Missed HIV Prevention Opportunities Associated With Perinatal Infection

First published online:

| DOI: https://doi.org/10.1363/4414012

Half (52%) of cases of mother-to-child transmission of HIV can be attributed to missed opportunities for prevention, according to an analysis of HIV surveillance data from 15 health departments in the United States and Puerto Rico.1 Infant HIV diagnosis occurred among 2% of the sample and was associated with the following missed opportunities: breast-feeding, not identifying women with HIV prior to labor and delivery, and not providing women with antiretroviral (ARV) medicine during pregnancy.

The data come from the Centers for Disease Control and Prevention’s Enhanced Perinatal Surveillance system, which draws information on mother-to-child transmission of HIV from the health departments of five U.S. cities, nine states and Puerto Rico. The surveillance system follows the live-born infants of HIV-infected mothers until the infants’ HIV status is determined; the researchers focused on HIV-exposed infants born in 2005–2008.

Missed opportunities to prevent mother-to-child HIV transmission were based on U.S. public health agency prevention guidelines and included the following binary variables: lack of prenatal care, early maternal HIV testing, prenatal ARV prescription, intrapartum ARV medications or an ARV prescription for the neonate; failure to perform a cesarean section for women with a high viral load (at least 1,000 copies per microliter); and breast-feeding. HIV diagnosis was classified as early if it occurred before labor and delivery, or as late if it happened after delivery. The researchers used chi-square and regression analyses to examine possible associations between infant infection status and missed opportunities for prevention and mothers’ demographic and behavioral characteristics. The sample included 8,054 mother-infant pairs, of whom 297 were excluded from the regression analyses because of missing data on possible HIV prevention strategies or on infant infection status.

Overall, 179 of the infants born to HIV-positive mothers became infected (2%). The HIV transmission rate was 1% among mother-infant pairs who had received all interventions and 3% among those who had missed at least one opportunity to prevent transmission. Among mother-infant pairs in whom transmission occurred, 74% had missed at least one opportunity to prevent infection, and 17% had received all recommended interventions; the status of the remaining 9% was unknown. In chi-square analyses, the incidence of HIV appeared to vary widely according to mothers’ characteristics and missed opportunities for prevention. Rates of HIV associated with breast-feeding (24%), lack of neonatal ARV treatment (15%) and late HIV diagnosis among mothers (16%) indicated potential areas of particular concern.

According to results of a multivariate analysis, the likelihood of infants’ contracting HIV was elevated if the mother had contracted HIV through injection-drug use (odds ratio, 1.7) or abused a substance (2.0); it was also higher if the mother was aged 13–19 or had a CD4 cell count below 200 than if she was 25–34 or had a count of 500 or higher (2.3–2.4). The missed opportunities for transmission prevention that significantly contributed to infant HIV acquisition were breast-feeding (4.6), lack of ARV treatment for the mother during pregnancy (3.5) and late diagnosis of maternal HIV (2.5).

A population-attributable risk analysis conducted among the entire sample revealed that 52% of the infant HIV infections were likely due to mother-infant pairs’ having missed at least one opportunity for prevention. Among infants who were HIV-positive, 45% of infections were attributable to mothers’ lack of ARV medications during pregnancy, 26% to late diagnosis and 10% to breast-feeding.

The researchers note several limitations to their study, including that ARV treatment measures do not necessarily reflect full prophylaxis and that the sample is not representative of the United States or the areas in which the study was fielded. However, they add, their findings on the most important contributors to infant HIV infection coincide with those of previous studies.

Because perinatal HIV infection is rare in the United States, the researchers point out, each case reveals a notable gap in care. They state that these missed opportunities for prevention "strongly [argue] for case investigation and addressing barriers to early HIV diagnosis and the prescription of ARV medications during pregnancy as an essential component of any perinatal HIV prevention plan."—H. Ball