A rare disease found in gay men in the Netherlands two years ago, and since reported in France, Sweden, Belgium, Germany and the United States, has now found its way into Britain, according to a report on Thursday.

The disease, lymphogranuloma venereum, affects the rectum and can, if not treated early, affect part of the immune system, according to the journal Sexually Transmitted Infections.

Thirty-four cases have been reported in Britain - all in gay men, of whom more than half were HIV-positive and a handful also were infected with Hepatitis C.

A bacterial infection caused by a particularly aggressive strain of Chlamydia trachomatis, it was considered relatively rare until 2003 when some 100 cases were reported in gay men in Rotterdam, according to the journal.

Since then it has been found in Antwerp, Hamburg, Paris, Sweden and several U.S. cities including New York, San Francisco and Atlanta.

If treated early it can responds to antibiotics. But if overlooked, surgery is often necessary, the journal noted.