The prevalence of vertical transmission of human immunodeficiency virus and associated factors among exposed infants in Eastern Lake zone and Southern Highland of Tanzania: a cross-sectional study.

BACKGROUND: Globally, the rate of antiretroviral therapy coverage for pregnant women living with human immunodeficiency virus (HIV) increased by 38% between 2010 and 2015 but only by 2% between 2016 and 2020. OBJECTIVES: We aimed to determine the prevalence of vertical transmission of HIV among infants from mothers living with HIV and associated factors in the Eastern Lake Zone and Southern Highland of Tanzania from January to December 2022. METHODS: This retrospective cross-sectional study extracted data from the Open Laboratory Data Repository database collected from January to December 2022 at 93 health facilities. A total of 1,411 infants exposed to HIV from the Mbeya (851), Songwe (304), and Mara regions (256) were enrolled. RESULTS: The prevalence for vertical transmission of HIV was 2.48% (35/1411). We observed a non-significant difference in the prevalence of vertical transmission in children whose first test was done below six weeks of life (1.89%) and other age groups (2.52-2.62%) (p < 0.917). Children not given antiretroviral prophylaxis had eleven times higher odds of acquiring infection (AOR 11.39, 95% CI: 3.61-35.97). Mothers who were not on ART during pregnancy had three times the odds of transmitting HIV to their infants (AOR 3.03, 95%CI: 0.91-10.15). CONCLUSIONS: We found a low prevalence of vertical transmission of HIV compared to previous studies done in Tanzania. The use of ART prophylaxis for infants exposed to HIV is significantly associated with the low rate of HIV transmission.

Long-term retention on antiretroviral treatment after enrolment in prevention of vertical HIV transmission services: a prospective cohort study in Dar es Salaam, Tanzania.

INTRODUCTION: To prevent vertical HIV transmission and ensure healthy mothers and children, pregnant women with HIV must remain on antiretroviral treatment (ART) for life. However, motivation to remain on ART may decline beyond the standard 2-year breastfeeding/postpartum period. We assessed attrition and retention in ART care among women with HIV up to 6 years since enrolment in vertical transmission prevention services in Dar es Salaam, Tanzania. METHODS: A prospective cohort of 22,631 pregnant women with HIV were enrolled in vertical transmission prevention services between January 2015 and December 2017 in routine healthcare settings and followed-up to July 2021. Kaplan-Meier was used to estimate time to ART attrition (died, stopped ART or was lost to follow-up [no show ≥90 days since scheduled appointment]) and the proportion retained in care. Cox proportional hazard models were used to estimate adjusted hazard ratios (aHR) of ART attrition in relation to predictors. RESULTS: Participants were followed-up to 6 years for a median of 3 years (IQR: 0.1-4). The overall ART attrition rate was 13.8 per 100 person-years (95% CI: 13.5-14.1), highest in the first year of enrolment at 27.1 (26.3-27.9), thereafter declined to 9.5 (8.9-10.1) in year 3 and 2.7 (2.1-3.5) in year 6. The proportion of women retained in care were 78%, 69%, 63%, 60%, 57% and 56% at 1, 2, 3, 4, 5 and 6 years, respectively. ART attrition was higher in young women aged <20 years (aHR 1.63, 95% CI: 1.38-1.92) as compared to 30-39 year-olds and women enrolled late in the third versus first trimester (aHR 1.29, 95% CI: 1.16-1.44). In contrast, attrition was lower in older women ≥40 years, women who initiated ART before versus during the index pregnancy and women attending higher-level health facilities. CONCLUSIONS: ART attrition among women with HIV remains highest in the first year of enrolment in vertical transmission prevention services and declines markedly following a transition to chronic HIV care. Targeted interventions to improve ART continuity among women with HIV during and beyond prevention of vertical transmission are vital to ending paediatric HIV and keeping women and children alive and healthy.