Demographic and reproductive factors for high seroprevalence of Chlamydia trachomatis among pregnant women in Japan

In order to elucidate demographic and reproductive factors associated with Chlamydia trachomatis seropositivity, serological screening and questionnaire survey were conducted on pregnant women in Negasaki Prefecture, Japan. Serum samples were taken from 1718 pregnant women between September and December, 1996, at the cooperative obstetric hospitals and clinics, and tested for the presence of antibodies to C. trachomatis using the enzyme immunoassay. A questionnaire was administered on a sub-sample (n = 409), among whom 85 (20.8%) were seropositive. A multiple logistic analysis revealed that four characteristics showed a significant association with the seropositivity: (i) experience of premarital pregnancy, (ii) non use of condoms, (iii) short duration of education, and (iv) more frequent induced abortion. The unsafe sexual behavior of young people lacking proper knowledge of how to prevent STD is the most important intervention target for control of the C. trachomatis epidemic in Japan.