Syphilis cases surging in Japan

Yomiuri Shimbun file photo
An official tests a sample for syphilis and HIV at a public health center in Hiroshima in May.

More than 8,000 syphilis cases have been diagnosed in Japan this year through Sept. 4, surpassing the record tally logged for the whole of the previous year, according to preliminary figures compiled by the National Institute of Infectious Diseases.

A total of 8,155 syphilis cases had been diagnosed as of Sept. 4, exceeding the 2021 figure of 7,983 cases, the highest annual tally since the current survey method was introduced in 1999.

Among the nation’s 47 prefectures, Tokyo had the highest tally with 2,343 cases, followed by Osaka with 1,091 and Aichi with 463, according to the preliminary data.

The institute did not offer an explanation for what was behind the surge in cases of the sexually transmitted disease.

In January-June, men accounted for 67% of the reported cases, and among female cases, women in their 20s accounted for nearly 60% of the total.

In the same period, nearly 40% of male patients had used the services of sex workers in the six months before their diagnosis, and nearly 40% of female patients worked in the sex industry.

Syphilis could be spreading more widely than the data indicates, with some experts blaming social media and dating apps for an increase in casual sex between people who meet through such services.

The infectious disease can be treated with antimicrobial drugs taken three times a day for four weeks, or a drug introduced in January that requires only a single shot, as long as it is administered within about three months of being exposed to the disease.