Growing Epidemic of Hepatitis C among Gay and Bisexual Men in Amsterdam

In the July 31, 2009 issue of AIDS, researchers described an ongoing epidemic of hepatitis C virus (HCV) infection among men who have sex with men (MSM) in Amsterdam, finding that the rate of HCV infection was nearly 18% among HIV positive men compared with less than 1% among HIV negative men.

Since 2000, clinicians in several large European cities have reported outbreaks of apparently sexually transmitted acute hepatitis C, primarily among HIV positive gay and bisexual men. Similar outbreaks have since been reported in Australia and the U.S.

Previous research has revealed that these outbreaks are connected through an international network of transmission among MSM.

Anouk Urbanus from the Amsterdam Public Health service and colleagues sought to learn more about the prevalence and risk factors associated with the ongoing hepatitis C epidemic in that city.

The analysis included 689 MSM (out of a total 3125 clients) at a large sexually transmitted disease clinic in Amsterdam who participated in an anonymous bi-annual cross-sectional survey during 2007-2008.

Participants were screened for HIV and HCV antibodies and interviewed about sexual activities, drug use, and other risk factors. The investigators performed a genetic analysis to compare HCV strains from the clinic patients to strains previously collected from MSM diagnosed with acute HCV from 2000 through 2007.

Results

• Only 2 of 532 HIV negative MSM (0.4%) were found to have HCV, compared with 28 of 157 HIV positive MSM (17.8%).
• Among HIV positive MSM, HCV prevalence increased from 14.6% to 20.9% over the study period.
• 7 of the 28 HIV-HCV coinfected men (25.0%) had acute HCV infection (estimated to have been contracted within the past 6 months).
• About one-third of the HCV positive men were not previously aware that they were infected.
• 5 of 28 coinfected men (17.9%) reported ever injecting drugs.
• In a univariate analysis, risk factors associated with HCV infection were:
• HIV infection;
• Higher number of life-time sexual partners;
• History of sexually transmitted diseases;Unprotected anal intercourse;
• Fisting;
• Injection drug use;
• Use of the club drug gamma hydroxy butyrate (GHB).
• In an adjusted analysis restricted to HIV positive men, the only significant predictors of HCV infection were:
• Injection drug use (adjusted OR 13.4).
• Fisting (adjusted OR 10.6);
• GHB use (adjusted odds ratio [OR] 4.6).
• Phylogenetic analysis revealed a high degree of clustering of HCV strains specifically among MSM.

"We found a high and increasing HCV prevalence in HIV-infected MSM," the study authors concluded. "Though not statistically significant, this trend, and the relatively large proportion of acute infections suggest ongoing transmission of HCV in HIV positive MSM."

In their discussion, they noted that "the relatively large proportion of acute infections strongly indicate a rapid and recent spread" of HCV among high-risk HIV positive gay and bisexual men.

"Regardless of [injection drug use], rough sexual techniques and use of recreational drugs were associated with HCV infection," they continued. "Targeted prevention, like raising awareness and routine testing, is needed to stop the further spread among HIV infected MSM, and to prevent possible spillover to HIV negative MSM."

Cluster of Infectious Diseases, Amsterdam Public Health Service, Amsterdam, Netherlands.

9/01/09

Reference

AT Urbanus, TJ van de Laar, IG Stolte, and others. Hepatitis C virus infections among HIV-infected men who have sex with men: an expanding epidemic. AIDS 23(12): F1-F7. July 31, 2009. (Abstract).