Characterizing viral load burden among HIV-infected women around the time of delivery : findings from four tertiary obstetric units in Gauteng, South Africa

Abstract

BACKGROUND : Elimination of mother-to-child transmission of HIV requires sustained viral load suppression during pregnancy and breastfeeding among women living with HIV (WLHIV). Antenatal antiretroviral therapy coverage is reported at .95% in South Africa, but viral load suppression rates are unknown. We describe maternal VL burden around time of delivery at 4 tertiary obstetric units (TOUs) in Gauteng Province. METHODS : Between June 2018 and March 2019, routine point-ofcare (PoC) maternal HIV VL and early infant diagnosis (EID) testing were implemented at 3 TOUs in Johannesburg and 1 in Tshwane district. WLHIV and HIV-exposed neonates were eligible for HIV VL (Xpert HIV-1 VL) and EID (Xpert HIV-1 EID or m-PIMA HIV1/2 detection) testing around time of delivery, respectively. Proportions of viremic women and intrauterine (IU)-infected neonates were calculated among valid PoC results. RESULTS : Among 8147 live births to WLHIV, 2769 (34.0%) women and 4333 (53.2%) neonates had valid PoC results. Median VL at delivery was ,40 copies/mL (interquartile range: 0–398). The proportion of women with a VL , 50, 50 to ,1000, and $1000 copies/mL was 63.6%, 13.9% and 22.4%, respectively. There were 65/4333 (1.5%) IU-infected neonates. Among 1449 mother–neonate pairs with both VL and EID results, IU transmission by VL threshold was 3/946 (0.3%), 6/187 (3.2%), and 25/316 (7.9%) for VL , 50, 50 to ,1000, and $1000 copies/mL, respectively (P , 0.001). CONCLUSIONS : Despite high antiretroviral therapy coverage, .1/3 of WLHIV had a VL $50 copies/mL at delivery. Among mother–neonate pairs, maternal VL $50 copies/mL accounted for 31/34 (91%) IU infections. Improvement in the quality of HIV care among WLHIV is essential if South Africa is to achieve elimination of mother-to-child transmission.