Rare STD crops up among gay men in London

The United Kingdom's Health Protection Agency has identified an outbreak of a rare sexually transmitted disease--shigellosis--among gay men in London. The STD is caused by the bacterium Shigella sonnei, and can cause severe, prolonged, and sometimes bloody diarrhea. The STD is particularly serious for HIV-positive people, health experts say. The HPA is investigating 14 cases of shigellosis reported among gay men since the beginning of August in London, primarily in north London. Many other gay men in the city are believed to be infected with the STD, says Paul Crook, the HPA's consultant on communicable disease control. Similar outbreaks of shigellosis have been reported in the past few years among gay men in the United States, Canada, the Netherlands, Germany, and Australia. Researchers in Australia linked their outbreak to men who visited sex clubs and bathhouses. German researchers say nearly all of the men who contracted shigellosis during a 2001 outbreak in Berlin did so through oral-anal contact.

Shigellosis is commonly transmitted by ingestion of the Shigella sonnei bacterium, which appears at high levels in the feces of someone infected with the STD. Sexual infection can occur when even microscopic amounts of bacteria-laden feces are ingested through oral-anal contact ("rimming"). Exposure to the bacterium also can occur through fingering or fisting, touching sex toys that have been used in the anus, and coming into contact with fecal matter when removing a condom after anal sex. Other symptoms of the STD include stomach cramps, fever, nausea, and sometimes vomiting. HIV-positive people who contract the disease can also experience arthritis, joint inflammation, or long-term diarrhea. U.K. health officials say gay men can avoid the STD by not engaging in rimming with anonymous sex partners and by washing their hands after sex, after using the toilet, and before eating or preparing food.

The shigellosis outbreak is the third STD outbreak identified during the past three weeks among gay men in London. Health officials have previously reported outbreaks of hepatitis A and lymphogranuloma venereum--an unusual form of chlamydia--among gay men in the city.