TOKYO -- The number of syphilis cases in Japan in 2024 totaled 14,663, according to provisional figures released by the National Institute of Infectious Diseases on Jan. 10. This was just under the record-breaking number of 14,906 patients in 2023, indicating that the infection rate remains high.

By prefecture, Tokyo topped the list with 3,703 cases, followed by 1,906 in Osaka, 880 in Fukuoka, 846 in Aichi and 792 in Kanagawa.

According to the Ministry of Health, Labor and Welfare and other sources, while syphilis infections have been on the increase in Japan since around 2011, the number surged in 2021. Since 2022, more than 10,000 cases have been annually reported.

When infected with syphilis, individuals may develop sores or lumps on their genitalia or mouth, or a rash that spreads on the palms of the hands, soles of the feet, and over the body. Even if the symptoms disappear, it could still be contagious.

Syphilis can be treated with antibiotics such as penicillin, but if left untreated, it can cause damage to the heart, blood vessels and nervous system after several years or even decades. A patient could become infected again, so early treatment with antibiotics is necessary.

Keiichi Furubayashi, a specialist in sexually transmitted infections at Taniyon Start Clinic in the city of Osaka, says diagnosis for syphilis is difficult as some patients can be asymptomatic, or develop varied symptoms including headaches and manic state. He advised, "If you suspect you are at risk of infection, such as having sexual relations with many unspecified people, please receive free testing provided by public health centers and elsewhere. Furthermore, please use condoms during sexual activities to reduce the risk of infection."

(Japanese original by Yukako Ono, Lifestyle, Science & Environment News Department)