A cluster of acute hepatitis C virus infection among men who have sex with men--results from contact tracing and public health implications.

Objective: An acute hepatitis C virus (HCV) infection in an HIV-positive man who had sex with men (MSM) was notified. In the period of his seroconversion he was also diagnosed with a rectal lymphogranuloma venereum (LGV) infection, and was part of a cluster of 15 LGV cases in 2003. Our aim was to investigate HCV transmission and to search for potential spread among sexual contacts and known LGV patients.
Methods: Our case series included the index, two recent contacts, and 14 LGV cases. They were interviewed about parenteral exposure for HCV, history of sexually transmitted diseases(STDs), sexual behaviour and drug use. Laboratory investigations included anti-HCV antibodies, HCV-polymerase chain reaction, and HCV genotyping.
Results: Seven out of 17 MSM recently seroconverted for HCV (41%). Three genotypes were found. Parenteral risk factors were excluded. Six out of seven had LGV proctitis coinciding with HCV seroconversion, six (86%) were HIV infected. Unprotected anal contact was practised by both HCV uninfected and infected cases. Unprotected active and passive fisting was reported by all seven HCV infected men, compared with two of nine uninfected men (P = 0.003). Non-intravenous drug use during sexual activities was common among all MSM. Numerous, often anonymous, sexual contacts in various European countries were reported.
Conclusions: A cluster of acute HCV infection is reported among mostly HIV-positive MSM, with multiple partners throughout Europe. Sexual techniques potentially leading to mucosal damage (fisting), concomitant STDs such as LGV and drug use seem facilitating factors for spread. Extensive case finding and partner tracing is advocated as well as targeted prevention messages.