To what extent antiretroviral therapy (ART) reduces mother-to-child HIV transmission (MTCT) during breastfeeding remains unclear. We assessed the MTCT risk from mothers on ART to their infants during breastfeeding.
Ifakara, rural Tanzania.
We included infants born between January 2013 and May 2016 to mothers who initiated ART before delivery, had a negative HIV DNA polymerase chain reaction at 4–12 weeks and exclusively breastfed for ≥6 months. Mothers' plasma HIV-RNA viral loads (VLs) were measured up to 11 months postdelivery. Infants were tested for HIV following national guidelines.
Among 214 women with 218 pregnancies and 228 infants (10 twins), the median age at delivery was 33 years (interquartile range 28–36 years), and the mean time on ART was 23 months (interquartile range, 4–52 months). VL was measured twice in 53% (113/218) of pregnancies. During breastfeeding, 91% of mothers (199/218) had VL of <1000 copies per milliliter, and 75% (164/218) had <100 copies per milliliter. To November 2017, 8% (19/228) of infants were lost to follow-up (LTFU), 2% (5/228) transferred, and 8% (18/228) died before the determination of final HIV serostatus. Among the remaining 186 infants, 2 (1%; 95% confidence interval: 0.3% to 4%) were HIV positive: 1 born from a mother with high VL 1-month postdelivery and 1 from a mother who interrupted ART. Assuming a 15% MTCT risk through breastfeeding among the 42 infants LTFU, transferred, or dead, the overall MTCT risk would be 4%.
We found no MTCT from mothers who were retained in care and had suppressed VL. Breastfeeding signifies a very low risk when mothers adhere to ART. Adherence counseling, VL monitoring, and strategies to trace back those LTFU should be a priority.
*Ifakara Health Institute, Ifakara, United Republic of Tanzania;
†Swiss Tropical and Public Health Institute, Basel, Switzerland;
‡University of Basel, Basel, Switzerland;
§ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain; and
║Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
Correspondence to: Anna Gamell, MD, PhD, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland (e-mail: firstname.lastname@example.org).
The Chronic Diseases Clinic of Ifakara and its Pediatric and PMTCT unit, the One Stop Clinic, are funded through the Ministry of Health and Social Welfare of Tanzania; the Swiss Tropical and Public Health Institute; the Ifakara Health Institute; the Government of the Canton of Basel; United States Agency for International Development (USAID) through the local implementer TUNAJALI-Deloitte; and the Merck for Mothers Global Giving Program. Part of this work was supported by the R Geigy Foundation (Switzerland).
Presented at the 16th European AIDS Conference; October 25–27, 2017; Milan, Italy.
The authors have no funding or conflicts of interest to disclose.
E.L. and F.V. have contributed equally to the work.
Members of the KIULARCO Study Group are listed in Appendix 1.
Received February 15, 2018
Accepted May 08, 2018