Early Diagnosis of Human Immunodeficiency Virus Infection in Children <6 Months of Age: Comparison of Polymerase Chain Reaction, Culture, and Plasma Antigen Capture Techniques

: Three techniques were evaluated for their ability to detect human immunodeficiency virus (HIV) in infants from birth to 6 months of age. Polymerase chain reaction (PCR) and HIV cocultivation were of comparable sensitivity, detecting 90% of all positive specimens. Both techniques found positive results in approximately 5% of samples from seroreverting children. Both assays detected HIV in only half of infected newborns, suggesting that this fraction of children was infected during gestation. Plasma p24 antigen was detected in three-fourths of all samples tested but in only half of infected children during the first 2 months of life and 88% of samples from children during the next 4 months. The specificity of p24 antigen detection was 100%.