Syphilis among people with HIV infection in southern Ethiopia: sero-prevalence and risk factors

BACKGROUND Syphilis facilitates both HIV (human immunodeficiency virus) transmission and acquisition, reflecting the complex interplay between the two infections. Scarce information exists regarding syphilis epidemiology in Ethiopian context. Thus, this study determined the sero-prevalence of syphilis and associated risk factors in people with HIV infection. METHODS A cross-sectional study was conducted at Hawassa Referral Hospital, southern Ethiopia from January to May, 2014. A consecutive 993 HIV-infected participants were studied; but individuals under 15 years of age or treated for syphilis or those with a CD4+ T-cell count below 50 cells/μl were excluded. Structured questionnaires were used to collect data on socio-demography and potential risk factors for syphilis. Moreover, blood samples were collected from all participants and screened for syphilis using rapid plasma reagin (RPR) test, and those found sero-positive were confirmed using treponema pallidum haemagglutination assay (TPHA). RESULTS The sero-prevalence of syphilis was found to be 7.3% (95% CI 5.7- 9%). The rate of infection was significantly higher among participants who were ART (antiretroviral therapy) naive (odds ratio (OR) = 2.2; 95% CI 1.22 - 4.1), men (OR = 2.2; 95% CI 1.22 - 3.87), older than 50 years of age (OR = 3.9; 95% CI 1.45 - 6.94), had only primary school level education (OR = 7.8; 95% CI 2.63 - 23.2) and had a history of blood transfusion (OR = 3.9; 95% CI 1.5 - 10.4). CONCLUSION The high prevalence of syphilis among HIV-infected population warrants integrating syphilis screening with HIV care to limit the clinical consequences of untreated syphilis as well as its adverse impact on HIV transmission.