No transmissions from breastfeeding in Tanzania cohort from mothers with undetectable viral load

No HIV exposed infants who were negative at birth, whose mothers started ART before delivery, had suppressed viral loads and exclusively breastfed, were HIV positive after breastfeeding, in a rural African cohort.

These findings from the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO), Tanzania were presented at EACS 2017.

This study included infants born between January 2013 and May 2016 to mothers enrolled in KIULARCO who started ART before delivery, exclusively breastfed for five months or more, and whose infants had a negative viral load test at age 4–12 weeks.

The mothers’ viral loads were measured once or twice up to 11 months after delivery. Infants testing was according to national guidelines.

Of 215 mothers with 219 pregnancies and 229 infants (10 twins), the median age at delivery was 33 years (IQR 29–36) and time since starting ART was 23 months (IQR 4–52).

Of the total mothers, 180 (84%) were in care, 2 (1%) died, 24 (11%) were lost to follow up and 9 (4%) transferred out.

A total of 335 viral load samples were tested from 219 post-partum in 215 women; 114 women had two samples.

During the breastfeeding period, 91% of mothers had viral <1000 copies/mL, with 75% <100 copies/mL.

As of 30 June 2017, of 229 infants 10% were lost to follow-up, 2% were transferred and 8% died 2% were still breastfeeding. Of 181 (79%) infants with final HIV status, 2 (1%) were infected through breastfeeding.

One HIV positive infant was born to a mother with high viral load (144,111 copies/mL) at one month post-delivery and the other to a mother who stopped ART during breastfeeding.

There was no vertical transmission through breastfeeding among mothers with suppressed viral load in this cohort, suggesting that this is very low risk. But loss to follow up and adherence problems can threaten the success of interventions to reduce vertical transmission through breastfeeding.

“Viral load monitoring during pregnancy and breastfeeding and strategies to trace back those lost to follow up should be a priority” the investigators recommended.

Luoga E et al. HIV transmission from mothers on antiretroviral therapy to their infants during breastfeeding in rural Tanzania. 16th European AIDS Conference (EACS 2017), 25–27 October 2017, Milan. Oral abstract PS5/5.