HIV-1 vertical transmission in Rio Grande, Southern Brazil

Abstract

The aim of this study was to determine the rate and risk factors of HIV-1 mother-to-child transmission (MTCT), the timing of transmission and the transmitted subtype in a population where subtypes B and C co-circulates. One hundred and fortyfour babies born to HIV-1-infected mothers were studied. Subtype and timing of transmission was determined by a nested polymerase chain reaction of gp41 gene. Seven children were infected (4.9%): four were infected intrautero and one intrapartum. The higher frequency of intrautero transmission was statistically significant (P ¼ 0.001). Use of antiretrovirals (ARVs) in the three stages of gestation was a protective risk factor for MTCT (PR ¼ 0.42; CI: 0.21–0.83; P ¼ 0.013). A higher HIV viral load at delivery was the only independent risk factor for MTCT. Early and universal access to ARVs during pregnancy is the most important measure to decrease vertical HIV-1 transmission even in areas where HIV clade distribution differs.