Low detectable postpartum viral load is associated with HIV transmission in Malawi's prevention of mother‐to‐child transmission programme

Abstract

Introduction In 2011, Malawi implemented “Option B+,” a test‐and‐treat strategy for the prevention of maternal to child transmission of HIV (PMTCT); however limited data on viral load (VL) suppression exist. We describe VL suppression in HIV‐infected women at four to twenty‐six weeks postpartum, factors associated with VL suppression and the impact of VL suppression levels on MTCT. Methods HIV‐positive mothers at four to twenty‐six weeks postpartum were enrolled in a nested cross‐sectional study within the “National Evaluation of Malawi's PMTCT Programme” cohort study between October 2014 and May 2016. HIV‐exposed infants received HIV‐1 DNA testing and venous samples determined maternal VL, classified as unsuppressed (>1000 copies/mL), low‐detectable (40 to 1000 copies/mL) or undetectable (<40 copies/mL). Socio‐demographic and PMTCT indicators were collected. Suboptimal adherence was defined as self‐reported ≥2 days missed ART in the month prior to visit. Results Of the 1274 women, 1191 (93.5%) knew their HIV status and 1154/1191 (96.9%) were on ART. VL was available for 1124/1154 (97.4%) of women on ART: 988/1124 (87.9%) had VL suppression of whom 86 (8.7%) had low‐detectable and 902 (91.3%) undetectable VL. Suboptimal adherence was associated with unsuppressed VL (vs. suppressed VL; aOR 3.1, 95% CI 2.0 to 4.9; p < 0.001). Women with low‐detectable VL were more likely to be adolescent (vs. undetectable VL; aOR 3.0, 95% CI 1.4 to 6.6), on ART <6 months (aOR 4.4, 95% CI 2.3 to 8.6), report suboptimal adherence (aOR 2.1, 95% CI 1.1 to 3.8; p = 0.02), and less likely to have primary or secondary education (vs. none; aOR 0.3, 95% CI 0.2 to 0.7 or aOR 0.3, 95% 0.1 to 0.6). MTCT ratios among women on ART who had undetectable VL, low‐detectable VL and unsuppressed VL were 0.9% (8/902; 95% CI 0.3 to 1.5), 7.0% (6/86; 95% CI 1.5 to 12.5) and 14.0% (19/136; 95% CI 8.1 to 20.0). Unsuppressed VL and low‐detectable VL (vs. undetectable VL) increased the risk of MTCT 17‐fold (aOR 17.4, 95% CI 7.4 to 41.1; p = 0.002) and ninefold (aOR 8.5, 95% CI 2.9 to 25.2; p < 0.001). Conclusions Unsuppressed and low‐detectable VL was strongly predictive of MTCT among women on ART and associated with suboptimal adherence. This urges further consideration of optimal VL monitoring and target levels to reach elimination of paediatric infection.

Unlikely SARS-CoV-2 vertical transmission from mother to child: A case report

“…However, the possibility of viral load influencing the transmission risk should be of concern. Published studies have demonstrated a positive relationship between the viral load of some viruses and their ability to spread from mother to child [12,13]; it is still unclear whether SARS-CoV-2 has similar characteristics. In this case, we cannot estimate the mother's highest viral load before delivery, because she received the initial test on 6d of symptom onset, already after viral load reached the peak at 3 to 5d [14][15][16].…”

Early post-partum viremia predicts long-term non-suppression of viral load in HIV-positive women on ART in Malawi: Implications for the elimination of infant transmission

“…However, despite comparatively higher rates of durable VLS over 24 months in this cohort, approximately 1 in 5 women still experienced at least one post-partum episode of viremia which likely has implications for MTCT, as well as the health of the mothers. While we cannot specifically comment on the duration or frequency of viremic episodes in relationship to individual level MTCT (as both were measured at yearly intervals over 24 months), we previously showed that non-suppressed VL, including low-level viremia (>40–1000 copies/ml) measured in the early post-partum period was predictive of MTCT at enrolment (4–26 weeks) in this same cohort of women [ 13 ]. Further, in Zimbabwe, a similar PMTCT program using a universal test and treat strategy linked non-durable VLS to increased MTCT risk to 18 months [ 8 ].…”

“…specifically comment on the duration or frequency of viremic episodes in relationship to individual level MTCT (as both were measured at yearly intervals over 24 months), we previously showed that non-suppressed VL, including low-level viremia (>40-1000 copies/ml) measured in the early post-partum period was predictive of MTCT at enrolment (4-26 weeks) in this same cohort of women [13]. Further, in Zimbabwe, a similar PMTCT program using a universal test and treat strategy linked non-durable VLS to increased MTCT risk to 18 months [8].…”

“…Data from South Africa show that during the first post-partum year, 30% of women on ART did not maintain VLS [ 11 , 12 ], and in Zimbabwe, 50% of women did not maintain durable VLS over 12 months [ 8 ]. As detectable viremia determines risk of MTCT during pregnancy and breastfeeding [ 11 , 13 ] as well as progression of illness in the mother, understanding and improving long-term VLS among women starting ART in pregnancy is key to eliminating MTCT and promoting the health of mothers.…”

“…The National Evaluation of Malawi’s PMTCT Program (NEMAPP) study was launched in 2014 to evaluate the effectiveness of Option B+ by enrolling HIV-infected women and their infants at 4–26 weeks post-partum and following them annually for 2 years [ 16 ]. Within this nationally representative cohort, uptake of PMTCT services was very high at the time of enrollment: 97.8% of women knew their HIV status, 96.3% of these were on ART, and among a sub-set of these women 87.9% had achieved VLS (<1000 copies/ml) [ 13 , 16 ]. Here we describe trends in detectable viral load (VL) among women on ART and retained until 24 months post-partum and we explore factors associated with VLS over time.…”