<prompt> Best test to diagnose prodrome of Hepatitis A ?HAV in bloodIgG anti-HAVIgM anti-HAVHAV in stool  <response>: Ans. is c i.e., IgM anti-HAV Lab diagnosis of HAV Detection of IgM - specific anti-HAV in the blood of an acutely infected patient confirms the diagnosis of hepatitis A. IgM appears in acute phase, peaking about 2 weeks after elevation of liver enzymes and becomes undetectable within 3-6 months. ELISA is the method of choice for measuring antibodies. Diagnosis can also be established by detection of virus in the stool from about 2 weeks prior to the onset of jaundice up to 2 weeks after. But these tests for detection of HAV, are not widely available or useful in practice. 