Responding to the syphilis outbreak in Japan: piloting a questionnaire to evaluate potential risk factors for incident syphilis infection among men who have sex with men in Tokyo, Japan, 2015

I n Japan, notifications of syphilis reported through the national surveillance system have been increasing recently 1,2 similar to many other developed countries.3,4 During 2013-2014, this increase was associated with men who have sex with men (MSM).1,2 In response to this increase, the Ministry of Health, Labour and Welfare of Japan has been raising awareness and disseminating prevention messages.Recent reports indicated that factors associated with syphilis among MSM were low educational attainment, sex with casual partners without a condom and coinfection with other sexually transmitted infections (STIs).5,6 Using mobile phone applications and the Internet to seek sex partners has also been reported as potential risk factors for STIs, including syphilis, among MSM.7,8 There has been no study regarding potential predictors for syphilis acquisition in Japan.To investigate the possible reasons for the syphilis outbreak among MSM in Tokyo, a case-control study based on a questionnaire assessing potential risk factors for incident syphilis was proposed.To pretest the tool, we piloted the questionnaire and report key findings.We remind those in public health practice of the importance of pretesting questionnaire tools whenever possible.The pilot was conducted at the same clinic proposed for the case-control study, located in central Tokyo, the epicentre of the syphilis outbreak in Japan.The clinic serves sexual minority populations, and the majorityResponding to the syphilis outbreak in Japan: piloting a questionnaire to evaluate potential risk factors for incident syphilis infection among men who have sex with men in Tokyo, Japan, 2015