Achieving maternal viral load suppression for elimination of mother-to-child transmission of HIV in South Africa

Abstract

Objective: To describe changes in maternal viral control over time in South African women living with HIV (WLHIV) using surveillance data from the National Health Laboratory Service's Corporate Data Warehouse (NHLS CDW). Design: A retrospective cohort analysis of maternal viral load during pregnancy and up to 15 months postpartum was performed amongst WLHIV (15–49 years) within the public-health sector between 2016 and 2017. Methods: HIV and pregnancy-related test data were used to create a synthetic cohort of pregnant WLHIV from the NHLS CDW. Syphilis-screening, in association with ward type and/or postpregnancy cervical screening and/or birth HIV test and/or positive β-hCG, was used as a proxy for pregnancy. The syphilis-screening date marked the first antenatal care visit (fANC). Fractional polynomial models described viral load evolution from fANC up to 15 months postdelivery. Piecewise linear regression models determined factors associated with viral load decline. Findings: Among 178 319 pregnant WLHIV, 345 174 viral load tests were performed [median = 2 (IQR: 2–3) per woman]. At fANC, 85 545 (48%) women were antiretroviral therapy (ART) experienced; 88 877 (49.8%) were not and 3897 (2.2%) unknown. Proportions of viraemia (viral load ≥50 copies/ml) were 39 756 (53.6%) at first viral load performed during pregnancy, 14 780 (36.9%) at delivery and 24 328 (33.5%) postpartum. Maternal age at least 25 years, CD4+ cell count at least 500 cells/μl and viral load less than 50 copies/ml at baseline predicted sustained viral load suppression during follow-up. Conclusion: Despite high-ART coverage among pregnant women in South Africa, only 63% of WLHIV achieved viral load less than 50 copies/ml at delivery. Maternal viral load monitoring requires prioritization for maternal health and eMTCT.

Population-level risk factors for vertical transmission of HIV in the national prevention of mother-to-child transmission programme in South Africa: An ecological analysis

“…This finding is suggestive of increased ART coverage among women newly diagnosed during pregnancy due to seroconversion. Approximately 1 in 2 pregnant WRLHIV included in the study were ART naive at the fANC visit, [20] and these figures were similar to reports from the DHIS during the study period. As a result, even though ART coverage during pregnancy was high, women initiating ART (particularly late in pregnancy) or seroconverting during pregnancy would not have had sufficient time to suppress their VL, hence transmitting HIV to their children.…”

“…The data source and creation of the study cohort have been described elsewhere. [20] In brief, a cohort of WRLHIV (age 15 -49 years) was identified from the National Health Laboratory Service's Corporate Data Warehouse (NHLS CDW) between 2016 and 2017 using HIV VL and CD4 count data. Because the NHLS CDW lacks a marker for pregnancy, a set of criteria based on syphilis screening and timing of HIV-related tests such as CD4 counts and VLs was applied to the routine data to differentiate pregnant from non-pregnant WRLHIV.…”

“…Because the NHLS CDW lacks a marker for pregnancy, a set of criteria based on syphilis screening and timing of HIV-related tests such as CD4 counts and VLs was applied to the routine data to differentiate pregnant from non-pregnant WRLHIV. [20] For pregnant WRLHIV, follow-up started at cohort entry (which was the fANC visit based on syphilis test date), through delivery to exit at the latest VL and up to 15 months post delivery. [20] All VLs performed during follow-up were included.…”

“…[20] For pregnant WRLHIV, follow-up started at cohort entry (which was the fANC visit based on syphilis test date), through delivery to exit at the latest VL and up to 15 months post delivery. [20] All VLs performed during follow-up were included. Eligible VLs were categorised into: (i) cohort entry VL: defined by the first VL performed during pregnancy, i.e.…”

Early structural brain development in infants exposed to HIV and antiretroviral therapy in utero in a South African birth cohort

“…Strengths of the study include a well-characterized cohort and an HEU group representative of other HEU populations across South Africa [63]. We present, to our knowledge, the largest neuroimaging study of children who are HEU during a period of importance for structural and functional development [17] that allows better differentiation between in utero versus postnatal risk factors than studies of older children.…”