Detection of incident HIV infection by PCR compared to serology

In order to determine the most sensitive method for the early detection of HIV infection, polymerase chain reaction (PCR) and serology were compared using matched peripheral blood mononuclear cells (PBMC) and serum samples taken sequentially at 3-month intervals on 17 HIV seroconverters. All samples from the time of enrollment in the study to the time of seroconversion were studied. [There were only two of the 17 cases where PCR and antigen positivity preceded EIA detectable seroconversion.] Initially, one of these cases was found to be PCR positive 11 months prior to seroconversion, however DNA fingerprinting techniques indicated that the early positive specimen did not belong to the subject in question. In a single subject, PCR was negative at the time of serologic evidence of infection but was positive at the next sampling 3 months later. In the remaining 14 cases, PCR was positive at the same sample time as full or partial seroconversion as determined by three EIA screening tests and Western blot. EIA antibody screen tests showed variability in detection of early HIV antibodies. We found no evidence for prolonged HIV infection prior to seroconversion. PCR offers little if any advantage over serology in the early detection of HIV infection in adults.