A METAANALYTIC EVALUATION OF THE POLYMERASE CHAIN-REACTION FOR THE DIAGNOSIS OF HIV-INFECTION IN INFANTS

Objective.-To evaluate the sensitivity and specificity of the polymera se chain reaction (PCR) for the diagnosis of infection with human immu nodeficiency Virus (HIV) in infants. Data Sources.-We used studies pub lished between 1988 and 1994 identified in a literature search of 17 d atabases, including MEDLINE. Study Selection.-Studies were included if DNA amplification by PCR was performed on peripheral blood mononuclea r cells from infants or children. Data Extraction.-Two investigators i ndependently extracted data, The study design was assessed independent ly by 2 investigators who were blinded to study results. Data Synthesi s.-Thirty-two studies met the inclusion criteria and were analyzed. Th e median reported sensitivity was 91.6% (range, 31%-100%), and the med ian specificity was 100% (range, 50%-100%), A summary receiver operati ng characteristic curve based on all 32 studies indicated that PCR has a maximum joint sensitivity and specificity between 93.2% and 94.9%. Subgroup analysis indicated that the joint sensitivity and specificity was significantly (P=.04) higher in older infants (98.2%) than in neo nates (aged less than or equal to 30 days; 93.3%). For infants at low risk of perinatal transmission (probability of transmission, 8.3%), th e positive predictive value for PCR is 55.8% in neonates and 83.2% in older infants. A negative PCR result reduces the probability of HIV in fection to less than 3%. No studies met all criteria for study design. Conclusions.-Although PCR is one of the best available tests for diag nosis of HIV infection in neonates and infants, it is not definitive. Therefore, PCR should be interpreted with the aid of careful clinical follow-up examinations. The sensitivity and specificity of PCR in neon ates is lower than in older infants, which results in a low positive p redictive value; however, negative tests are informative, Delaying the use of PCR until after the neonatal period or repeating PCR on indepe ndent samples obtained 30 to 60 days later will reduce test errors.