Eliminating vertical transmission of HIV in São Paulo, Brazil: progress and challenges.

Background: HIV infection in children is an important public health problem in the world, mainly in poorer countries. If all recommendations are followed, the elimination of HIV vertical transmission is a concrete possibility. This study aims to estimate vertical transmission rates of HIV in São Paulo State, Brazil, based on pregnant women diagnosed and reported in 2006, identifying potentially associated factors.

Methods: This study involves a retrospective cross-sectional analysis of information systems and records of infected pregnant women and children exposed to HIV. The rate of vertical transmission was estimated and variables associated with the antenatal, delivery, and postnatal periods were analyzed by the chi-square test, and Fisher exact test was used for variables with an expected frequency <5. The relative risks were calculated with 95% confidence intervals.

Results: The rate of vertical transmission in São Paulo state was 2.7% (95% confidence interval: 1.86 to 3.94) in 2006, decreasing 83.1% in comparison with 1988-1993. The main associated variables were lack of prenatal visits or <6 visits, no antiretroviral prophylaxis during labor or neonatal use for <6 weeks, and maternal breastfeeding.

Conclusions: There is a decreasing trend of HIV vertical transmission in São Paulo with levels approaching elimination, which seems to be associated with antiretroviral policy and interruption of breastfeeding. Although there are serious operational issues, conditions exist to respond effectively. São Paulo state demonstrates that it is possible to achieve advanced levels of control for this mode of HIV transmission.