Syphilis and HIV-1 among parturient women in Salvador, Brazil: low prevalence of syphilis and high rate of loss to follow-up in HIV-infected women

BACKGROUND: The occurrence of syphilis and HIV-1 infections during pregnancy are major risks to the fetus due to mother-to-child transmission (MTCT). OBJECTIVES: To determine peripartum seroprevalence and risk factors of syphilis and HIV-1 infection among pregnant women in Salvador, Brazil, and the rate of HIV-1 MTCT. METHODS: Cross-sectional study of pregnant women who were admitted for delivery in a reference maternity hospital between May 2008 and March 2009 was conducted. Women were screened for HIV-1 infection and syphilis, and interviewed regarding demographic, behavioral and obstetric data. Newborns to HIV-infected mothers were tested by b-DNA and DNA-PCR to detect HIV-1. RESULTS: A total 3300/8516 women were evaluated. Mean age was 25.8 ± 7.3 years. HIV-1 and syphilis seroprevalence rates were 0.84% (28/3300) and 0.51% (17/3300), respectively. HIV-1 infection was associated with: low education (p = 0.04), having a partner with known HIV infection (p < 0.0001) or with previous sexually transmitted infection (p < 0.0001), blood transfusion (p = 0.003), or accidental exposure to blood (p = 0.003). Syphilis was associated with being Caucasian (p = 0.02), having no steady partner (p = 0.02), being a housewife (p = 0.01), having an intravenous drug user (IVDU) sexual partner (p = 0.04) or a sexual partner with previous STI (p < 0.001). Higher education (p = 0.04) was protective against HIV-infection. Attending a prenatal care program was protective against syphilis (p = 0.008) and HIV-1 (p = 0.02). No case of HIV-1 MTCT was detected, but 25% of children born to HIV-infected mothers were lost to follow up. CONCLUSIONS: In Salvador, peripartum prevalence of syphilis and HIV-1 infection among pregnant women were low, and associated with classic risk factors for both infections. The great proportion of very late diagnosis of HIV infection, and the high rate of loss of follow-up among positive mothers and their infants are of high concern.