Gay men are not a risk group for HIV and hepatitis C virus (HCV) coinfection according to a large US study published in the May 15th edition of the journal Clinical Infectious Diseases. This contradicts the findings of several earlier studies and evidence that HCV is being sexually acquired by HIV-positive gay men (see links below).
The study, involved over 2,700 HIV-positive patients involved in HIV treatment trials in several US cities between 1998 and 2001 and was part of the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). Investigators found a coinfection rate at baseline of 16.6%. A history of injecting drug use, older age (52 years versus baseline average of 39 years), being African-American or Latino-Hispanic, and not taking anti-HIV therapy were found by the investigators to be positively associated with HIV-HCV coinfection. However, a history of sex with other men was not associated with coinfection, contradicting the findings of several earlier studies. Neither CD4 count nor HIV viral load were predictive of HIV-HCV coinfection.
Indeed, when the investigators further analysed the prevalence of HIV-HCV coinfection amongst injecting drug users, they found that men who had had sex with other men who injected drugs were less likely to be coinfected than men reporting only heterosexual contacts.
The investigators sought to explain their findings. The older age of the coinfected patients “reflect[s] the cohort effect of persons infected 1970-90, the time of the highest incidence of HCV infection” suggest the investigators. As regards not taking anti-HIV therapy, this may reflect the delayed entry into HIV care of injecting drug users, delayed prescription of HAART, or a reluctance by either patient or doctor to enter clinical trials.
As expected, men with a history of injecting drug use had a higher prevalence of coinfection. However, the prevalence was lower amongst men with a history of sex with other men than men reporting only heterosexual contacts. “The lower prevalence of HCV coinfection among those with a history of mal-e-male sexual contact is surprising”, note the investigators, particularly as it “does not support the studies of behaviors among urban IDUs and sexual practices (eg., sex for drugs or money and needle sharing)."
The investigators suggest that gay men could be more likely to practice risk-reduction, such as not sharing needles, not using shooting galleries or using non-injectable drugs.
Amongst men with no history of injecting drug use, the investigators were at a loss to explain the lower rates of coinfection seen amongst gay men. They conclude that more studies are needed to “elucidate the interplay between sexual behavior IDU, and the risk of acquisition of HIV-HCV coinfection.”
Further information on this website
Hepatitis C - overview
Hepatitis C - factsheet
HIV and hepatitis - booklet in the information for HIV-positive people series (pdf)
Fisting, drug use, syphilis; risk factors for hepatitis C transmission in HIV-positive gay men - news story
London clinic reports rising cases of sexually transmitted hepatitis C - news story
Tedaldi EM et al. Prevalence and characteristics of hepatitis C virus coinfection in a human immunodeficiency virus clinical trials group: The Terry Beirn Community Programs for Clinical Research on AIDS. Clinical Infectious Diseases, 36 (online-edition), 2003.