This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Transmission of hepatitis A virus occurs -( \nSelect and explain. \nA. One week before and one week after onset of symptom, B. 2 weeks before onset of symptoms, C. 2 weeks after onset of symptoms, D. All', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., 2 weeks before onset of symptoms . The risk of transmission of HAV is greatest from 2 weeks before to I week after the onset of jaundice. . Infectivity falls rapidly with onset of jaundice. . HAV is excreted in feces for about 2 weeks before the onset of jaundice and for up to one week there after. . Infective material is mainly man's feces. . Blood and serum are infective during the brief period of viremia.", 'role': 'assistant'}]