HIV-Positive Gay Men May Have No Idea That They're Infected

May 3, 2007

LONDON -- More than a third of the HIV-positive gay men in England may be HIV-positive and not know it, according to researchers here.

LONDON, May 3 -- More than a third of the HIV-positive gay men in England may be HIV-positive and not know it, according to researchers here.

In a cross-sectional survey here and in Brighton and Manchester -- the three cities considered to have the largest gay communities in England -- the overall prevalence of HIV among gay men ranged from 8.6% to 13.7%, found Danielle Mercey, MBChB, of University College London.

But the proportion of men who were HIV-positive but did not know their status was 44.1%, 33.3%, and 36.7% in London, Brighton, and Manchester, respectively, Dr. Mercey and colleagues reported online in Sexually Transmitted Infections.

Those percentages are slightly lower than the most recent comparable U.S. figure, according to the CDC in Atlanta. In June 2005, the agency's National HIV Behavioral Surveillance System reported that 48% of infected gay men had not been aware of their status before they took part in a five-city study.

The study is likely to provide a more accurate picture of English HIV trends than standard surveillance data, Dr. Mercey and colleagues said, because they drew their survey sample from men at more than 90 gay clubs, saunas, and bars rather than from clinic patients.

The men were asked to fill in a short questionnaire and give an oral fluid sample. The questionnaire and the sample were linked by a bar code, but no personal identifiers were collected. Nearly 3,600 questionnaires were handed out and 2,640 were returned. A linked oral sample was collected from 2,311 men.

Among the study findings:

  • 18% of HIV-negative men and 37% of HIV-positive men reported having unprotected anal intercourse with more than one partner in the previous year.
  • 20% of HIV-negative men and 41% of HIV-positive men reported having a sexually transmitted infection in the previous year.
  • Of the men who reported attending a genitourinary clinic in the previous year, 20.2% were HIV-positive in London compared with 23.8% in Brighton. The rate was significantly lower, (P=0.05) at 13.2%, in Manchester.
  • Even among those who visited genitourinary clinics, a large proportion were HIV-positive but undiagnosed -- 30.8% in London, 28.2% in Brighton, and 19.0% in Manchester.

In the 2005 U.S. study, according to the CDC, about 47% of gay men reported having unprotected anal sex in the previous year, but the agency did not break the number down by HIV status.

The English data "demonstrate the country-wide high levels of risk behavior, (sexually transmitted infections), and HIV prevalence," Dr. Mercey and colleagues said. Combined, the information accounts for the "worrying trend" of continuing high HIV rates in gay men.

"The high levels of HIV prevalence and risk behavior in all three cities indicate a need for more effective HIV prevention," the researchers said.