Teenage toll of sex disease

The incidence of sexually-transmitted disease has risen

One in five teenagers has an undiagnosed sexually-transmitted disease, according to American researchers.

The shocking figure was uncovered after doctors sent "home-test kits" for various infections to a random sample of teenagers aged between 15 and 19.

Their results were published in the journal Sexually Transmitted Diseases.

The result is worrying because it suggests that far higher than expected numbers of young women are carrying infections such as chlamydia, which, if left untreated, can severely damage their reproductive health.

Professor Harold Weisenfeld, who led the study, said that it was a clear message that home testing should be encouraged.

He said: "Nearly 13% of women who had never previously had a gynaecological examination tested positive for an STD, and 51% of infected students would never have pursued STD testing by traditional gynaecological examination."

The study looked at 288 women students who visited health clinics in high schools across Pennsylvania.

No symptoms

In all, 10% were found to have trichomoniasis, an infection which causes inflammation, itching and discharge, 8% had chlamydia and 2% tested positive for gonorrhoea.

Chlamydia is dangerous because it may be relatively symptomless, but can damage a woman's fertility if left untreated.

Most of the women said that home-testing with swabs was far preferable to going for a gynaecological examination, and that they would be prepared to test on a six monthly basis if such facilities became available.

The UK is recognised as having one of the poorest rates of sexually-transmitted diseases among the young.

Rates of gonorrhoea have been rising steadily since the mid 1990s, and public health experts suggest that more teenagers, who have grown up in the wake of massive safe sex publicity campaigns, are tending to be more complacent about protecting themselves.

Statistics suggest that both girls and boys are starting to have sex at a much earlier age than in previous decades.

Tests on every teenager attending a family planning clinic in Nottingham revealed that one in eight had gonorrhoea.