Background Little information is available on the epidemiology of syphilis in West Africa, where this infection is routinely screened in antenatal clinics to prevent congenital infection. In order to inform control programmes, the burden of active syphilis was estimated among pregnant women and adults in Burkina Faso.

Methods This study enrolled 2136 pregnant women from 98 healthcare facilities and 1679 consenting women and men from the general population of Ouagadougou, the capital city. After a face-to-face interview on demographic characteristics, blood samples were collected and tested for syphilis. Active syphilis was defined by a dually positive result on rapid plasma reagin and Treponema pallidum haemagglutination antibody tests.

Results The overall seroprevalence of active syphilis was 1.7% (95% CI 1.3 to 2.2), with similar rates between women (1.2%, 95% CI 0.7 to 2.3) and men (1.8%, 95% CI 1.0 to 3.0) in Ouagadougou, and a trend for higher prevalence among pregnant women from semi-urban areas (2.2%, 95% CI 1.0 to 4.5) compared with rural areas (1.7%, 95% CI 1.2 to 2.4, p=0.06). The prevalence tended to be higher among women aged 20–24 years (2.6%, 95% CI 1.3 to 7.6) and men aged 30–34 years (3.9%, 95% CI 0.8 to 11.0) than at other ages. However, age, marital status, location and education were not associated with syphilis.

Conclusion The low prevalence of syphilis among pregnant women and the adult general population is very encouraging but should not challenge the amount of resources dedicated to sexually transmitted infection and HIV prevention.