Treatment of syphilis in HIV


64 HIV-positive patients with early syphilis were randomized to single dose versus 3 dose regimen of 2.4 million units of intramuscular benzathine penicillin G. Early syphilis was defined as primary, secondary or early latent syphilis. Syphilis diagnosis was based on positive rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TP-PA) test. Primary syphilis classification was based on anal, oral or genital ulcers and secondary syphilis on cutaneous rash or mucosal lesions. Early latent syphilis was defined as positive serology without clinical signs and documented negative serology or a fourfold titer increase within the last 12 months. Patients were followed up after 3, 6, 9 and 12 months. Treatment success was defined as at least fourfold RPR titer decrease at 12 months. Four patients had primary syphilis, 39 secondary syphilis and the remaining 21 had early latent syphilis. The overall per protocol serologic response was 96 %. CD4 baseline level, HIV virologic suppression or syphilis stage did not impact on treatment response. There was no statistically significant difference in treatment outcome between single dose and 3 doses of benzathine penicillin. However, 2 patients in the single dose group did not achieve a fourfold decrease in RPR titers at 12 months but did have a fourfold titer decrease at follow up at a later time point.

Andrade et al. Clin Infect Dis 2017;64:759-764

Comment: Syphilis is increasingly common in HIV infection. Treatment recommendations are to a large extent based on expert opinions rather than clinical trials. The present study is therefore
a valuable addition to our knowledge. The results indicate that 3 doses of benzathine penicillin offers no advantage to a single dose in early syphilis in HIV coinfected patients.