High incidence of HCV reinfection among HIV-positive MSM in Western Europe

There is a very high incidence of hepatitis C virus (HCV) reinfection among HIV-positive men who have sex with men (MSM) in western Europe, according to research presented to the International Liver Congress in Barcelona. Investigators found that a quarter of HIV-positive MSM who cleared an initial HCV infection were reinfected with HCV within three years. The researchers believe that current prevention strategies are failing and call for the intensive monitoring of people who have apparently cleared an HCV infection.

There are ongoing HCV epidemics among HIV-positive MSM in many industrialised countries. There is convincing evidence of sexual transmission, with unprotected anal sex, fisting and re-use of injecting equipment identified as high-risk activities. A recent meta-analysis suggested that prevalence of HCV co-infection among HIV-positive MSM is between 5 and 6%.

HCV infection can be cured with therapy and spontaneous clearance of acute infection has also been documented.

Research conducted in Amsterdam and London has found a high incidence of HCV reinfection after successful treatment or spontaneous clearance. There are several reasons why it is important to establish a clearer understanding of the incidence of reinfection and its risk factors, including prevention and screening strategies. Moreover, reinfection could affect the cost/benefit of expensive, but highly effective new therapies.

Investigators from the UK, Germany, Austria and France therefore designed a study to estimate the incidence of HCV reinfection among HIV-positive MSM who cleared the virus either after therapy or spontaneously.

The study population consisted of 606 men with confirmed cure or spontaneous clearance. Patients who received therapy were considered cured if they had a negative HCV PCR twelve weeks after the completion of therapy; cure following spontaneous clearance was a negative HCV PCR result 24 weeks after the first negative PCR.

Data were collected on age, date of HCV diagnosis, HCV genotype, HCV and HIV viral load, use of antiretroviral therapy (ART), CD4 count and liver function (maximum ALT). Data were also requested on presence of the IL28B gene – associated with favourable outcomes – but response rates were poor.

Reinfection was defined as a positive HCV PCR after confirmed cure/spontaneous clearance.

Over three years of follow-up, 149 patients (24.6%) were reinfected. The median time to reinfection was 1.8 years. Median age at the time of reinfection was 41 years. Most individuals – 91 of 111 patients with available data – had an undetectable HIV viral load at the time of reinfection and median CD4 cell count was 533 cells/mm³.

Spontaneous clearance of the initial infection was observed in 15% of patients after reinfection. 113 people received antiviral treatment, of whom 87 were cured.

A second reinfection was recorded in 29 patients, four patients were reinfected three times and a single individual had four reinfections.

Just over a quarter (29%) of patients spontaneously cleared their second reinfection and a third experienced spontaneous clearance of their third reinfection.

Overall incidence of reinfection was 7.6 per 100 person-years. Incidence of second reinfection was even higher at 19.9 per 100 person years.The incidence of reinfection was markedly higher in Paris (21.8 per 100 p.y.) and Vienna (16.8 per 100 p.y.) than in London (7 per 100 p.y. ) and German centres (5-8 per 100 p.y.) but the amount of patient follow-up available for analysis makes it difficult to draw firm conclusions.

Spontaneous clearance of the initial infection was associated with a significant reduction in the risk of reinfection (HR = 0.55; 95% CI, 0.32-0.95) and also the chances of spontaneous clearance if reinfected (OR = 12.7; 95% CI, 2.3-70.2).

The investigators conclude that there is a substantial risk of HCV reinfection for HIV-positive MSM. They believe their results show the failure of current prevention interventions and underline the need for new strategies. The researchers also suggest their findings have implications for the monitoring of co-infected MSM and call for HCV PCR testing to be performed every three to six months after HCV infection and every three months after reinfection.