Identification of recent HIV infections and of factors associated with virus acquisition among pregnant women in 2004 and 2006 in Swaziland.

Background: HIV continues to spread at high rates in sub-Saharan Africa. In particular, Swaziland is one of the countries most affected by the HIV/AIDS pandemic. Monitoring of HIV infection in Swaziland is being made by periodical investigations on HIV prevalence in pregnant women. However, knowledge of proportion of recent HIV infections is important for epidemiologic purposes to assess HIV transmission patterns.

Objectives: To evaluate the proportion of recent HIV infections among pregnant women and its change overtime and to analyze factors associated with recent HIV infection in Swaziland.

Study Design: HIV-positive sera from pregnant women were collected during the 2004 and 2006 National HIV Serosurveys conducted in Swaziland and tested for the HIV antibody avidity, in order to identify recent HIV infections. Socio-demographic and clinical information was also collected. A multivariate analysis was conducted to assess the association between recent HIV infection and socio-demographic and clinical factors.

Results: A total of 1636 serum samples were tested for HIV antibody avidity. The overall proportion of recent infections was 13.8%, with no significant difference between 2004 and 2006 (14.6% vs. 13.1%, P>0.05, respectively). At the multivariate analysis, the younger age [14-19 vs. >or=20 years; adjusted odds ratio (aOR) 2.17, 95% CI: 1.45-3.24], as well as being at first pregnancy (1 vs. >or=2; aOR 1.61, 95% CI: 1.10-2.35) was independently associated with recent HIV infection.

Conclusions: This study shows no significant difference in the proportion of recent infections between 2004 and 2006 and suggests that young women and women at their first pregnancy are currently high-risk groups for HIV acquisition, highlighting the importance of developing targeted youth programmes to reduce the spread of HIV infection in the country.