How to Diagnose this hepatitis A, B and C case?
The last sentence of the question doesn't make it clear what's being asked. But it seems to be asking: What version of Hepatitis did he get from the contaminated blood?

To that end...


  Serum antigen of HB tells us about the levels of IgM and IgG. If vaccinated, then IgG should be positive, I think? What does HBsAg tell you?


HBsAg gives you the knowledge of whether or not there's an acute infection of Hep-B. Hep-B IgM antibodies indicate an acute infection, whilst IgG antibodies would show up due to his previous exposure/immunization. If the patient has Hep-B IgM, the icteric illness was probably a re-infection of Hep-B.


  Why do we need to detect anti-HCV? If they are found, what does it mean? I think that then it means if found that he does not have hepatitis C then.


That would my assumption as well.

You run the HBsAg and can get two outcomes: IgM(+)/IgG(+) or IgM(-)/IgG(+). The former indicates the icteric illness was probably a reinfection of Hep-B.

You run the anti-HCV and get two outcomes: (+) or (-). The former indicates a present infection, the latter indicates no Hep-C.

What might throw you off is the wife's anti-HepC antibodies. If she was formerly infected and infected the patient (or vice versa) then you'd expect to find a (+) anti-HCV result.

I might come back to this after thinking on it a bit more, but that's the best I have for now.