A survey by the Health, Labor and Welfare Ministry has found that 10% of Japan’s high school students are infected with chlamydia, a sexually transmitted disease.

In collecting its data, the ministry research team questioned 5,700 male and female students from 13 high schools in prefectures whose teen abortion rates were about the same as the nationwide average. The survey was conducted over a period of roughly one year, beginning in the autumn of 2003. Students were asked to anonymously fill in questionnaires and provide urine samples.

The survey found 31. 1 percent of male high school students and 43.6 percent of female high school students had experienced sex. Of these, 6.7 percent of male students and 13.1 percent of female students were infected with chlamydia. The overall infection rate among students was 10.6 percent.

16-year-old Japanese girls had an infection rate of 17.3%, compared with 1% to 4% in Europe and the U.S.