Question

Q) What is considered an outbreak?

Q) How to investigate a disease outbreak?

Not less than 350 words

Answer 1

The occurrence of disease cases than normal expected number is called an outbreak. The outbreak of disease are usually by an infection, person to person contact, transmit through animal contact or from environment etc. The exposure to chemicals or radioactive elements can also cause outbreaks.

Investigating an outbreak is a step by step process.

1. Field work preparation: The investigators usually search for the cause and course of the illness from the clinic itself. If they feel a field investigation is essential, then they make ready for one.

Before starting field work, the investigator must have clear idea about the possible cause, risk and course of illness. They must discuss on the scientific aspects and lab studies with the concerned people and also regarding the personal protective equipments. The investigators must make a team and a leader must be there to co ordinate , manage and collaborate the activities.

2. Make sure its an outbreak: The cases may be an outbreak or just a cluster of cases of unrelated origin. The investigator has to establish it as an outbreak
3. Verify the diagnosis: The diagnosis are to be verified in order to identify the correct diagnostic and treatment measure for the disease. Also make clear lab investigations of the reported cases were done correctly, without error.
4. Define the case: This is done with the clinical criteria of the case, the time, location and person.
5. Orderly identify case and record them: Passive and active surveillance are made use and the cases are recorded with clear identification of case criteria. The identity of cases, demographic information, clinical information, risk factors identified, and reporter data.
6. Perform descriptive epidemiology: The systematic description of the key characteristics of the people affected with time, place and person is called descriptive epidemiology. Summarize the key characteristics of the people, identify at risk people from the data, getting clues on the etiology, source and modes of transmission, are done. descriptive epidemiology hints at where to start interventions and preventive actions.
7. Develop hypotheses: The hypothesis is formulated addressing the source agent, the mode of transmission and the exposures that caused the disease.
8. Epidemiologically evaluate hypotheses: This is done using the epidemiology, laboratory science and environmental evidence. The hypothesis can be compared with the facts and also relationships between variables can be quantified using analytic epidemiology.
9. Re evaluate hypothesis: The analytic studies may not reveal the causes sometimes. In such situation, the investigator may have to revisit the cases, their environments and the situations that caused the illness.
10. Comparison with environmental and lab studies : The lab reports can confirm the findings and the epidemiological studies can guide to appropriate action.
11. Implement control and prevention measures: Prevention is the primary control measure in most outbreaks. If appropriate control measures are available , that should be initiated, as soon as possible.
12. Initiate or maintain surveillance: Continuous monitoring along with the prevention and control measures has to be done. this makes sure the efficiency of control and prevention methods as well the reduction of new cases is happening.
13. Communicate findings: The task of summarizing the investigation, its findings and its outcome in a report and communicate it effectively.