Hepatitis A: serological and virological course after exposure

How it is diagnosed

HAV can be followed over the weeks after exposure by four things that do not all rise at once. Fecal HAV comes first. IgM Anti-HAV rises next, and jaundice with a rise in ALT comes at about the same time. IgG Anti-HAV is the last to rise, and it is still high past 16 weeks after exposure, at the end of the plot, when the others are low or gone. The whole course is drawn from 0 to 20 weeks after exposure, so the number of weeks since exposure is what tells you which of the four is likely to be there.