Question

Which of the following is NOT an example of a common source epidemic?

a. Salmonella traced to undercooked turkey at a potluck dinner

b. Thyroid cancer associated with radiation exposure

c. Typhoid fever traced to contaminated food

d. HIV/AIDS

Answer 1

Ans. d) HIV/AIDS

It is an example of propogated outbreak or epidemic and not a common source epidemic.

A common-source outbreak is one in which a group of persons are all exposed to an infectious agent or a toxin from the same source.

a) Salmonella traced to undercooked turkey at a potluck dinner where Salmonella is the common source affecting all the people at the dinner.

b)Thyroid cancer associated with radiation exposure. Where radiation is the common source or common injurious agent affecting a group people say those working in a nuclear power plant.

c)Typhoid fever traced to contaminated food where the contaminated food is the common source of typhoid for all those consuming contaminated food.

Whereas,

A propagated outbreak results from transmission from one person to another. Usually, transmission is by direct person-to-person contact (transmission of HIV by sexual contact)or the transmission may also be vehicleborne (e.g., transmission of HIV by sharing needles).