Background: Sexually transmitted infections (STIs) increased rapidly in Japan during the 1990s.
Methods: To determine the epidemiologic characteristics of STI patients, male cases (n = 765) from 21 clinics across Japan and controls from the general population (n = 1,167), both aged 18 to 59 years, were compared using two datasets of nationwide sexual behavior surveys conducted in 1999.
Results: Male STI patients were more likely to be <40 years of age (OR = 3.94, 95% CI: 2.17, 7.15), unmarried (OR = 2.65, 95% CI: 1.80, 3.91), and at least college/university educated (OR = 2.03, 95% CI: 1.45, 2.83). They were also more likely to have had multiple partnerships in the previous year (OR = 3.33, 95% CI: 2.20, 5.05 for 2-3 partners, OR = 6.29, 95% CI: 3.81, 10.37 for >or=4 partners), unprotected vaginal sex with regular partners (OR = 2.70, 95% CI: 1.75, 4.17), unprotected vaginal and/or oral sex with casual partners (OR = 2.14, 95% CI: 1.40, 3.26), and unprotected vaginal (OR = 2.64, 95% CI: 1.46, 4.80) and oral sex with paid partners (OR = 4.72, 95% CI: 3.04, 7.32) in the previous year.
Conclusions: These results suggest that male STI patients in Japan are highly educated and have a diverse occupational background, and that STI risks exist universally for various types of sex and sexual partnerships.