Symptomatic primary HIV infection in a 49-year-old man who has sex with men: beware of the window phase

A 49-year-old man with a history of receptive unprotected anal intercourse with multiple anonymous men presented with a symptomatic primary HIV infection. Upon his initial visit the rapid HIV antibody screening test was negative but a p24 antigen test suggested a highly infectious phase in the HIV infection. An immunoblot assay confirmed the HIV diagnosis only 14 days later. Recent infections are characterised by a highly infectious phase and, if gone unnoticed, can have a large contribution to the ongoing transmission of HIV. Healthcare providers should be aware of primary HIV infection and the pitfalls in its diagnosis.