Prefecture-Level Association Between Reported Syphilis Cases and Sexually Oriented Establishments in Japan: An...

Area of Science:

• Public Health
• Epidemiology
• Infectious Disease Surveillance

Background:

• Syphilis cases are rising in Japan, with unclear regional influences.
• Japan's sex industry has a unique structure with concentrated establishments and online services.
• Understanding regional factors is crucial for addressing syphilis transmission.

Purpose of the Study:

• To investigate the association between syphilis incidence and the number of sexually oriented establishments in Japan at the prefecture level.
• To analyze regional variations in syphilis rates in relation to the sex industry's structural factors.

Main Methods:

• Ecological study using prefectural data from April 2023 to March 2024.
• Analyzed reported syphilis, chlamydia, and gonorrhea cases alongside data on sexually oriented establishments.
• Employed simple linear regression to assess associations between infection rates and establishment numbers.

Main Results:

• A significant positive association was found between the number of sexually oriented establishments and reported syphilis incidence (R²=0.5157, p<0.0001).
• No statistically significant associations were observed for chlamydia or gonorrhea rates.
• Syphilis incidence rates were calculated per 1,000,000 population.

Conclusions:

• Prefecture-level data in Japan show a significant link between sexually oriented establishments and syphilis incidence.
• This ecological study suggests regional structural factors may play a role in syphilis transmission dynamics.
• Public health strategies should continue focusing on education, testing, and treatment in high-burden areas.