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MCQs in Tropical Medicine

Rob Skelly DTM+H FRCP

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Answer 60

Hepatitis A
False a. the virus has double stranded DNA
True b. the incubation period is 2-6 weeks
True c. the illness is milder in young people

False d. is maximally infectious at the peak of jaundice
True e. can be prevented by active immunisation

Hepatitis A is a single stranded RNA virus.
In children the illness may be very mild. Clinical jaundice might not occur.
The infectious period is from 2 weeks before the onset of jaundice until 1 week after. The most infectious time is just before onset of jaundice.
Hepatitis A is usually acquired by consumption of faecally contaminated food or water. Other gastrointestinal pathogens may be acquired from the same source. Many patients recall having had diarrhoea a few weeks before their jaundice and upto 15% have other pathogens isolated from the stool.

Copyright: Rob Skelly 2006