Repeat syphilis is more likely to be asymptomatic in HIV-infected individuals; a retrospective cohort analysis with important implications for screening

There is conflicting evidence as to whether repeat syphilis is more likely to present asymptomatically than initial syphilis. If it is, then this would motivate more frequent and long-term syphilis screening in persons with a history of multiple episodes of syphilis. We conducted detailed folder reviews of all individuals with 4 or more diagnoses of syphilis between 2000 and 2017 at the Institute of Tropical Medicine, Antwerp, and assessed if there was a difference in the proportion presenting with symptomatic (primary and secondary) vs asymptomatic (latent) syphilis in initial vs repeat syphilis. Forty-five clients with 4 or more episodes of syphilis were included in the study. All were HIV-infected. Repeat episodes of syphilis were less likely to be symptomatic than initial episodes (35/160 [21.9%] vs 28/45 [62.2%]; P < .001). Frequent screening in those with HIV infection may be the only way to diagnose repeat episodes of syphilis. Care providers can use this information to motivate persons with multiple episodes of syphilis to be screened every 3 to 6 months.