Mother-baby dyads enrolled in PMTCT care in western Kenya: characteristics and implications for ART programmes.

The objective of the study was to establish the mother-baby pair characteristics that contribute to vertical transmission of HIV and elucidate on remediation. We assessed for factors increasing the odds of HIV transmission in children born to HIV-infected mothers in western Kenya. We used a retrospective study which reviewed routinely collected data of 1 028 mother-baby pairs enrolled in a prevention of mother-to-child transmission (PMTCT) programme in western Kenya from January to December 2015. We compared the transmission rates amongst mothers known to have a positive HIV status before conception (known positives/KPs) versus the transmission amongst those who were newly diagnosed during maternal and child health (MCH) clinic attendance (new positives/NPs). We compared the socio-demographic and clinical characteristics of the mothers using chi square and Kruskal-Wallis tests at 95% confidence interval (CI). We assessed for factors associated with the infants' HIV status using a logistic regression model. The results revealed that 60% (622) of the mothers were KPs, and that KPs and NPs had mother-to-child transmission (MTCT) rates of 5.5% and 20.7% respectively. Close to 90% of the NP Mothers were at an early HIV clinical stage at enrolment and 40% were enrolled after delivery. The infants of NPs were enrolled at a mean age of 18.3 weeks compared to 6.6 weeks for the infants of the KPs. On adjusted multivariable analysis, child's age at enrolment (AOR = 1.05, 95%CI = 1.036-1.064) and mother's status at conception (AOR = 1.96, 95%CI = 1.042-3.664) were significantly associated with the infant's HIV status. None of the HIV infected infants had received nevirapine prophylaxis. Most of the mothers enrolling into the PMTCT programme have a known HIV-positive status, however, NPs are the largest contributors to continued MTCT.