Cases of the sexually transmitted infection lymphogranuloma venereum (LGV) have been recorded in London's gay community, despite efforts to raise awareness of the threat facing gay men.

More than 34 cases of the virus have been recorded in the capital since January. Previously there were virtually no reports of the virus in the United Kingdom, although last year saw a sudden increase in Rotterdam in the Netherlands.

This quickly spread across the gay communities in France, Germany and Belgium, before crossing the Atlantic to the United States.

The batch of new cases comes despite awareness campaigns launched by the Health Protection Agency, which hoped to warn gay men of the virus.

Writing in the Sexually Transmitted Infections journal, the HPA says other cases may be going undetected.

LGV is thought to be a strain of the chlamydia infection, and can lead to genital ulcers, rectal inflammation and abdominal pain. It can be treated by antibiotics.

The HPA says it will now look to extend its surveillance system in a bid to warn more gay men about the infection, and also crack down on the rising number of cases.

"The first steps in understanding and controlling this outbreak are to increase community and clinician awareness of LGV, to further develop our surveillance system and to monitor clinical manifestations," researchers said in the journal.