• Must confirm all positives from less specific screening tests.
• HIV proteins and glycoproteins are electrophoretically separated on nitrocellulose paper.
• The antigen impregnated paper is reacted with the patient's serum.
• If present, antibodies react with specific HIV antigens.
• HIV bands are visualized using anti-human immunoglobulin conjugated with biotin or an enzyme marker.
• IMPORTANT: Antibodies may be negative in early phase of infection.

Mr. Baldwin's Western Blot test is positive.  

The most sensitive test for HIV would be polymerase chain reaction (PCR) to detect the actual viral genome in the subject's T- lymphs. This test doesn't seem indicated here as his history and presenting symptoms are all consistent with the diagnosis of HIV disease.

Mr. Baldwin's P. carinii pneumonia is secondary to  AIDS.