Traditionally,
it has been assumed that hepatitis C virus (HCV)
was rarely transmitted through sexual activity, largely basis on the low rates
(0%-5%) observed in epidemiological studies of monogamous heterosexual couples.
In
recent years, however, this assumption has been called into question due to outbreaks
of apparent sexually transmitted HCV infection among gay men in the U.K. and Europe.
Most such cases have been seen in HIV positive men who have sex with men (MSM),
but a few have been reported in HIV negative MSM and HIV positive women.
In
the U.S., HCV is most commonly transmitted through shared use of drug injection
equipment. However, the contribution of sexual transmission among injection
drug users (IDUs) is unclear, and prior studies have produced conflicting
data.
As reported in the June 1, 2007 Journal of Infectious Diseases,
researchers assessed multiple risk factors for HCV infection using a novel multilevel
modeling technique designed to overcome the limitations of previous research.
The analysis included data on 265 drug-using couples in East Harlem in New York
City. Results
•
In a multivariate
analysis, significant individual risk factors for HCV included a history of injection
drug use, tattooing, and older age.
•
At
the couple level, HCV infection tended to cluster within couples, and was accounted
for by drug-injection behavior.
•
Individual-level
and couple-level sexual behavior was not associated with HCV infection in this
model.
Conclusion
In
conclusion the authors wrote, "Our results are consistent with prior research
indicating that sexual contact plays little role in HCV transmission. Rather,
couples' injection behavior appears to account for the clustering of HCV within
heterosexual dyads."
The greater apparent risk of sexual transmission
of HCV among gay men may be due to specific practices such as anal sex, fisting,
group sex, and use of intrnasal recreational drugs, that are more common in the
MSM population.
05/04/07
References
JM
McMahon, ER Pouget, S Tortu. Individual and Couple-Level Risk Factors for Hepatitis
C Infection among Heterosexual Drug Users. Journal of Infectious Diseases 195(11):
1572-1581. June 1, 2007.
JA
Hahn. Sex, Drugs, and Hepatitis C Virus. Journal of Infectious Diseases
195(11): 1556-1559. June 1, 2007.
In
recent years, however, this assumption has been called into question due to outbreaks
of apparent sexually transmitted HCV infection among gay men in the U.K. and Europe.
Most such cases have been seen in HIV positive men who have sex with men (MSM),
but a few have been reported in HIV negative MSM and HIV positive women.
