C. Vandelli1 ,F. Renzo1 ,L. Romano2 S. Tisminetzky3 ,M. De Palma4 , T. Stroffolini5 ,E. Ventura1, A. Zanetti2
1Department of Internal Medicine, Policiinico of Modena, Modena, Italy; 2 of Virology, University of Milano, Milano, Italy; 3 Trieste, Italy; 4 Bank, Policlinico of Modena, Modena, Italy; 5 Department, S. Giacomo Hospital, Roma, Italy
We 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.
Methods / Results
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
Sexual transmission of (HCV) is rare in monogamous heterosexual couples
Sexual transmission of hepatitis C virus (HCV) is rare in monogamous heterosexual couples, according to the results of a 10-year prospective study published in the May issue of the American Journal of Gastroenterology.
"The rate of HCV infection in sexual partners of anti-HCV-positive individuals has been shown to range between very low and as high as 30%," write Carmen Vandelli, MD, from the Universita di Modena e Reggio Emilia in Italy, and colleagues. "These discordant findings may partly be explained by the confounding effect of nonsexual transmission routes."
In a long-term study, 895 monogamous heterosexual partners of individuals chronically infected with HCV were followed for a total of 8,060 person-years. Of these 895 partners, 776 spouses (86.7%) were followed for 10 years, corresponding to 7,760 person-years. An additional 300 person-years were contributed by spouses whose infected partners cleared the virus during treatment, who ended the relationship, or who were lost to follow-up. All of these couples denied practicing anal intercourse, vaginal intercourse during menstruation, or condom use. Average frequency of sexual intercourse was 1.8 times per week.
During follow-up, there were three HCV infections, corresponding to an incidence rate of 0.37 per 1,000 person-years. HCV genotyping, sequence analysis, and phylogenetic analysis suggested that the corresponding partners carried different viral isolates, which would rule out spousal transmission of HCV.
However, the authors note that in 33 (3.4%) of 967 couples initially investigated, both partners were anti-HCV positive, suggesting the possibility that HCV could have been transmitted earlier in their relationship.
"Our data indicate that the risk of sexual transmission of HCV is extremely low or even null," the authors write. "No general recommendations for condom use seem required for individuals in monogamous relationships with HCV-infected partners."
Based on other studies, however, the authors strongly advised these couples to avoid sharing personal hygiene items such as toothbrushes, razors and nail clippers.
The Association for the Study of Infectious and Metabolic Diseases of the Liver supported this study.
Am J Gastroenterol. 2004;99:855-859
Approximately 2.3% of U.S. adults are positive for anti-HCV antibody, according to a review of screening for HCV, which appeared in the March 16, 2004, issue of the Annals of Internal Medicine. The U.S. Preventive Services Task Force report also noted that most of those infected acquire HCV by large or repeated percutaneous exposures to infected blood, and up to 84% of patients with a positive antibody test will develop chronic infection.
Given the large number of people with chronic HCV infection and the need to control the spread of the disease, accurate data regarding risky behavior for transmission is essential. A common question from patients involves the risk of sexual transmission and the means they might take to prevent their partner from becoming infected. However, according to the authors of the current study, rates of HCV infection from sexual transmission have been estimated to be from less than 1% to 30%.
The authors of the current study performed a prospective trial to determine the risk of sexually acquired HCV infection.
a.. Subjects included patients from an internal medicine practice with positive anti-HCV antibody and HCV RNA tests. Participants were involved in heterosexual relationships with a partner who had tested negative for HCV.
b.. Partners of HCV-infected patients were tested annually for liver function tests and anti-HCV antibody over a 10-year period. Those who had one of these tests return positive underwent further HCV RNA testing. Sexual practices and possible parenteral HCV exposure were monitored via questionnaires.
c.. Subjects having extramarital affairs were excluded from participation. Participants were advised not to share personal products such as razors, toothbrushes, and nail scissors. Regular use of condoms was not recommended.
d.. 967 sexual partners of patients with HCV infection were identified, and 3.4% of these partners were anti-HCV positive at baseline and thus excluded from participation. 84.5% of these infected partners had a history of a significant risk factor other than sexual intercourse that could have served as a source of infection. Only 2 infected partners displayed a concordant HCV genotype compared with their partner at baseline.
e.. Mean age of subjects at enrollment was 44.2 years, and the average length of marriage was 23.7 years. The mean HCV RNA level in index cases was 6.7 mEq/L. 90% of index subjects had either moderate or severe hepatitis on analysis of liver biopsy.
f.. 230 index patients had undergone interferon-alpha treatment, and 30% had achieved long-term responses. Spouses of these patients were excluded from the analysis.
g.. 93.9% of couples completed the 10-year follow-up period, accounting for 7,760 person-years of observation. Including patients who subsequently cleared the infection and couples who separated during the study period, the total follow-up was 8,060 person-years.
h.. No patients reported condom use, anal intercourse, or sex during menstruation. The average weekly rate of intercourse was 1.8.
i.. Three spouses, 2 women and 1 man, acquired HCV infection during the follow-up period, an incidence rate of 0.37 per 1,000 person-years. They became infected 7, 8, and 9 years into the monitoring period, respectively.
j.. One of the spouses infected with HCV reported receiving a dental implant 3 months before her positive test, and her HCV genotype was discordant with that of her husband. Another spouse who converted had suffered a needle stick injury involving a patient positive for HCV and HIV. Her HCV genotype was also discordant from that of her spouse. The third spouse who became infected reported no other HCV risk factors and displayed a concordant HCV genotype when compared with his spouse. However, phylogenetic testing revealed that this couple's HCV strains were not linked.
Pearls for Practice
a.. HCV is a common infection in the U.S., and it frequently becomes chronic.
b.. Vaginal sexual intercourse appears to present a very low risk of HCV transmission