Affordable diagnosis of human immunodeficiency virus infection in infants by p24 antigen detection.

The expense of PCR testing limits diagnosis of HIV infection in infancy in low resource settings. The ultrasensitive p24 antigen assay has been proposed as an accurate substitute; however, its ability to detect different HIV viral subtypes remains to be determined. A sensitivity of 98.1% and specificity of 98.7% was obtained testing 203 samples from 24 HIV-infected and 66 uninfected infants born to HIV subtype C-infected women.