Many gay men are being infected with hepatitis C virus soon after they contract HIV, according to a study conducted in London and published in the March 12th edition of AIDS. The study, conducted at St Mary’s Hospital, found that 7% of gay men diagnosed with HIV at the hospital between 1999 and 2006 went on to become infected with hepatitis C virus through sex.
A separate study published in the same edition of AIDS described two cases of hepatitis C-superinfection in HIV-positive gay men.
Several outbreaks of sexually transmitted hepatitis C virus have been reported in HIV-positive gay men. HIV treatment guidelines in the UK recommend that patients should be tested for hepatitis C infection soon after their HIV is diagnosed and at intervals after that according to their risk.
The guidelines do not, however, define what this risk is, and investigators were concerned that this could mean that patients with recent hepatitis C infection were going undiagnosed. The response to anti-hepatitis C treatment in patients with HIV is approximately 66% in those who receive such treatment soon after they are infected with hepatitis C, but only 33% in patients who receive treatment when they have chronic hepatitis C infection.
Primary HIV infection in gay men is associated with unprotected sex and the presence of other sexually transmitted infection such as gonorrhoea and syphilis. As unprotected sex and sexually transmitted infections have been implicated in the sexual transmission of hepatitis C virus, investigators at St Mary’s Hospital hypothesised that patients with primary HIV infection may be vulnerable to infection with hepatitis C virus.
Between 1999 and 2006 a total of 155 gay men were diagnosed with primary HIV infection at the hospital. Sexual histories were obtained from these men and blood samples were taken every three months to monitor liver function and to screen for hepatitis C virus.
A total of eleven men (7%) became infected with hepatitis C virus. No cases were recorded before 2003. But in 2004, one (3%) of the 40 men with primary HIV infection was diagnosed with hepatitis C. A total of 130 cases of primary HIV infection in gay men were seen at the hospital in 2005 and four (3%) of these patients were diagnosed with hepatitis C. Of the 155 gay men diagnosed with primary HIV infection in 2006, six (4%) were also diagnosed with hepatitis C.
The median time between primary HIV infection and the detection of hepatitis C was 23 months. Nine of the patients were diagnosed because of symptoms suggestive of acute hepatitis C infection or because of abnormal liver function. The remaining two patients had normal liver function, but were tested for hepatitis C after mentioning high-risk behaviour.
Analysis of stored blood samples showed that none of the men were infected with hepatitis at the time of primary HIV infection. All the men were infected with the harder-to-treat hepatitis C genotypes 1a and 4. In seven of the men, HIV viral load increased at the time of hepatitis C infection.
None of the men had used intravenous drugs, but in the three months before infection with hepatitis C ten had used recreational drugs, eight reported fisting and four reported sharing sex toys with casual partners.
“This study supports the enhanced surveillance of high-risk groups to identify new hepatitis C virus cases and prevent the onward transmission of both hepatitis C and HIV and to allow the opportunity for early treatment intervention to enhance hepatitis C clearance rates”, write the investigators.
They add, “we recommend the use of targeted sexual histories in conjunction with regular serum ALT and directed hepatitis C virus testing.”
Hepatitis C superinfection
Investigators from Paris report two cases of hepatitis C superinfection in HIV-positive gay men whose only risk factor was unprotected sex.
The first case involved an HIV-positive man who was diagnosed with hepatitis C virus genotype 4a in 2002. Phylogenetic analysis showed that this was part of a cluster of sexually transmitted hepatitis C virus being transmitted amongst HIV-positive gay men in Paris at that time. In December 2003 the patient was also found to be infected with hepatitis C genotype 3. The man had been infected with syphilis on numerous occasions and reported unprotected sex with multiple anonymous partners.
The second HIV-positive patient was diagnosed with hepatitis C genotype 1a and syphilis in 2004. He was provided with therapy for hepatitis C infection and had an undetectable hepatitis C viral load three months after completing this treatment.
However, six months after the completion of treatment, the patient was diagnosed with syphilis and tests also revealed the presence of hepatitis C. Phylogenetic analysis showed that although this infection was with hepatitis C genotype 1a, it was distinct from the virus with which the man had originally been infected and therefore represented superinfection rather than relapse after treatment.
“Hepatitis C virus/HIV-coinfected men who have sex with men with high-risk mucosal traumatic sexual practices should be aware of sexually transmitted hepatitis C virus superinfection”, conclude the investigators.
Fox J et al. Increasing incidence of acute hepatitis C in individuals diagnosed with primary HIV in the United Kingdom. AIDS 22: 666 – 668, 2008.
Ghosn J et al. Sexually transmitted hepatitis C virus superinfection in HIV/hepatitis C virus-coinfected men who have sex with men. AIDS 22: 658 – 661, 2008.