• HIV
• SYPHILIS
• HIV THERAPEUTICS
• GAY MEN

Dramatic and concerning increases in syphilis have been reported in men who have sex with men (MSM) across Western Europe, the USA and China.1 ,2 A large proportion of these patients have been noted to be HIV co-infected.1 The article by Bissio et al published in this issue extends these findings to Argentina, noting a high rate of incident syphilis in HIV-infected MSM residing in Buenos Aires. In this retrospective cohort study, the authors reviewed records of HIV-positive MSM attending an HIV clinic in Buenos Aires for follow-up at least twice in the period from March 2015 to February 2016. Although limited by the lack of treponemal antibody confirmatory testing, they detected 171 new cases of syphilis during the study period, translating to an incidence of 14.9/100 patients/year.

Why these significant increases in syphilis have been seen in MSM, and HIV-infected MSM in particular, is the subject of the paper by Rekart et al also published in this issue. Here, the authors put forth the novel hypothesis that antiretroviral therapy (ART) may have the potential to alter the innate and acquired immune responses in ways that enhance susceptibility to Treponema pallidum, and that this enhanced susceptibility could be a significant factor contributing to the rise in incident syphilis in HIV-positive MSM. It is critical to note that the authors are in no way suggesting that ART be reconsidered for the treatment and prevention of HIV. Rather, their aim is to put forth a hypothesis which may serve to stimulate discussion and inform research and (perhaps) future interventions to help …