Sustained maternal human immunodeficiency virus viral load suppression and cascade of human immunodeficiency virus testing among exposed infants in Rwanda.

Abstract

Background: To prevent mother to child transmission (MTCT) of human immunodeficiency virus (HIV), sustained maternal viral load suppression (VLS) and early HIV testing among HIV exposed infants (HEI) is critical.

Aim: To investigate maternal viral load results and infant HIV testing uptake at 6-weeks, and 9-months and 18-months in Rwanda.

Methods: Between 2015 and 2022, VLS (< 200 copies/mL) was measured among pregnant women living with HIV (WLHIV) from 38-healthcare facilities. Viral loads (VL) were measured at 6-months, 12-months and 24-months, respectively. For maternal VL, the unit of analysis was visit-pair, and the pairs were created to define those with VL < 200 copies/mL at two consecutive visits as having sustained VLS, persistent viremia (VL ≥ 200 copies/mL at two consecutive visits), viral rebound (VL < 200 copies/mL at prior visit only) and newly suppressed (VL < 200 copies/mL at subsequent visit only). HEI were considered to have persistent HIV testing if they had all three HIV tests. Poisson regression models with generalized estimating equations were used to estimate the adjusted incidence rate ratio (aIRR) and 95%CI for factors associated with sustained VLS and persistent HIV testing.

Results: A total of 1145 mother-infant pairs were analyzed. Infant HIV testing uptake at 6- weeks, 9-months and 18-months was 1145 (100.0%), 1089 (95.1%), 1006 (87.9%) respectively. Nine hundred ninety-nine HEI (87.3%) tested for HIV persistently. At 18-months, the incidence of HIV among HEI was 8 (0.7%). Of 1145 mothers, 1076 (94.0%) had ≥ 2 VL results making a total of 2010 visit-pairs (142-single; 934-double visit-pairs). The incidence rate of sustained VLS, persistent viremia, viral rebound and new suppression were 91.0%, 1.3%, 3.6% and 4.0% respectively. Maternal disclosure of HIV status (aIRR = 1.08, 95%CI: 1.02-1.14) was associated with increased likelihood of sustained VLS. Having peer support (aIRR = 1.05 95%CI: 1.01-1.10) was associated with persistent HIV testing among HEI.

Conclusion: Sustained VLS is high among pregnant WLHIV in Rwanda. The low incidence of HIV among HEI may be attributed to high VLS levels. Targeted interventions, including enhanced HIV disclosure and peer support, are crucial for improving sustained VLS and increasing infant HIV testing uptake to reduce MTCT.