Lack of evidence of sexual transmission of Hepatitis C among monogamous couples

Italian researchers have evaluated the risk of sexual transmission of hepatitis C virus (HCV) infection among 895 monogamous heterosexual partners of HCV chronically infected individuals in a long-term prospective study.

The follow up period was 8060 person-years; 776 (86.7%) spouses were followed up for ten years. corresponding to 7760 person-years of observation and 119(13.3%) spouses (69 whose infected partners cleared the virus following treatment and 50 who ended their relationship or were lost at follow- up) contributed for additional 300 person-years.

During the follow-up three HCV infections were observed corresponding to an incidence rate of 0.37 per 1,000 person-years. However, in one case the infecting HCV genotype in a spouse was different from that of the partner ((2a, 1b), likely excluding a sexual route of transmission. Despite the remaining two couples had concordant genotypes, sequence analysis of the NS5b region of the HCV genome, coupled with a phylogenetic analysis showed that the corresponding partners carried different viral isolates, again excluding the possibility of intraspousal transmission of HCV.

These findings indicate an extremely low or even null risk of HCV transmission within heterosexual monogamous couples.

Department of Internal Medicine, Policiinico of Modena, University of Milano, S. Giacomo Hospital, Roma, Italy