information overload negatively impacted decision making and response efforts. The document then discusses the concepts of information overload, big data, and emerging novel syndromic surveillance systems using social media data like Twitter to monitor influenza trends.
Epidemiology is the study of disease occurrence and distribution in populations. It derives from Greek words meaning "upon people." Key concepts in epidemiology include disease frequency (prevalence and incidence), distribution (who, where, when disease occurs), and determinants (causes and spread). The epidemiological triad of host, agent, and environment, along with their interactions in a disease cycle, help explain how diseases manifest and spread. Understanding epidemiology allows public health efforts to better control health problems.
This document discusses the classification and determinants of disease. It identifies three main ways to classify determinants: primary vs secondary, intrinsic vs extrinsic, and those associated with the host, agent, or environment. Primary determinants have a major effect in inducing disease, while secondary determinants are predisposing or enabling factors. Intrinsic determinants are internal to the host, while extrinsic determinants are external. Virulence refers to an agent's ability to cause disease severity, while pathogenicity is an agent's ability to induce disease. Pathogenicity and virulence can be conditioned intrinsically by an agent's characteristics or extrinsically by environmental factors.
Epidemiology is a scientific discipline that studies the causes and spread of infectious diseases in human populations. It aims to apply knowledge about infectious disease processes to fight against, restrict, and eventually eradicate diseases. The epidemiological method involves observation, description, comparison, statistical analysis, and diagnostic methods to characterize disease processes and evaluate prevention and control measures. Descriptive epidemiology collects data on disease incidence, risk factors, and impact to form hypotheses for prevention, while analytical epidemiology discovers causal relationships between diseases and risk factors. Experimental and mathematical modeling methods are also used.
The document discusses the threat of pandemic influenza and the need for healthcare systems to prepare for disease outbreaks. It notes that recent outbreaks of avian influenza A(H5N1) are a reminder that a human pandemic could occur at any time, causing major suffering and economic losses. Past pandemics like the 1918 Spanish flu prompted authorities to plan for preparedness, but structured planning is still lacking in many healthcare systems. The ability of influenza viruses to mutate and reassort means a new pandemic strain could emerge.
Epidemiology is the study and analysis of the patterns, causes, and effects of health and disease conditions in defined populations. It is the cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences
This document discusses epidemiology and screening. It defines epidemiology as the study of distribution and determinants of health-related states or events in populations. The history and scope of epidemiology are described, including key figures like John Snow. The aims and approaches of epidemiology, like asking questions and making comparisons, are outlined. Concepts around disease causation and the natural history of disease are explained. Finally, the document defines screening as searching for unrecognized disease in healthy individuals and discusses the aims, uses, and types of screening.
The document models the potential impact of non-pharmaceutical interventions on the COVID-19 epidemic in the UK. It finds that without interventions, there could be 23 million cases and 350,000 deaths by December 2021. Individual interventions like school closures or physical distancing may lower transmission rates but may not be enough. A combination of interventions is more effective but lockdown measures that substantially limit contacts outside the home are needed to reduce transmission to sustainable levels and prevent overwhelming health services. Intensive lockdown periods may need to continue for much of the year to control the epidemic.
The document summarizes the problems with pursuing a "community infection approach" or widespread community spread of COVID-19 in Switzerland. It argues that this approach would cause widespread damage to health, society, and the economy for several key reasons: (1) It is unclear if and how long infection leads to lasting immunity; (2) It would lead to a massive health toll in terms of deaths and severe disease; and (3) Containing the spread until effective vaccines are available is more beneficial and in line with protecting public health.
This document discusses self hygiene in epidemic areas. It begins with definitions of key terms like self hygiene, personal hygiene, self care, and epidemic. It then describes major factors that allow viruses to cause epidemics, like human behavior, changes in insect/reservoir populations, weather, technology, and changes in viruses. It discusses challenges of new epidemics and outlines personal hygiene practices, properties of self care, and actual simple self care that can be done in epidemic areas. It concludes with potential nursing diagnoses, interventions, and care related to hygiene.
This document discusses lessons that can be learned from past influenza pandemics and applied to understanding the future course of the COVID-19 pandemic. It outlines three possible scenarios for the future trajectory of COVID-19 based on patterns seen in influenza. Scenario 1 involves repetitive smaller waves over 1-2 years as immunity gradually increases. Scenario 2 consists of a large second peak in cases around 6 months after the first. Scenario 3 follows a seasonal pattern with peaks in winter. The pandemic may last 18-24 months until 60-70% of the population is immune through natural infection or vaccination.
This document discusses epidemiology and communicable disease control in public health nursing. It provides historical context on epidemiology dating back to Hippocrates and outlines key terms and concepts. The document also describes methods of epidemiological investigation and sources of epidemiological information. It examines global and national trends in communicable disease control and prevention as well as major communicable diseases in the US and emerging infectious diseases globally.
The document discusses the history and evolution of theories of disease causation and treatment from ancient Greece to modern times. It describes how theories have progressed from associating disease with humors and elements, to ideas of contagion and miasmas, to the germ theory of disease established by Pasteur and Koch. It also outlines the development of veterinary medicine and changing roles of veterinarians from a focus on individual animal treatment to herd health management, food safety, and animal welfare.
This document evaluates the surveillance components of national and state pandemic preparedness plans based on criteria from the WHO Checklist for Influenza Pandemic Preparedness Planning. Thirty-six national and forty-nine state plans were reviewed. While some plans were more thorough than others, the evaluation found that all plans could benefit from additional surveillance planning. Surveillance will play a key role in pandemic response by identifying cases, characterizing viruses, tracking spread, and monitoring health impacts.
This document discusses community health nursing, epidemiology, communicable disease control, and environmental health. It defines key concepts in epidemiology like causality, risk, and rate of occurrence. It compares the community health nursing and epidemiological processes. It describes modes of transmission for communicable diseases and strategies for prevention. It also outlines major areas related to environmental health like living patterns, work risks, atmospheric quality, water quality, housing, food quality, waste control, and radiation risks.
This document provides an introduction to the course MPH 5101: Epidemiology. It defines epidemiology as the study of the distribution and determinants of health-related states or events in human populations. The document summarizes the historical evolution of epidemiology, from Hippocrates to John Snow. It also lists the key features and uses of descriptive and analytic epidemiology, and components of the epidemiologic triad.
Epidemiology is defined as the study of the distribution and determinants of health-related states or events in populations and the application of this study to control health problems. The key components of an epidemiological model are the agent, host, and environment. Agents can be biological, nutritional, physical, chemical, mechanical, or social. Host factors include demographic, biological, socioeconomic, and lifestyle characteristics. Environments encompass physical, biological, and psychosocial factors. Descriptive epidemiology studies measure disease frequency, distribution over time, place and person. Analytical studies test etiological hypotheses and identify risk factors. Experimental studies manipulate suspected causes to confirm relationships.
Imperial college-covid19-npi-modelling-16-03-2020Mumbaikar Le
This document summarizes the results of epidemiological modelling to assess the potential impact of non-pharmaceutical interventions (NPIs) aimed at reducing COVID-19 transmission in the UK and US. It finds that while mitigation strategies could reduce healthcare demand and deaths, hundreds of thousands may still die and healthcare systems would be overwhelmed. Suppression, including social distancing and case isolation, is the preferred option but would need to be maintained until a vaccine is available, around 18 months. Intermittent distancing may allow temporary relaxation but cases would likely rebound without continuous measures. Experience in China and South Korea shows suppression is possible short-term, but long-term feasibility and economic costs require further analysis.
On July 1, 1665, the lordmayor and aldermen of thecity of Lo.docxvannagoforth
On July 1, 1665, the lordmayor and aldermen of the
city of London put into place a set
of orders “concerning the infec-
tion of the plague,” which was
then sweeping through the popula-
tion. He intended that these
actions would be “very expedient
for preventing and avoiding of
infection of sickness” (1).
At that time, London faced a
public health crisis, with an inade-
quate scientific base in that the
role of rats and their fleas in dis-
ease transmission was unknown.
Nonetheless, this crisis was faced
with good intentions by the top
medical and political figures of
the community.
Daniel Defoe made an observation that could apply to
many public health interventions then and today, “This
shutting up of houses was at first counted a very cruel and
unchristian method… but it was a public good that justi-
fied a private mischief” (1). Then, just as today, a complex
relationship existed between the science of public health
and the practice of public health and politics. We address
the relationship between science, public health, and poli-
tics, with a particular emphasis on infectious diseases.
Science, public health, and politics are not only com-
patible, but all three are necessary to improve the public’s
health. The progress of each area of public health is relat-
ed to the strength of the other areas. The effect of politics
in public health becomes dangerous when policy is dictat-
ed by ideology. Policy is also threatened when it is solely
determined by science, devoid of considerations of social
condition, culture, economics, and public will.
When using the word “politics,” we refer not simply to
partisan politics but to the broader set of policies and sys-
tems. Although ideology is used in many different ways, in
this case, it refers to individual systems of belief that may
color a person’s attitudes and actions and that are not nec-
essarily based on scientific evidence (2).
Public Health Achievements
Science influences public health decisions and conclu-
sions, and politics delivers its programs and messages.
This pattern is obvious in many of public health’s greatest
triumphs of the 20th century, 10 of which were chronicled
in 1999 by the Centers for Disease Control and Prevention
(CDC) as great public health achievements, and several of
which are presented below as examples of policy affecting
successes (3). These achievements remind us of what can
be accomplished when innovation, persistence, and luck
converge, along with political will and public policy.
Vaccination
Childhood vaccinations have largely eliminated once-
common, terrible diseases, such as polio, diphtheria,
measles, mumps, and pertussis (4). Polio is being eradicat-
ed worldwide. The current collaboration between the
World Health Organization, the United Nations Children’s
Fund, CDC, and Rotary International is a political as well
as biological “tour de force,” and eradication of polio in
Nigeria has been threatened by local political struggles and
decisions. ...
When a pandemic sickness emerges in the future, vaccination will be one aspect of a comprehensive public health response. Vaccine Production Helped to Stop Pandemic, Effective vaccine deployment has the ability to save lives and restrict disease transmission in addition to other measures meant to react to and contain a pandemic, such as monitoring
OUTBREAK INVESTIGATION 1
OUTBREAK INVESTIGATION 2
Outbreak Investigation
Introduction
Epidemiology deals with the study of the determinants and distribution of disability or disease in the population groups (Szklo & Nieto, 2014). Epidemiology is one of the core areas in public health study and is essential for the evaluation of the efficacy of the new therapeutic and preventive modalities as well in the new organizational health care delivery patterns. I have for a long time developed a lot of interest in the area towards learning more on finding the causes of diseases and health outcomes in populations. Epidemiology views the individuals collectively, and the community is considered to be patient. The area of public health study is systematic, scientific, and data-driven in analyzing the pattern or frequency of the distributions and the risk factors or causes of specific diseases in the neighborhood, city, school, country, and global levels. Epidemiology handles various areas including environmental exposures, infectious diseases, injuries, non-infectious diseases, natural disasters and terrorism (Szklo & Nieto, 2014). Specifically, this paper explores epidemiology in addressing infectious disease, food-borne illness in the community. Also, the paper examines outbreak investigations as an intervention towards addressing the foodborne illness in the society. Further, an evaluation of the intervention and the expected results are discussed to examine or analyze the contributions of the intervention.
Foodborne Illness
Foodborne illness is any illness that results from food spoilage of the contaminated food. Food can be contaminated by the pathogenic bacteria, contaminated food, parasites, or viruses, as well as natural or chemical toxins including several species of beans, and poisonous mushrooms. In the United States, food-borne illness is estimated to impact negatively over 76 million people annually (Jones, McMillian, Scallan et al., 2007). This is translated to 5,2000 deaths, and 325,000 hospitalizations. However, the true incidence of food-borne illness is unknown. The majority of food-borne illness and most of the deaths are linked to “unknown agents” following the difficulties encountered in the diagnosis a foodborne disease. An estimated $7 billion is lost regarding productivity and medical expenses and is attributed to the most prevalent but diagnosable foodborne illnesses. Comment by Vetter-Smith, Molly J: Reference needed for this statement Comment by Vetter-Smith, Molly J: References needed for these statements
The under diagnosis in foodborne illnesses is further contributed by the majority who has the symptoms and signs of the disease but totally fail to seek medical attention. This circumstance coupled with the global and national distribution of foo.
Imperial college covid19 europe estimates and npi impactValentina Corona
The document summarizes estimates from a model analyzing COVID-19 mortality data from 11 European countries. Key findings include:
- Millions of infections have likely occurred, far more than the number detected. Italy may have had 5.9 million infections (9.8% of population) as of March 28th.
- Non-pharmaceutical interventions have likely reduced the reproduction number (Rt) substantially, though estimates vary by country. On average, interventions represent a 64% reduction from initial Rt of around 3.87.
- Interventions may have averted 59,000 deaths by March 31st across the 11 countries. More data is needed to determine if Rt has been driven below 1 in
This review summarizes evidence on the burden of tuberculosis in populations affected by crises such as armed conflict, displacement, and natural disasters. 51 reports were identified that provided data on tuberculosis notification rates, prevalence, incidence, case fatality ratios, and drug resistance levels among crisis-affected populations. Most studies found elevated notification rates and prevalence compared to reference populations, with incidence and prevalence ratios over 2 in 11 of 15 reports that could make comparisons. Case fatality ratios were generally below 10% and drug resistance levels were usually comparable to background levels, with some exceptions. Analysis of surveillance data from refugee camps also suggested a pattern of excess tuberculosis risk. National tuberculosis notification data analysis found that more intense conflicts were associated with decreases in reported tuberculosis cases
In today's interconnected world, the term "pandemic" has become all too familiar. But what exactly does it mean, and why is it so significant? A pandemic can be defined as a global health crisis caused by the outbreak of an infectious disease that spreads across multiple countries or continents. It is a term that denotes the severity and scale of an epidemic.
To understand the significance of a pandemic, it is essential to differentiate between a pandemic and an epidemic. While both refer to the spread of infectious diseases, an epidemic is typically confined to a specific region or community. In contrast, a pandemic transcends borders, affecting people worldwide.
The impact of a pandemic goes beyond its immediate health consequences. It can disrupt economies, strain healthcare systems, and cause social upheaval. The COVID-19 pandemic serves as a stark reminder of how vulnerable our global society can be in the face of such crises.
this ppt is made by shrikrishna kesharwani , student of urban planning,4th year, Manit , Bhopal,
in this ppt, I have discussed how to do pandemic or epidemic management in detail.,
The document provides an overview of computational epidemiology through three sentences:
It discusses the history and basic concepts of computational epidemiology, from early mathematical models of diseases like smallpox and cholera to modern networked and data-driven approaches. Computational epidemiology uses mathematical and computational methods to study disease transmission and inform public health responses to epidemics. The field aims to attract computing and data scientists to help address open problems through frameworks like graphical dynamical systems.
The document discusses various concepts in epidemiology including:
1) The epidemiologic triangle which includes the agent, host, and environment as factors that influence disease.
2) Observational study designs like cross-sectional studies which assess disease prevalence at a point in time, and cohort studies which follow groups over time to compare disease rates between exposed and unexposed individuals.
3) Key figures in the history of epidemiology like John Snow who conducted seminal investigations tracing cholera outbreaks to contaminated water sources in London in the 1850s.
4) The overall goal of epidemiology is to identify and quantify relationships between exposures and health outcomes in populations in order to control disease. Descriptive and analytical approaches are used.
3 best reasons that describe Will There Be a Next Pandemic? | The Lifescience...The Lifesciences Magazine
Here are 3 best reasons that describe Will There Be a Next Pandemic? ;
1. What role does climate change play in the next pandemic?
2. How do we monitor for the next outbreak?
3. How do we prepare for the next pandemic?
This document discusses the importance of global disease surveillance for national security. It notes that while some disease surveillance systems exist, there is no comprehensive international system with leadership over both human and animal diseases. The lack of coordination and data sharing poses challenges. Intentional disease outbreaks also complicate surveillance efforts, as does the increasing threat of emerging zoonotic diseases. The document argues that improving global disease surveillance should be a high priority for national security.
Epidemic diseases are spread by insects passing on microorganisms like bacteria, viruses, and protozoa when they feed or bite. Mosquitoes in particular spread serious epidemic diseases such as malaria, yellow fever, African sleeping sickness, and West Nile virus. Malaria is one of the deadliest diseases worldwide, spread by the bite of the Anopheles mosquito between dusk and dawn across over 100 countries. Yellow fever is also spread by mosquitoes and causes varied symptoms with most improving after a few days but some experiencing liver and kidney failure. Vaccines exist for these diseases but are not always accessible in developing areas.
The document discusses the Rockwall County Cities Readiness Initiative and its efforts around pandemic preparedness. It outlines the purpose of establishing point of dispensing (POD) sites to rapidly distribute medications and vaccines. It also discusses POD site exercises that were conducted, volunteer roles at POD sites, and educational resources for the public around staying healthy.
The document discusses 5 signature features of past influenza pandemics that can inform pandemic preparedness planning: 1) a shift in the virus subtype, 2) a shift in the highest death rates to younger populations, 3) successive pandemic waves over multiple years, 4) higher transmissibility than seasonal influenza, and 5) differences in impact across geographic regions. Understanding these features is important for optimizing control strategies, prioritizing vaccine distribution, and emphasizing the need for international collaboration on surveillance, data sharing, and response.
This document discusses the 2009 H1N1 influenza pandemic and its impact on pregnant women. It notes that pregnant women were hospitalized at over four times the rate of the general population during the pandemic due to increased risk. Pregnant women infected with H1N1 experienced more severe complications like pneumonia and respiratory distress compared to other groups. Diagnosis is through rapid testing, PCR, or culture of respiratory samples, though treatment should not wait for test results.
This document provides an overview of epidemiological methods and concepts. It defines epidemiology as the study of disease distribution, determinants, and control in populations. Key concepts discussed include agents, hosts, and environments that influence disease occurrence. Descriptive epidemiology aims to describe disease distribution by time, place and person, while analytical epidemiology identifies risk factors. Observational and experimental study designs are classified. The document outlines the scope, aims, history and uses of epidemiology to understand and control health problems.
This document discusses chronic diseases and their control. It notes that chronic diseases have replaced infectious diseases as the leading causes of death in the United States. Chronic diseases are characterized by uncertain causes, multiple risk factors, long development periods, and disability rather than cure. The document outlines the continuum of chronic disease from upstream social determinants to behavioral risks to conditions to diseases to impairment. It provides examples of how chronic diseases and their risk factors are interrelated and complex. Effective control requires addressing many determinants and preventing progression along the continuum.
Similar to Disease Mitigation Measures in the Control of Pandemic Influenza (20)
Este documento repite varias veces la frase "EJEMPLAR PARA DIFUSIÓN NO VÁLIDO PARA VOTAR" y menciona a la "JUNTA ELECTORAL DE LA PROVINCIA DE MENDOZA" y la ciudad de "SAN RAFAEL". Parece tratarse de un ejemplar de muestra o para difusión de algún tipo de material electoral que no es válido para votar según una junta electoral de la provincia de Mendoza en San Rafael.
El documento es un ejemplar de muestra de un boleta electoral para la provincia de Mendoza, Argentina. Se indica que el ejemplar es solo para difusión y no es válido para votar.
Este documento es un ejemplar de muestra de una boleta electoral emitida por la Junta Electoral de la provincia de Mendoza para las elecciones en el distrito de Maipú. El ejemplar no puede utilizarse para votar.
Este documento es un ejemplar de muestra de una boleta electoral para la provincia de Mendoza, Argentina. Proporciona información sobre el distrito de Tunuyán pero no es válido para votar.
El documento es un ejemplar de muestra de un boleta electoral emitida por la Junta Electoral de la provincia de Mendoza para las elecciones en la localidad de Santa Rosa. El ejemplar no puede utilizarse para votar.
Este documento es un ejemplar de muestra de una boleta electoral emitida por la Junta Electoral de la provincia de Mendoza, Argentina. No puede ser utilizada para votar.
El documento es un ejemplar de muestra de una boleta electoral emitida por la Junta Electoral de la provincia de Mendoza para las elecciones en el distrito de Lavalle. El ejemplar no puede utilizarse para votar.
El documento es un ejemplar de muestra de un boleta electoral para la provincia de Mendoza, Argentina, específicamente para la localidad de Malargüe. Se indica claramente que el ejemplar es solo para difusión y no es válido para votar.
El documento es un ejemplar de muestra de un boleta electoral emitida por la Junta Electoral de la provincia de Mendoza para las elecciones en el distrito de General Alvear. El ejemplar no puede ser usado para votar.
El documento provee instrucciones sobre boletas de votación no válidas para votar, indicando que los ejemplares son solo para difusión y no pueden usarse para emitir un voto.
Este documento repite la frase "EJEMPLAR PARA DIFUSIÓN NO VÁLIDO PARA VOTAR" tres veces, indicando que el documento es para difusión pero no válido para votar.
Este documento es un ejemplo de boleta electoral para difusión que no es válida para votar. Se repite el mensaje de que es un ejemplar para difusión y no válido para votar en las elecciones.
El documento es un ejemplar de muestra de un boleta electoral para la provincia de Mendoza, Argentina. Se indica que el ejemplar es solo para difusión y no es válido para votar. También se muestra el nombre del distrito electoral "Junín".
Este documento contiene información sobre la Junta Electoral de la provincia de Mendoza. Se trata de un ejemplar para difusión y no es válido para votar. Indica el lugar de Mendoza, Argentina donde se emitió el documento.
Este documento es un ejemplar de muestra de un boleta electoral para la provincia de Mendoza, Argentina. Proporciona información sobre la Junta Electoral de Mendoza y especifica que el ejemplar no es válido para votar, sino que es solo para difusión.
Este documento es un ejemplar de muestra de un boleta electoral para la provincia de Mendoza, Argentina. Proporciona información sobre el distrito de Guaymallén pero no es válido para votar.
Este documento repite la frase "EJEMPLAR PARA DIFUSIÓN NO VÁLIDO PARA VOTAR" tres veces, aparentemente para enfatizar que el documento no es válido para votar y solo es para difusión.
El documento es un ejemplar de muestra de una boleta electoral emitida por la Junta Electoral de la provincia de Mendoza para su difusión pública. Se indica en la boleta que el ejemplar no es válido para votar.
Este documento propone reducir la edad de imputabilidad en Argentina de 16 a 14 años para abordar mejor los casos de menores que cometen delitos graves. Argumenta que fijar la edad en 14 años estaría más en línea con otros países y que permitiría evitar la impunidad en delitos aberrantes cometidos por menores. El proyecto declara que la legislatura provincial vería con agrado que el Congreso nacional trate de establecer la edad de imputabilidad en 14 años.
The Limited Role of the Streaming Instability during Moon and Exomoon FormationSérgio Sacani
It is generally accepted that the Moon accreted from the disk formed by an impact between the proto-Earth and
impactor, but its details are highly debated. Some models suggest that a Mars-sized impactor formed a silicate
melt-rich (vapor-poor) disk around Earth, whereas other models suggest that a highly energetic impact produced a
silicate vapor-rich disk. Such a vapor-rich disk, however, may not be suitable for the Moon formation, because
moonlets, building blocks of the Moon, of 100 m–100 km in radius may experience strong gas drag and fall onto
Earth on a short timescale, failing to grow further. This problem may be avoided if large moonlets (?100 km)
form very quickly by streaming instability, which is a process to concentrate particles enough to cause gravitational
collapse and rapid formation of planetesimals or moonlets. Here, we investigate the effect of the streaming
instability in the Moon-forming disk for the first time and find that this instability can quickly form ∼100 km-sized
moonlets. However, these moonlets are not large enough to avoid strong drag, and they still fall onto Earth quickly.
This suggests that the vapor-rich disks may not form the large Moon, and therefore the models that produce vaporpoor disks are supported. This result is applicable to general impact-induced moon-forming disks, supporting the
previous suggestion that small planets (<1.6 R⊕) are good candidates to host large moons because their impactinduced disks would likely be vapor-poor. We find a limited role of streaming instability in satellite formation in an
impact-induced disk, whereas it plays a key role during planet formation.
Unified Astronomy Thesaurus concepts: Earth-moon system (436)
Detecting visual-media-borne disinformation: a summary of latest advances at ...VasileiosMezaris
We present very briefly some of the most important and latest (June 2024) advances in detecting visual-media-borne disinformation, based on the research work carried out at the Intelligent Digital Transformation Laboratory (IDT Lab) of CERTH-ITI.
Order : Trombidiformes (Acarina) Class : Arachnida
Mites normally feed on the undersurface of the leaves but the symptoms are more easily seen on the uppersurface.
Tetranychids produce blotching (Spots) on the leaf-surface.
Tarsonemids and Eriophyids produce distortion (twist), puckering (Folds) or stunting (Short) of leaves.
Eriophyids produce distinct galls or blisters (fluid-filled sac in the outer layer)
Measuring gravitational attraction with a lattice atom interferometerSérgio Sacani
Despite being the dominant force of nature on large scales, gravity remains relatively
elusive to precision laboratory experiments. Atom interferometers are powerful tools
for investigating, for example, Earth’s gravity1
, the gravitational constant2
, deviations
from Newtonian gravity3–6
and general relativity7
. However, using atoms in free fall
limits measurement time to a few seconds8
, and much less when measuring
interactions with a small source mass2,5,6,9
. Recently, interferometers with atoms
suspended for 70 s in an optical-lattice mode fltered by an optical cavity have been
demonstrated10–14. However, the optical lattice must balance Earth’s gravity by
applying forces that are a billionfold stronger than the putative signals, so even tiny
imperfections may generate complex systematic efects. Thus, lattice interferometers
have yet to be used for precision tests of gravity. Here we optimize the gravitational
sensitivity of a lattice interferometer and use a system of signal inversions to suppress
and quantify systematic efects. We measure the attraction of a miniature source mass
to be amass = 33.3 ± 5.6stat ± 2.7syst nm s−2, consistent with Newtonian gravity, ruling out
‘screened ffth force’ theories3,15,16 over their natural parameter space. The overall
accuracy of 6.2 nm s−2 surpasses by more than a factor of four the best similar
measurements with atoms in free fall5,6
. Improved atom cooling and tilt-noise
suppression may further increase sensitivity for investigating forces at sub-millimetre
ranges17,18, compact gravimetry19–22, measuring the gravitational Aharonov–Bohm
efect9,23 and the gravitational constant2
, and testing whether the gravitational feld
has quantum properties24.
Dr. Firoozeh Kashani-Sabet is an innovator in Middle Eastern Studies and approaches her work, particularly focused on Iran, with a depth and commitment that has resulted in multiple book publications. She is notable for her work with the University of Pennsylvania, where she serves as the Walter H. Annenberg Professor of History.
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...Sérgio Sacani
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System,and they preserve information about conditions and planet-forming processes in thesolar nebula. In this study, we include comprehensive elemental compositions andfractional-crystallization modeling for iron meteorites from the cores of five differenti-ated asteroids from the inner Solar System. Together with previous results of metalliccores from the outer Solar System, we conclude that asteroidal cores from the outerSolar System have smaller sizes, elevated siderophile-element abundances, and simplercrystallization processes than those from the inner Solar System. These differences arerelated to the formation locations of the parent asteroids because the solar protoplane-tary disk varied in redox conditions, elemental distributions, and dynamics at differentheliocentric distances. Using highly siderophile-element data from iron meteorites, wereconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across theprotoplanetary disk within the first million years of Solar-System history. CAIs, the firstsolids to condense in the Solar System, formed close to the Sun. They were, however,concentrated within the outer disk and depleted within the inner disk. Future modelsof the structure and evolution of the protoplanetary disk should account for this dis-tribution pattern of CAIs.
BIRDS DIVERSITY OF SOOTEA BISWANATH ASSAM.ppt.pptxgoluk9330
Ahota Beel, nestled in Sootea Biswanath Assam , is celebrated for its extraordinary diversity of bird species. This wetland sanctuary supports a myriad of avian residents and migrants alike. Visitors can admire the elegant flights of migratory species such as the Northern Pintail and Eurasian Wigeon, alongside resident birds including the Asian Openbill and Pheasant-tailed Jacana. With its tranquil scenery and varied habitats, Ahota Beel offers a perfect haven for birdwatchers to appreciate and study the vibrant birdlife that thrives in this natural refuge.
Embracing Deep Variability For Reproducibility and Replicability
Abstract: Reproducibility (aka determinism in some cases) constitutes a fundamental aspect in various fields of computer science, such as floating-point computations in numerical analysis and simulation, concurrency models in parallelism, reproducible builds for third parties integration and packaging, and containerization for execution environments. These concepts, while pervasive across diverse concerns, often exhibit intricate inter-dependencies, making it challenging to achieve a comprehensive understanding. In this short and vision paper we delve into the application of software engineering techniques, specifically variability management, to systematically identify and explicit points of variability that may give rise to reproducibility issues (eg language, libraries, compiler, virtual machine, OS, environment variables, etc). The primary objectives are: i) gaining insights into the variability layers and their possible interactions, ii) capturing and documenting configurations for the sake of reproducibility, and iii) exploring diverse configurations to replicate, and hence validate and ensure the robustness of results. By adopting these methodologies, we aim to address the complexities associated with reproducibility and replicability in modern software systems and environments, facilitating a more comprehensive and nuanced perspective on these critical aspects.
https://hal.science/hal-04582287
SAP Unveils Generative AI Innovations at Annual Sapphire ConferenceCGB SOLUTIONS
At its annual SAP Sapphire conference, SAP introduced groundbreaking generative AI advancements and strategic partnerships, underscoring its commitment to revolutionizing business operations in the AI era. By integrating Business AI throughout its enterprise cloud portfolio, which supports the world's most critical processes, SAP is fostering a new wave of business insight and creativity.
Rodents, Birds and locust_Pests of crops.pdfPirithiRaju
Mole rat or Lesser bandicoot rat, Bandicotabengalensis
•Head -round and broad muzzle
•Tail -shorter than head, body
•Prefers damp areas
•Burrows with scooped soil before entrance
•Potential rat, one pair can produce more than 800 offspringsin one year
Continuing with the partner Introduction, Tampere University has another group operating at the INSIGHT project! Meet members of the Industrial Engineering and Management Unit - Aki, Jaakko, Olga, and Vilma!
2. DISEASE MITIGATION MEASURES 367
the social functioning of communities and result in possibly
serious economic problems. Such negative consequences
might be worth chancing if there were compelling evidence
or reason to believe they would seriously diminish the con-
sequences or spread of a pandemic. However, few analyses
have been produced that weigh the hoped-for efficacy of
such measures against the potential impacts of large-scale
or long-term implementation of these measures.
EPIDEMIOLOGIC EXPECTATIONS
Historically, it has been all but impossible to prevent
influenza from being imported into a country or political
jurisdiction, and there has been little evidence that any
particular disease mitigation measure has significantly
slowed the spread of flu. The clinical and epidemiologic
characteristics of influenza explain why:
• The influenza virus is known to spread rapidly from
one person to the next, with a second generation of pa-
tients occurring within 2–4 days following exposure.4
• People infected with influenza may shed virus for 1–2
days before becoming symptomatic.5
• Some flu-infected individuals may be asymptomatic
and so would not be recognized as being infected. In
seasonal flu outbreaks, this group may represent a sig-
nificant proportion of infected people.6,7
Asymptomatic
individuals infected with flu have been shown to shed
virus, although the extent to which these individuals
transmit infection to others is not known.8
• Many patients who are symptomatic are not readily di-
agnosed because their symptoms differ little from indi-
viduals with other respiratory illnesses or allergies.
PANDEMIC PLANNING PREMISES
A new pandemic strain can be expected to spread
rapidly and widely, but it is not likely to be constantly
present in any given area. In both 1918 and 1957, there
were some outbreaks in the U.S. of disease in the late
spring, but the outbreaks were geographically limited.
This has been referred to as the “first wave” of the pan-
demic. There were very few cases in the summer, but in
the autumn a major pandemic wave of disease swept
across the country during a 3–4-month period—the so-
called “second wave.” This was followed by a compara-
tively quiescent period, and then a “third wave” occurred
the following spring. Subsequently, the new strain in
each of these pandemics displaced the then-currently cir-
culating strains and continued to recur every 2–3 years as
seasonal flu, although it caused fewer serious illnesses.9
For planning purposes, the U.S. Department of Health
and Human Services (HHS) and the White House Home-
land Security Council (HSC) make the assumption that the
expected attack rate in the next influenza pandemic would
be comparable to the other 20th century pandemics—that
is, about 25–30% of the population would become ill.10,11
It is also assumed that the virus’s ability to spread rapidly
and widely would be comparable to past pandemics and
that the duration of the outbreak in any given community
would be about 8 weeks.10,11
While government planners
estimate that as much as 30% of the U.S. population would
fall sick from the next pandemic, any given community
would see those illnesses spaced over a period of at least 8
weeks, not all occurring at one time. Since the average du-
ration of illness would be expected to be about 10 days,
only a subset of flu victims in any community would be ill
at once. Given this, even in the peak weeks of a pandemic
it would seem reasonable to expect that no more than 10%
of a community’s population would be ill at any time.
The HHS and HSC documents assume that, in the
worst case, the case-fatality ratio would be equal to that
of 1918 (about 2.5%).10,11
Such data as are available from
the past 300 years show the 1918 influenza pandemic
was, by far, the most lethal.
To date, the current H5N1 influenza case-fatality ratios
have been 50% or more. H5N1 infection has been clini-
cally more severe, and many patients have exhibited
symptoms that differ from those caused by other in-
fluenza strains.12,13
So far, the virus has exhibited little
ability to spread from human to human. It has been
widely assumed that if the current avian strain of virus
did transform into one that is more readily transmissible,
the virus would assume characteristics and case-fatality
rates more closely resembling previous pandemic strains.
A range of possible measures for containing the spread
of influenza during a pandemic are set forth in HHS’s
Pandemic Influenza Plan10
and HSC’s National Strategy
for Pandemic Influenza: Implementation Plan.11
Both
documents outline possible actions that might be taken
during a pandemic to minimize transmission and control
the spread of infection. Disease mitigation measures are
presented as a series of options, but the criteria for pursu-
ing any particular measure are not articulated nor are op-
erational details provided regarding how these measures
should be implemented.
It has been recognized that most actions taken to counter
pandemic influenza will have to be undertaken by local
governments, given that the epidemic response capacity of
the federal government is limited.14
This is reflected in
HHS Secretary Michael Leavitt’s statement at a February
2006 State and Local Pandemic Preparedness Meeting:
“Any community that fails to prepare [for an influenza pan-
demic] with the idea that somehow, in the end, the federal
government will be able to rescue them will be tragically
wrong.”15
But a recent review of the current pandemic in-
3. fluenza plans of 49 states reveals that few explicitly discuss
implementing community mitigation strategies.16
The au-
thors of the review attribute this lack of planning for in-
fluenza in part to “weak central (federal) direction and the
lack of key epidemiological data.”16
One of the better-de-
veloped plans is that of the New York City Department of
Health and Mental Hygiene,17
whose staff considered the
use of disease mitigation measures but decided to incorpo-
rate few of the measures now described in federal plans.
A fundamental premise of disease mitigation that has
been advanced by some in the policymaking community
is that a less intense but more prolonged pandemic may
be easier for society to bear,18
but this is speculative.
CLARIFICATION OF TERMS
There is widespread confusion about the terms used to
describe measures for controlling disease spread. The prin-
cipal confusion is between use of the words quarantine and
isolation. Isolation properly refers only to the confinement
of symptomatic patients in the hospital (or at home) so that
they will not infect others. Quarantine has traditionally
been defined as the separation from circulation in the com-
munity of asymptomatic people who may have been ex-
posed to infection and might—or might not—become ill.
Home quarantine refers to voluntary confinement of
known contacts of influenza cases in their own homes.
Large-scale quarantine typically refers to confinement of
large groups of possibly infected people—for example, all
passengers on an airplane, or the residents of an apartment
building or an entire city—for periods of days to weeks.
In recent years the term social distancing has come
into use. Social distancing has been used to refer to a
range of measures that might serve to reduce contact be-
tween people. These may include closing schools or pro-
hibiting large gatherings, such as church services and
sporting events. Others have used the term to refer to ac-
tions taken to increase the distance of individuals from
each other at the work site or in other locations—for ex-
ample, substituting phone calls for face-to-face meetings
or avoiding hand-shaking. The term has come to describe
fundamentally different approaches to disease mitiga-
tion. This document will refer only to specific interven-
tions rather than to the catch-all term social distancing.
EVALUATION OF DISEASE
MITIGATION MEASURES
Epidemiologic Assessment: Do available data or
experience suggest the measure will work?
It is difficult to evaluate the effectiveness of specific
measures to control disease spread in epidemiologic
terms because of the complex interrelationships between
individuals and groups and the individual biological dif-
ferences in response to influenza. Some historical studies
have tried to evaluate the efficacy of specific influenza
containment efforts,2
and, although they are informative,
the relative paucity of such studies and the differences
between past historical moments and the present limit the
conclusions that can be drawn.
Recently, a number of mathematical models have ex-
amined various combinations of disease mitigation mea-
sures for pandemic influenza.19–21
Such models consist of
computer simulations of disease outbreaks that are devel-
oped from very limited data regarding the epidemiologi-
cal and biological characteristics of influenza and a series
of assumptions about the likely compliance of the popu-
lation, the feasibility of applying various interventions,
and so on. The predictions provided by such models can
vary widely depending on the assumptions that are made
in their construction.
What the computer models cannot incorporate is the
effects that various mitigation strategies might have on
the behavior of the population and the consequent course
of the epidemic. There is simply too little experience to
predict how a 21st century population would respond, for
example, to the closure of all schools for periods of many
weeks to months, or to the cancellation of all gatherings
of more than 1,000 persons. Would these closures serve
to decrease contacts between people and so retard the
spread of the epidemic? Or would those affected spend
more time in malls, in fast-food restaurants, and in other
social settings that might result in more contacts and
more rapid spread of influenza?
No model, no matter how accurate its epidemiologic as-
sumptions, can illuminate or predict the secondary and ter-
tiary effects of particular disease mitigation measures. Nor,
for example, can it assess the potential effects of high ab-
sentee rates resulting from home or regional quarantine on
the functioning integrity of essential services, such as hos-
pital care or provision of food and electrical service to the
community. If particular measures are applied for many
weeks or months, the long-term or cumulative second- and
third-order effects could be devastating socially and eco-
nomically. In brief, models can play a contributory role in
thinking through possible mitigation measures, but they
cannot be more than an ancillary aid in deciding policy.
Logistical Assessment: Is the disease mitigation
measure feasible?
Many communitywide disease mitigation measures
would be intrinsically difficult to implement. Considera-
tion must be given to the resources required for imple-
mentation, to the mechanisms needed to persuade the
public to comply (or to compel the public, if the mea-
INGLESBY ET AL.368
4. DISEASE MITIGATION MEASURES 369
sures are mandatory), and to the length of time that they
would need to be applied. Potential disease mitigation
measures presumably would have to be maintained for
the duration of the epidemic in a community—a pre-
dicted period of 8 or more weeks—or, perhaps, in the
country as a whole—as long as 8 months.18
Recent experiences in endeavoring to quarantine large
numbers of people during the 2003 SARS outbreaks illus-
trate why feasibility must be a central consideration. Cana-
dian health officials implemented a voluntary home quar-
antine in Toronto, where an estimated 30,000 people who
came in contact with SARS cases (fewer than 500 actual
cases in all) were asked to stay home until it became clear
that they were not infected.22
Although the efficacy of the
home quarantine in Toronto is not clear, the public health
resources needed to implement this policy were prodigious,
as it was necessary not only to persuade each family of the
rationale of the measures and inform them how to comply
but also to arrange to provide food and other support ser-
vices. As a result of this and other experiences, medical au-
thorities have expressed doubts about the efficacy and fea-
sibility of large-scale and home quarantines.14,23,24
Social, Economic, and Political Assessment:
What are the possible unintended adverse
societal consequences?
Disease mitigation measures, however well inten-
tioned, have potential social, economic, and political
consequences that need to be fully considered by politi-
cal leaders as well as health officials. Closing schools is
an example. Some have suggested closure might be rec-
ommended for as long as a pandemic persists in a single
community (perhaps 8 weeks) or for as long as a pan-
demic persists in the country (as long as 8 months).18
The
rationale for the strategy is to diminish contacts between
students and so retard epidemic spread. However, if this
strategy were to be successful, other sites where school-
children gather would also have to be closed: daycare
centers, cinemas, churches, fast-food stores, malls, and
athletic arenas. Many parents would need to stay home
from work to care for children, which could result in high
rates of absenteeism that could stress critical services, in-
cluding health care. School closures also raise the ques-
tion of whether certain segments of society would be
forced to bear an unfair share of the disease control bur-
den. A significant proportion of children in lower-income
families rely on school feeding programs for basic nutri-
tion.
Political leaders need to understand the likely benefits
and the potential consequences of disease mitigation
measures, including the possible loss of critical civic ser-
vices and the possible loss of confidence in government
to manage the crisis.
POTENTIAL DISEASE CONTROL
MEASURES: BENEFITS
AND CONSEQUENCES
Large-Scale Community Vaccination
Vaccines are the best mechanism for preventing in-
fluenza infection and spread in the community and for
protecting healthcare workers caring for those who do
become ill. Once an influenza strain capable of sustained
human-to-human transmission emerges, a vaccine spe-
cific to the pandemic strain will need to be made. It is ex-
pected that it will be at least 6 months after the emer-
gence of the pandemic strain before the initial supplies of
vaccine can be produced. Current vaccine manufacturing
techniques and limitations on vaccine production con-
strain the total amount of vaccine that can be manufac-
tured. Special efforts are being made to increase this ca-
pacity,25
but under current conditions, according to the
National Strategy for Pandemic Influenza, it will be as
much as 5 years (i.e., 2011) before domestic vaccine pro-
duction capacity is in place to create enough vaccine for
the entire U.S. population within 6 months of the start of
a pandemic.11
Isolation of Sick People in Hospitals
Beyond widespread vaccination, isolating sympto-
matic influenza patients, either at home or in the hospital,
is probably the most important measure that could be
taken to reduce the transmission and slow the spread of
illness within a community. The sickest (and presumably
most contagious) patients are most likely to seek hospital
care. The critical importance of hospitals in providing
health care during a pandemic cannot be overstated and
has been addressed by a number of sources.26–30
In an influenza epidemic, hospitals will face several
key challenges. First, hospitals must protect their own
staffs from infection and avoid becoming “amplifiers” of
disease. Historically, hospitals have often accelerated the
spread of contagious disease because of the presence of
highly contagious patients and their close proximity to
the medical staff who care for them and to other patients
who are ill and vulnerable to infection.31
Modern hospi-
tals are not designed to accommodate large numbers of
highly contagious patients, and special measures, includ-
ing cohorting of patients, adjustments to HVAC systems,
and use of personal protective gear, will need to be made
to protect healthcare workers and patients from infection.
Second, hospitals must establish strategies for coping
with what will presumably be a large and relatively sus-
tained surge in demand for medical care. At present, hos-
pitals have little capacity to meet such demands.27,30,32
Hospital care will be needed not only for those who are
ill with influenza itself but also for patients with chronic
5. conditions made critical by acute influenza infection. Ac-
commodating the increased demand for hospital care will
require coordination and collaboration between hospitals
in a given region and among hospital leaders, public
health authorities, and elected officials. Some jurisdic-
tions have taken steps to establish the organizational
framework, communication networks, and operational
principles needed to do this,29
but most have not. It is
noteworthy that, in spite of the predominant role that hos-
pitals must play in pandemic response, the federal alloca-
tions for pandemic flu preparedness have included little
financial support either for regional medical care plan-
ning or for the hospitals themselves.33
In 1918–19, even the best-equipped hospitals had lit-
tle to offer flu victims. Today, however, although mod-
ern medicine offers limited remedies for influenza, the
availability of oxygen, ventilators, antibiotics, and par-
enteral fluids could make a critical difference in surviv-
ing flu, especially among those with underlying chronic
disease.
It has been suggested that alternative care sites, such as
gymnasiums and armories, could lessen the demand on
hospitals.10,34
In 1918, such alternative care facilities
were set up in many cities. However, patients housed in
alternative sites received little more than food and water.
Such sites realistically would represent alternatives to
home care, not hospital care, given the practical prob-
lems of safely managing services such as respiratory sup-
port, intravenous medication, oxygen, and the like out-
side of a hospital setting. A major challenge for all
authorities charged with managing a pandemic will be
how to allot scarce, possibly life-saving medical re-
sources and how to maintain hospitals’ capacity to care
for critically ill flu victims while continuing to provide
other essential medical services.
Home Isolation of Sick People
In light of the expected shortages of medical beds and
personnel, home isolation of non–critically ill influenza
patients would be necessary in a major pandemic. A pol-
icy that persuades sick individuals to voluntarily stay at
home unless they are critically ill would allow hospitals
to focus efforts on those most seriously threatened.
There are a number of logistical considerations that
could prevent people from being able to remain isolated
in their homes. Special measures would be needed to pro-
vide basic medical and food supplies, perhaps through
the use of neighborhood volunteers and supplemented by
communication by phone or internet. It may not be easy
to persuade those without paid sick leave (some 59 mil-
lion persons35
) to absent themselves from work, unless
employers address this problem directly. A recent review
of state pandemic influenza plans found that only one-
third of the 49 states examined have explicit plans to en-
courage voluntary home isolation.16
Use of Antiviral Medications
Antiviral drugs for influenza are available in limited
quantities. Data on how antivirals might perform in the
prevention or treatment of the H5N1 strain are scant.
Prominent authorities think the likelihood of “quench-
ing” an emergent pandemic strain through the rapid, re-
gionwide use of antivirals is low because of technical and
logistical difficulties, even if the pandemic strain proves
to be sensitive to such drugs.36
Several countries have
recommended that the top priority for antivirals is to treat
the ill.37,38
If antivirals were to be used for prevention, it
would imply the need for much longer administration of
the drug to cover the period of a community epidemic.
Specifically, using oseltamivir as the most available ex-
ample, the quantity of antivirals used to prevent infection
in a single healthcare worker during an 8–10-week epi-
demic period would serve to treat an estimated 5 to 7 pa-
tients (assumes prophylaxis with 75 mg, twice daily, for
8–10 weeks versus treatment with 150 mg, twice daily,
for 5 days).39
Moreover, available data indicate that antiviral treat-
ment is effective only if antivirals are given within 24–48
hours after onset of initial symptoms.40
Some authorities
doubt the feasibility of administering the drugs soon
enough to make a difference during a pandemic.16,32,41
Because of this concern, at least one Canadian teaching
hospital is planning to use all its antiviral stocks for pro-
phylaxis of healthcare workers.42
The European Union,
on the other hand, decided not to stockpile any antiviral
medicines, although some European countries have done
so.43
The effectiveness and optimal use of antivirals remain
uncertain because of several factors: the propensity of the
influenza virus to mutate, thus increasing the possibility
that resistance could develop; the quantities of antivirals
required for prophylaxis; and the logistical challenges in-
volved in providing sufficiently rapid treatment. Contex-
tual variables that cannot be predicted ahead of time—
such as the quantity of medicines available and the
development of resistance—will probably determine
antiviral strategy.
Hand-Washing and Respiratory Etiquette
The influenza virus actually survives on the hands for
less than 5 minutes,4
but regular hand-washing is a com-
monsense action that should be widely followed. It has
been shown to reduce the transmission of respiratory ill-
ness in a military trainee setting,44
although there are no
data to demonstrate that hand-washing deters the spread
of influenza within a community.
INGLESBY ET AL.370
6. DISEASE MITIGATION MEASURES 371
General respiratory hygiene, such as covering one’s
mouth when coughing and using disposable paper tis-
sues, is widely believed to be of some value in diminish-
ing spread, even though there is no hard evidence that
this is so.
Large-Scale Quarantine Measures
There are no historical observations or scientific stud-
ies that support the confinement by quarantine of groups
of possibly infected people for extended periods in order
to slow the spread of influenza. A World Health Organi-
zation (WHO) Writing Group, after reviewing the litera-
ture and considering contemporary international experi-
ence, concluded that “forced isolation and quarantine are
ineffective and impractical.”2
Despite this recommenda-
tion by experts, mandatory large-scale quarantine contin-
ues to be considered as an option by some authorities and
government officials.35,43
The interest in quarantine reflects the views and condi-
tions prevalent more than 50 years ago, when much less
was known about the epidemiology of infectious diseases
and when there was far less international and domestic
travel in a less densely populated world. It is difficult to
identify circumstances in the past half-century when
large-scale quarantine has been effectively used in the
control of any disease. The negative consequences of
large-scale quarantine are so extreme (forced confine-
ment of sick people with the well; complete restriction of
movement of large populations; difficulty in getting crit-
ical supplies, medicines, and food to people inside the
quarantine zone) that this mitigation measure should be
eliminated from serious consideration.
Home Quarantine
Voluntary home quarantine would be requested of indi-
viduals who are asymptomatic but who have had substan-
tial contact with a person who has influenza—primarily
household members. The aim of voluntary home quaran-
tine is to keep possibly contagious, but still asymptomatic,
people out of circulation. This sounds logical, but this mea-
sure raises significant practical and ethical issues.
If implemented on a communitywide scale, logistical
requirements related to ensuring that quarantined house-
holds across a community had appropriate care and
support would be necessary. How compliant the public
might be is uncertain. Parents would presumably be will-
ing to stay home and care for sick children, but it is not
known, for example, whether college students would
agree to be interned with infected dorm-mates.
Even if home quarantine were generally acceptable to
the community, individuals may not have the economic re-
sources to stay at home. Few employers currently have
provisions for paid absence unless the workers themselves
are ill. For those who are hourly workers or who are self-
employed, the potential loss of wages as a result of having
to stay home simply because an individual had had contact
with sick people might not be acceptable or feasible.
Home quarantine also raises ethical questions. Imple-
mentation of home quarantine could result in healthy, un-
infected people being placed at risk of infection from sick
household members. Practices to reduce the chance of
transmission (hand-washing, maintaining a distance of 3
feet from infected people, etc.) could be recommended,
but a policy imposing home quarantine would preclude,
for example, sending healthy children to stay with rela-
tives when a family member becomes ill. Such a policy
would also be particularly hard on and dangerous to peo-
ple living in close quarters, where the risk of infection
would be heightened.
Travel Restrictions
Travel restrictions, such as closing airports and screen-
ing travelers at borders, have historically been ineffec-
tive. The World Health Organization Writing Group
concluded that “screening and quarantining entering
travelers at international borders did not substantially de-
lay virus introduction in past pandemics . . . and will
likely be even less effective in the modern era.”2
Similar conclusions were reached by public health au-
thorities involved in the international efforts to control
SARS. Canadian health authorities report that “available
screening measures for SARS were limited in their effec-
tiveness in detecting SARS among inbound or outbound
passengers from SARS-affected areas.”45
A review by a
WHO Working Group on SARS also concluded that “en-
try screening of travelers through health declarations or
thermal scanning at international borders had little docu-
mented effect on detecting SARS cases.”46
The authors have concluded in a previous analysis47
that screening individuals on domestic interstate flights
for symptoms of flu, as has been proposed in revisions to
the Federal Quarantine Rule (42 CFR Parts 70 and 71),48
would not be effective and would have serious adverse
consequences.
It is reasonable to assume that the economic costs of
shutting down air or train travel would be very high, and
the societal costs involved in interrupting all air or train
travel would be extreme. Shutting down public trans-
portation for an extended period is not an option in many
cities. In New York City, an average of 4.7 million peo-
ple ride the subway each weekday;49
the Los Angeles
Metro averages 1.3 million riders daily.50
Prohibition of Social Gatherings
During seasonal influenza epidemics, public events
with an expected large attendance have sometimes been
7. cancelled or postponed, the rationale being to decrease
the number of contacts with those who might be conta-
gious. There are, however, no certain indications that
these actions have had any definitive effect on the sever-
ity or duration of an epidemic. Were consideration to be
given to doing this on a more extensive scale and for an
extended period, questions immediately arise as to how
many such events would be affected. There are many so-
cial gatherings that involve close contacts among people,
and this prohibition might include church services, ath-
letic events, perhaps all meetings of more than 100 peo-
ple. It might mean closing theaters, restaurants, malls,
large stores, and bars. Implementing such measures
would have seriously disruptive consequences for a com-
munity if extended through the 8-week period of an epi-
demic in a municipal area, let alone if it were to be ex-
tended through the nation’s experience with a pandemic
(perhaps 8 months).22
In the event of a pandemic, atten-
dance at public events or social gatherings could well de-
crease because people were fearful of becoming infected,
and some events might be cancelled because of local con-
cerns. But a policy calling for communitywide cancella-
tion of public events seems inadvisable.
School Closures
In previous influenza epidemics, the impact of school
closings on illness rates has been mixed.2
A study from
Israel reported a decrease in respiratory infections after a
2-week teacher strike, but the decrease was only evident
for a single day.51
On the other hand, when schools
closed for a winter holiday during the 1918 pandemic in
Chicago, “more influenza cases developed among pupils
. . . than when schools were in session.”2,52
Schools are often closed for 1–2 weeks early in the de-
velopment of seasonal community outbreaks of influenza
primarily because of high absentee rates, especially in el-
ementary schools, and because of illness among teachers.
This would seem reasonable on practical grounds. How-
ever, to close schools for longer periods is not only im-
practicable but carries the possibility of a serious adverse
outcome. For example, for working parents, school
serves as a form of day care and, in some areas, a source
of nutritional meals for children from lower-income fam-
ilies. In 2005, some 29.5 million children were fed
through the National School Lunch Program; 9.3 million
children received meals as part of the School Breakfast
Program.53
A portion of America’s workforce would be
unable to go to work as long as children were out of
schools. Heightened absentee rates could cripple essen-
tial service industries. Teachers might not be paid and a
great many hourly workers (mall and fast-food employ-
ees; school janitorial, security, and kitchen staff; bus dri-
vers) would face particular financial hardship.
Maintaining Personal Distance
It has been recommended that individuals maintain a
distance of 3 feet or more during a pandemic so as to di-
minish the number of contacts with people who may be
infected.10,54
The efficacy of this measure is unknown. It
is typically assumed that transmission of droplet-spread
diseases, such as influenza, is limited to “close con-
tacts”—that is, being within 3–6 feet of an infected per-
son.4
Keeping a space of 3 feet between individuals
might be possible in some work environments, but it is
difficult to imagine how bus, rail, or air travelers could
stay 3 feet apart from each other throughout an epidemic.
And such a recommendation would greatly complicate
normal daily tasks like grocery shopping, banking, and
the like.
Use of Masks and Personal
Protective Equipment
Masks and other personal protective equipment (PPE)
are essential for controlling transmission of influenza in
hospitals. For people who work in hospitals, current CDC
guidelines for influenza infection control recommend
droplet precautions, including the use of surgical masks.
But HHS planning guidelines also rightly acknowledge that
the uncertainties regarding the potential of virus transmis-
sion at the start of a new pandemic would recommend that
airborne precautions be used in hospitals—that is, N95
masks (already in short supply)7
or powered air purifying
respirators (PAPRs).10
Patients would be advised to wear
surgical masks to diminish the number of infectious respi-
ratory particles being dispersed into the air, thereby dimin-
ishing the likelihood of further spread.55
In Asia during the SARS period, many people in the
affected communities wore surgical masks when in pub-
lic. But studies have shown that the ordinary surgical
mask does little to prevent inhalation of small droplets
bearing influenza virus.56
The pores in the mask become
blocked by moisture from breathing, and the air stream
simply diverts around the mask. There are few data avail-
able to support the efficacy of N95 or surgical masks out-
side a healthcare setting. N95 masks need to be fit-tested
to be efficacious and are uncomfortable to wear for more
than an hour or two.55,57
More important, the supplies of
such masks are too limited to even ensure that hospitals
will have necessary reserves.58
COMMUNITY RESPONSE TO
A PANDEMIC: A SUMMARY
OF POSSIBLE ACTIONS
There is no question but that another influenza pan-
demic will occur and that every community needs to be
INGLESBY ET AL.372
8. DISEASE MITIGATION MEASURES 373
prepared for that eventuality. Influenza is unlike any
other disease epidemic in the rapidity with which it
spreads and, as it emerges, the number of illnesses that it
can cause over a period of a few months. It is unpre-
dictable as to when a pandemic might begin. It could be
next autumn or it may not be for a number of years. The
world has weathered three pandemics during the past
century and will certainly surmount the next one. How
much damage the pandemic will cause depends to a large
extent on the state of readiness of each community and
each metropolitan region and the efficacy and reason-
ableness of its response. The following is a synopsis of
the authors’ judgments regarding possible disease miti-
gation measures.
Vaccination. Vaccination is, by far, the most important
preventive measure, but pandemic strain vaccine will not
be available for at least the next season. Meanwhile,
communitywide use of the seasonal influenza vaccine is
desirable, as it is likely that outbreaks of seasonal flu will
occur even if there is pandemic influenza.
Provision for isolation and medical care of in-
fluenza patients. A Regional Health Care Operations
Committee27
is a priority need to assure collaboration
and cooperation across the community (hospitals, med-
ical care providers, Red Cross, law enforcement, me-
dia, and others), both for advanced planning and during
the epidemic to assure that the large numbers of flu-in-
fected patients can be cared for in hospital, at home, or
in special facilities. Special arrangements are needed
for expanding surge capacity in hospitals, for support
to permit home care of patients, and for the provision
of additional volunteer healthcare staff.
A communication strategy and plans. Open and fre-
quent communications with the public are essential. This
involves regular press conferences, hot lines, and provi-
sion of information through civic leaders, churches,
schools, and businesses. An important message is to re-
quest that all who are ill remain isolated at home or in the
hospital but to encourage others to continue to come to
work so that essential services can be sustained.
Closure of schools. It has been the practice in many
communities to close the schools for 10–14 days at the
beginning of an epidemic of seasonal flu, primarily be-
cause of the number of both teachers and pupils who are
absent. This is a reasonable initiative, often expected in
many communities, that also serves to demonstrate ac-
tion on the part of officials. Closing schools for longer
periods in hopes of mitigating the epidemic by decreas-
ing contacts among students is not warranted unless all
other likely points of assembly are closed (e.g., malls,
fast-food restaurants, churches, recreation centers, etc.).
Such widespread closures, sustained throughout the pan-
demic, would almost certainly have serious adverse so-
cial and economic effects.
Hand-washing and respiratory hygiene. Everyone
should be encouraged to wash their hands after coming in
contact with people who are ill and to cover their mouths
when coughing or sneezing.
Cancelling or postponing meetings or events in-
volving large numbers of people. Intuitively, this
would appear to be a helpful adjunct to reduce contacts
among people and so mitigate the effects of the epi-
demic. However, individuals normally have a great
many contacts throughout the community on a daily
basis: shopping in stores, attending church, traveling
on public transport, and so on. Recognizing that the
spread of influenza is primarily by person-to-person
contact, any one individual, even in a large gathering,
would have only a limited number of such close en-
counters with infected people. Thus, cancelling or
postponing large meetings would not be likely to have
any significant effect on the development of the epi-
demic. While local concerns may result in the closure
of particular events for logical reasons, a policy direct-
ing communitywide closure of public events seems in-
advisable.
Quarantine. As experience shows, there is no basis for
recommending quarantine either of groups or individu-
als. The problems in implementing such measures are
formidable, and secondary effects of absenteeism and
community disruption as well as possible adverse conse-
quences, such as loss of public trust in government and
stigmatization of quarantined people and groups, are
likely to be considerable.
Screening passengers at borders or closing air or rail
hubs. Experience has shown that these actions are not ef-
fective and could have serious adverse consequences;
thus, they are not recommended.
An overriding principle. Experience has shown that
communities faced with epidemics or other adverse
events respond best and with the least anxiety when the
normal social functioning of the community is least dis-
rupted. Strong political and public health leadership to
provide reassurance and to ensure that needed medical
care services are provided are critical elements. If either
is seen to be less than optimal, a manageable epidemic
could move toward catastrophe.
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Manuscript received July 1, 2006;
accepted for publication September 5, 2006.
Address reprint requests to:
Jennifer B. Nuzzo, SM
Senior Analyst
Center for Biosecurity of UPMC
Pier IV Building, Suite 210
621 E. Pratt St.
Baltimore, MD 21202
E-mail: jnuzzo@upmc-biosecurity.org