This document provides an overview of epidemiology. It defines epidemiology as the study of the distribution and determinants of health-related states in populations. It discusses descriptive epidemiology, which investigates disease occurrence, and analytical epidemiology, which studies risk factors. It also covers epidemiological study designs like cohort studies and case-control studies. Finally, it defines key epidemiological terms like incidence, prevalence, and outbreak.
Epidemiology is 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 goals of epidemiology are to describe the magnitude of health problems, identify risk factors, and provide data to plan, implement, and evaluate health services. Epidemiologists use various tools like rates, ratios, and proportions to measure factors like mortality, morbidity, and environmental exposures. Descriptive epidemiology involves defining populations, diseases, and distributions by time, place, and person to form hypotheses about disease etiology, while analytical studies like case-control and cohort studies aim to determine associations between risk factors and diseases.
5 concepts of control and prevention community medicineSiham Gritly
This document discusses concepts of control, prevention, and intervention in community medicine as presented by Dr. Siham Gritly. It defines disease control, elimination, eradication, monitoring, surveillance, levels of prevention (primordial, primary, secondary, tertiary), modes of intervention (health promotion, specific protection, early diagnosis, disability limitation, rehabilitation). It also describes concepts related to impairment, disability, and handicap. The overall purpose is to outline key terms and approaches in public health.
India is the highest TB burden country in the world & accounts for nearly 1/5th (20 per cent) of global burden of tuberculosis, 2/3rd of cases in SEAR. Every year approximately 1.8 million persons develop tuberculosis, of which about 0.8 million are new smear positive highly'- infectious cases.Annual risk of becoming infected with TB is 1.5 % and once infected there is 10 % life-time risk of developing TB disease
Epidemiology of Non Communicable Diseases (NCDs)Prabesh Ghimire
Declaration: The materials incorporated in this document have come from variety of sources and compiler bears no responsibilities for any information contained herein. The compiler acknowledges all the sources although references have not been explicitly cited for all the contents in this document.
This document provides information on leprosy (Hansen's disease), including its causes, signs and symptoms, transmission, diagnosis, classification, treatment, and control. It discusses that leprosy is caused by Mycobacterium leprae, affects the skin and nerves, and manifests as tuberculoid, borderline, or lepromatous forms depending on the host's immune response. Diagnosis involves clinical examination of skin and nerves as well as bacteriological examination of skin and nasal smears. Multidrug therapy including rifampicin, dapsone and clofazimine is recommended. Control relies on case detection, treatment, surveillance, and health education to prevent disability.
William Shakespeare was an English poet and playwright from the late 16th and early 17th centuries. He is widely considered the greatest writer in the English language. Shakespeare wrote comedies, histories, and tragedies, including Romeo and Juliet, Hamlet, and Macbeth. Some of his most famous works are listed in the document.
This document provides an overview of the history, epidemiology, and prevention of tuberculosis (TB). It discusses how TB was historically known by other names and was a common fatal disease until scientific discoveries in the 1800s proved it was caused by the bacterium Mycobacterium tuberculosis and was contagious. It also outlines the global burden of TB, how it is transmitted between people, diagnostic methods, treatment approaches including drug-resistant TB, and newer diagnostics.
As per John M. Last (1988) 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.
Epidemiology is 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 goals of epidemiology are to describe the magnitude of health problems, identify risk factors, and provide data to plan, implement, and evaluate health services. Epidemiologists use various tools like rates, ratios, and proportions to measure factors like mortality, morbidity, and environmental exposures. Descriptive epidemiology involves defining populations, diseases, and distributions by time, place, and person to form hypotheses about disease etiology, while analytical studies like case-control and cohort studies aim to determine associations between risk factors and diseases.
5 concepts of control and prevention community medicineSiham Gritly
This document discusses concepts of control, prevention, and intervention in community medicine as presented by Dr. Siham Gritly. It defines disease control, elimination, eradication, monitoring, surveillance, levels of prevention (primordial, primary, secondary, tertiary), modes of intervention (health promotion, specific protection, early diagnosis, disability limitation, rehabilitation). It also describes concepts related to impairment, disability, and handicap. The overall purpose is to outline key terms and approaches in public health.
India is the highest TB burden country in the world & accounts for nearly 1/5th (20 per cent) of global burden of tuberculosis, 2/3rd of cases in SEAR. Every year approximately 1.8 million persons develop tuberculosis, of which about 0.8 million are new smear positive highly'- infectious cases.Annual risk of becoming infected with TB is 1.5 % and once infected there is 10 % life-time risk of developing TB disease
Epidemiology of Non Communicable Diseases (NCDs)Prabesh Ghimire
Declaration: The materials incorporated in this document have come from variety of sources and compiler bears no responsibilities for any information contained herein. The compiler acknowledges all the sources although references have not been explicitly cited for all the contents in this document.
This document provides information on leprosy (Hansen's disease), including its causes, signs and symptoms, transmission, diagnosis, classification, treatment, and control. It discusses that leprosy is caused by Mycobacterium leprae, affects the skin and nerves, and manifests as tuberculoid, borderline, or lepromatous forms depending on the host's immune response. Diagnosis involves clinical examination of skin and nerves as well as bacteriological examination of skin and nasal smears. Multidrug therapy including rifampicin, dapsone and clofazimine is recommended. Control relies on case detection, treatment, surveillance, and health education to prevent disability.
William Shakespeare was an English poet and playwright from the late 16th and early 17th centuries. He is widely considered the greatest writer in the English language. Shakespeare wrote comedies, histories, and tragedies, including Romeo and Juliet, Hamlet, and Macbeth. Some of his most famous works are listed in the document.
This document provides an overview of the history, epidemiology, and prevention of tuberculosis (TB). It discusses how TB was historically known by other names and was a common fatal disease until scientific discoveries in the 1800s proved it was caused by the bacterium Mycobacterium tuberculosis and was contagious. It also outlines the global burden of TB, how it is transmitted between people, diagnostic methods, treatment approaches including drug-resistant TB, and newer diagnostics.
As per John M. Last (1988) 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.
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 the epidemiology of tuberculosis. It begins by defining tuberculosis and how it is transmitted. Globally, the mortality and prevalence of TB is highest in India, which accounts for 20% of global cases. Key epidemiological factors that influence the spread of TB are the bacterial agent, host susceptibility, and social determinants. TB is typically transmitted through droplets in the air and has an incubation period of weeks to years. While pulmonary TB is most common, extrapulmonary TB can also occur. Despite prevention and control efforts like BCG vaccination and India's Revised National Tuberculosis Control Programme, TB remains a major public health challenge in India due to ongoing issues with awareness and socioeconomic factors.
This document discusses tuberculosis (TB) in India. It notes that India has the highest TB burden in the world, accounting for nearly 1/5 of global cases. Every year approximately 1.8 million people develop TB in India, of which around 800,000 are new smear-positive cases. India also has the fastest expanding DOTS program for treating TB, which has treated over 7.3 million patients since 1997.
This document discusses various measures used to quantify drug use and outcomes in pharmacoepidemiological studies. It describes prevalence as the proportion of people with a disease or exposed to a drug at a given time. Incidence is the number of new cases within a time period, while incidence rate is the number of new cases per unit of person-time at risk. Drug use is commonly measured by the number of prescriptions, units of drug dispensed, defined daily doses which estimates average maintenance dose, and prescribed daily doses which is the average dose actually prescribed. Adherence is often measured through biological assays, pill counts, pharmacy records, and patient interviews.
Revised definitions of tb cases and management as per ntepDrSmritiMadhusikta
The document provides revised definitions and management guidelines for tuberculosis (TB) cases according to India's National Tuberculosis Elimination Program (NTEP). Key changes include:
- Updated case definitions for presumptive TB, DR-TB, pediatric TB, and EPTB.
- Classification based on history of treatment and drug resistance is revised.
- Diagnostic algorithms and tools are introduced, including new molecular tests.
- Treatment is shifted to daily fixed-dose combinations administered according to weight bands, with an 8-week intensive phase and 16-week continuation phase.
- Guidelines for managing DR-TB, hospitalized patients, EPTB and special groups are provided.
Tuberculosis infection is very common in the world and the disease manifest when ever either the virulence of the organism increases or the resistance of the host goes down.it can affect any part of the body.the best method of control of tuberculosis is early diagnosis and treatment.despite international cooperation the problem of resistance in tuberculosis is increasing and great efforts are being made to tackle this problem both in diagnostic tools as well as in treatment modalities. the social factors also play a big role in the causation as well as emergence of resistance is concerned . a participatory approach is required to combat the problem.
This document provides an overview of epidemic investigation. It begins with definitions of key terms like epidemic, outbreak, endemic, and pandemic. It describes the objectives of epidemic investigation as defining the scope and identifying the causative agent. The steps in an investigation are outlined as verifying diagnoses, defining the population at risk, analyzing data, formulating hypotheses, and writing a report. Recent outbreaks around the world are briefly discussed.
It gives all the important definitions used in infectious disease epidemiology and continues to elaborate on dynamics of disease transmission followed by prevention and control of infectious diseases.
This document provides an overview of epidemiology. It defines epidemiology as the study of disease distribution, patterns, and determinants in populations along with the application of this study to disease control and prevention. It discusses key epidemiological topics like descriptive epidemiology, analytical epidemiology, measures of disease frequency, and types of epidemiological study designs including case-control and cohort studies. The aims and scope of epidemiology are to describe disease burden in populations, identify risk factors, provide data to inform disease prevention and control, and evaluate health interventions.
This document provides an overview of the dynamics of disease transmission. It discusses the key elements involved, including:
1) The infectious agent - the pathogen that causes disease. It covers aspects like infectivity, pathogenicity, and virulence.
2) The source or reservoir - where the infectious agent lives and multiplies, such as humans, animals, or the environment. It can be the starting point for disease occurrence.
3) Modes of transmission - how the pathogen moves between the reservoir and a susceptible host. This includes direct contact, droplets, vectors, and indirect transmission through vehicles like food, water, fomites etc.
It describes other important epidemiological concepts like incubation period, generation
The specialty which deals with population.
Comprises those doctors who try to measure the needs of sick and healthy.
Who plan and administer the services to meet the needs.
Who are engaged in research & teaching in the field.
The document discusses descriptive epidemiology and provides definitions and examples. Descriptive epidemiology studies the occurrence and distribution of disease. It describes the who, where, and when of diseases. Key terms discussed include:
- Time trends which can be secular (long-term), periodic (interruptions to secular trends), or seasonal (cyclical yearly variations).
- Place patterns looking at geographic distributions of disease.
- Person characteristics of those affected such as age, sex, occupation.
Descriptive studies are the first step in understanding diseases and include case reports, case series, and cross-sectional prevalence studies.
Measles is a highly contagious viral infection that is transmitted through respiratory droplets. It causes a rash and fever and can lead to severe complications without vaccination. Before widespread vaccination, measles killed millions of children globally each year. Two doses of the measles vaccine, usually combined in the MMR vaccine, are effective at preventing the disease and its complications. Public health efforts aim to achieve at least 90% vaccination coverage to eliminate measles through both routine immunization and supplemental catch-up campaigns.
Part 1 of the Epidemiology Exercises for the Practical Exam in the subject of Social and Preventive Medicine at Shadan Institute of Medical Sciences
Covering Questions 1 to 10 along with their detailed answers
This document outlines the steps for investigating an epidemic. It describes defining the scope of the epidemic in terms of time, place, and affected individuals. Key steps include verifying diagnoses, confirming the epidemic's existence, defining case criteria, identifying the at-risk population, analyzing data to form hypotheses about the cause, and testing hypotheses. The investigation aims to control the current outbreak and make recommendations to prevent future epidemics.
Hypertension is the leading modifiable risk factor for stroke globally. Stroke is a major cause of death and disability worldwide, with low and middle income countries like those in Africa having the highest burden. While prevention through control of risk factors like hypertension is critical, many resource-limited areas lack adequate acute stroke care and rehabilitation services.
This document discusses disease screening and provides information on various aspects of screening programs and tests. It defines screening as actively searching for unrecognized disease in apparently healthy individuals using simple tests. The key points are:
- Screening is part of secondary prevention and aims to detect diseases early when they may be still curable. It involves testing populations, not individuals with symptoms.
- An ideal screening test is both highly sensitive and specific, but in practice these factors typically have an inverse relationship. Sensitivity and specificity can be adjusted by changing the test cutoff criteria.
- For a screening program to be effective, the disease must be an important health problem that can be detected early and treated effectively to improve outcomes. The screening test
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. It uses a systematic and unbiased approach to collect, analyze, and interpret data. Some core functions of epidemiology include public health surveillance, field investigations, analytic studies, evaluation of public health programs and services, linkages with other disciplines, and policy development. Epidemiology provides an evidence base for effective public health action and disease prevention.
This document discusses and compares case-control and cohort studies in epidemiology. It defines epidemiology as the study of health-related states in populations and applying this to control health problems. Analytical epidemiology focuses on testing hypotheses about individuals within populations. Both case-control and cohort studies are described as types of analytical epidemiology. Case-control studies are retrospective while cohort studies are prospective. The key differences and advantages/disadvantages of each study type are outlined.
Rickettsial diseases are caused by obligately intracellular, gram-negative bacteria that are most often transmitted by ticks, mites, fleas, or lice. The diseases include epidemic typhus caused by Rickettsia prowazekii transmitted by human body lice, murine typhus caused by R. typhi transmitted by fleas, and scrub typhus caused by Orientia tsutsugamushi transmitted by mite bites. They present with fever, rash, and lymphadenopathy and are treated with doxycycline. Prevention involves controlling insect vectors.
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 the epidemiology of tuberculosis. It begins by defining tuberculosis and how it is transmitted. Globally, the mortality and prevalence of TB is highest in India, which accounts for 20% of global cases. Key epidemiological factors that influence the spread of TB are the bacterial agent, host susceptibility, and social determinants. TB is typically transmitted through droplets in the air and has an incubation period of weeks to years. While pulmonary TB is most common, extrapulmonary TB can also occur. Despite prevention and control efforts like BCG vaccination and India's Revised National Tuberculosis Control Programme, TB remains a major public health challenge in India due to ongoing issues with awareness and socioeconomic factors.
This document discusses tuberculosis (TB) in India. It notes that India has the highest TB burden in the world, accounting for nearly 1/5 of global cases. Every year approximately 1.8 million people develop TB in India, of which around 800,000 are new smear-positive cases. India also has the fastest expanding DOTS program for treating TB, which has treated over 7.3 million patients since 1997.
This document discusses various measures used to quantify drug use and outcomes in pharmacoepidemiological studies. It describes prevalence as the proportion of people with a disease or exposed to a drug at a given time. Incidence is the number of new cases within a time period, while incidence rate is the number of new cases per unit of person-time at risk. Drug use is commonly measured by the number of prescriptions, units of drug dispensed, defined daily doses which estimates average maintenance dose, and prescribed daily doses which is the average dose actually prescribed. Adherence is often measured through biological assays, pill counts, pharmacy records, and patient interviews.
Revised definitions of tb cases and management as per ntepDrSmritiMadhusikta
The document provides revised definitions and management guidelines for tuberculosis (TB) cases according to India's National Tuberculosis Elimination Program (NTEP). Key changes include:
- Updated case definitions for presumptive TB, DR-TB, pediatric TB, and EPTB.
- Classification based on history of treatment and drug resistance is revised.
- Diagnostic algorithms and tools are introduced, including new molecular tests.
- Treatment is shifted to daily fixed-dose combinations administered according to weight bands, with an 8-week intensive phase and 16-week continuation phase.
- Guidelines for managing DR-TB, hospitalized patients, EPTB and special groups are provided.
Tuberculosis infection is very common in the world and the disease manifest when ever either the virulence of the organism increases or the resistance of the host goes down.it can affect any part of the body.the best method of control of tuberculosis is early diagnosis and treatment.despite international cooperation the problem of resistance in tuberculosis is increasing and great efforts are being made to tackle this problem both in diagnostic tools as well as in treatment modalities. the social factors also play a big role in the causation as well as emergence of resistance is concerned . a participatory approach is required to combat the problem.
This document provides an overview of epidemic investigation. It begins with definitions of key terms like epidemic, outbreak, endemic, and pandemic. It describes the objectives of epidemic investigation as defining the scope and identifying the causative agent. The steps in an investigation are outlined as verifying diagnoses, defining the population at risk, analyzing data, formulating hypotheses, and writing a report. Recent outbreaks around the world are briefly discussed.
It gives all the important definitions used in infectious disease epidemiology and continues to elaborate on dynamics of disease transmission followed by prevention and control of infectious diseases.
This document provides an overview of epidemiology. It defines epidemiology as the study of disease distribution, patterns, and determinants in populations along with the application of this study to disease control and prevention. It discusses key epidemiological topics like descriptive epidemiology, analytical epidemiology, measures of disease frequency, and types of epidemiological study designs including case-control and cohort studies. The aims and scope of epidemiology are to describe disease burden in populations, identify risk factors, provide data to inform disease prevention and control, and evaluate health interventions.
This document provides an overview of the dynamics of disease transmission. It discusses the key elements involved, including:
1) The infectious agent - the pathogen that causes disease. It covers aspects like infectivity, pathogenicity, and virulence.
2) The source or reservoir - where the infectious agent lives and multiplies, such as humans, animals, or the environment. It can be the starting point for disease occurrence.
3) Modes of transmission - how the pathogen moves between the reservoir and a susceptible host. This includes direct contact, droplets, vectors, and indirect transmission through vehicles like food, water, fomites etc.
It describes other important epidemiological concepts like incubation period, generation
The specialty which deals with population.
Comprises those doctors who try to measure the needs of sick and healthy.
Who plan and administer the services to meet the needs.
Who are engaged in research & teaching in the field.
The document discusses descriptive epidemiology and provides definitions and examples. Descriptive epidemiology studies the occurrence and distribution of disease. It describes the who, where, and when of diseases. Key terms discussed include:
- Time trends which can be secular (long-term), periodic (interruptions to secular trends), or seasonal (cyclical yearly variations).
- Place patterns looking at geographic distributions of disease.
- Person characteristics of those affected such as age, sex, occupation.
Descriptive studies are the first step in understanding diseases and include case reports, case series, and cross-sectional prevalence studies.
Measles is a highly contagious viral infection that is transmitted through respiratory droplets. It causes a rash and fever and can lead to severe complications without vaccination. Before widespread vaccination, measles killed millions of children globally each year. Two doses of the measles vaccine, usually combined in the MMR vaccine, are effective at preventing the disease and its complications. Public health efforts aim to achieve at least 90% vaccination coverage to eliminate measles through both routine immunization and supplemental catch-up campaigns.
Part 1 of the Epidemiology Exercises for the Practical Exam in the subject of Social and Preventive Medicine at Shadan Institute of Medical Sciences
Covering Questions 1 to 10 along with their detailed answers
This document outlines the steps for investigating an epidemic. It describes defining the scope of the epidemic in terms of time, place, and affected individuals. Key steps include verifying diagnoses, confirming the epidemic's existence, defining case criteria, identifying the at-risk population, analyzing data to form hypotheses about the cause, and testing hypotheses. The investigation aims to control the current outbreak and make recommendations to prevent future epidemics.
Hypertension is the leading modifiable risk factor for stroke globally. Stroke is a major cause of death and disability worldwide, with low and middle income countries like those in Africa having the highest burden. While prevention through control of risk factors like hypertension is critical, many resource-limited areas lack adequate acute stroke care and rehabilitation services.
This document discusses disease screening and provides information on various aspects of screening programs and tests. It defines screening as actively searching for unrecognized disease in apparently healthy individuals using simple tests. The key points are:
- Screening is part of secondary prevention and aims to detect diseases early when they may be still curable. It involves testing populations, not individuals with symptoms.
- An ideal screening test is both highly sensitive and specific, but in practice these factors typically have an inverse relationship. Sensitivity and specificity can be adjusted by changing the test cutoff criteria.
- For a screening program to be effective, the disease must be an important health problem that can be detected early and treated effectively to improve outcomes. The screening test
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. It uses a systematic and unbiased approach to collect, analyze, and interpret data. Some core functions of epidemiology include public health surveillance, field investigations, analytic studies, evaluation of public health programs and services, linkages with other disciplines, and policy development. Epidemiology provides an evidence base for effective public health action and disease prevention.
This document discusses and compares case-control and cohort studies in epidemiology. It defines epidemiology as the study of health-related states in populations and applying this to control health problems. Analytical epidemiology focuses on testing hypotheses about individuals within populations. Both case-control and cohort studies are described as types of analytical epidemiology. Case-control studies are retrospective while cohort studies are prospective. The key differences and advantages/disadvantages of each study type are outlined.
Rickettsial diseases are caused by obligately intracellular, gram-negative bacteria that are most often transmitted by ticks, mites, fleas, or lice. The diseases include epidemic typhus caused by Rickettsia prowazekii transmitted by human body lice, murine typhus caused by R. typhi transmitted by fleas, and scrub typhus caused by Orientia tsutsugamushi transmitted by mite bites. They present with fever, rash, and lymphadenopathy and are treated with doxycycline. Prevention involves controlling insect vectors.
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.
epidemiology with part 2 (complete) 2.pptAmosWafula3
This document provides an overview of epidemiology. It begins by defining epidemiology as the study of what falls upon populations in terms of health and disease. A modern definition is provided that describes epidemiology as studying the distribution and determinants of health states in populations.
The objectives and purposes of epidemiology are then outlined, which include describing disease distribution and magnitude, identifying risk factors, providing data for prevention/control programs, and recommending interventions. Key epidemiological terms like incidence, prevalence, endemic, epidemic, and pandemic are also defined. Descriptive and analytical study designs commonly used in epidemiology like cross-sectional and case-control studies are described. The document concludes by contrasting the approaches of epidemiology versus clinical medicine
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 discusses epidemiological methods for studying the distribution and determinants of health events and applying that knowledge to disease control. It defines descriptive epidemiology as the study of disease occurrence, distribution, and patterns in populations. Descriptive methods are observational and can be cross-sectional or longitudinal. Descriptive epidemiology provides insights into disease frequency, trends, and risk factors to inform public health planning and resource allocation.
This document discusses descriptive and cross-sectional studies. It outlines the steps in the scientific method and differentiates between observational and experimental studies. Descriptive studies examine health status based on routine data to describe disease patterns without testing hypotheses. Cross-sectional studies can test hypotheses by including study and control groups to examine prevalence and potential causative factors. The document discusses the types, uses, advantages, and disadvantages of descriptive and cross-sectional studies, and outlines the steps to carry out a cross-sectional study.
This document discusses different epidemiological research designs including cross-sectional studies, cohort studies, and case-control studies. Cross-sectional studies measure prevalence of disease or risk factors at a single point in time. Cohort studies follow groups over time to measure incidence. Case-control studies identify existing cases and look back to compare exposures between cases and controls. Each design has advantages and limitations for establishing causality and informing public health strategies.
This document provides an introduction to epidemiology. It begins with definitions of epidemiology as the study of patterns, causes, and effects of health and disease conditions in populations. It then discusses the history of epidemiology from Hippocrates' observations to modern uses. The types of epidemiological studies covered are descriptive studies like cross-sectional and analytical studies like cohort and case-control studies. The aims and uses of epidemiology are also summarized, including describing disease problems, assessing population health, informing individual decisions, understanding disease natural history, identifying causes and risks, and planning/evaluating interventions.
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.
This document provides an introduction to epidemiology. It defines epidemiology as the study of disease occurrence and distribution in populations as well as the determinants that influence health states. Descriptive epidemiology involves characterizing disease distribution according to person, place, and time, while analytical epidemiology aims to identify risk factors and causes of disease. Common study designs in epidemiology include observational studies like cohort and case-control studies as well as experimental designs like randomized controlled trials.
1. 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 control health problems. Descriptive epidemiology aims to describe patterns of disease, while analytical epidemiology aims to identify risk factors.
2. Key approaches in epidemiology include observational studies like cross-sectional and case-control studies, as well as experimental studies like randomized controlled trials. Important concepts include rates, ratios, and proportions used to describe disease frequency and distribution.
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.
This document discusses epidemiology and describes various epidemiological study designs used to determine disease etiology and distribution. Descriptive epidemiology involves studying disease distribution by person, place and time, while analytic epidemiology aims to explain disease occurrence. Common study designs include descriptive studies like case reports and cross-sectional surveys, as well as analytic observational studies like case-control and cohort studies and experimental randomized controlled trials. The key steps in epidemiological investigations and considerations for assessing causal relationships are also outlined.
This document discusses epidemiology, which is the study of the distribution and determinants of health and disease in populations. It covers the components, characteristics, and types of epidemiology studies. Descriptive epidemiology involves studying disease distribution by person, place, and time variables. Analytic epidemiology uses epidemiologic methods to explain disease occurrence and identify causal mechanisms. Key topics include descriptive variables, temporal variations, community diagnosis, epidemics, and determination of disease etiology through descriptive and analytical studies.
This document discusses epidemiology, which is the study of the distribution and determinants of health and disease in populations. It covers the components, characteristics, and types of epidemiology studies. Descriptive epidemiology involves studying disease distribution by person, place, and time variables. Analytic epidemiology uses epidemiologic methods to explain disease occurrence and identify causal mechanisms. Key topics include descriptive variables, temporal variations, community diagnosis, epidemics, and determination of disease etiology through descriptive and analytical studies.
Investigation of an epidemic by taking ebola as an example...Grandhe Sumanth
investigation of an epidemic by taking ebola as an example....................................................................................................................................................................................................................................................................
This document provides an overview of epidemiology in public health. It defines epidemiology as the study of disease distribution and determinants in populations. Some key points made include:
- Epidemiology aims to identify patterns of disease and investigate factors that contribute to disease development.
- It plays a significant role in shaping public health policy and practice.
- Important concepts in epidemiology include measures of disease frequency and association, and addressing bias and confounding.
- Epidemiology helps with disease prevention, outbreak investigation, health promotion, and evaluating health interventions.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
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- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
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Integrating Ayurveda into Parkinson’s Management: A Holistic ApproachAyurveda ForAll
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Osteoporosis - Definition , Evaluation and Management .pdfJim Jacob Roy
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
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There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
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Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
2. Epidemiology
EPI DEMO LOGOS
Upon,on,befall People,population,man the Study of
The study of anything that happens to
people
“That which befalls man”
12/16/2018 2SUNNY YADAV BPH/BEd
3. Epidemiology: Definition
Dynamic study of the
Determinants
Occurrence
Distribution
Control
Pattern
Of health and disease in a population
12/16/2018 3SUNNY YADAV BPH/BEd
4. Definition of Epidemiology
"The STUDY of the DISTRIBUTION and
DETERMINANTS of HEALTH-RELATED STATES
in SPECIFIED POPULATIONS, and the
APPLICATION of this study to control of health
problems."
*Last, J.M. 1988. A Dictionary of Epidemiology, 2nd ed.
12/16/2018 4SUNNY YADAV BPH/BEd
6. Purposes of Epidemiology
1. To investigate nature / extent of health-
related phenomena in the community /
identify priorities
2. To study natural history and prognosis
of health-related problems
3. To identify causes and risk factors
4. To recommend / assist in application of /
evaluate best interventions (preventive
and therapeutic measures)
5. To provide foundation for public policy
6SUNNY YADAV BPH/BEd12/16/2018
7. Function / Uses of Epidemiology
• Study historically rise and fall of disease
• Conduction of a community diagnosis
• Health planning and evaluation
• Evaluation of individual’s risk and changes
• Syndrome identification
• Completion of natural history of disease
• Searching for causes and risk factors
12/16/2018 7SUNNY YADAV BPH/BEd
8. Components of Epidemiology
• Disease frequency: Measurement of frequency of
disease, disability or death in the forms of rate and
ratio (Incidence rate, prevalence rate and death
rate)
• Disease distribution: Measurement of distribution
of disease in population by time, place and person
which helps in prevention and control of disease
• Disease determinant: Measurement of risk factors
or causes of disease
12/16/2018 8SUNNY YADAV BPH/BEd
9. Kinds of Epidemiology
• Descriptive
• Analytic
• Experimental
Further studies to determine the
validity of a hypothesis concerning
the occurrence of disease.
Deliberate manipulation of the
cause is predictably followed
by an alteration in the effect
not due to chance
Study of the occurrence and
distribution of disease
12/16/2018 9SUNNY YADAV BPH/BEd
10. Overview of epidemiologic design strategies
• Descriptive
Case Report
Case Series
Cross-sectional
• Analytical
Cross-sectional
Case-Control
Cohort
Correlation (ecological)
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Interventional/Experimental
Randomized controlled trial
Field trial
Clinical trial
Community trial
Observational: help to generate hypotheses
(descriptive) or to test hypotheses (analytic)
11. • First phase of epidemiological
investigation
• It formulates hypothesis
• Describes in term of person, place and
time
• This type of study is appropriate in acute
infectious diseases like cholera, typhoid,
dysentery, ARI, etc.
• The unit of study is population at risk
Descriptive Epidemiology
PERSON
PLACE
TIME
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12. Procedure of descriptive epidemiology
• Defining the population
• Defining the disease under study
• Describing the disease in term of time , place and person
• Measurement of disease
• Comparison with known indices
• Formation of hypothesis
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13. Person Distribution of disease
• Age: measles in childhood , cancer in middle age and
arthrosclerosis in old age
• Sex: lung cancer and coronary heart disease are more
common in male while obesity , diabetes and
hyperthyroidism are more common in female
• Marital status: STDs are more common in unmarried
• Occupation: silicosis is more common in workers of coal
• Socioeconomic status
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14. Time Distribution of Disease
1. Short term fluctuation or outbreak
(Epidemic)
– Common source epidemic
• Point source or single exposure
• Continuous or repeated exposure
– Propagated epidemic
– Slow epidemic or modern epidemic
2. Midterm fluctuation or Periodic fluctuation
– Seasonal trend
– Cyclic trend
3. Long term fluctuation (Secular trend):
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If normal expectancy is
zero, even one case is
considered “epidemic”
Epidemic
No. of cases > Mean +
2 SD
15. Common Source Eidemic
1. Group of people
2. Common exposure of
pathogen
3. Short incubation
period
E.g. food poisoning,
measles, chicken pox,
cholera, Bhopal gas
tragedy, etc
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16. Propagated epidemic
1. Person
2. Individual contact
3. Spreading in
community
E.g. HIV, TB,
Arthropod vector,
animal reservoir,
etc.
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17. Compare Common Source Propagated source
1.Curve Bell curve Scatter bell
3.Transmission One source From person to
person
4.Duration Short Long
5. control Eradicate source Health education
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18. Seasonal Variation
• Seasonal variation
can be seen for some
diseases or conditions
falling within a
calendar year
• E.g. measles-early
spring, URTI-winter,
GI infection-summer,
typhoid-rainy, etc
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19. Cyclic Trends
• occurrence of disease in a cycle.
• E.g. measles (every 2-3 years), rubella (every 6-9
years), influenza pandemic (every 10-15 year), etc.
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20. Secular trend (Long term fluctuation)
• Temporal variation
occur slowly over
long periods of time
generally several
years or decades
• E.g. Diabetes,
obesity,
hypertension are
increased in past few
decades, polio,
pertusis,12/16/2018 20SUNNY YADAV BPH/BEd
21. Place Distribution of disease
• International
• Variation within
countries
– Urban-rural
– Local
• Building Maps
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22. Analytical Epidemiology
• Deals with risk factors of diseases
• Test hypothesis
• Unit of study is individual
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23. Cross sectional study
• Prevalence study
• simplest form of
observational study
• SNAPSHOT of the
population study
• This type of study is
appropriate for chronic
diseases
Ecological study
• Co-relational study
• Only in this study, unit
of study is population
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24. Cohort Study
• Prospective study /
forward study / follow up
study
• Study proceeds forward
from cause to effect
• Risk factor to Disease
• Measures incidence study
• Measured by relative risk
Case control study
• Retrospective study /
backward study
• Study proceeds backward
from effect to cause or
outcome to exposure
• Disease to Risk factor
• Measured by odd’s ratio
and Chi Square test (for
comparisons)
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27. Infection/Disease/Infestation
• Infection: entry, development and multiplication of
an infectious agent in the body of man
• Disease: derangement in the function of the whole
body of the host or any of its parts
• Infestation: lodgment, development and
reproduction of arthropods on the surface of body
• Nosocomial infection: hospital acquired infection
– E.g. infection of surgical wound, Hepatitis B, AIDS,
UTI, Hospital acquired pneumonia
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28. • Iatrogenic infection: physician induced infection
– E.g. drug therapy, reaction to penicillin and
immunizing agent, aplastic anemia from
chloramphenicol, childhood leukemia due to prenatal
x-rays, etc
• Opportunistic infection: infection by any
organism that takes opportunity to provide other
infection to host.
– Very common in AIDS
– E.g. Tuberculosis in AIDS (common in Nepal),
pneumocystic cairini pneumonia in AIDS (common in
world), Cryptosporidium diarrhea in AIDS, Cytomegalo
viral infection in kidney transplant
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29. Pollution/Contamination
• Pollution: presence of offensive but not
necessarily infectious matter in the
environment
• Contamination: presence of an infectious agent
in the body surface or other inanimate articles
or substances (water, milk, food)
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30. Disease Distribution
• Endemic: constant presence of disease or infectious agent within
a given geographical area. E.g.:- malaria, kala-azar, etc
• Epidemic: unusual occurrence in a community or region of
disease or specific health related states or events clearly in excess
of expectation. E.g.:- cholera, measles, diarrhea, etc
• Sporadic: occurrence of irregular, haphazardly from time to time
and generally infrequently. E.g.:- tetanus, herpes zoster,
meningitis, etc
• Pandemic: affecting large proportion of population covering wide
geographical area. E.g.:- influenza pandemic in 1918 and 1957.
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31. Screening and Surveillance
• Active search for unrecognized
disease or detects by rapidly
applied test , examination or
other procedures
• Find out sick people from
apparently healthy people
• 3 types
1. Mass screening
2. High risk screening
3. Multi-stage screening
• Continuous scrutiny factors
that determine the occurrence
and distribution of disease and
other condition of ill health
• Finds out the trends or
distribution of disease to
control disease
• 3 types
1. Active surveillance
2. Passive surveillance
3. Sentinel surveillance
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Notifiable diseases of Nepal: Cholera, Plague, Yellow fever and AIDS
32. Other Terminologies
• Disease control: reduction of disease incidence, prevalence,
morbidity or mortality to a locally acceptable level
– Reduction in transmission that no longer public health problem
• Outcome of disease control: reduction in
– Incidence of disease
– Duration of disease
– Effect of infection
– Financial burden to the community
• Disease elimination: reduction of disease to zero of incidence in
defined geographical area (complete interruption of transmission)
• Disease eradication: permanent reduction of disease to zero of
worldwide incidence (extermision of disease)
• Fatality: it is percentage of death among these attacked by a given
disease. It is the measure of the severity of disease12/16/2018 32SUNNY YADAV BPH/BEd
33. • Incubation period: the time interval between invasion
by an infectious agent and appearance of first sign or
symptoms of the disease
• Latent period: period from disease initiation to disease
detection
• Communicable period: the time during which an
infectious agent may be transferred directly or
indirectly from one host to another
• Serial interval: the gap between onset of primary case
and secondary case
• Generation time: the time interval between receipt of
infection by host and maximum infectivity of the host
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34. • Lead time: time interval between diagnosis by early
detection and diagnosis by other means.
• ''Lead time" is the advantage gained by screening,
i.e., the period between diagnosis by early detection
and diagnosis by other means. In Figure, A is the
usual outcome of the disease, and B is the outcome
to be expected when the disease is detected at the
earliest possible moment
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35. • Secondary attack rate: the number of exposed
persons developing the disease within the range of
incubation period following exposure to primary case
• It shows communicability of disease
• E.g. Chicken pox (90%), measles (80%), mumps
(86%), etc
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36. Incubation period
• the time interval between invasion by an infectious
agent and appearance of first sign or symptoms of the
disease
• Depends on generation time, portal of entry, infective
dose, individuals (susceptibility)
• Use of incubation period
– Trace the source of infection and contact
– Determining the period of surveillance
– Apply immunization principle for prevention of disease
– Identification of point source or propagated epidemics
– Estimated prognosis of disease
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37. Epidemiological measurement
1. Rate
– Measure the occurrence of some particular events in population
during a given time period, time always related to dinominator
– In rate , numerator is the part of denominator
– E.g. :- crude rate , standardize rate , specific rate , etc
2. Ratio
– Measure a relation in size between two random quantities
(x/x+y)
– In ratio, numerator is not the part of denominator (x/y)
– E.g. :- MMR, doctor-population ratio , sex ratio , bed-patient ratio
3. Proportion
– It is a ratio which indicates a relation in magnitude of a part of
whole
– In proportion , the numerator is always included in denominator
– E.g. Proportion, Case fatality rate
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38. Measurement of morbidity
• By incidence, prevalence and case fatality rate
12/16/2018 SUNNY YADAV BPH/BEd 38
Incidence
• It is a rate
• Measures new cases of specific disease
39. Prevalence
• Prevalence is a proportion
• Prevalence = incidence x mean duration
• Prevalence increases with increase in duration of disease
• If population is stable then incidence and duration are
unchanged.
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40. Case Fatality Rate
• Killing power of a disease
• Closely related to virulence of organism
• Proportion always represents in 100
• E.g. Rabies (100%), Yellow fever (80%), JE (30-50%),
chicken pox (<1%), Cholera (30-40%), tetanus (80-90%)
etc
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43. Concept of causation
1. Germ theory (Louis Pasteur in 1873)
– One relationship between causative agent and disease
1. Multi-factorial causation (Pattenkoffer)
– Multiple factors in disease causation (E.g. TB)
2. Epidemiological triad
– Shows relation between agent , host and environment
3. Web causation (Mac Mohan and Pugh)
– The predisposing factors of any type and their complex
interrelationship with each other (E.g. MI, cancer)
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44. Iceberg phenomenon of disease
• Tip of iceberg (above
water line):
symptomatic/diagnostic
/clinical – applied
Diagnosis
• Submerged portion
(Below waterline):
asymptomatic/undiagn
osed/latent/carrier –
applied screening
12/16/2018 SUNNY YADAV BPH/BEd 44
45. • Disease is physiological and psychological
dysfunction (D – Doctor)
• Illness is subjective state of person who feels
aware of not being well (I – I am or Patient)
• Sickness is a state of social dysfunction (S –
Society)
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47. Agent
• Entity necessary to cause disease in a susceptible host
• Types
1. Biological agents: Bacteria, virus, fungi, protozoa, hookworm, etc
2. Physical agents: heat, cold, pressure, radiation, etc
3. Chemical: 2 types – exogenous (allergens, metals, dust, gas, poison,
etc) and endogenous (uric acid-gout, urea-uremia)
4. Mechanical agents: Wound fracture, sprain, etc
5. Nutritional agents: Obesity, night blindness, PEM, goiter, etc
6. Social factors: smoking, alcoholism, unhealthy life style, etc
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48. Host
• An organism which harbors the disease agent
• Types of host are
1. Definite or primary host: the host in which the adult stage or
sexual mode of reproduction takes place. E.g. mosquitoes in
malaria, man in filarial
2. Intermediate or secondary host: the host in which larval stage or
asexual mode of reproduction takes place. E.g. man in malaria,
hydatid disease, toxoplasmosis
3. Obligate host: only one host e.g. man for typhoid, tuberculosis,
cholera etc
4. Transport host: organism remains alive but does not undergo
development, host factor (age) – strongly related to disease
12/16/2018 48SUNNY YADAV BPH/BEd
49. Environment
• Conditions / influences that influence
interaction between agents & host
• Types of environment
1. Physical environment: air, water, soil,
climate, noise, heat, light, radiation, etc.
2. Biological environment: bacteria, virus, etc.
3. Psychosocial environment: culture, tradition,
health service, etc.
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53. 1 - The Infectious Agent
• Any microorganism that is capable of producing an
infection. E.g. Bacteria, virus, protozoa, etc
12/16/2018 53SUNNY YADAV BPH/BEd
54. 2 - The Reservoir
• The habitat in or on which an infectious agent
normally lives, grows and multiplies
12/16/2018 54SUNNY YADAV BPH/BEd
55. • Source of infection is defined as “the person , animal ,
object or substance from which an infectious agent
passes or is disseminated to host”
• Reservoir of infection is defined as “any person , animal
, plant or substance in which an infectious disease lives
and multiplies , on which it depends for survival”
• The reservoir may or may not be the source from which
an agent is transferred to a host. For example, the
reservoir of Clostridium botulinum is soil, but the source
of most botulism infections is improperly canned food
containing C. botulinum spores
12/16/2018 55SUNNY YADAV BPH/BEd
56. • Reservoir may be of 3 types
1. Human reservoir
2. Animal reservoir
3. Reservoir in non-living things
Types of reservoir
• Human reservoir serves in the form of case or
careers
12/16/2018 56SUNNY YADAV BPH/BEd
57. Case
• Case: a person in a population identifies as having a
particular disease, health disorder or condition under
investigation.
• On the basic of state , case are of following types
– Clinical case
– Subclinical case
– Latent case
• According to epidemiology host may be classified into
– Primary case: first case of communicable disease
– Index case: first case come to investigator
– Secondary case: case developing from primary case
12/16/2018 57SUNNY YADAV BPH/BEd
58. Features Clinical
case
Subclinical case Latent case
Agent √ √ √
Signs and
Symptoms
√ X X
Transfer √ √ X
Examples Cholera,
Typhoid,
measles, etc
Poliomyelitis,
Mump,
influenza,
Hepatitis A and
B, etc
Herpes
simplex,
ancylostomias
is, etc
12/16/2018 58SUNNY YADAV BPH/BEd
59. Carrier
• Carriers: an infected person or animal that Shows
– Presence of infectious agent
– Absence of signs and symptoms
– Transmission of disease
– Disease agent seen in discharge
12/16/2018 59SUNNY YADAV BPH/BEd
60. Types of carriers
1. According to types – 3 types
• Incubatory carrier: E.g. measles, polio, mumps, hepatitis B,
pertusis, influenza, diphtheria
• Convalescent carrier: E.g. typhoid, bacillary dysentery,
cholera, diphtheria, pertusis
• Healthy carrierE.g. polio, typhoid, cholera, diphtheria,
meningococcal infection
2. According to duration – 2 types
• Temporary carrier: shed the infection for short time. It may
be incubatory, convalescent and healthy carriers.
• Chronic carrier: excretes the infectious agent for long
period of time. E.g. typhoid, malaria, dysentery, hepatitis,
gonorrhea.
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61. 3. According to portal of exits
• Urinary
• Intestinal
• Respiratory
• Urinary carrier more dangerous than intestinal
carrier
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62. Animal and Non-living Reservoir
• Animal reservoir: animals and birds may be
reservoir.
• Animal reservoir found in two forms – case or
carriers.
E.g. rabies (case), influenza (carrier), plague,
anthrax, bovine tuberculosis, brucellosis, etc
• Reservoir in non-living thing: water- typhoid,
soil-tetanus, cane food- food poisoning.
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63. 3 - The Portal of Exit
Path by which an agent leaves the reservoir or host
E.g. hepatitis A- stool, SARS-droplet, AIDS- vaginal
discharge or semen, etc.
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64. Portals of Exit
• Respiratory Tract (Coughing or Sneezing)
• Gastrointestinal Tract (Saliva or Feces)
• Urogenital Tract (Secretions from the Vagina or
Penis)
12/16/2018 64SUNNY YADAV BPH/BEd
65. 4 - Mode of Transmission (Spread)
the mechanism of
spread of infection
through the
environment or through
another person
12/16/2018 65SUNNY YADAV BPH/BEd
66. Modes of Transmission
1. Direct Transmission
a) Direct contact
b) Droplet infection
c) Contact with soil
d) Inoculation into skin
e) Vertical (transplacental)
2. Indirect Transmission
(@5F – flies, food, finger, fluid and
fomites)
a) Vehicle borne
b) Vector borne
c) Air borne
d) Unclean hands and fingers
e) Fomite borne
12/16/2018 66SUNNY YADAV BPH/BEd
67. E.g. Droplet Transmission
Direct Spread by Droplets
• Close contact with infected person (<3 ft)
• Infected person coughs, sneezes, talks, sings
• Droplets land directly on mucous membranes (eyes,
nose, mouth) of susceptible person
12/16/2018 67SUNNY YADAV BPH/BEd
68. Indirect Spread by Droplets
Droplets with the infectious
agent land on a table,
doorknob etc.
Someone touches
contaminated object
12/16/2018 68SUNNY YADAV BPH/BEd
69. 5 - The Portal of Entry
• Route through
which the pathogen
enters its new
susceptible host
12/16/2018 69SUNNY YADAV BPH/BEd
75. Objectives of epidemiological investigation
• To define magnitude of problem (time, place,
person)
• To determine responsible condition and
factors
• To identify causes, sources and mode of
transmission
• To make recommendations to prevent
reoccurrence
12/16/2018 75SUNNY YADAV BPH/BEd
77. • The science and art of preventing disease, prolonging life,
promoting physical and mental health
• It is not necessary to know everything about natural history of
disease to initiate preventive measures, removal of single known
essential cause is sufficient to prevent a disease
Successful prevention depends upon:
• A knowledge of causation
• Dynamics of transmission,
• Identification of risk factors and risk groups,
• Availability of prophylactic or early detection & treatment
• An organization for applying these measures to appropriate
persons or groups
• Continuous evaluation of & development of procedures applied
12/16/2018 77SUNNY YADAV BPH/BEd
78. Levels of Prevention
Stage of disease Level of prevention Type of response
Pre-disease Primary
Prevention
Health promotion
Specific protection
Latent
Disease
Secondary
Prevention
Early Diagnosis
Prompt Treatment
Symptomatic
Disease
Tertiary
Prevention
Disability limitation
Rehabilitation
12/16/2018 78SUNNY YADAV BPH/BEd
79. Primordial prevention
• Prevention of emergence or development of risk
factors in countries or population groups in which
they may have not yet appeared
• Intervention that is taken when the risk factors are
not even present
• Best prevention for non-communicable diseases start
from early childhood by Health Education
• Main intervention- individual and mass education
12/16/2018 79SUNNY YADAV BPH/BEd
80. Primary prevention
• Action taken prior to onset of disease which removes
the possibility that the disease will ever occur
• Intervention that is taken when the risk factors are
present but disease has not developed
• Intervention in pre-pathogenesis phase
• applied for chronic disease such as hypertension,
cancer, diabetes, asthma, COPD, etc
• Primary prevention may be accomplished by measures
of “Health promotion” and “specific protection”
12/16/2018 80SUNNY YADAV BPH/BEd
81. Primary prevention
Specific protection
Health
promotion
Health education
Environmental
modifications
Nutritional
interventions
Life style and
behavioral changes
Immunization and seroprophylaxis
Chemoprophylaxis
Use of specific nutrients or
supplementations
Protection against occupational
hazards
Safety of drugs and foods
Control of environmental hazards,
e.g. air pollution
Achieved by
12/16/2018 81SUNNY YADAV BPH/BEd
82. Secondary prevention
• Strategies applied in early disease
e.g. preclinical & clinical
• Interrupts the disease process before it becomes
symptomatic
• directed to finding the sick component of the
community
• mostly applied for acute diseases such as tuberculosis,
leprosy, syphilis, cholera, typhoid, etc It halts the
progress of a disease at its incipient stage and
prevents complications
12/16/2018 82SUNNY YADAV BPH/BEd
83. Nature of measures
Early diagnosis and Prompt treatment.
to limit spread of infectious diseases
Example
• screening and individual case finding
• recognition and treatment of hypertension and transient
ischemic attack for preventing a stroke
12/16/2018 83SUNNY YADAV BPH/BEd
84. Tertiary prevention
• Applied when disease is advanced
• Direct to the sick component of the community
• Nature of measures
Disability limitation
Rehabilitation
12/16/2018 84SUNNY YADAV BPH/BEd
85. Disability limitation
• Prevention of
complications of a disease
before irreversible
changes set in
Example
• Early mobilization or
splinting for stroke patients to
prevent contractures
Disease
Impairment
Disability
Handicap
Accident
Loss of foot
Cannot walk
Unemploym
ent
12/16/2018 85SUNNY YADAV BPH/BEd
86. Rehabilitation
• Alleviation of disability resulting from disease
• Attempts to restore functioning
• Components
– Medical – restoration of function
– Vocational-restoration of capacity to earn
– Social-restoration of family and social relationship
– Psychological- restoration of personal dignity and confidence
• Example
A stroke patient-rehabilitated physically, mentally and socially to
take part in daily social life and be a productive member of the
society
12/16/2018 86SUNNY YADAV BPH/BEd
87. 12/16/2018 SUNNY YADAV BPH/BEd 87
Risk Factor Disease Complication
Primordial X X X
Primary √ X X
Secondary √ √ X
Tertiary √ √ √
99. • The resistance exhibited by the host towards injury
caused by micro-organism or their products
Innate immunity Acquired immunity
Defense First line of defense Second line of defense
Specificity Non-specific Specific
Immunological memory Absent Present
Control of infection Able to control infection Not able to control
infection
Prior contact not affected by prior
contact with micro-
organism
affected by prior contact
with micro-organism
Presence of immunity Present since birth Immunity persists life long
Cellular components Macrophages, granulocytes,
mast cells, NK cells
T cells, B cells
Time scale of response Quick (maximal in minutes
to hours)
Slow (maximal in days to
weeks)
Phylogeny Ancient (all multicellular
organisms)
Recent (vertebrates only)12/16/2018 99SUNNY YADAV BPH/BEd
100. Innate immunity Acquired immunity
Functions Prevents infection to host
by microbes and can
eliminate the microbes
•Effectors mechanisms of
innate immunity are often
used to eliminate microbes
even in adaptive immunity
•Stimulates and influence
the nature of adaptive
responses
Humoral Immunity:
provided by antibodies
floating free in body fluids
Cell mediated immunity:
lymphocytes directly
attack specific invaders by
lysis or indirect attack
• Interferon: protein inhibits replication of virus
12/16/2018 100SUNNY YADAV BPH/BEd
101. Antibody Isotypes and their properties
IgA IgD IgE IgG IgM
Molecular forms Monomer
or dimer
monomer monomer monomer pentamer
% total Ig in
serum
10-20 <1 <1 70-85 10
Where found in
body
Found in
bodily
secretions
Found on
B-cell
surface
Attach to
basophils
and mast
cells
Blood &
extracellula
r fluid
Blood &
extracellular fluid
Functions Protect
external
openings
Unknown
; maybe
antigen
detection
Allergic
response
and defend
infection by
large
parasite
Long term
Ab that
protect the
body
Appear ealier in
the infection and
offer valuable
defense during
critical stage of
the infection
Trasferrable to
offsprings?
Via
Mother
milk
No No Via
placenta
No
12/16/2018 101SUNNY YADAV BPH/BEd
102. Vaccines
• Immuno-biological substance designed to produce
specific protection against a given disease
• Vaccine – Louis Pasteur
• Vaccination – Edward Jenner
• First developed vaccine is small pox (1798) by Edward
Jenner
• All vaccines are contra-indicated in pregnancy except
Yellow fever vaccine
12/16/2018 SUNNY YADAV BPH/BEd 102
104. Live vaccine @ BOY LOVE THE CRIME
B – BCG
O – OPV (Sabin)
Y – Yellow fever
LOVE – Live vaccine
Th – Typhoid
E – Japanese Encephalitis
C – Chicken pox (Varicella)
R – Rubella
I – Influenza
M – Measles Mumps
E – Epidemic typhus
12/16/2018 SUNNY YADAV BPH/BEd 104
Coverage percentage =
Vaccine Coverage
105. Routine Vaccination Schedule of Nepal
Name Protect against Use and dose Age Time
BCG TB meningitis ID/0.05ml At birth 1
DPT-HepB-
Hib
Diptheria, pertussis,
Tetanus,
Hepatitis B, Influenza
IM/0.5ml 6,10 and 14 weeks 3
Polio
(OPV)
poliomyelitis Oral/2 drop 6,10 and 14 weeks 3
IPV Poliomyelitis IM/0.5 ml 14 week 1
PCV Pneumonia IM/0.5 ml
6 week, 10 week, 9
month
3
MR Measles, rubella SC/0.5ml 9 and 15 month 2
Td Tetanus, Diptheria IM/0.5ml
Pregnant women (First as
early as possible of
pregnancy period and
next after 1 month
2
JE JE SC/0.5ml 12 – 23 month 1
Typhoid Typhoid SC/0.5ml >10 years 212/16/2018 SUNNY YADAV BPH/BEd 105
107. • Demography: scientific study of human population
• Demographic process: fertility, mortality, marriage, migration and
social mobility
• Population pyramid (age-sex or age structure): graphical
presentation that shows the distribution of various age groups in
a population which normally forms the shape of pyramid
• There are three types of population pyramid –
1. Expansive pyramid
•Fertility is high, mortality is high
•Life expectancy is shorter
•Population of children is higher
•Population growth rate is +ve
(i.e. increasing)
•E.g. India, Nigeria, Nepal, etc
2. Constructive Pyramid
•Low birth and low death
•Life expectancy is longer
•Older population is high
•Population growth rate is -ve
(i.e. decreasing)
•E.g. US, China, etc
12/16/2018 107SUNNY YADAV BPH/BEd
108. 3. Stationary Pyramid
• In this, low birth and low death but death exceeds birth
• High proportion of aged population
• Population growth rate is zero (i.e. remains constant)
• It is the population structure of typically developed
countries such as Spain, etc
12/16/2018 108SUNNY YADAV BPH/BEd
109. Demographic cycle
Stage 1 - High stationery
• Both death and birth
rate high and cancel
each other, population
remain stationary at
high Level
12/16/2018 109SUNNY YADAV BPH/BEd
110. Stage 2 - Early Expanding
• Birth rates remain high, but
death rates fall rapidly
causing a high population
growth
Stage 3 - Late Expanding
• Birth rates now fall rapidly
while death rates continue to
fall
• The total population begins
to peak and the population
increase slows to a constant
12/16/2018 110SUNNY YADAV BPH/BEd
111. Stage 4 - Low Stationery
• Both birth rates and death
rates remain low,
fluctuating with 'baby
booms
• Population becomes
stationary
Stage 5 – Declining
• Population begins to
decline because birth rate
is lower than death rate
12/16/2018 111SUNNY YADAV BPH/BEd
112. Relation between growth rate and
population
• Population doubling time =
• Sex ratio =
• Dependency ratio =
12/16/2018 112SUNNY YADAV BPH/BEd
113. Important Indicators
Human Development
Index (HDI): 0 to 1
• Knowledge
• Income (real GDP per
capita in dollar)
• Life expectancy at birth
(Longevity)
Physical Quality of Life
Index (PQLI): 0 to 100
• Life expectancy at 1
year age
• Infant mortality rate
• Literacy rate
•Life expectancy is positive mortality indicator
•Disability free life expectancy = Sullivan’s index
•DALY (Disability Adjusted Life Year): best measure of burden of
disease in a population and effectiveness of interventions12/16/2018 113SUNNY YADAV BPH/BEd
114. Standard of Living
• Income and occupation,
• Standards of housing,
• Sanitation and nutrition,
• Level of provision of health,
• Educational, recreational
and other services
Standard of living depends on
“per capita GNP”
Quality of Life
• Determining health
• happiness (including
comfort in the physical
environment and a
satisfying occupation),
• Education,
• Social and intellectual
attainments,
• Freedom of action,
• Justice,
• Freedom of expression
12/16/2018 SUNNY YADAV BPH/BEd 114
116. • Disaster is defined as “Any occurrence that cause
damage, economic disruptions, loss of human life,
deterioration in health and health service on a scale
sufficient to warrant an extraordinary response from
outside the affected community or area.” –WHO
• Hazard: Any phenomenon that has the potential to
cause disruption or damage to people and their
environment
• Disaster area: A place where a disaster has happened
and which needs special help
• Main features of disaster: Unpredictability,
Unfamiliarity, Speed, Urgency, Uncertainty, Threat
12/16/2018 116SUNNY YADAV BPH/BEd
117. TYPES OF DISASTER
1. Natural Disaster:
a) Acute or sudden onset: Earthquake, flood, landslide,
volcanic eruption, etc,
b) Chronic: Desertification, Famine, etc
2. Man-made disaster: Bhopal gas tragedy (methyl isocyanide),
chemical explosion, bomb blast, road accidents, bomb blast,
etc.
3. Complex emergencies: global warming, war and conflict
4. Pandemic/epidemic Emergencies: influenza pandemic, ebolla
pandemic, etc.
12/16/2018 117SUNNY YADAV BPH/BEd
118. Effects or consequences of disaster
Short term
• Disability, injuries, death
• Shortage of food
• Shortage of drugs and other
equipments
• Increase in communicable
disease
• Environmental disruption
• Socio-economic losses,
Psychological problems
• Destruction of
infrastructure
Long term
• Ecological disruption
• Destruction of
governmental, public
infrastructure and
industries
• Destruction of health care
infrastructure
• Disruption of essential
drugs for many years
12/16/2018 118SUNNY YADAV BPH/BEd
119. Disaster management cycle
• Disaster mitigation: minimize effects of disaster:
E.g. public education, building codes,
immunization, protection of vulnerable groups
• Emergency preparedness: Activities that are taken
to strengthen the capacity of a country to manage
all types of emergencies. E.g. development of
multi-agency co-ordination, preparedness plan,
water and sanitation, warning system, etc.
•
• Disaster response: efforts to minimize the hazards
created by disaster. E.g. rapid health assessment,
collection of health status information,
surveillance, rescue, relief, search, triage, etc.
• Rehabilitation: restoration of affected area to its
previous state. E.g. temporary housing, re-
employment, debris removal, etc.
12/16/2018 119SUNNY YADAV BPH/BEd
120. Triage
• Method of ranking injured people according to
the severity of their injuries
• There are four priorities –
– Red (immediate, first and highest priority, for
severe cases)
– Yellow (second priority, necessary, moderate
cases)
– Green (third priority, wait, mild injuries)
– Black (last or lowest priority, death)
12/16/2018 120SUNNY YADAV BPH/BEd
121. Rapid Response Team (RRT)
• It is also called as medical emergency team or medical response team.
• In 2000 AD, EDCD (DoHS)/MoH established a mechanism of RRT for
managing epidemics. This mechanism consists of RRT at 3 levels –
central -1, Regional-5 and district-75
• RRT consists of Medical doctors, HA, Nurses, AHW, ANM, Public health
professionals, Clinical respiratory, therapist and technician
• Objectives of RRT
– To establish early warning and respiratory mechanism for potential
epidemics
– To prepare for potential epidemics
– To manage disease outbreak
– Institutionalization of disaster management
12/16/2018 121SUNNY YADAV BPH/BEd
122. Central Natural Disaster Relief
Committee (CNDRC)
• CNDRC takes overall responsibilities of coordination
and policy decision regarding any disaster
• Defines the national disaster relief system with relief
committee at the national, regional and district level to
coordinate the implementation
• MoHA chairs the committee with members from line
ministries, police, army, scout, Red Cross, etc
• Natural disaster relief act (milestone for disaster
management in Nepal) was developed in 1982 AD12/16/2018 122SUNNY YADAV BPH/BEd
123. Important Remember
• Nepal is 30th rank of risk of water related disease in World
• Nepal is in 11th rank in risk of earthquake
• Minimum standard in disaster response is based on sphere guideline
• Most commonly reported disease in post disaster phase is
gastroenteritis
• Common micronutrient deficiencies in disaster are Vitamin A
Deficiency, scurvy, anemia, TB, malaria, measles, diarrhea, niacin
deficiency, parasitic disease, etc
• Most practical and effective strategy of disease prevention and
control in post-disaster phase is supplying safe drinking water and
proper disposal of excreta
• Foremost step for disease prevention and control of post disaster
phase is chlorination
• The current disaster management system in Nepal is leading by
MoHA.
• The current disaster (earthquake) occurred in Nepal in 2072-01-12 (at
12:50 PM of 7.9 Rector scale) and 2072-2-01 (of 7.8 Rector scale)
12/16/2018 123SUNNY YADAV BPH/BEd
124. International code – green signal:
ambulatory patient isolation period of time
• Chicken pox: 6 days after onset of
rash (until crust)
• Measles: starting of catarrhal
stage through 3rd day of rash
• Mumps: until swelling subside
• Influenza: 3 days after onset
• Pertusis: 4 weeks or until
paroxysm cease
• Cholera and diphtheria: 3 days
after antibiotic or culture
negative
• Sigellosis and salmonellosis: until
3 consecutive negative stool
culture
• Hepatits A: 3 weeks
• Polio: 2 weeks adult and 6 weeks
pediatrics
• Herpes: 6 days after onset of rash
• TB: until 3 weeks of
chemotherapy
• Meningitis, pharyngitis: until the
first 6 hours of effective
antibiotics
12/16/2018 124SUNNY YADAV BPH/BEd