Investigators recommend annual testing for HCV in gay men living with HIV

Investigators in the US have found a high incidence of hepatitis C virus (HCV) infection among HIV-positive gay men. Annual incidence was 1.6% – the highest ever seen in research involving HIV-positive gay men in the United States – among patients receiving care at the Fenway Institute in Boston. The study is published in the online edition of Clinical Infectious Diseases.

“This is the highest HCV incidence reported in the United States among HIV-infected MSM [men who have sex with men] to date and suggests that incident HCV is common in this population,” comment the authors. The study’s findings also showed that infections were most likely due to sexual risk behaviour or non-injecting drug use.

Hepatitis C is a blood-borne infection and injecting drug use is a major risk factor for infection.

Glossary detectable viral load When viral load is detectable, this indicates that HIV is replicating in the body. If the person is taking HIV treatment but their viral load is detectable, the treatment is not working properly. There may still be a risk of HIV transmission to sexual partners. epidemiology The study of the causes of a disease, its distribution within a population, and measures for control and prevention. Epidemiology focuses on groups rather than individuals. retrospective study A type of longitudinal study in which information is collected on what has previously happened to people - for example, by reviewing their medical notes or by interviewing them about past events. person years In a study “100 person years of follow-up” could mean that information was collected on 100 people for one year, or on 50 people for two years each, or on ten people over ten years. In practice, each person’s duration of follow-up is likely to be different. IDU Injecting drug user.

However, there is accumulating evidence of hepatitis C transmissions not linked to injecting drug use among HIV-positive gay men. These infections appear to be due to traumatic sexual practices such as fisting and non-injecting drug use, especially in the context of group sex.

Much of this evidence comes from Europe. However, hepatitis C infections in the absence of injecting drug use have also been reported among HIV-positive gay men in New York and other US cities. But low rates of baseline screening have made it difficult to accurately assess incidence of hepatitis C among HIV-infected gay men in the US.

The Fenway Institute in Boston provides care to a large number of HIV-positive gay men. The prevalence of self-reported injecting drug use among these patients is low at below 3%. Researchers at the Institute therefore believed their patients offered “a unique opportunity to explore the epidemiology of HCV among a population of patients previously perceived to be at low risk”.

Doctors from the Institute designed a retrospective study involving all HIV-infected men who had at least two appointments at the clinic between June 2008 and June 2009. The authors extracted data from patient records to determine prevalence and incidence of hepatitis C infection between 1997 and 2009. They also examined the factors associated with both prevalent and incident infections.

A total of 1160 HIV-positive gay men were included in the study, and 1059 (91%) had at least one hepatitis C antibody test. Men who reported sex with men as their only risk factor for infection with HIV were more likely to be screened for hepatitis C than men who reported both sex with another man and injecting drug use (p < 0.01). Men with a detectable viral load were also more likely to have a hepatitis C antibody test than patients with an undetectable viral load (p = 0.01).

Initial screening showed that 64 (6%) of men were co-infected with hepatitis C virus.

Of the 995 men who were initially negative for hepatitis C, 616 (62%) did not have a repeat test. Participants were more likely to have a follow-up screen for the infection if their viral load was detectable (p < 0.01).

“This low rate of repeat…testing may in part be due to healthcare provider perceptions that their patients are at low risk for HCV,” suggest the authors.

The 379 men who had a repeat test contributed 1408 person-years of follow-up. In all, 6% became infected with hepatitis C, providing an incidence of 1.6 per 100 person-years.

Injecting drug use was reported by a third of those with prevalent and incident hepatitis C. Non-injecting drug use was reported by 46% of men, and 16% of individuals denied any substance use. Cocaine was the most widely used non-injected drug. The majority of co-infected patients had a history of at least one sexually transmitted infection.

Compared to participants with hepatitis C at baseline, men with incident infections were younger (37 vs 44 years, p < 0.01) and were more likely to have a history of sexually transmitted infections (87 vs 64%, p = 0.04).

“Our findings support the growing body of evidence that the epidemiology of HCV infection may be changing among HIV-infected MSN in the United States,” comment the authors. “In the absence of IDU [injecting drug use], high risk sexual behaviors and non-injecting drug use appear to play an important role in transmission.”

A liver biopsy was performed on 26 co-infected patients. The results showed that 50% had no or very mild fibrosis and 31% had more advanced liver damage or cirrhosis.

Seven men with incident infections underwent hepatitis C therapy and six achieved a sustained virological response. A successful treatment outcome was also achieved by seven of the 15 men with prevalent infection who underwent therapy.

The authors conclude that HIV-positive gay men should be tested annually for hepatitis C. They also recommend that “HIV-infected MSM who use recreational drugs and/or engage in unprotected sex should receive education and services related to sexual risk reduction…preventative interventions are crucial to stemming the ongoing spread of HCV.”