Bacterial STIs more common in HIV-positive gay men since HAART

The rate of bacterial sexually transmitted infections (STIs) amongst HIV-positive gay men in Brighton, which has one of the UK’s largest gay populations, has increased significantly since the introduction of HAART, according to a poster presentation to last week’s International AIDS Society Conference on HIV Pathogenesis and Treatment in Paris. Investigators also found that the majority of HIV-positive gay men with STIs had a detectable HIV viral load, and that a significant number carried drug resistant strains of HIV, raising the possibility that onward transmission of potentially drug resistant virus was occurring.

Investigators at the Brighton and Sussex University Hospital reviewed the notes of HIV-positive gay men between 1996-99 and in 2002 to determine the incidence of bacterial STIs, and whether STIs were diagnosed after the patient attended for treatment due to symptoms or as part of an asymptomatic sexual health screen. Whenever an STI was detected, the investigators recorded the HIV viral load closest to the diagnosis of the infection, along with details of current or previous antiretroviral therapy and the presence of any known resistance mutations. Finally, investigators recorded how many STIs individual patients contracted.

STI rates were significantly higher in HIV-positive gay men in 2002 than in 1996-99 for all bacterial STIs, gonorrhoea (p

The percentage of gay men attending for a sexual health screen increased ten-fold over this period from 3% in 1996-99 to 32% in 2002, however, this increase was largely due to men seeking treatment after the appearance of symptoms of STIs.

Of the 136 episodes of an STI detected, 94 (69%) occurred in men with a detectable HIV viral load, with 85 of these cases (62%) in men with a viral load above 5,000 copies/mL. When compared to the entire clinic cohort, men with an STI were less likely to be receiving treatment with HAART (39% versus 64%), and if they were receiving HAART there was a trend for those with an STI to be less likely to have a viral load below 50 copies/mL (84% versus 90%).

Of the 81 men with an STI who were not receiving treatment, 38 had previously received antiretrovirals, 18 of whom had experienced virological failure with significant resistant mutations present in six patients. Further, of the 43 antiretroviral naïve patients, five were infected with a strain of drug resistant HIV.

The investigators also established that although 70% of men had only one STI, 18% of men had three or more over the period of the study, and these men accounted for 38% of all the infections seen in HIV-positive gay men.

The investigators concluded that the rate of bacterial STIs was increasing amongst HIV-positive gay men, and that a substantial proportion of these men had a detectable viral load representing “an onward risk of transmission.” Further, a significant minority of STI episodes also represented an opportunity for the transmission of drug resistant virus.

It is also suggested by the investigators that gay men with STIs may have different health seeking behaviour and levels of adherence to STI-free gay men, noting that men with infections were less likely to be taking HAART, and when they were, were less likely to have an undetectable viral load.