One in three HIV-positive gay men in London unaware they are infected - www.aidsmap.com

A third of HIV-positive gay men in London are unaware that they have the infection, according to a study published in the June 2nd 2004 edition of Sexually Transmitted Infections. The study also found that the proportion of gay men reporting unprotected anal sex has been rising steadily since 1996.

These worrying findings are based on the results of annual questionnaires completed by over 1200 gay men recruited in bars, clubs and saunas across London between 1996 and 2000. The surveys covered demographic details, sexual health service use, HIV testing history, HIV status and sexual behaviour.

In 2000, the men were also asked to provide saliva samples, which were tested for antibodies to HIV and anonymously linked to survey responses.

One thousand two hundred and six saliva samples were collected, 132 (11%) of which were found to be positive for HIV antibodies. Of these, 43 (33%) were from men who had not been diagnosed as HIV-positive.

Of the 996 (83%) of the men who said they knew their HIV status, 41 (4%) were mistaken.

The HIV-positive men were more than twice as likely to have had a sexually transmitted infection in the past year than those without HIV (adjusted odds ratio [OR] = 2.13; 95% CI, 1.40 - 3.24). They were also more likely to have had unprotected sex with more than one partner, and to have had more than one casual partner (adjusted OR = 2.21; 95% CI, 1.46 - 3.33). The HIV-positive men were more likely to be above 35 years of age, to have had fewer than three years of education after the age of 16 and to be unemployed (OR = 2.26; 95% CI = 1.46 - 3.51).

Across HIV-positive and HIV-negative groups, the proportion of men reporting unprotected anal sex increased significantly each year, from 30% in 1996 to 42% in 2000 (p Around one half of the diagnosed and undiagnosed HIV-positive men reported having had unprotected anal sex in the last year. The authors comment, "despite emphasis on risk reduction counselling in clinics, men who were diagnosed were as likely to engage in high risk sexual behaviour as undiagnosed men."

"The high level of risky behaviour in HIV positive men, regardless of whether they are diagnosed, is of public health concern," conclude the authors, "in an era when HIV prevalence, antiretroviral resistance, and sexually transmitted infection incidence are increasing."

Reference

Dodds J P et al. Increasing risk behaviour and high levels of undiagnosed HIV infection in a community sample or homosexual men. Sex Transm Infect 80:236-240, 2004.