Fisting was the sexual risk practice most strongly associated with the sexual transmission of hepatitis C virus amongst HIV-positive gay men in a study conducted in London and published in the August 1st edition of Sexually Transmitted Infections. Although unprotected anal sex has been associated with the transmission of hepatitis C in previous studies, investigators from the Sex, Health and Anti-Retrovirals Project (SHARP) found that after controlling for numbers of sexual partners, fisting was the only factor significantly associated with contracting hepatitis C during four years of follow-up.
In recent years there has been a marked increase in the incidence of acute hepatitis C infection seen in HIV-positive gay men in the UK. Unprotected anal intercourse and fisting have been particularly linked with the sexual transmission of hepatitis C, but the exact factors affecting transmission are uncertain. Investigators therefore analysed data provided by 308 HIV-positive gay men about their recent sexual, behaviour together with blood tests used to monitor hepatitis C seroconversion, to see if there were any sexual or other risk factors associated with the transmission of hepatitis C.
Patients were recruited to the study between 1999 and 2000 and had CD4 cell counts, HIV viral load and hepatitis C infection status monitored until April 2005. A total of eleven men seroconverted for hepatitis C during this period.
Factors associated with an increased risk of infection with hepatitis C were more than 30 sexual partners in the past year (p = 0.023); new anal sex partners in the past year (p < 0.001); and unprotected anal sex with a new partner in the past year (p = 0.037).
The investigators then looked at the men’s sexual behaviour with their last two partners. They found that seroconversion with hepatitis C was significantly associated with fisting (p < 0.001), rimming (p = 0.047), use of sex toys (p = 0.016), and snorting recreational drugs (p = 0.042).
Fisting, the investigators stress, was the sexual activity most strong associated with sexual transmission of hepatitis C, with individuals engaging in this practice being at least nine times more likely to become infected with hepatitis C. However, five of the eleven men who contracted hepatitis C did not report fisting as a sexual activity. All but one of those who contracted hepatitis C reported anal fingering, and nine of eleven reported rimming.
Further statistical analysis was then performed by the investigators who found that, once they controlled for new anal sex partners and more than 30 sexual partners in the past year, fisting remained the only sexual activity significantly associated with the transmission of hepatitis C.
The investigators observe that the men “who reported fisting with subsequent hepatitis C diagnosis, all reported at least one other rectal sex practice” and many also reported unprotected anal sex as part of the same sexual episode. They add, “these findings suggest an association between hepatitis C virus infection and a number of sexual practices with increased risk of sexual trauma”, continuing, “our results show a clear association between fisting and hepatitis C infection.”
However, the investigators do not rule out a role for unprotected sex in the transmission of hepatitis C – but only as part of a wider sexual repertoire that includes fisting. The investigators postulate “hepatitis C transmission may occur when mucosal disruption as a consequence of receptive fisting occurs and is followed by receptive unprotected anal intercourse either within the same sexual episode or another one.”