Chlamydia is increasingly common among young men

A study in Sweden involved mailing out thousands of urine sample pots to 22-year-old men and asking them to return them to be tested for chlamydia.

Instead of having to visit a clinic, the volunteers could anonymously visit a website to see their results.

Almost two in five men sent the pots took part in the testing programme - far more than expected.

Chlamydia is a rising concern for sexual disease experts in the UK and other European countries.

In many cases, it does not produce obvious symptoms in either men or women, but it can cause lasting damage to infected women - including reduced fertility.

The prevalence of the disease is rising fast in the UK, say statisticians.

Scientists at the Unit for General Medicine at Emea University in Sweden were looking for a way to make sure as many young men as possible took part in a screening programme.

They decided that men might be more willing to be screened provided they did not have to have any direct contact with a clinic or doctor during the screening process.

The personally-addressed mailshot was sent to each man at home, with a questionnaire and information sheet included alongside the sample pot.

Men sent urine samples back to the researchers, where they were tested as normal for chlamydia.

Personal code

However, instead of having to attend a doctor's appointment to receive their results, each man was given a code which gave him access to his own results on a webpage.

In all just under 400 out of 1,000 men asked to take part did so.

This is the highest recorded response rate for a chlamydia screening programme in men of this age.

The percentage who actually had the infection was 1.1% - a lower figure than normal - perhaps reflecting the fact that the screening initiative was reaching far more low-risk men who would not normally approach a doctor for a test.

Of the four infected men, three viewed their results on the web and sought medical help independently.

The other man was contacted by researchers after he did not check his results on the web.