Erroneously low or undetectable plasma human immunodeficiency virus type 1 (HIV-1) ribonucleic acid load, determined by polymerase chain reaction, in West African and American patients with non-B subtype HIV-1 infection.

The polymerase chain reaction (PCR) assay for plasma human immunodeficiency virus type 1 (HIV-1) ribonucleic acid (RNA) inadequately quantitates virus load for some non-B HIV- 1 subtypes because of genetic diversity in the gag region targeted by the PCR primers. Unexpectedly low or undetectable plasma HIV-1 RNA findings by PCR were a clue to non-B HIV-1 infections in patients in whom plasma HIV-1 RNA was found to be substantially higher when determined by a branched-chain deoxyribonucleic acid assay.