Sexual transmission of hepatitis C virus in a cluster of mainly HIV-positive gay men is reported in the June 10th edition of AIDS. Recent infection with the sexually transmitted infection lymphogranuloma venereum (LGV) and unprotected fisting were identified by investigators as risk factors for infection with hepatitis C virus during sex.
In early December 2003 hepatitis C virus infection was diagnosed in a 29-year-old HIV-positive gay man. In March 2003 he had suffered from proctitis, which was diagnosed as LGV in May of that year. His hepatitis C seroconversion was determined to have occurred between January and May 2003. The individual was part of a cluster of mainly HIV-positive gay men reported as having LGV to Dutch health authorities in late 2003.
Investigators hypothesised that infection with LGV might facilitate the sexual transmission of hepatitis C virus. They therefore initiated intensive contact tracing to identify the man’s sexual partners. They also assessed the prevalence of hepatitis C virus infections amongst men diagnosed with LGV earlier in 2003.
Sexual contacts of the individual in the previous six months and four recent contacts were identified. Consent was also obtained from 14 men with known LGV infection for the testing of serum samples obtained at the time of LGV diagnosis for hepatitis C virus antibodies.
Identified individuals were asked to complete a questionnaire providing socio-demographic details, hepatitis C virus transmission risk activity, history of sexually transmitted infections, the number of sexual partners in the previous six months, sexual practices and drug use.
The index patient had had approximately 30 partners in Europe in the six months before his hepatitis C diagnosis. Nine of these individuals were identified as being part of the LGV cluster. He also reported four recent contacts at a sex party. Two of these men were found to have hepatitis C virus and one man had recent LGV infection.
Four cases of hepatitis C virus were identified in the cluster of 14 men with LGV. In three cases, hepatitis C virus seroconversion coincided with proctitis/LGV diagnosis. None of the men had a history of injecting drug use.
Infection with a sexually transmitted infection other than LGV was frequent, being present in two of the seven men with hepatitis C virus.
Investigators tried to determine which sexual practices were associated with hepatitis C virus transmission.
There was no difference in the number of hepatitis C virus-infected (86%) and hepatitis C virus uninfected (89%) gay men reporting unprotected insertive or receptive anal sex.
However, unprotected fisting was reported by all seven men with hepatitis C virus compared with only two men in the uninfected group (p = 0.003).
There was no significant difference in the number of sexual partners reported by the hepatitis C virus-infected and uninfected men. Use of non-injected recreational drugs was frequent and reported by all men, regardless of their hepatitis C virus infection status.
"Within this group of 11 [gay] men identified in cluster of mainly HIV-positive LGV cases, seven recent HCV infections were diagnosed, sexual behaviour techniques being the unique risk of transmission", note the investigators, who note that their findings are in line with recent reports of sexual transmission of hepatitis C amongst HIV-positive gay men from the UK and France.
However, although unprotected anal sex with ejaculation has been reported as a risk factor for hepatitis C virus transmission, the investigators "found no difference in reported unprotected anal intercourse between hepatitis C virus-infected an uninfected cases, and transmission by sperm is unlikely." They note that "this finding is supported by studies isolating hepatitis C virus RNA, in which minority of sperm samples were positive for hepatitis C virus RNA and positive samples were of low titre."
Unprotected fisting during group sex was more common among hepatitis C virus infected men. "One can imagine that fisting and the use of rectal enema may cause mucosal damage, thereby increasing the risk of transmission", they note.
In addition, the investigators suggest that rectal infection with LGV "probably facilitated transmission of hepatitis C virus."
Several hepatitis C genotypes were found within the cluster indicating "several entries for hepatitis C virus. Within this greatly anonymous network, still only the tip of the iceberg is traced."
The investigators note that HIV-positive gay men often select partners of the same HIV status, so called "serosorting." They note that unprotected anal sex and fisting at "serosorting parties provide ideal conditions for the spread of highly virulent sexually transmitted infections and blood-born diseases and form hazards for individuals and are reservoirs for infections in the community."
Gotz HM et al. A cluster of acute hepatitis C virus infection among men who have sex with men – results from contact tracing and public health implications. AIDS 19: 969 – 974, 2005.