Margaret A.WinkerMD, Senior EditorIndividualAuthorPhil B.FontanarosaMD, Senior EditorIndividualAuthor
To the Editor.—Although we agree wholeheartedly that identifying mothers infected with the human immunodeficiency virus 1 (HIV-1) to reduce vertical transmission can be implemented systematically as suggested by Drs Minkoff and O'Sullivan,1 we do not agree that rapid HIV-1 antibody testing at the time a woman gives birth is the solution because of the way this practice would affect our obstetrics population. The rapid HIV-1 antibody test licensed by the Food and Drug Administration (SUDS, Murex Corp, Norcross, Ga) has stated sensitivity and specificity of 99.9% and 99.6%, respectively. Even with this superb performance, the positive predictive value (PPV) of a positive test result can exceed 50% only when the prevalence of HIV-1 infection exceeds 0.5%. Seroepidemiology data collected from our obstetrics population revealed an overall HIV-1 seroprevalence of 0.2% in 1992 and 0.1% in 1994. Thus, the PPV of a positive SUDS test result in our population could be no higher than 33%. In other words, 2 of every 3 positive results would be false-positive, and 2 women and their newborns would be treated unnecessarily for every mother-child pair treated appropriately. A subset of our population may benefit from testing: the seroprevalence in our white population was 1 in 611, or 0.16%, which would have a PPV of 29%, whereas the seroprevalence in our black population was 3 in 279, or 1.08%, which would have a PPV of 73%.
Balano K, Beckerman K, Ng V. Rapid HIV Screening During Labor. JAMA. 1998;280(19):1664. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-19-jbk1118