Prevalence of syphilis infection among migrant workers in Qatar: a nationwide cross-sectional survey

Objectives Scant data are available on syphilis infection within migrant populations worldwide and in the population of the Middle East and North Africa region. This study investigated the prevalence of both lifetime and recent syphilis infections among migrant craft and manual workers (MCMWs) in Qatar, a diverse demographic representing 60% of the country’s population.Methods Sera specimens collected during a nationwide cross-sectional survey of SARS-CoV-2 seroprevalence among the MCMW population, conducted between 26 July and 9 September 2020, were analysed. Treponema pallidum antibodies were detected using the Mindray CL-900i Chemiluminescence Immunoassay Analyzer. To differentiate recent infections, rapid plasma reagin (RPR) testing was performed, with an RPR titre of ≥1:8 considered indicative of recent infection. Logistic regression analyses were employed to identify factors associated with lifetime syphilis infection. Sampling weights were incorporated into all statistical analyses to obtain population-level estimates.Results T. pallidum antibodies were identified in 38 of the 2528 tested sera specimens. Prevalence of lifetime infection was estimated at 1.3% (95% CI 0.9% to 1.8%). Among the 38 treponemal-positive specimens, 15 were reactive by RPR, with three having titres ≥1:8, indicating recent infection. Prevalence of recent infection was estimated at 0.09% (95% CI 0.01 to 0.3%). Among treponemal-positive MCMWs, the estimated proportion with recent infection was 8.1% (95% CI: 1.7 to 21.4%). The adjusted OR for lifetime infection increased with age, reaching 8.68 (95% CI 2.58 to 29.23) among those aged ≥60 years compared with those ≤29 years of age. Differences in prevalence were observed by nationality and occupation, but no differences were found by educational attainment or geographic location.Conclusions Syphilis prevalence among MCMWs in Qatar is consistent with global levels, highlighting a disease burden with implications for health and social well-being. These findings underscore the need for programmes addressing both sexually transmitted infections and the broader sexual health needs of this population.