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.