HIV-positive gay men in Western Europe disproportionately affected by STIs

Sexually transmitted infections (STIs) – including syphilis, gonorrhoea, LGV and hepatitis C – are disproportionately affecting HIV-positive gay men, according to a review of STIs amongst gay men in Western Europe published in the October 2007 edition of the journal Sexually Transmitted Diseases. The authors conclude that this not only highlights the need to routinely test HIV-positive gay men for STIs and hepatitis C, but also suggests that changes in STI incidence may no longer reflect corresponding changes in HIV incidence amongst gay men as a whole.

Since 1996, when the era of effective antiretroviral therapy began, the number of diagnosed HIV-positive gay men who are well and sexually active has increased substantially. In order to understand trends in HIV prevalence and STIs amongst HIV-positive gay men in Western Europe, researchers from London undertook a review of published reports between 1996 and 2006.

They focused on twelve countries (Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom) and four STIs in particular: gonorrhoea, syphilis, lymphogranuloma venereum (LGV), and sexually transmitted hepatitis C. They picked these STIs due to their epidemiologic synergies with HIV, their historical use as markers of high-risk sex and their recent (re-) emergence among gay men.

However, the authors note the heterogeneity of the studies and surveillance systems from which their data are drawn.

Syphilis

The first post-HAART, syphilis outbreak amongst gay men was reported in Hamburg in 1997. Since then, large outbreaks have been reported in London, Paris and Dublin.

Although HIV prevalence varied widely amongst gay men diagnosed with syphilis by country and region, they note that HIV-positive gay men were disproportionately diagnosed with syphilis. HIV-positive gay men with syphilis were also more likely to be older than their HIV-negative counterparts, and to be diagnosed with secondary syphilis, rather than primary or early latent syphilis.

The majority of HIV-infected gay men were already aware of their HIV-positive status, and syphilis reinfections were seen more often in diagnosed HIV-positive gay men.

Gonorrhoea

Although increases in diagnoses of gonorrhoea were seen across Western Europe in the late 1990s, there has been some levelling off or even a decline in some countries.

HIV-positive gay men appeared to be much more likely than their HIV-negative counterparts to be diagnosed with gonorrhoea.

Notably, a study from Paris found that the main risk for gonorrhoea was via oral sex. This suggests that gonorrhoea may not be a reliable proxy for high-risk sex amongst gay men.

LGV

As noted in many previous stories on aidsmap, the emergence of LGV has been seen primarily amongst HIV-positive gay men, accounting for 75% of all reported cases, on average.

LGV outbreaks amongst gay men have been documented in nine Western European counties, the largest being in the UK and France.

The researchers note that the LGV outbreaks have shared similar characteristics with the syphilis outbreaks amongst HIV-positive gay men. In Rotterdam and the UK, LGV infection has been associated with concurrent STIs, particularly sexually transmitted hepatitis C.

Hepatitis C

Hepatitis C has now been identified as a sexually transmitted infection that apparently disproportionately affects HIV-positive gay men. Cases in Western Europe have been reported in Rotterdam, Paris, Amsterdam, and the United Kingdom.

The researchers note that most of the reports of sexually transmitted hepatitis C have been due to active case finding. They add, however, that the incidence of sexually transmitted hepatitis C amongst HIV-negative gay men appears to be low.

Explanations and implications

In their discussion, the researchers point towards improved survival in the HAART era, harm-reduction strategies such as serosorting, and sexual networks facilitated by the internet, as some of the reasons for the increase in STIs amongst HIV-positive gay men.

Why, though, is LGV and hepatitis C seen almost exclusively in gay HIV-positive men, whereas gonorrhoea and syphilis are not? The researchers suggest several reasons: differences in transmission probabilities and epidemiological synergies with HIV; time since the introduction of STIs into sexual networks; differential sexual behaviours; differences in testing and case finding; and the differential impact of public health interventions.

Taken together, they note, “the epidemiologic and behavioural data highlight a role for ‘positive prevention’ - i.e. prevention that focuses on the sexual health of HIV-positive [men who have sex with men; MSM] in ‘high-risk’ sexual networks as well as on the transmission of STIs and HIV to uninfected MSM.”

They also point out that using syphilis or gonorrhoea as proxy markers for high HIV risk-taking is increasingly flawed. “STI incidence may no longer be a suitable proxy for HIV incidence among MSM and... care should be taken when interpreting these epidemiological trends.”

Conclusions and recommendations

The researchers conclude that STIs have been disproportionately diagnosed among HIV-positive gay men in the post-HAART era in Western Europe. Although there were variations between countries and STIs, the majority of HIV-positive gay men diagnosed with these STIs were already aware of positive HIV status.

“These findings highlight the need for routine testing for STIs amongst known HIV-positive MSM in Western Europe,” they write. They add that since their findings also suggest that in some settings a large proportion of HIV-positive MSM with STIs were unaware of their HIV status that routinely screening all gay men for HIV would help to diagnose more HIV-infected gay men.

They suggest that safer sex messages should focus on more than HIV prevention and also highlight the consequences of STI infection. “These messages,” they write, “should also underline the risks associated with sexual practices other than unprotected anal intercourse with a partner of unknown or discordant HIV status.”