Being the passive partner during unprotected anal intercourse is emerging as the main sexual practice associated with gay HIV-positive men becoming co-infected with hepatitis C (HCV), according to a presentation in Warsaw today from Professor Brian Gazzard of the Chelsea & Westminster Hospital, London's largest HIV clinic.
In the past 21 months, 44 new, acute HCV infections have been diagnosed at the C&W, all of whom have been in gay HIV-positive men. "It is clear there is an epidemic going on within the London gay community of acute hepatitis C infection," Professor Gazzard told the conference, "and this is also being seen in a number of other units across London." The Royal Free and Mortimer Market Centre presented data earlier this year about their own experiences with the epidemic.
Modes of transmission have not been identified in four co-infected gay men, and another four also injected drugs (two of whom also had unprotected anal intercourse).
It was just over a year ago that AIDS Treatment Update published the first reports about this new sexually transmitted epidemic, and since then aidsmap has reported on its developments. One of the major issues is exactly how and why HCV is being sexually transmitted amongst gay HIV-positive in London. As well as barebacking, associations with fisting, sharing drug-snorting paraphernalia, and particularly syphilis have been made, but according to Professor Gazzard receptive unprotected anal intercourse was the single common factor amongst the 44 out of the total of 50 gay men seen at their HIV/HCV co-infection clinic since it began in January 1997.
"They all had passive anal sex," he told aidsmap, "but many of them were also fisting. We did ask about [snorting drugs] and we didn't find any association, so I don't think that was a risk factor." The C&W also found that around 40% had been diagnosed with syphilis in the year prior to HCV seroconversion.
At the moment, it is not known whether it is other acutely or chronically co-infected HCV/HIV-positive men who are most likely to transmit HCV to their sexual partners, but extremely high HCV viral loads are seen during acute infection and just like HIV, HCV is more likely to be transmitted when viral loads are high, and possibly in the presence of an STI, like syphilis. The next step will be to do "DNA fingerprinting, to see if it comes from a common source or many difference sources," Professor Gazzard said. "The suspicion is that it may well come from a common source."
The C&W has learned lessons about identifying and treating new cases of HCV co-infection from its past experiences, and now does routine liver function tests every three months on all of their HIV-positive patients. If they are abnormal, they are then screened for HCV antibody and HCV PCR (viral load. Thirty-nine of the 50 co-infection cases reported so far in the epidemic were picked up in this way, another three told their doctors they had had barebacked with a known HCV-positive sexual partner, four presented at the clinic with jaundice, and the rest were screened for HCV during seroconversion for HIV antibodies.
Although treatment with the 'gold standard' of pegylated interferon/ribavirin is standard practice at the C&W, they now wait 12 weeks to see if the HCV co-infection spontaneously clears, since so far 12 out of the 22 patients who did not take any treatment spontaneously converted to HCV PCR negative within that time. "We were surprised by the relatively high rate of spontaneous conversion to PCR negative," said Professor Gazzard, "since it is not that different to what it is seen in HIV-negative patients."
Factors associated with spontaneously converting to HCV PCR negative including having a CD4 count above 500 (70% vs 30%) and higher peak ALT levels at diagnosis, indicating a greater hepatic inflammatory response.
Of the 24 individuals who received anti-HCV therapy, 15 finished treatment, and nine are continuing. One received interferon/ribavirin, one pegylated interferon alone, and the rest pegylated interferon/ribavirin. 10 out of the 15 have been successfully treated to PCR negativity with a follow-up of between 1-8 months. Of the five that failed treatment, one was due to toxicity, and four due to lack of response.
However, of the nine individuals presently receiving treatment, four have a poor anti-HCV response. Putting a positive spin on things, Professor Gazzard reported that they had found that the short-term success rate of treatment of acute HCV co-infection "was close to 60%."
Further information on this website
Fisting, drug use, syphilis; risk factors for hepatitis C transmission in HIV-positive gay men - news story, April 2003
Hepatitis C virus a new sexual health risk for gay men according to UK doctors - news story, September, 2002
Nelson M. et al. Increasing Incidence Of Acute Hepatitis C In HIV Positive Men Secondary To Sexual Transmission, Epidemiology And Treatment Ninth European AIDS Conference, Warsaw, abstract F12/3, 2003.