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. INVESTIGATION OF EPIDEMIC DR. N.C DAS

2. EPIDEMIC Epidemic is defined as sudden unexpected increase in a disease or health related event among population in a defined geographical area, in a specified time. The severity of the epidemic depends on- -- Geographic (environment) condition. Characteristic of host population. Socio cultural behavior.

3. Types of Epidemics: EPIDEMICS EPIDEMICS NON-COMMUNICABLE DISEASES COMMON SOURCE CYCLIC SEASONAL PROPAGATED POINT OR SINGLE EXPOSURE TO MANY CONSTANT SOURCE MULTIPLE EXPOSURE

4. WHY INVESTIGATE ? - To define the magnitude in terms of time, place and person. To identity source and possible cause. Factors contributing to spread. To make recommendation to prevent.

5. EPIDEMIC INVESTIGATION B) By making comparison: (i) Between two groups (ii) Between two locations Compare to find out the crucial difference between the host or environmental factors of effected area and not effected area. BY ASKING QUESTION BY COMPARISION

6. HOW TO START INVESTIGATION QUESTIONS TO ASK What is the problem Where is the problem When is the problem What is the magnitude Who all are effected Why did it happen How did it started PLAN TO CONTAIN What action to be taken by different groups What can be done to limit the problem How activities to be planned. What resources are required What constraints may be faced To what extent these can be over come. What action be taken to prevent in future

7. 10 STEPS IN INVESTIGATION OF EPIDEMICS VARIFICATION OF DIAGNOSIS CONFIRMATION OF EXISTANCE DEFINE POPULATION AT RISK SEARCH FOR ALL CASES ANALYSE THE DATA FORMULATE THE HYPOTHESIS TEST THE HYPOTHESIS EVALUATE ECOLOGICAL FACTORS EXPAND SEARCH IN OTHER AREAS WRITE FINAL REPORT 1 2 3 4 5 6 7 8 9 10

8. VERIFICATION OF DIAGNOSIS Confirm diagnosis though Lab. Tests. Clinical exam of cases CONFIRMATION OF EXISTANCE Compare disease frequency with past in the same population. Common source epidemics is obvious like cholera, food poising. But non- communicable disease epidemics require confirmation like heart attack, cancer, goiter, flurosis, etc . (1) (2)

9. DEFINE THE POPULATION AT RISK Mapping of clusters in the map. Total susceptible population in the affected area Age and Sex distribution . SEARCH FOR ALL CASES Infected Cases Contacts tracing in communicable diseases Fill up necessary epidemiological case sheet Movement of cases from and to other areas (3) (4)

10. DATA ANALYSIS Chronological distribution of cases Common source or propagated Seasonal or Cyclic pattern Contact relation be watched Clustering or wide spread Possible source and mode of spread (5)

11. FORMULATION OF HYPOTHESIS Possible Source (Agent, Host, Environment) Causative Organism EXAMINATION OF ECOLOGICAL FACTORS Environment, Sanitation, Air Pollution, Food for taking further preventive measures . (6) - Tentative hypothesis helps in further investigation. - Testing of hypothesis under similar situation. (7) (8) TESTING OF HYPOTHESIS EXPAND SEARCH IN OTHER AREAS S earch for cases in adjacent areas, Areas where people have migrated. New locations for the disease .

12. (10) WRITE A FINAL REPORT Final report writing and recommendation for future preparedness. Preparedness to meet the Epidemic A complete step by step action plan to be prepared with respect to--- - Manpower - Logistics - Training - Diagnosis - Treatment - Prevention

13. SCREENING OF SUSPECTED CASES Presumptive identification of unrecognized disease or disability by the application of examination, lab tests and other procedures. Mass screening High risk screening Multi phasic screening Assessment of screening tests criteria's Validity Sensitivity Specificity Repeatability Predictive value Validity: To what extent the test accurately measures which it suppose to measure. Sensitivity: The capability to identify who has the disease. Specificity: The capability to identify who do not have the disease. Repeatability: Consistent result in repeated screening. Predictive value: Denotes predictive value of + ve & - ve cases.

14. Test Results: Screening test result Diseased Not diseased Total Test + ve True (a) False (b) a + b Test – ve False (c) True (d) c + d Total (a +c) (b + d) (a +b +c +d) Sensitivity = a x 100 a + c Specifically = d x 100 b + d Predictive of + ve test = a x 100 a + b Predictive of – ve test = d x 100 c + d % of false (+ ve) = b x 100 b + d % of false (- ve) = c x 100 a + c

15. SURVEILLANCE It is the systematic and continuous collection, compilation, analysis and dissemination of information for acti on. It is used to forecast impending epidemics and prepare in advance for successfully meeting the situation. It helps in assessing the change in the trend of disease or its distribution. Helps in prediction of the pattern of occurrence of the disease. Helps in assessing the impact of programe intervention.

16. TYPES OF SURVEILLANCE

17. Types of Surveillance: Passive - Through examination of reports and returns. Active - Field surveillance, door to door survey. Sentinel Surveillance – Regular reporting by sentinel hospitals. Investigation of death/ Verbal autopsy. Vital registration system. Limitations of surveillance: It is a labor intensive activity. Regular collection of data to asses the trend. Data is either incomplete or not received in time.

18. STEPS FOR DEVELOPING SURVEILLANCE SYSTEM: Declare the disease/ condition on which surveillance is required. What is the objective of the surveillance. Develop the standard case definition. Develop the criteria to be included for diagnosis. Identify the information to be collected. Decide the method of surveillance to be under taken. Develop data collection tools. Designate the reporting units. Categorize the cases into suspected, probable and confirmed cases. Collection, transportation and testing of specimens for confirmation. Decide frequency of reporting and reporting authority. Ensure correct, complete and timely reporting. Analysis of data and interpretation.

19. Hospital Administration Made Easy http//hospiad.blogspot.com An effort solely to help students and aspirants in their attempt to become a successful Hospital Administrator. hospi ad DR. N. C. DAS