Background: The number of new syphilis diagnoses in Slovenia is steadily increasing, especially among HIV-infected men who have sex with men (MSM). We studied the effect of penicillin for treating syphilis in HIV co-infected patients and risk factors for treatment failure. The primary endpoint was response to therapy (fourfold reduction of VDRL at month 12).
Methods: Three hundred forty-two paper records were reviewed and MSM with positive VDRL and/or TPHA and serological follow up of at least 12 months were enrolled in the survey.
Results: Incidence of syphilis increased from 1.2% (2005) and 2.9% (2007) to 6.4% (2009) and 3.8% (2011, until July). Two hundred sixty-one (76.3%) were MSM and 102 (29.8%) were co-infected; 54.0% had primary/secondary syphilis, 37.0% latent syphilis, and 9.0% neurosyphilis. Patients with primary/secondary/latent syphilis were treated with three doses of benzathine penicillin (2.4 MU i.m.). Treatment was successful in 92.2%. With respect to risk factors, there was no difference between the "success" and "failure" group. Twenty-six patients (25.5%) had re-infections.
Conclusions: The rate of cure in our study population was excellent, probably due to a low degree of immunosuppression and a three-dose benzathine penicillin regimen.