Repeat testing necessary to detect HIV among infants receiving ART via breast-feeding
SEATTLE — WHO recommendations for HIV testing 6 weeks after breast-feeding cessation may need to be re-evaluated, as study findings presented at CROI 2015 suggest testing at that interval failed to identify HIV infection among infants exposed to ART via breast-feeding.
“In settings with limited resources and an unsafe water supply, the WHO guidelines recommend that HIV-infected mothers breast-feed uninfected infants for at least 1 year while taking antiretroviral drugs,” study researcher Caroline C. King, PhD, of the CDC, said during a press conference. “These antiretroviral drugs limit HIV transmission while reducing the high risk for infant disease and death associated with formula feeding that relies on an unsafe water supply.
“However, it is possible, in an infant who becomes infected, that these antiretroviral drugs to the mother and infant may limit HIV replication enough to delay detection of the virus in the infant.”
The Breastfeeding, Antiretrovirals and Nutrition study explored efficacy of 28 weeks of infant nevirapine or maternal ART in preventing HIV transmission during breast-feeding among a cohort of 2,369 mother-infant pairs.
To determine if HIV infections detected after 28 weeks of drug therapy occurred during the breast-feeding and ART phases, the investigators conducted ultrasensitive HIV testing on nine infants who had HIV infections first detected after 28 weeks. The substudy cohort consisted of three infants who received nevirapine, four infants who breast-fed from mothers receiving ART and two controls.
Two infants who received maternal ART, all infants who received nevirapine and one control had detectable HIV DNA at 24 weeks. Among these infants, median delay in detection between ultrasensitive and routine assays was 18.3 weeks for the nevirapine arm, 15.4 weeks for the maternal arm and 9.4 weeks among controls.
There were no significant differences in maternal viral loads or antiretroviral adherence between arms.
“WHO currently recommends testing of all HIV exposed breast-feeding infants at 6 weeks or more after breast-feeding cessation. Testing at 6 weeks early would have failed to have captured seven of the nine infants in our study who remained HIV negative on standard assays more than 6 weeks after breast-feeding cessation,” King said. “This study suggests that repeat testing is needed more than 6 weeks after stopped breast-feeding to enable HIV-infected infants to be identified and receive timely treatment to reduce their high risk for disease progression and death.” – by Amanda Oldt
King CC, et al. Abstract 33. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 23-26, 2015; Seattle.
Disclosure: The researchers report no relevant financial disclosures.