Longitudinal adherence to maternal antiretroviral therapy and infant Nevirapine prophylaxis from 6 weeks to 18 months postpartum amongst a cohort of mothers and infants in South Africa

Abstract

Background Despite improved policies to prevent mother-to-child HIV transmission (MTCT), adherence to maternal antiretroviral therapy (ART) and infant Nevirapine prophylaxis (NVP) is low in South Africa. We describe ART adherence amongst a cohort of HIV-positive mothers and HIV-exposed but uninfected infants from 6 weeks until 18 months post-delivery and identify risk factors for nonadherence. Methods Data were collected in 2012–2014 through a nationally representative survey of PMTCT effectiveness. Mother-infant pairs were enrolled during the infant’s first immunization visit at 6 weeks. Mothers and HIV-exposed infants (2811 pairs) were followed to 18 months at 3-month intervals. Mothers who self-reported being on ART at 6 weeks postpartum (N = 1572 (55.9%)) and infants on NVP at 6 weeks (N = 2370 (84.3%)) were eligible for this analysis and information about their adherence was captured at each interview they attended thereafter. We defined nonadherence within each 3-month interval as self-report of missing > 5% of daily ART/NVP doses, estimated adherence using a Cox survival curve with Andersen & Gill setup for recurring events, and identified risk factors for nonadherence with an extended Cox regression model (separately for mothers and infants) in Stata 13. Results are not nationally representative as this is a subgroup analysis of the follow-up cohort. Results Amongst mothers on ART at 6 weeks postpartum, cumulative adherence to maternal ART until 18 months was 63.4%. Among infants on NPV at 6 weeks postpartum, adherence to NVP was 74.5%.. Risk factors for nonadherence to maternal ART, controlling for other factors, included mother’s age (16–24 years vs. ≥34 years, adjusted Hazard Ratio (aHR): 1.9, 95% CI: 1.4–2.5), nondisclosure of HIV status to anyone (nondisclosure vs. disclosure: aHR: 1.7, 95% CI: 1.3–2.1), and timing of ART initiation (initiated ART after delivery vs. initiated ART before delivery: aHR: 1.6, 95% CI: 1.3–2.0). Provincial variation was seen in nonadherence to infant NVP, controlling for other factors. Conclusion Maintaining ART adherence until 18 months postpartum remains a crucial challenge, with maternal ART adherence among the six week maternal ART cohort below 65% and infant NVP adherence among breastfeeding infants in this cohort below 75%.This is gravely concerning, given the global policy shift to lifelong ART amongst pregnant and lactating women, and the need for extended infant prophylaxis amongst mothers who are not virally suppressed. Our findings suggest that young mothers and mothers who do not disclose their status should be targeted with messages to improve adherence, and that late maternal ART initiation (after delivery) increases the risk of maternal nonadherence.

The magnitude of adherence to option B plus program and associated factors among women in eastern African countries: a systematic review and meta-analysis

“…Accordingly, women who disclosed their HIV/AIDS status were 4.38 (95%CI: 1.79, 10.70) times more likely to have good adherence to ART than those who had didn’t disclose their HIV/AIDS status to their partner. A study on longitudinal adherence to maternal ART in South Africa similarly revealed that non-disclosure of HIV serostatus was negatively associated with good adherence [ 38 ]. According to a study conducted in KwaZulu-Natal, and Eastern Cape, South Africa, the issue related to disclosure was a reason for sub-optimal adherence to ART medications among women [ 32 , 33 ].…”

Barriers and enablers of adherence to infant nevirapine prophylaxis against HIV 1 transmission among 6-week-old HIV exposed infants: A prospective cohort study in Northern Uganda

“…We relied on the mother or caregiver’s report in measuring adherence of the infant to nevirapine prophylaxis. Studies done in South Africa [ 9 , 13 , 19 ], have reported levels of non-adherence to infant nevirapine prophylaxis ranging from 12.3%–30% within which range the incidence of non-adherence in our study falls. The reported non-adherence rates vary across study contexts because different methods were used while measuring infant adherence.…”

“…The majority of the women in our cohort who never received nevirapine for the baby actually had a non-clinic delivery, mostly a home delivery. Studies done in Zambia [ 13 ], South Africa [ 19 ] and a systematic review for sub-Saharan Africa [ 12 ] have demonstrated the association between home delivery and non-adherence to infant prophylaxis. Home deliveries have also been associated with the mother not receiving the nevirapine syrup for the baby from the health worker at the time of delivery [ 10 , 12 ].…”

Accelerating progress towards the elimination of mother‐to‐child transmission of HIV: a narrative review

“…To reach the ambitious targets of EMTCT, ART adherence and programme retention are critical; unfortunately, both present unique challenges over the course of pregnancy and breastfeeding [65‐68]. In their review of the literature, Stover, et al estimated that maternal PMTCT retention to ART programmes at 80% at time of delivery [47].…”