Abstract: Objective To investigate the manisfetations of coincident infection syphilis with HIV.Methods Patients diagnosed as having HIV and syphilis coinfection in Beijing Youan Hospital were retrospecpectively studied.Their demorgraphic data,clinical manisfetations,diagnostic means,treatment and follow-up results were analyzed.Results 6 patients with syphilis and HIV coinfection were all homosexual men,among them three cases had abnormal CSF,all patients responded well to penicillin.Conclusion There is a high incidence of HIV and syphilis coinfection in homosexual men.Syphilis may present with atypical features in the HIV-positive patients,serious courses with rapid progression and CNS involvement are observed more frequently.Diagnosis is generally made with serology,but the clinician should be aware of the potential for false-negative serology.All HIV-positive patients should be treated with a penicillin-based regimen.All HIV-positive patients should be considered for the evaluation of neurosyphilis.Relapse is a real concern and careful follow up is required.

Key words: syphilis, HIV, coinfection, neurosyphilis