Investigation of an Epidemic

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Introduction:

A medical officer will often be required to investigate an outbreak of a disease in his area. He may pertinently ask Epidemiological investigation of an outbreak necessary. Principle reason behind such an investigation is firstly to control the outbreak and prevent future occurrence of disease / epidemic with the application of knowledge gained from investigations. Such an action will stimulate interest in the staff to understand the unfulness of investigation.

Step in Investigation of an Epidemic

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1. Steps in investigation of an Epidemic

2. Verification of diagnosis

3. Confirmation about the existence of an epidemic

4. Description of the epidemic

5. Assessment of environmental conditions including entmological and zoondtic conditions depending upon the nature of outbreak.

6. Laboratory confirmation,if possible

7. Formulation of hypothesis about source and me ‘ thod of transmission

8. Management/ control of the outbreak

9. Documentation of the outbreak incorporating all relevant information.

 

Verification of Diagnosis:

Whenever you ” suspect” large number of cases, on the J) asis of the presentation of signs and symptoms, a report about outbreak of a disease in your area, should be reported to the medical officer. Your initial responsibility is to report the suspect cases, along with details such as name, adress, age,date on set etc .

 

Confirmation of the Existence of Epidemic:

You can confirm the existence of an Epidemic by studying the records available with you in relation to the disease you have confirmed. You may also need to study such records from other institutions or survey reports as are available. You may also be required to study records pertaining to dusaese which closely resemble the suspected diagnosis in the present situation.

Description of the Epidemic:

You are now required to find out the number of cases and death due to that disaese with break up of age. Occupation,social class,ethnic group etc. This you can do on the basis of information collected from the families in the affected area. For this purpose you may have visit all the families or a few randomly selected families in the area. After collection of necessary data you will have to work out attack rate, inclubation period, source and spread of the infection. If you follow these steps you will be able to describe the Epidemic according to variables of time,place and person.

Assessment of Environmental conditions:

Environmental conditions which include physical, chemical, biological and social environments are then assessed to the factor involving transmission. In addition, meteorological information,status of water supply and sweage disposal and laboratory findings,are also obtained.

If you suspect the outbreak under investigation to be vector- Brone, you must study various entromological incidices and try to isolate the causative from the agent indentifed.

In case of outbreak is due to zoontic reservoir, you must make an attempt to find out the natural zoonatic reservoir.