Rapid increase of syphilis in Tokyo: an analysis of infectious disease surveillance data from 2007 to 2016

The objective of this study was to examine the trends of primary and secondary syphilis in Tokyo between 2007 and 2016 using national infectious disease surveillance data. We analysed all 3269 cases reported during these 10 years. A statistically significant increase in cases was observed after 2010 with a more rapid rate of increase after 2014 mainly in urban areas in Tokyo. The notification rates per 100 000 population in 2010, 2014 and 2016 were 0.9 (n = 113), 2.2 (n = 295) and 8.7 (n = 1190), respectively. Domestic syphilis transmission was suspected in 92.6–99.3% of cases during the period 2007–2016