Treatment of syphilis in HIV-infected subjects: A systematic review of the literature

Background: The optimal antimicrobial regimen to treat syphilis in HIV-infected subjects remains controversial. Objective To systematically assess the literature for studies evaluating syphilis treatment regimens in this population. Methods: Two reviewers independently assessed studies published between 1980 and June 2008 in electronic databases, trial registries and bibliographies (with no language restrictions) for content and quality. Studies that included 10 or more people, with documented HIV status, type and duration of syphilis treatment and at least 6 months of follow-up were included. The primary outcome was syphilis serological or clinical failure stratified by syphilis stage. Results: Of 1380 unique citations, 23 studies (22 published papers and 1 conference abstract) were included in the systematic review. Owing to the significant heterogeneity among studies, pooled summary statistics could not be generated. The range of probabilities for serological failure with 2.4 million units (MU) of intramuscular benzathine penicillin G (BPG) was 6.9% (95% CI 2.6% to 14.4%) to 22.4% (11.7% to 36.6%); that of 7.2 MU of BPG in late latent syphilis was 19.4% (11.9% to 28.9%) to 31.1% (22.3% to 40.9%) and failure estimates with 18-24 MU of aqueous penicillin for the treatment of neurosyphilis were 27.3% (6.0% to 61.0%) to 27.8% (14.2% to 45.2%). Conclusions: The optimal antimicrobial regimen to treat syphilis in HIV-infected subjects is unknown; guideline recommendations in this population are based on little objective data.