steps in epidemic investigation
Prepare for field work
Confirm the existence of an outbreak
Verify the diagnosis and determine the etiology of the disease.
Define the population at risk
Develop case definition, start case finding, and collect information on the cases(after choosing study design)
Describe person, place and time (by questionnaire)
Evaluation of ecological factors
Formulate several possible hypothesis hypotheses.
Test hypotheses using analytical study
Refine hypotheses and carry out additional studies
Draw conclusions to explain the causes or determinants of outbreak based on clinical, laboratory, epidemiological & environmental evidence
Report and recommend appropriate control measures to concerned authorities at the local/national, and if appropriate at international levels
Communication of the findings
Follow up of the recommendation to assure implementation of control measures
This document outlines the steps and objectives for investigating an epidemic outbreak. It details verifying diagnoses, confirming the epidemic's existence, defining the at-risk population, rapidly searching for all cases and their characteristics, analyzing the data, formulating hypotheses, testing hypotheses, evaluating ecological factors, further investigating the population at risk, writing reports, and implementing control measures. The overall goal is to determine the cause and transmission modes of the epidemic in order to prevent future occurrences.
This document provides an overview of public health surveillance. It defines surveillance as the ongoing collection, analysis, and interpretation of health data to inform public health programs and actions. The document outlines the historical origins of surveillance dating back to ancient Greece. It describes various types of surveillance including community-level surveillance, routine reporting systems, active and passive surveillance, sentinel surveillance, and surveys. It also discusses the integrated disease surveillance program in India and how it aims to strengthen surveillance systems at the state and district levels.
This document discusses healthcare-associated infections (HAIs) and outbreak investigations. It defines key terms like clusters, outbreaks, and epidemics. It also outlines the reasons to investigate outbreaks, how to recognize them, and the goals and steps of investigations. The steps include defining cases, identifying cases, analyzing person, place and time factors, developing and evaluating hypotheses, implementing controls, and communicating findings. The overall purpose is to identify the cause of the outbreak and implement measures to control it.
The document defines key terms related to epidemics such as epidemic, endemic, outbreak, sporadic, and pandemic. It discusses the iceberg concept of infectious disease and explains that only a small portion of cases are clinically apparent. The levels of response to different disease triggers are outlined. The document also covers the objectives and steps of an epidemic investigation including developing a case definition, confirming the existence of an epidemic, defining the population at risk, rapidly searching for cases, analyzing data through epidemiological curves, and formulating and testing hypotheses. Control measures and the importance of forecasting and preventing future epidemics are also summarized.
outbreak investigation - types of epidemics and investigating themTimiresh Das
This document discusses an upcoming presentation on outbreak investigation. It begins with definitions of key terms like epidemic, outbreak, endemic, and pandemic. It then discusses determinants of disease outbreaks and types of epidemics. The objectives, steps, and examples of outbreak investigation are provided. Various factors related to outbreaks like incubation period, quarantine, herd immunity, and triggers for surveillance are defined.
The document describes the steps taken to investigate an outbreak of jaundice in Rohtak, India. People first noticed an unusual occurrence of jaundice cases that had not been seen in over 10 years. A house-to-house survey confirmed it was an outbreak. Laboratory tests of water samples found one-third failed orthotolidine tests and 3 of 5 samples had unsafe coliform counts. Additional observations revealed poor sanitation practices in the community that could have contributed to the spread of the disease.
An epidemic curve (or epi curve) is a graphical depiction of the number of illness cases by date of onset that can help characterize outbreaks. The shape and features of the curve can reveal the pattern of spread (e.g. common source, point source, propagated), magnitude, outliers, time trends, and estimate the exposure period. Epi curves are useful for outbreak investigation and response.
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 outlines the steps and objectives for investigating an epidemic outbreak. It details verifying diagnoses, confirming the epidemic's existence, defining the at-risk population, rapidly searching for all cases and their characteristics, analyzing the data, formulating hypotheses, testing hypotheses, evaluating ecological factors, further investigating the population at risk, writing reports, and implementing control measures. The overall goal is to determine the cause and transmission modes of the epidemic in order to prevent future occurrences.
This document provides an overview of public health surveillance. It defines surveillance as the ongoing collection, analysis, and interpretation of health data to inform public health programs and actions. The document outlines the historical origins of surveillance dating back to ancient Greece. It describes various types of surveillance including community-level surveillance, routine reporting systems, active and passive surveillance, sentinel surveillance, and surveys. It also discusses the integrated disease surveillance program in India and how it aims to strengthen surveillance systems at the state and district levels.
This document discusses healthcare-associated infections (HAIs) and outbreak investigations. It defines key terms like clusters, outbreaks, and epidemics. It also outlines the reasons to investigate outbreaks, how to recognize them, and the goals and steps of investigations. The steps include defining cases, identifying cases, analyzing person, place and time factors, developing and evaluating hypotheses, implementing controls, and communicating findings. The overall purpose is to identify the cause of the outbreak and implement measures to control it.
The document defines key terms related to epidemics such as epidemic, endemic, outbreak, sporadic, and pandemic. It discusses the iceberg concept of infectious disease and explains that only a small portion of cases are clinically apparent. The levels of response to different disease triggers are outlined. The document also covers the objectives and steps of an epidemic investigation including developing a case definition, confirming the existence of an epidemic, defining the population at risk, rapidly searching for cases, analyzing data through epidemiological curves, and formulating and testing hypotheses. Control measures and the importance of forecasting and preventing future epidemics are also summarized.
outbreak investigation - types of epidemics and investigating themTimiresh Das
This document discusses an upcoming presentation on outbreak investigation. It begins with definitions of key terms like epidemic, outbreak, endemic, and pandemic. It then discusses determinants of disease outbreaks and types of epidemics. The objectives, steps, and examples of outbreak investigation are provided. Various factors related to outbreaks like incubation period, quarantine, herd immunity, and triggers for surveillance are defined.
The document describes the steps taken to investigate an outbreak of jaundice in Rohtak, India. People first noticed an unusual occurrence of jaundice cases that had not been seen in over 10 years. A house-to-house survey confirmed it was an outbreak. Laboratory tests of water samples found one-third failed orthotolidine tests and 3 of 5 samples had unsafe coliform counts. Additional observations revealed poor sanitation practices in the community that could have contributed to the spread of the disease.
An epidemic curve (or epi curve) is a graphical depiction of the number of illness cases by date of onset that can help characterize outbreaks. The shape and features of the curve can reveal the pattern of spread (e.g. common source, point source, propagated), magnitude, outliers, time trends, and estimate the exposure period. Epi curves are useful for outbreak investigation and response.
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
An outbreak of Burkholderia cepacia bloodstream infections occurred among newborns in the NICU, with 16 of 59 newborns infected over a month. This was a significant increase over the unit's typical infection rate of 2% per month. The ICC nurse investigated by learning about B. cepacia, verifying the diagnoses, establishing the outbreak, and defining cases. Preliminary findings identified a cluster of infections in October, with all blood cultures from within 24 hours of birth testing positive for B. cepacia. The source and mode of transmission were still unknown.
1) The document discusses surveillance in public health and describes its key components and purposes. Surveillance involves the systematic collection, analysis, and interpretation of health data to provide information for action.
2) An effective surveillance system is simple, flexible, timely, and produces high-quality data. It addresses an important public health problem and accomplishes its objectives of understanding disease trends, detecting outbreaks, and evaluating control measures.
3) The document outlines how to establish a surveillance system, including selecting priority diseases, defining standard case definitions, and developing regular reporting and data dissemination processes. Both passive and active surveillance methods are described.
The document outlines the basic steps for investigating disease outbreaks. It discusses establishing a team with roles like epidemiologist, microbiologist, and environmental health specialists. The steps of an outbreak investigation include preparing, confirming the outbreak, verifying diagnoses, establishing case definitions, finding cases, descriptive epidemiology, developing and evaluating hypotheses, implementing control measures, and communicating findings. Key factors in investigating outbreaks are determining exposure time, disease onset, and incubation period. Effective communication between team members is also emphasized.
The 10-step approach to outbreak investigations involves:
1) Identifying an investigation team and resources.
2) Establishing the existence of an outbreak.
3) Verifying the diagnosis, constructing a case definition, and finding cases systematically.
Descriptive epidemiology is then used to develop hypotheses, which are evaluated through additional studies if needed, before implementing control measures, communicating findings, and maintaining surveillance to confirm the outbreak has ended. Being systematic and following these steps is key to determining the source and controlling outbreaks.
Life is full of curves and thus the epidemiology. However, some curves are important as Epidemic Curves and Survival Curves. This presentation is an attempt to know about epidemic curves.
Epidemiology is the study and analysis of the patterns, causes, and effects of health, disease & production conditions in defined populations, in terms of space and temporality.
This document discusses the concepts of association and causation in epidemiology. It defines key terms like correlation, relative risk, odds ratio, and attributable risk which are used to measure the strength of association between different factors. It also differentiates between association and causation, explaining that correlation does not necessarily imply causation. The document outlines different types of causal relationships like necessary and sufficient, necessary but not sufficient, and neither necessary nor sufficient. It also discusses approaches used to study disease etiology and evaluate evidence for a causal relationship.
Descriptive epidemiology is the first phase of epidemiological investigation which aims to observe disease distribution in a population and identify characteristics associated with disease. It involves defining the population and disease, describing disease occurrence by time, place and person, measuring disease burden, comparing data to indices, and formulating hypotheses about potential causes. Key aspects include examining time trends, geographical variation, and characteristics of individuals with disease like age and sex. The goal is to understand basic features of a health problem and generate ideas about causal factors.
A great presentation from a well versed friend in research and EBM, Dr Yaser Faden.
This is a simple introduction to study design with an accompanying workshop to simplify the different types of research study designs.
This document discusses causation in epidemiology. It defines causation as an event, condition, or characteristic that plays an important role in producing a disease. A cause can be sufficient, meaning it inevitably produces the disease, or necessary, meaning the disease cannot develop without it. Most diseases have multiple contributing factors rather than a single cause. Guidelines for determining a causal relationship include considering the temporal relationship between cause and effect, consistency of association, strength of association, and whether removing the potential cause reduces disease risk. Correctly establishing causation is important for disease prevention and control.
History Of Epidemiology for Graduate and Postgraduate studentsTauseef Jawaid
This document provides a summary of the history of epidemiology from ancient times to the present. It describes key figures and discoveries such as Hippocrates' association of disease with environment, Jenner's pioneering of vaccination, Snow's mapping of a cholera outbreak to a contaminated well. More recent developments discussed include the founding of the U.S. Public Health Service, landmark studies like the Tuskegee syphilis study, and future challenges of globalization and overcrowding facilitating disease spread.
This document provides an overview of the key steps involved in research methodology. It discusses 14 steps that should be followed in research studies: 1) formulating the research question, 2) literature review, 3) drawing up a protocol, 4) formulating objectives, 5) defining the study population, 6) determining the sample and sampling technique, 7) defining the variables, 8) defining the disease, 9) determining the type and scale of measurements, 10) constructing questionnaires, 11) methods of data collection, 12) data processing methods, 13) analyzing and interpreting results, and 14) writing the report. For each step, important considerations and definitions are outlined.
Surveillance involves the systematic collection, analysis, and use of health data for decision-making. It serves as an early warning system and monitors the impact of interventions. There are different types of surveillance including community-based, hospital-based, and active/passive surveillance. Community-based surveillance engages community members to detect and report health events. Hospital-based surveillance relies on regular reporting from hospitals. Active surveillance actively seeks out cases, while passive surveillance waits for cases to be reported. The appropriate surveillance method depends on the context and challenges.
Introduction to Epidemiology
History of Epidemiology.
Definition of Epidemiology and its components.
Epidemiological Basic concepts.
Aims of Epidemiology.
Ten Uses of Epidemiology.
Scope or The Areas of Application .
Types of Epidemiological Studies.
This document discusses the importance of vaccine preventable disease (VPD) surveillance systems and provides details on setting up and monitoring different types of surveillance. It describes passive, sentinel, and active surveillance and compares their methods. Guidelines are provided for setting up each type of surveillance, including selecting reporting sites, collecting standardized case information, and monitoring the quality and timeliness of reporting. Methods for confirming vaccine preventable disease cases and preparing line lists and reports are also outlined.
An epidemic occurs when there is an unusual increase in the occurrence of a disease within a community or region beyond what is normally expected. To determine if an epidemic has occurred, one must consider the magnitude of cases, factors responsible, and cause/mode of transmission. Investigating an epidemic involves 10 steps: 1) verifying diagnoses, 2) confirming the epidemic's existence, 3) defining the at-risk population, 4) rapidly searching for all case characteristics, 5) analyzing data, 6) formulating hypotheses, 7) testing hypotheses, 8) evaluating ecological factors, 9) further investigating the at-risk population, and 10) writing a report of the background, methodology, data analysis, and control recommendations.
This document discusses hospital outbreak investigations. It defines endemic and epidemic infections in hospitals. Common source and propagated epidemics are described. Steps in investigating outbreaks in hospitals and communities are provided, including forming an investigation team, developing a case definition, conducting epidemiological and laboratory analyses. The goals of outbreak investigations are outlined. Methods for confirming and controlling outbreaks are discussed.
This document outlines the steps for investigating an outbreak, including how outbreaks are recognized, why they should be investigated, and the epidemiological investigation process. It describes the 10 key steps in an outbreak investigation: 1) confirming the outbreak, 2) verifying diagnoses, 3) preparing for field work, 4) defining a case definition, 5) identifying and listing cases, 6) performing descriptive epidemiology, 7) generating hypotheses, 8) testing hypotheses, 9) implementing control measures, and 10) communicating findings. The goal of an outbreak investigation is to uncover public health problems, identify risk factors, prevent future outbreaks, and train health staff.
Guidelines for Management of Outbreak in Healthcare Organizationdrnahla
Guidelines for Management of Outbreak in Healthcare Organization
Dr. NAHLA ABDEL KADERوMD, PhD.
INFECTION CONTROL CONSULTANT, MOH
INFECTION CONTROL CBAHI SURVEYOR
Infection Control Director, KKH.
An outbreak of Burkholderia cepacia bloodstream infections occurred among newborns in the NICU, with 16 of 59 newborns infected over a month. This was a significant increase over the unit's typical infection rate of 2% per month. The ICC nurse investigated by learning about B. cepacia, verifying the diagnoses, establishing the outbreak, and defining cases. Preliminary findings identified a cluster of infections in October, with all blood cultures from within 24 hours of birth testing positive for B. cepacia. The source and mode of transmission were still unknown.
1) The document discusses surveillance in public health and describes its key components and purposes. Surveillance involves the systematic collection, analysis, and interpretation of health data to provide information for action.
2) An effective surveillance system is simple, flexible, timely, and produces high-quality data. It addresses an important public health problem and accomplishes its objectives of understanding disease trends, detecting outbreaks, and evaluating control measures.
3) The document outlines how to establish a surveillance system, including selecting priority diseases, defining standard case definitions, and developing regular reporting and data dissemination processes. Both passive and active surveillance methods are described.
The document outlines the basic steps for investigating disease outbreaks. It discusses establishing a team with roles like epidemiologist, microbiologist, and environmental health specialists. The steps of an outbreak investigation include preparing, confirming the outbreak, verifying diagnoses, establishing case definitions, finding cases, descriptive epidemiology, developing and evaluating hypotheses, implementing control measures, and communicating findings. Key factors in investigating outbreaks are determining exposure time, disease onset, and incubation period. Effective communication between team members is also emphasized.
The 10-step approach to outbreak investigations involves:
1) Identifying an investigation team and resources.
2) Establishing the existence of an outbreak.
3) Verifying the diagnosis, constructing a case definition, and finding cases systematically.
Descriptive epidemiology is then used to develop hypotheses, which are evaluated through additional studies if needed, before implementing control measures, communicating findings, and maintaining surveillance to confirm the outbreak has ended. Being systematic and following these steps is key to determining the source and controlling outbreaks.
Life is full of curves and thus the epidemiology. However, some curves are important as Epidemic Curves and Survival Curves. This presentation is an attempt to know about epidemic curves.
Epidemiology is the study and analysis of the patterns, causes, and effects of health, disease & production conditions in defined populations, in terms of space and temporality.
This document discusses the concepts of association and causation in epidemiology. It defines key terms like correlation, relative risk, odds ratio, and attributable risk which are used to measure the strength of association between different factors. It also differentiates between association and causation, explaining that correlation does not necessarily imply causation. The document outlines different types of causal relationships like necessary and sufficient, necessary but not sufficient, and neither necessary nor sufficient. It also discusses approaches used to study disease etiology and evaluate evidence for a causal relationship.
Descriptive epidemiology is the first phase of epidemiological investigation which aims to observe disease distribution in a population and identify characteristics associated with disease. It involves defining the population and disease, describing disease occurrence by time, place and person, measuring disease burden, comparing data to indices, and formulating hypotheses about potential causes. Key aspects include examining time trends, geographical variation, and characteristics of individuals with disease like age and sex. The goal is to understand basic features of a health problem and generate ideas about causal factors.
A great presentation from a well versed friend in research and EBM, Dr Yaser Faden.
This is a simple introduction to study design with an accompanying workshop to simplify the different types of research study designs.
This document discusses causation in epidemiology. It defines causation as an event, condition, or characteristic that plays an important role in producing a disease. A cause can be sufficient, meaning it inevitably produces the disease, or necessary, meaning the disease cannot develop without it. Most diseases have multiple contributing factors rather than a single cause. Guidelines for determining a causal relationship include considering the temporal relationship between cause and effect, consistency of association, strength of association, and whether removing the potential cause reduces disease risk. Correctly establishing causation is important for disease prevention and control.
History Of Epidemiology for Graduate and Postgraduate studentsTauseef Jawaid
This document provides a summary of the history of epidemiology from ancient times to the present. It describes key figures and discoveries such as Hippocrates' association of disease with environment, Jenner's pioneering of vaccination, Snow's mapping of a cholera outbreak to a contaminated well. More recent developments discussed include the founding of the U.S. Public Health Service, landmark studies like the Tuskegee syphilis study, and future challenges of globalization and overcrowding facilitating disease spread.
This document provides an overview of the key steps involved in research methodology. It discusses 14 steps that should be followed in research studies: 1) formulating the research question, 2) literature review, 3) drawing up a protocol, 4) formulating objectives, 5) defining the study population, 6) determining the sample and sampling technique, 7) defining the variables, 8) defining the disease, 9) determining the type and scale of measurements, 10) constructing questionnaires, 11) methods of data collection, 12) data processing methods, 13) analyzing and interpreting results, and 14) writing the report. For each step, important considerations and definitions are outlined.
Surveillance involves the systematic collection, analysis, and use of health data for decision-making. It serves as an early warning system and monitors the impact of interventions. There are different types of surveillance including community-based, hospital-based, and active/passive surveillance. Community-based surveillance engages community members to detect and report health events. Hospital-based surveillance relies on regular reporting from hospitals. Active surveillance actively seeks out cases, while passive surveillance waits for cases to be reported. The appropriate surveillance method depends on the context and challenges.
Introduction to Epidemiology
History of Epidemiology.
Definition of Epidemiology and its components.
Epidemiological Basic concepts.
Aims of Epidemiology.
Ten Uses of Epidemiology.
Scope or The Areas of Application .
Types of Epidemiological Studies.
This document discusses the importance of vaccine preventable disease (VPD) surveillance systems and provides details on setting up and monitoring different types of surveillance. It describes passive, sentinel, and active surveillance and compares their methods. Guidelines are provided for setting up each type of surveillance, including selecting reporting sites, collecting standardized case information, and monitoring the quality and timeliness of reporting. Methods for confirming vaccine preventable disease cases and preparing line lists and reports are also outlined.
An epidemic occurs when there is an unusual increase in the occurrence of a disease within a community or region beyond what is normally expected. To determine if an epidemic has occurred, one must consider the magnitude of cases, factors responsible, and cause/mode of transmission. Investigating an epidemic involves 10 steps: 1) verifying diagnoses, 2) confirming the epidemic's existence, 3) defining the at-risk population, 4) rapidly searching for all case characteristics, 5) analyzing data, 6) formulating hypotheses, 7) testing hypotheses, 8) evaluating ecological factors, 9) further investigating the at-risk population, and 10) writing a report of the background, methodology, data analysis, and control recommendations.
This document discusses hospital outbreak investigations. It defines endemic and epidemic infections in hospitals. Common source and propagated epidemics are described. Steps in investigating outbreaks in hospitals and communities are provided, including forming an investigation team, developing a case definition, conducting epidemiological and laboratory analyses. The goals of outbreak investigations are outlined. Methods for confirming and controlling outbreaks are discussed.
This document outlines the steps for investigating an outbreak, including how outbreaks are recognized, why they should be investigated, and the epidemiological investigation process. It describes the 10 key steps in an outbreak investigation: 1) confirming the outbreak, 2) verifying diagnoses, 3) preparing for field work, 4) defining a case definition, 5) identifying and listing cases, 6) performing descriptive epidemiology, 7) generating hypotheses, 8) testing hypotheses, 9) implementing control measures, and 10) communicating findings. The goal of an outbreak investigation is to uncover public health problems, identify risk factors, prevent future outbreaks, and train health staff.
Guidelines for Management of Outbreak in Healthcare Organizationdrnahla
Guidelines for Management of Outbreak in Healthcare Organization
Dr. NAHLA ABDEL KADERوMD, PhD.
INFECTION CONTROL CONSULTANT, MOH
INFECTION CONTROL CBAHI SURVEYOR
Infection Control Director, KKH.
The document provides definitions and guidelines for conducting an outbreak investigation, including defining cases, collecting data on time, place and person, developing hypotheses, and implementing control measures. It outlines the 10 steps of an outbreak investigation which include preparing for field work, verifying diagnoses, establishing the existence of an outbreak, and describing data to characterize the outbreak and identify potential causes. The goal is to control ongoing outbreaks, prevent future outbreaks, and advance knowledge of the disease.
The document discusses challenges in conducting clinical research on rare tumors due to small patient populations. Conventional statistical methods require large sample sizes to prove efficacy, but rare tumors may only have a few hundred worldwide cases per year. This makes it difficult to demonstrate efficacy of new treatments according to standard evidence-based medicine criteria. International cooperation is needed but faces challenges related to funding, bureaucracy and standardization across countries.
(E pi !!)epidemiological investigation doc. doychevaJasmine John
The document outlines the 10 steps for investigating an outbreak of disease: 1) establish existence of outbreak, 2) confirm diagnoses, 3) define cases, 4) relate cases to time, place and person, 5) identify those at risk, 6) form hypothesis, 7) test hypothesis, 8) plan detailed investigation, 9) prepare written report, and 10) implement controls. It also provides an example structure for the outbreak investigation report.
- Association means there is a relationship between factors but does not necessarily imply causation. Causation requires additional evidence.
- There are different types of associations - spurious associations are not real, indirect associations involve a confounding factor, and direct associations can involve one-to-one or multifactorial causation.
- Several criteria must be met to determine if an association is likely causal, including temporal relationship, strength, specificity, consistency, biological plausibility, and coherence of the association. Establishing causation requires systematically evaluating an association against these epidemiological considerations.
this presentation takes you through the concept of association observed between variables in a study and how could it become a causative association in step-wise manner.Exemplify using Bradford hill criteria. slides after references are extra slides not covered in the presentation.
An outbreak occurs when there are more cases of a disease than expected. Outbreaks can be caused by a common source of infection or person-to-person transmission. It is important to investigate outbreaks to control ongoing spread, implement prevention measures, and strengthen disease surveillance. The steps of an outbreak investigation include confirming the outbreak, defining cases, identifying cases, analyzing descriptive data, developing hypotheses, testing hypotheses, implementing control measures, and communicating findings. Challenges include pressure to conclude investigations quickly despite limited data and potential for bias from early media reports.
Outbreak management ppt comprises the definition , history , investigations and the steps of management of outbreak. This was my seminar and UG class tpoic
November 2009 Selected Zoonotic Diseases Conference Callgoa4
The document discusses a conference call on selected zoonotic diseases from November 4, 2009. It provides updates on H1N1 influenza, brucellosis in the United States, and bat-associated rabies virus in Arizona. It also discusses oral rabies vaccination opportunities, complexities, and challenges in North America.
This outbreak investigation identified an outbreak of E. coli O157:H7 infections in Michigan in June-July 1997. Initial calls reported 6 patients infected. Molecular fingerprinting of isolates found they were identical, confirming an outbreak. A case-control study identified alfalfa sprout consumption as the likely source, with an odds ratio of 25. Traceback studies traced the implicated sprouts to contaminated seed lots from Idaho alfalfa fields, possibly due to cattle manure, irrigation water, or deer feces. Further studies cultured implicated sprouts and investigated contamination routes on alfalfa farms.
The document discusses District Health Systems (DHS) in Thailand. It outlines the structure and components of DHS, including establishing primary healthcare centers (PHCs) as health hubs that provide essential care services. The goals of DHS include strengthening community and home-based care through resource sharing between PHCs, hospitals, and other partners using a bottom-up approach. Metrics are presented on service expansion and quality improvements across several DHS pilot sites from 2554-2557, including increased access to care, personnel, and community participation. The document advocates for people-centered, age-friendly primary healthcare through DHS that enables active aging in the community.
Typhus is caused by Rickettsia bacteria, which are intracellular parasites carried by arthropod hosts like lice and ticks. There are several types of typhus including epidemic typhus spread by human lice and Rocky Mountain spotted fever spread by ticks. Symptoms can range from mild to severe fever, headache, rash and organ damage. Diagnosis involves identifying the bacteria through PCR testing, antibody levels or tissue staining. Treatment is with doxycycline or chloramphenicol antibiotics.
The document discusses district health planning for program implementation plans (PIPs) in India. It provides guidance on conducting a situational analysis, setting objectives, defining strategies and activities, and establishing an institutional framework for convergent planning and action across different levels from village to district. The planning process involves assessing health needs, infrastructure, programs and community participation to identify priority problems and develop targeted, feasible and measurable plans.
This document summarizes a training on outbreak investigation held from May 23-27, 2016 at Central Luzon State University. It discusses emerging and re-emerging diseases, examples of case definitions, confirming an outbreak, analyzing outbreak data through time, place and other factors, and establishing hypotheses. The training covered the nine steps of outbreak investigation including confirming diagnoses, defining cases, collecting and analyzing data, establishing hypotheses, and communicating findings.
An outbreak investigation was conducted after 48 people attended a village feast on September 29th, where 24 people subsequently developed gastrointestinal symptoms requiring treatment. The illnesses were reported on September 29th (7 cases), September 30th (13 cases), and October 1st (4 cases). An investigation team traced 47 of the 48 exposed villagers. The team would first design an investigation plan and conduct the investigation according to steps like establishing the presence of an epidemic, conducting case finding and contact tracing, compiling information, and communicating findings.
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This document outlines the process for developing District Health Action Plans (DHAPs) in India. It discusses how DHAPs are created through participatory planning at the village, block, and district levels. The planning process involves forming teams, conducting surveys, developing village health plans, and holding consultations. DHAPs include a situational analysis, objectives, interventions, work plans, budgets, and monitoring plans. They are meant to guide implementation and be tailored to local health needs and resources. The document reviews framework, components, strategy for technical assistance, and provides a critical appraisal to improve the DHAP process.
The document discusses the management of epidemics through various steps including forecasting, investigation, and control. It describes how forecasting involves studying past disease trends to predict future outbreaks. Investigation aims to define the scope of an epidemic by confirming diagnoses, identifying the at-risk population, and screening affected areas. Control methods center around removing infection sources, preventing transmission, and vector control such as mosquito elimination. The overall management of epidemics requires coordinated preparedness, surveillance, health education, and preventive measures to contain disease spread and severity.
This document outlines the educational objectives and content for a lecture on epidemiology. The objectives are to define key epidemiology terms, discuss the functions and modes of epidemiologic investigation, and identify sources of data and potential sources of error. The content includes definitions of epidemiology and related terms, the main functions of epidemiology, descriptive and analytic modes of investigation, how surveillance system data is applied through outbreak investigation, and sources of epidemiological data and potential sources of error.
1. A district in India with a population of 20 lakhs experienced heavy rainfall and two new brick kilns starting operation. One CHC reported 1300 fever cases, much higher than usual.
2. A private practitioner near another CHC reported 5 cases of high fever and unconsciousness, despite that CHC only reporting average fever cases.
3. This raises the possibility of a malaria outbreak in the district, given the heavy rainfall and fever cases exceeding expectations. Additional information needed includes laboratory testing of fever cases, investigation of the source of fever near the new brick kilns, and checking other areas for higher than usual fever incidents.
The document summarizes the key steps in investigating an epidemic:
1) Verify the diagnosis and confirm the existence of an epidemic by comparing to previous years.
2) Define the population at risk by obtaining maps, counting population size, and initial line-listing of cases.
3) Conduct a rapid search for all cases through medical surveys, case sheets collecting details of identified cases, and searching for additional cases.
4) Analyze the collected data to understand patterns in time, place and person which can reveal the source and spread of disease. Formulate and test hypotheses based on this analysis.
This document outlines the steps involved in investigating an epidemic:
1. Verification of diagnoses and defining cases is the first step to understand the scope and characteristics of the epidemic.
2. Confirmation of an actual epidemic involves comparing case numbers to historical data to determine if there is unusual disease occurrence.
3. Defining the population at risk, rapidly searching for all cases, collecting data on characteristics, and analyzing patterns in time, place and person help identify potential causes and transmission routes.
This document outlines the steps for investigating an outbreak. It defines key epidemiological terms and discusses when to investigate an outbreak. The 10 steps of an outbreak investigation are described as: 1) defining the problem, 2) generating hypotheses, 3) testing hypotheses, 4) verifying diagnoses, 5) finding and counting cases, 6) performing descriptive epidemiology, 7) analyzing data, 8) communicating findings, 9) implementing control measures, and 10) preventing future outbreaks. Preparedness, the roles of NGOs, recent outbreak examples, and the importance of surveillance and inter-sectoral coordination are also covered.
Investigation of an epidemic by taking ebola as an example...Grandhe Sumanth
investigation of an epidemic by taking ebola as an example....................................................................................................................................................................................................................................................................
An outbreak is an unexpected increase in cases of a disease compared to expected numbers. Outbreaks are detected through surveillance systems, health professional reports, and informal reports. An outbreak is declared when case numbers exceed thresholds, which vary by disease based on response urgency. Investigating outbreaks aims to control the disease, prevent future outbreaks, gain disease knowledge, and evaluate response systems. The steps of outbreak investigation include verifying the diagnosis, defining cases, descriptive epidemiology, developing and evaluating hypotheses, implementing control measures, communicating findings, and ramping down the response once the outbreak ends.
The document outlines the key principles and steps of conducting an outbreak investigation. It defines what constitutes an outbreak and explains that the purpose is to control the current outbreak, prevent future occurrences, and evaluate existing surveillance and prevention programs. The main steps described are confirming the outbreak, defining cases, collecting descriptive data, developing hypotheses, testing hypotheses through analytical studies, communicating conclusions, and recommending control measures.
The document provides an overview of investigating disease outbreaks through a 13-step approach. It defines key epidemiological concepts like outbreak, epidemic, endemic and pandemic. The 13 steps include: 1) forming an investigation team, 2) verifying the existence of an outbreak, 3) verifying diagnoses, 4) defining cases, 5) finding cases systematically, 6) descriptive epidemiology, 7) developing hypotheses, 8) evaluating hypotheses, 9) refining hypotheses, 10) additional studies, 11) control measures, 12) surveillance, and 13) communication. Descriptive epidemiology involves characterizing cases by time, place and person. Hypothesis development and evaluation use epidemiological and analytical methods.
The document provides guidance on conducting an epidemiological investigation of an epidemic, outlining the objectives, team roles and responsibilities, and steps of an investigation which include establishing the existence of an outbreak, verifying diagnoses, constructing a case definition, systematically finding and recording information on cases, developing and evaluating hypotheses, and implementing control measures. The goal of an epidemic investigation is to understand the factors driving the outbreak in order to control spread and prevent future occurrences.
An outbreak is defined as a sudden rise in cases of a disease in a community or geographic area. It can last from a few days to several years. An outbreak investigation aims to establish the existence and cause of the outbreak through descriptive epidemiology, developing and evaluating hypotheses, and implementing control measures. The steps include preparing, verifying diagnoses, defining cases, identifying cases, analyzing data, developing and testing hypotheses, and communicating findings. Current outbreaks reported by CDC include various foodborne illnesses and respiratory disease.
Step 1: The document summarizes the steps of an epidemic investigation, beginning with confirming the existence of an outbreak, verifying the diagnosis, and gathering case information.
Step 2: Key steps include developing a case definition, finding additional cases, collecting information on individual cases, and analyzing patterns among cases to generate hypotheses. Hypotheses are then tested using analytical studies.
Step 3: The investigation also draws conclusions, reports findings to authorities, recommends control measures, communicates results to educate the public, and follows up to ensure recommendations are implemented. The overall goal is to control the current epidemic and prevent future outbreaks.
This document summarizes the general approach to conducting an outbreak investigation. It outlines that outbreak investigations have three main components - the epidemiologic investigation to identify the source and prevent additional cases, the environmental investigation, and interacting with the public. The epidemiologic investigation involves establishing case definitions, confirming cases, determining the background disease rate, generating and testing hypotheses. Even when an outbreak is over, investigating can help prevent future outbreaks by increasing knowledge of the disease.
The document outlines the steps for investigating an epidemic. It defines what constitutes an epidemic and lists different types. The key steps for an epidemic investigation include:
1. Verifying diagnoses of cases and confirming the existence of an epidemic.
2. Defining the population at risk by mapping cases.
3. Searching for all cases, including infected individuals and their contacts.
4. Analyzing collected data to form a hypothesis about the source and spread.
5. Evaluating environmental factors and testing the initial hypothesis.
6. Writing a final report with recommendations to prevent future epidemics.
1. The document defines key epidemiological terms like epidemic, outbreak, endemic, pandemic, herd immunity, incubation period, and quarantine. It also describes different types of epidemics such as point source, propagated, and continuous exposure epidemics.
2. The stages of outbreak investigation are outlined which include verifying the diagnosis, confirming the outbreak, defining the population at risk, conducting a rapid search for cases, analyzing the data, formulating hypotheses, and reporting findings.
3. Trigger levels for different diseases are discussed to determine the appropriate response level based on the number and severity of cases. Line listing of cases is also described as a tool to collect epidemiological information during an outbreak investigation.
Similar to Investigation of an epidemic dr. yks (20)
CLASSIFICATION OF H1 ANTIHISTAMINICS-
FIRST GENERATION ANTIHISTAMINICS-
1)HIGHLY SEDATIVE-DIPHENHYDRAMINE,DIMENHYDRINATE,PROMETHAZINE,HYDROXYZINE 2)MODERATELY SEDATIVE- PHENARIMINE,CYPROHEPTADINE, MECLIZINE,CINNARIZINE
3)MILD SEDATIVE-CHLORPHENIRAMINE,DEXCHLORPHENIRAMINE
TRIPROLIDINE,CLEMASTINE
SECOND GENERATION ANTIHISTAMINICS-FEXOFENADINE,
LORATADINE,DESLORATADINE,CETIRIZINE,LEVOCETIRIZINE,
AZELASTINE,MIZOLASTINE,EBASTINE,RUPATADINE. Mechanism of action of 2nd generation antihistaminics-
These drugs competitively antagonize actions of
histamine at the H1 receptors.
Pharmacological actions-
Antagonism of histamine-The H1 antagonists effectively block histamine induced bronchoconstriction, contraction of intestinal and other smooth muscle and triple response especially wheal, flare and itch. Constriction of larger blood vessel by histamine is also antagonized.
2) Antiallergic actions-Many manifestations of immediate hypersensitivity (type I reactions)are suppressed. Urticaria, itching and angioedema are well controlled.3) CNS action-The older antihistamines produce variable degree of CNS depression.But in case of 2nd gen antihistaminics there is less CNS depressant property as these cross BBB to significantly lesser extent.
4) Anticholinergic action- many H1 blockers
in addition antagonize muscarinic actions of ACh. BUT IN 2ND gen histaminics there is Higher H1 selectivitiy : no anticholinergic side effects
Storyboard on Skin- Innovative Learning (M-pharm) 2nd sem. (Cosmetics)MuskanShingari
Skin is the largest organ of the human body, serving crucial functions that include protection, sensation, regulation, and synthesis. Structurally, it consists of three main layers: the epidermis, dermis, and hypodermis (subcutaneous layer).
1. **Epidermis**: The outermost layer primarily composed of epithelial cells called keratinocytes. It provides a protective barrier against environmental factors, pathogens, and UV radiation.
2. **Dermis**: Located beneath the epidermis, the dermis contains connective tissue, blood vessels, hair follicles, and sweat glands. It plays a vital role in supporting and nourishing the epidermis, regulating body temperature, and housing sensory receptors for touch, pressure, temperature, and pain.
3. **Hypodermis**: Also known as the subcutaneous layer, it consists of fat and connective tissue that anchors the skin to underlying structures like muscles and bones. It provides insulation, cushioning, and energy storage.
Skin performs essential functions such as regulating body temperature through sweat production and blood flow control, synthesizing vitamin D when exposed to sunlight, and serving as a sensory interface with the external environment.
Maintaining skin health is crucial for overall well-being, involving proper hygiene, hydration, protection from sun exposure, and avoiding harmful substances. Skin conditions and diseases range from minor irritations to chronic disorders, emphasizing the importance of regular care and medical attention when needed.
A congenital heart defect is a problem with the structure of the heart that a child is born with.
Some congenital heart defects in children are simple and don't need treatment. Others are more complex. The child may need several surgeries done over a period of several years.
Part III - Cumulative Grief: Learning how to honor the many losses that occur...bkling
Cumulative grief, also known as compounded grief, is grief that occurs more than once in a brief period of time. As a person with cancer, a caregiver or professional in this world, we are often met with confronting grief on a frequent basis. Learn about cumulative grief and ways to cope with it. We will also explore methods to heal from this challenging experience.
Congestive Heart failure is caused by low cardiac output and high sympathetic discharge. Diuretics reduce preload, ACE inhibitors lower afterload, beta blockers reduce sympathetic activity, and digitalis has inotropic effects. Newer medications target vasodilation and myosin activation to improve heart efficiency while lowering energy requirements. Combination therapy, following an assessment of cardiac function and volume status, is the most effective strategy to heart failure care.
Nutritional deficiency Disorder are problems in india.
It is very important to learn about Indian child's nutritional parameters as well the Disease related to alteration in their Nutrition.
2. Endemic versus epidemic
Endemics
Disease occurring in a population regularly at a usual
level
Tuberculosis, Malaria
Epidemics
Unusual occurrence of the disease in excess of its
normal expectation
In a geographical location
At a given point of time
e.g. Hepatitis E, measles, cholera
DR YKS
2
3. Outbreaks versus epidemics
Occurrence of cases of an illness in excess of expected
numbers
Scale
Outbreak
Limited to a small area, within one district or few blocks
Epidemic
Covers larger geographic areas
Linked to control measures in district/state
No exact precise threshold: Use a word or the other according to
whether you want to generate or deflect attention
Be aware of legal implications of the use of the term “Epidemic” in India
(Epidemic disease act, being revised)
DR YKS
3
4. Outbreaks can occur anywhere, from a very remote
area where no health facility exists to nosocomial
outbreaks in a very sophisticated hospitals
Many of these diseases have seasonal and cyclic
trends which can be discerned through the
surveillance system. These diseases can also cause
outbreaks with the potential to spread rapidly and
cause many deaths.
Outbreaks cannot always be predicted or prevented,
Outbreaks
DR YKS
4
5. Limit the spread of the outbreak by:
recognition of early warning signals,
timely investigations and
application of specific control measures
An effective surveillance system is essential for
planning, implementation and monitoring of the
diseases.
DR YKS
5
6. Epidemiological Triad
Host
Environment Agent
An outbreak comes from a change in the way the host, the
environment and the agent interact: This interaction needs to be
understood to propose recommendations.
DR YKS
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7. Sources of information to detect
outbreaks
Event-based surveillance
Rumour register
To be kept in standardized format in each institution
Rumours need to be investigated
Community informants
Private and public sector
Media
Important source of information, not to neglect
Case-based surveillance
Review of routine surveillance data and triggers
DR YKS
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8. Information of outbreak:
Health Personnels
Nurses and doctors working in any hospital can report the
unexpected number of cases of any particular disease
Laboratory:
Every laboratory /network can serve as an excellent source
of outbreak investigation e.g in case of Avian influenza
Official disease notification system/or surveillance system
Newspaper or media
Village health volunteers
Calls from a Citizen
DR YKS
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9. Early warning signals for an outbreak
Clustering of cases or deaths
Increases in cases or deaths
Single case of disease of epidemic potential
Acute febrile illness of an unknown etiology
Two or more linked cases of disease with outbreak potential
(e.g., Measles, Cholera, Dengue, Japanese encephalitis or plague)
Unusual isolate (Cholera O 139)
Shifting in age distribution of cases (Cholera O 139)
High vector density
Natural disasters
DR YKS
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10. CHALLENGES (during an epidemic)
To initiate control measures as quickly as possible
To study the situation in detail at the same time
Steps designed to address both the concerns
simultaneously
DR YKS
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11. The first information report
Filled by the reporting unit
Submitted to the District Surveillance Officer as
soon as the suspected outbreak is verified
Sent by the fastest route of information available
Telephone
Fax
E-mail
DR YKS
11
12. Investigative team (The rapid response team) includes
Investigator
Epidemiologist, clinician and microbiologist, Entomologist when vector-borne disease
Disease control people e.g sanitary inspector, ANM
Laboratory technicians
Specialist in particular areas e.g veterinarian would be very helpful in outbreak of zoonotic
disease
Public health administration for providing logistic support, mobilizing resources and
providing administrative support.
Public relation person :In certain conditions when the outbreak has caused panic or gained the
intense attention of public, the investigative team should recruit or appoint a person to be in
charge of public relations and press releases. This person should appropriately reassure and
not unduly alarm the public
Role
Confirm and investigate outbreaks
Responsibility
Assist in the investigation and response
Primary responsibility rests with local health staff
DR YKS
12
13. Objectives of an outbreak investigation
1. Verify
2. Recognize the magnitude
3. Diagnose the agent
4. Identify the source and mode of transmission
5. Identify population at risk
6. Identify risk factors
7. Formulate prevention and control measures
DR YKS
13
14. Investigate an Outbreak......Why?
Stop the epidemic
Prevent new episodes
Increase our knowledge
Evaluate the surveillance system
Put in place a surveillance system
Learn to teach
DR YKS
14
15. DR YKS
Yes
-> Control measures
Hypothesis fit the facts:
-> Control measures
Hypothesis does not fit the facts:
-> Analytical investigations
Time, place person description
Formulation of hypothesis
No
-> Clinical, microbiological
and epidemiological investigation
Yes
-> Are the source and
modes of transmission
known?
No
Unusual event:
Is this an outbreak?
Investigating an outbreak
15
16. Investigate an Outbreak
In investigating an outbreak, speed is essential, but
getting the right answer is essential, too. To satisfy
both requirements, Public Health personnel should
approach investigations systematically, using the
following 14 steps:
DR YKS
16
17. Steps in outbreak response
1. Prepare for field work
2. Confirm the existence of an outbreak
3. Verify the diagnosis and determine the etiology of the disease.
4. Define the population at risk
5. Develop case definition, start case finding, and collect information on the cases(after
choosing study design)
6. Describe person, place and time (by questionnaire)
7. Evaluation of ecological factors
8. Formulate several possible hypothesis hypotheses.
9. Test hypotheses using analytical study
10. Refine hypotheses and carry out additional studies
11. Draw conclusions to explain the causes or determinants of outbreak based on clinical,
laboratory, epidemiological & environmental evidence
12. Report and recommend appropriate control measures to concerned authorities at the
local/national, and if appropriate at international levels
13. Communication of the findings
14. Follow up of the recommendation to assure implementation of control measures
DR YKS
17
18. 1. Prepare for Field Work
(a) Activities to Begin
• Researching the
disease
• Identifying team
members
• Assign duties
• Determine local
contacts
• Activate department
protocol
(b) Equipment for the
Field
• Laptop
• Cell Phone
• Camera
• Specimen Collection
kits
• interview forms
• Infectious Disease
Manual
(c) Possible Team
Members
• Epidemiologist
• Clinicians
• Lab Personnel
• Sanitarians
• Infection Control
Staff
• Administrators
(large outbreaks)
Preparations can be grouped into three categories:
DR YKS
18
19. 2. Confirm the existence of an outbreak:
When reports of illness begin to surface, it is important to determine if an
outbreak is truly occurring. A true outbreak may be occurring or it may be
periodic and unrelated cases of the same disease or even unrelated cases
of similar, but different diseases.
Step 1: To decide whether the observed number of cases exceeds the
expected numbers we need to first ddetermine the expected number of
cases before deciding if the observed number exceeds the expected
Step 2: Collect data of expected values using surveillance records, hospital
discharge data, disease registries, mortality statistics, lab data, other
agencies, health care providers & community surveys.
Compare the current number of cases with the number from the previous
few weeks or months or from a comparable period during the previous few
years
Before launching a full investigation, verify signs, symptoms & test
results DR YKS
19
20. 3. Verify the diagnosis and determine the etiology
Verification of diagnosis
clinical findings
laboratory results
Investigator should visit several patients with the disease. In case if a sound
clinical background is not known than a qualified physician can be taken for
the investigation.
Certain questions can be asked to the patients to reach to a
diagnosis
What were their exposures before becoming ill?
What do they think caused their illness?
Do they know anyone else with the disease?
Do they have anything in common with others who have the disease?
DR YKS
20
21. 4. Define the population at risk
Defining whole population which is exposed
Census data
Local health centre data
Voter’s list
Actual counting of the population
The latest map of the area is obtained with the
important landmarks and divisions
DR YKS
21
22. 5. Develop case definition, start case finding, and
collect information on cases
Confirmed cases– have a positive laboratory result (isolation of the
causative agent or positive serological test).
e.g outbreak of bloody diarrhoea E.coli 0157:H7 is isolated from a stool
culture
Probable cases – have the typical clinical features of the illness but
without laboratory confirmation.
e.g bloody diarrhoea or hemolytic uremia syndrome without
microbiological confirmation
Possible case: have fewer or atypical clinical features.
e.g. non-bloody diarrhoea without microbiological confirmation
Continue……………..DR YKS
22
23. Steps:
Active surveillance
-peripheral health personnel,
- personnel from other government departments,
-NGOs and community representatives
Valuable information can be obtained by contacting
community representatives, especially if the outbreak is focal.
Passive surveillance
DR YKS
23
24. Collect the following type of information about every
case
Identifying information: name, address, and telephone
number
Demographic information: age, sex, race, and occupation
Clinical information:
Risk factor information:
Investigation of hepatitis A, information regarding
exposure to food and water
Reporter information:
Line listing: Collected information is described on a standard
case report form known as line listing.
In a line listing each column represents an important variable
such as name or identification number ,age ,sex ,case
classification etc. while each row represents a different case
.New cases are added to a line listing as they are identifiedDR YKS
24
25. Do not wait for laboratory results before starting
treatment and control activities
POINT TO
REMEMBER
DR YKS
25
26. 6. Describe time, person, place and generate
hypotheses.
Distribution by time:
The onset of illness of the cases should be graphed(histogram)
by hours, days, weeks or months. This graph is known as
epidemic curve
Continue……………..
DR YKS
26
27. 6. Describe person, place and time and generate hypotheses.
Epidemic curve
confirming the existence of an epidemic
forecasting of the further evolution of the epidemic
identifying the mode of transmission
determining the possible period of exposure and/or the
incubation period of the disease under investigation
identifying outliers in terms of onset of illness, which might
provide important clues as to the source.
Two types of outbreaks
1. Common source 2. Propagated source
Continue……………..
DR YKS
27
29. 1.Common source outbreak: This outbreak occurs when people
gets the infection by exposure to the same source of infection.
These are two types
A. Point common source: When there is single source that
exists for the short time and all cases have common exposure to
it in that same particular period.
Continue……………..DR YKS29
30. B. Continuous common source: The epidemic curve shows an
abrupt increase in number of cases but instead of having a
peak decline within incubation period new cases persist for a
longer time with a plateau shape instead of peak before
decreasing.
If there are many peaks or irregular jagged curves this
suggest an intermittent common source
Continue……………..
DR YKS30
31. 2. Propagated source: This type of outbreak is caused by a
transmission from one person to another person which requires
direct contact such as touching, bite, sexual contact
Slow increase in number of cases with progressive peaks
approximately one incubation period apart. The span of 1st and
last case will also last longer than several incubation period e.g
HIV
Continue……………..
DR YKS31
32. Distribution by person
Index case: The first case on epidemic curve is index case. It is
important with the possibility that he/she brought the infection to
the community.
Outlier case: The case which appears at the beginning and at the
end of the curve are known as outlier case. They provide
information about the source and the way disease is spreading in
that territory.
Continue……………..
DR YKS
32
33. DISTRIBUTION BY PLACE
The investigator can calculate the attack rate of case by
different place. This can be place of residence, place of
work and place of exposure and soon plot a spot map
showing the source of infection or contamination
If cases are scattered in many place, investigator should
explore the secular pattern of the case over time. This
will indicate about the spread of outbreak from one
area to another area or whether people living in
different place had a common exposure
Continue……………..
DR YKS
33
35. 7. Evaluation of ecological factors
Ecological factors which have made the epidemic
possible should be investigated such as sanitary
status of eating establishments, water and milk
supply, movement of human population, humidity,
air pollution, population dynamics of insects, animal
reservoirs.
Relate the disease to environmental factors to know
the source of infection, reservoirs and modes of
transmission.
DR YKS
35
36. 8. Generation of hypothesis :
Hypothesis can be generated by 2ways
1)First- Consider what you know about the disease itself?
-What is the agent’s usual reservoir?
-It’s transmission
-What vehicles are commonly implicated?
-What are the know risk factors?
2)Second- talk to few case patients by visiting to their
homes to search for common exposures.
-Local staff community will provide information
Continue……………..
DR YKS
36
37. 8. Generation of hypothesis :
Descriptive epidemiology provides some information
If the epidemic curve points to a narrow period of
exposure
What events occurred around that time?
Why do the people living in a particular area have the
highest attack rates?
Why are some groups with particular age, sex & other
person characteristics, at greatest risk than other group
with different person characteristics
DR YKS
37
38. 9. Test hypotheses using analytical studies
Hypothesis can be tested by comparing the hypothesis with the
established facts or by using analytical epidemiology to quantify
relationship & explore the role of chance.
Analytical studies like-cohort &case-control studies.
Do necessary environmental or other studies to supplement the
epidemiological study:
Although an analytical study might be able to confirm the
hypothesis ,the investigator still needs to find environment or
other evidence to support and explain the epidemiological
evidence
DR YKS
38
39. 10. Refine Hypotheses and Carry Out Additional
Studies
When analytic epidemiological studies do not confirm your
hypotheses, you need to reconsider your hypotheses and look for new
vehicles or modes of transmission. This is the time to meet with case-
patients to look for common links and to visit their homes.
Even when your analytic study identifies an association between an
exposure and a disease, you need to obtain more specific exposure
histories or a more specific control group.
When an outbreak occurs, whether it is routine or unusual, you should
consider what questions remain unanswered about the disease and
what kind of study you might use in the particular setting to answer
some of these questions. The circumstances may allow you to learn more
about the disease, its modes of transmission, the characteristics of the
agent, and host factors.
DR YKS
39
40. 11. Draw conclusions to explain the causes or
determinants of outbreak based on clinical, laboratory,
epidemiological& environmental evidence
The investigator must identify the cause of outbreak based on the
agreement of following piece of evidence
Laboratory
Clinical
Environmental
Epidemiological
The epidemiological evidence found by the descriptive and analytical
study should explain
Pattern of spread as described by epidemic curve
Statistical strength of association between exposure an developing the
disease. The dose response relationship which demonstrates high
strength by association when exposure is increased
Exposure should precede illness DR YKS
40
41. 12. Report and recommend appropriate control
measures to concerned authorities at the
local/national/international levels:
The investigator should timely report the findings to
the responsible individuals at local, national and
international levels, so that appropriate action should
be taken
Don’t wait the end of the investigation :
— General measures at beginning
— Specific measures according to the results
Two task should be completed before leaving the field
1) Complete analysis and data interpretation
2) Present main finding with recommendation
DR YKS
41
42. " The art of epidemiological reasoning is to
make some reasonable conclusions starting
from imperfect data”
George VIL Comstock
But try to have soma data almost perfect. .. it
is easier.
an epidemiologist
DR YKS
42
43. 13. Communicate Findings
Your final task in an investigation is to communicate your findings to others who need to
know. This communication usually takes two forms: 1) an oral briefing for local health
authorities and 2) a written report.
Your oral briefing should be attended by the local health authorities and people
responsible for implementing control and prevention measures. This presentation is an
opportunity for you to describe what you did, what you found, and what you think should
be done about it. You should present your findings in scientifically objective fashion, and
you should be able to defend your conclusions and recommendations.
You should also provide a written report that follows the usual scientific format of
introduction, background, methods, results, discussion, and recommendations. By
formally presenting recommendations, the report provides a blueprint for action. It also
serves as a record of performance, a document for potential legal issues, and a reference
if the health department encounters a similar situation in the future. Finally, a report that
finds its way into the public health literature serves the broader purpose of contributing to
the scientific knowledge base of epidemiology and public health.DR YKS
43
44. 14. Follow up of the recommendation to assure
implementation of control measures
DR YKS
44
45. • Don’t forget ! (last but not least)
— Ethical aspects, (animaIs ????)
— Respect the participants (obtain their agreement)
— Iocal debriefing
DR YKS
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48. Year 2015 : Outbreaks in Udaipur
Swine flu : Feb, March, April
Acute diarrheal cases: April, may, June
Acute Viral fever: July, August
Malaria
Dengue Going on
Scrub typhus
DR YKS
48
49. Exercise 1 :
During the previous year, nine residents of a
community died from the same type of cancer.
List some reasons that might justify an
investigation.
DR YKS
49
50. Exercise Answer 1 :
One reason to investigate is simply to determine how many cases you would expect in the community. In a
large community, for instance, nine cases of a common cancer (e.g., lung, breast, or colon cancer) would not
be unusual. In a very small community, nine cases of even a common cancer may seem unusual. If the
particular cancer is rare, then nine cases even in a large community may be unusual.
If the number of cases turns out to be high for that community, we might pursue the investigation further. Our
motive might be research—perhaps we will identify a new risk factor (workers exposed to a particular
chemical) or predisposition (people with a particular genetic marker) for the cancer. Control and prevention
may also be a justification. If we find a risk factor, control and prevention measures could be developed.
Alternatively, if the cancer is generally treatable when found early and a screening test is available, then
we might try to determine not why these people developed the disease, but why they died from it. For
instance, if the problem were cancer of the cervix, detectable by Pap smear and generally treatable if
caught early, we might find (1) problems with access to health care, or (2) physicians not following the
recommendations to screen women at the appropriate intervals, or (3) laboratory error in reading or
reporting the test results. We could then develop measures to correct the problems we found (public
screening clinics, education of physicians, or laboratory quality assurance).
If new staff need to gain experience on a cluster investigation, training may be a reason to investigate. If
there is public concern, it may generate political pressure. Perhaps one of the people affected is a member
of the mayor's family. A health department must respond to such concerns, but does not usually need to
conduct a full-blown investigation. Finally, legal concerns may prompt an investigation, especially if a
particular site in the community is implicated.
DR YKS
50
51. Exercise 2 :
During August, district health department received
reports of 12 new cases of tuberculosis and 12
new cases of aseptic meningitis. Tuberculosis does
not have a striking seasonal distribution; however,
aseptic meningitis, which is caused primarily by a
viral infection, is highly seasonal and peaks from
August–October. What additional information is
needed to determine whether either of these
groups of cases is an outbreak?
DR YKS
51
52. Exercise Answer 2
We need to know how many cases of each of these diseases
usually occurs in this area during August. Because tuberculosis is
not seasonal, the number of cases could be compared with (a)
the numbers reported during the preceding several months and
(b) the numbers reported during August of the preceding few
years.
However, since aseptic meningitis is seasonal and peaks from
August–October, the number of cases during August is
expected to be higher than the number reported during the
preceding several months, so you would need to compare with
the numbers reported during August of the preceding few
years.
DR YKS
52
53. Exercise 3 : Review the six case report forms in the Appendix
and create a line listing based on the information.
Exercise Answer 4
DR YKS
53
54. Exercise 4 :
You are called to help investigate a cluster of
17 men who developed leukemia in a
community. Some of them worked as electrical
repair men, and others were ham radio
operators. Which study design would you
choose to investigate a possible association
between exposure to electromagnetic fields
and leukemia?
OPTION (A) case control (B) cohort
DR YKS
54
55. Exercise Answer 4
Because the total population at risk is not well defined,
you would use a case-control study. You would begin by
enrolling the 17 people already identified with leukemia
as the case group. You would also need to determine
what group might serve as an appropriate comparison,
or control, group. Neighbours might be used for the
control group, for example. In your case-control study,
you would determine whether each case-patient and
each control had been exposed to electromagnetic
fields (however you defined that exposure). Finally, you
would compare the exposures of case-patients and
controls.
DR YKS
55
56. Exercise 5 :
The manager of a grocery store has reported a rash
illness among the store’s workers. What type of study would
you use to determine the source of the outbreak? Why?
What is the appropriate measure of association? After
reviewing the table showing the data on exposure to celery
for these workers, calculate the measure of association and
interpret your results.
Rash No Rash
Exposed to celery(56) 25 31
Not exposed to celery(70) 5 65
DR YKS
56
57. Exercise Answer 5
You would use a cohort study because the outbreak is small and confined. The
appropriate measure of association for a cohort study is relative risk, which is
calculated in this case as the attack rate for workers exposed to celery divided
by the attack rate for those who were not exposed.
The attack rate for exposed workers is 25 / 56, or 44.6%. The attack rate for
workers who were not exposed is 5 / 70, or 7.1%. Thus, the relative risk for
exposure to celery is 44.6 / 7.1, or 6.3. This means that workers who were
exposed to celery were 6.3 times more likely to develop the rash illness than
those who were not exposed, and it is therefore likely that celery was the source
of the outbreak. However, before you could draw this conclusion, you would
need to compare the relative risk for celery with that for other vegetables and
fruits to see if the implication is stronger for any of them.
Then, to test the likelihood of your findings, you would need to calculate a test
of statistical significance such as chi-square for the item with the highest relative
risk and look up the corresponding p-value in a table of p-values. If the p-value
was below .05, your findings would be considered statistically significant.
DR YKS
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58. DR YKS
Take home messages
1. Do not ignore or hide outbreaks
2. Respond to early warning signals
3. Investigate outbreaks to:
Control the current outbreak
Learn about the disease in the local setting
4. Outbreaks require an organized, well managed
response
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