Further
Evidence of Sexual Transmission of Hepatitis C Virus among HIV Positive Men Who
Have Sex with Men By
Liz Highleyman
 Over
the past few years, researchers have reported outbreaks of apparently sexually
transmitted acute hepatitis C virus (HCV) infection
in several U.K. and European cities, mainly among HIV
positive men who have sex with men (MSM).
Such cases initially caught
experts by surprise, since HCV was previously thought to be rarely transmitted
via sex. Indeed, studies have shown that sexual transmission is very uncommon
(in the range of 0%-3%) among monogamous HIV negative heterosexual couples.
At
the XVII International AIDS Conference this month in
Mexico City, Anouk Urbanus and colleagues provided further details about a cluster
of cases in the Netherlands.
The researchers studied HCV prevalence and
determinants of infection among clients visiting a large Amsterdam sexually transmitted
disease clinic with 24,000 new consultations per year. In May and November 2007
and in April 2008 researchers interviewed 3124 clinic attendees (448 of them MSM)
about risk factors for blood-borne and sexually transmitted infections and anonymously
screened them for HIV and HCV antibodies. HIV positive participants received HCV
RNA tests regardless of HCV antibody status. Phylogenetic analysis was used to
identify evidence of sexual transmission. Results •
Among 2435
heterosexual men and women, 7 (0.3%) were infected with HCV.
•
2 of 532 HIV
negative MSM (0.4%) were found to be infected with HCV.
•
By contrast,
28 of 157 HIV positive MSM (17.8%) were coinfected with HCV.
•
5 of the 28 HIV-HCV coinfected MSM (17.9%) reported ever injecting drugs.
•
9 of the 28
HIV-HCV coinfected men (32.0%) tested HCV antibody negative but HCV RNA positive,
indicating possible acute infection.
•
The rate of HCV infection among HIV MSM rose over time:
•
7 of 48 (14.6%) tested in May 2007;
•
7 of 42 (16.7%) in November 2007;
•
14 of 67 (20.9%) in April 2008.
•
In a multivariate analysis, the following factors were significantly associated
with HCV infection:
•
HIV infection (OR 38.4; P < 0.001);
•
History of injection drug use (OR 15.5; P = 0.004);
•
Fisting (OR 15.0; P < 0.001);
•
Fisting was strongly correlated with use of sex toys, group sex, bleeding during
sex, and use of gamma hydroxybutyrate (GHB).
•
Phylogenetic analysis that included previously known cases of acute HCV infection
among MSM revealed a high degree of clustering within this population.
The
investigators concluded that the prevalence of HCV was nearly 18% among HIV-infected
MSM attending the STI clinic in 2007, whereas before 2000 the rate was 1-4%. "This
increasing HCV prevalence and the possibly acute infections suggest a rapid spread
of HCV," they said.
"Independently of [injection drug use], rough
sexual techniques were associated with HCV," they continued. "Phylogenetic
analysis reveals the presence of MSM-specific HCV strains, also supporting sexual
transmission."
Finally, they recommended that "Targeted interventions
including raising awareness are needed to stop the further spread among HIV-infected
MSM, and a possible spill over to HIV negative MSM."
Public Health
Service, Cluster of Infectious Diseases, Amsterdam, Netherlands; Academic Medical
Center, Department of Clinical Virology, Amsterdam, Netherlands; National Institute
for Public Health and the Environment, Center for
Infectious Disease Control,
Bilthoven, Netherlands. 8/19/08
Reference
At
Urbanus, T van de Laar, J, Schinkel and others. HCV
is emerging as an STI among HIV-infected MSM: a threat to the MSM community?
XVII International AIDS Conference. Mexico City. August 3-8, 2008. Abstract
THPDC200 (powerpoint slides.
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