Background: Preventing mother-to-child transmission of human immunodeficiency virus transmission (MTCT) depends on early initiation of antiretroviral therapy (ART). We report the 18-month MTCT risk during the transition from Option A to Option B+ in Zimbabwe, and assess whether ART preconception could eliminate MTCT in breastfeeding populations.
Methods: In 2013, we consecutively recruited a nationally representative sample of 6051 infants aged 4-12 weeks and their mothers from 151 immunization clinics using a multistage stratified cluster sampling method. We identified 1172 human immunodeficiency virus (HIV)-exposed infants and evaluated them at baseline and every 3 months until the child became HIV-infected, died, or reached age 18 months.
Results: The cumulative MTCT risk through 18 months postdelivery was 7.0%. Of the HIV-infected mothers, 35.3% started ART preconception, 28.9% during pregnancy, and 9.7% after delivery, and 16.0% received zidovudine during pregnancy. Compared to mothers without antiretroviral drug use, MTCT among those starting ART preconception and during pregnancy was lower by 88% (adjusted hazard ratio [aHR], 0.12; 95% confidence interval [CI], .06-.24) and 75% (aHR, 0.25; 95% CI, .14-.45), respectively. HIV-exposed infants with birth weight <2.5 kg (low birth weight) were 2.6-fold more likely to acquire HIV infection compared to those with birth weight ≥2.5 kg (aHR, 2.57; 95% CI, 1.44-4.59). Controlling for other factors, breastfeeding was not significantly associated with MTCT.
Conclusions: ART preconception has the highest impact on reducing MTCT, indicating that HIV-infected, reproductive-age women should be prioritized in "treat-all" strategies. HIV-infected mothers without ART use should be identified at the first immunization visit and treatment initiated to reduce postdelivery MTCT. MTCT risk is higher in mothers with low-birth-weight deliveries.
Keywords: ART initiation; Zimbabwe; birth weight; mother-to-child HIV transmission.
Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.