Mother-To-Child HIV Transmission using Single, Dual and Triple ARV Prophylaxis Regimens and their Correlates in Western Kenya: Chart Review - SUPPORTING INFORMATION

Background: It is estimated that 2.1 million individuals worldwide became newly infected with HIV in 2013, and this included 240,000 children (<15 years). Most of these children live in sub-Saharan Africa and were infected by their HIV-positive mothers during pregnancy, childbirth or breastfeeding. Objective: This study sought to ascertain the different PMTCT approaches or regimens that mothers and infants receive, their Mother-To-Child Transmission of HIV (MTCT) rates and associated correlates in Western Kenya. Methods: A retrospective cohort study using prospectively collected data in Ministry of Health HIV-Exposed Infant (HEI) register from 24 health facilities. The study population was HIV-positive mothers enrolled from January 2012 to June 2013. The main outcomes were infant HIV status at 6 weeks, 9 to <18 months and 18-24 months. The correlates were maternal haemoglobin levels, WHO staging, CD4 counts, duration between enrolment and delivery, duration between enrolment and ART initiation, TB status, place of delivery, mode of delivery, and infant feeding options at 6 weeks, 9 to <18 months and 18-24 months. Proportions were analyzed using Chi-square tests while associations between MTCT correlates and outcomes were established using logistic regression. Results: 1,751 HIV mother-baby pairs were enrolled in the 24 health facilities: 78.1% received Highly Active Antiretroviral Therapy (HAART), 14.2% received Zidovudine (AZT), 1.7% received Single-dose Nevirapine (SdNVP), and 4.3% received no prophylaxis. MTCT rates were 5.5%, 7.4% and 5.6% at 6 weeks, 9 to <18 months and 18-24 months, respectively. MTCT rate at 18-24 months showed a significant difference (p<0.001) across PMTCT regimens. Women with CD4 cells between 350 to 500 cells/mm3 were about twice as likely to have HIV-negative babies compared to those with CD4 cells count <350cells/mm3. Women on TB treatment are less likely to have HIV-negative babies compared to those without TB. Exclusive breastfeeding at 6 weeks was associated with lower MTCT rates. Feeding option at 6 weeks is a strong predictor of HIV status (p<0.001) as compared to babies on exclusive breastfeeding (EBF). Conclusion: Most of the mother-baby pairs received HAART. AZT depicted the lowest MTCT rate at 18-24 months. Higher CD4 counts, no TB signs, and EBF at 6 weeks were associated with lower MTCT rates at 18-24 months Key words: Antiretroviral prophylaxis, Mother-To-Child Transmission of HIV rates