Transmission of Hepatitis C among HIV Positive Men in the U.S.
Nearly three-quarters of new
hepatitis C virus (HCV) infections among HIV positive
gay and bisexual men in the U.S. are likely due to
sexual transmission, according to an analysis described
in the January 31, 2011 advance online issue of Clinical
Infectious Diseases. An Australian study published
in the same issue found that sexual transmission accounted
for a majority of cases among men who have sex with
men, but injection drug use also played a role. These
findings suggest that HIV positive people who have
risky sex should undergo regular hepatitis C testing.
the past decade researchers have reported outbreaks of apparently
sexually transmitted acute hepatitis C among HIV positive men
who have sex with men in cities in Europe, Australia, and the
U.S. HCV infection has been linked to fisting, unprotected anal
intercourse, group sex, having multiple partners, use of non-injected
recreational drugs, and presence of other sexually transmitted
is estimated that approximately one-third of HIV
positive people also have HCV.
Coinfected people tend to experience more
rapid liver disease progression and do not respond as well
to hepatitis C treatment.
Currently, however, many people with HIV do not routinely receive
HCV screening, and hepatitis C often has no symptoms until advanced
stages of liver disease.
study, Lynn Taylor from Brown University and colleagues
analyzed HCV incidence (new infections) during 1996-2008 among
men participating in the AIDS Clinical Trial Group Longitudinal
Linked Randomized Trials (ALLRT) cohort, made up of people taking
part in selected HIV treatment trials.
researchers evaluated associations between hepatitis C and self-reported
injection drug use, CD4 T-cell count, and HIV RNA viral load.
Given the retrospective nature of the study, however, information
on sexual activity and HCV risk factors other than injection
drug use was unavailable.
total of 1830 men who initially tested HCV negative had
at least 1 subsequent positive HCV antibody test.
the time of the initial negative HCV test, 94% of the men
were receiving combination antiretroviral therapy (ART).
were current or prior injection drug users (IDUs).
men experienced HCV seroconversion during an average 3-year
follow-up period, for an overall incidence rate of 0.51
cases per 100 person-years.
average age at the time of HCV seroconversion was 46 years.
expected, HCV seroconversion was significantly associated
with injection drug use (25% of seroconverters vs 5% of
75% of seroconverters (27 men) reported no history of drug
incidence rates were 2.67 cases per 100 person-years among
IDUs, compared with 0.40 cases per 100 person-years among
seroconversion was associated with HIV RNA > 400 copies/mL,
but there was no observed link between seroconversion and
CD4 cell count.
HCV infection occurs in HIV-infected men involved in U.S. HIV
therapeutic trials, primarily through non-parenteral [injection]
means," despite engagement in care and use of ART, the
study authors concluded.
added that, "HCV antibody development was not related to
immune status but was associated with inadequate HIV suppression."
In the second
study, Gail Matthews and fellow investigators with the Australian
Trial of Acute Hepatitis C (ATAHC) Study Group looked at the
overlap between hepatitis C epidemics attributed to injection
drug use and sexual transmission.
The trial enrolled 163 individuals with recent HCV infection,
of whom 29% were already HIV positive. The researchers analyzed
HCV genetic sequences (E1/HVR1) and constructed phylogenetic
trees to show clusters of infection caused by the same or related
of HCV infections were attributed to injection drug use.
transmission accounted for only 18% of HCV infections overall,
or 29 cases:
cases, or 92%, were HIV positive people, all of them
HIV negative men had probable sexually transmitted
HCV, one of whom reported sex with another man and
the other only with women.
cases were women with HCV positive male partners.
112 individuals with available genetic sequence data, 23
(20%) were infected with an HCV strain identical to that
of another participant.
infections could be groups into 4 homologous (related) clusters
and 3 monophyletic (identical) pairs.
majority of clustered infections (78%) occurred in HIV positive
people, while just 8% of HIV negative people could be placed
in one of these transmission clusters.
half of gay/bi men could be placed in clusters, and all
but 1 cluster included men who have sex with men.
included individuals infected through both injection drug
use and sexual transmission.
on these results, the investigators concluded, "This large
unique study of HIV-infected and HIV-uninfected individuals
with recently acquired HCV infection demonstrates that clustering
is common in the HIV-infected population and that it occurred
almost invariably among men who have sex with men, irrespective
of the actual mode of acquisition."
drug use] remains overwhelmingly the most common mode of [HCV]
infection among HIV-uninfected populations but is less common
than sexual transmission among HIV-infected populations,"
they elaborated. "In this group, both IDU-related and sexual
exposures occur and are involved as mechanisms of transmission
in the same social networks, which appear to be based on sexual
orientation rather than specific risk-taking behavior."
together, the 2 studies suggest that HIV positive people, especially
men who have sex with men, should receive regular HCV screening.
This could reduce new infections by encouraging safer sex practices,
and hepatitis C treatment during the acute stage when it is
much more likely to produce a cure.
study: Department of Medicine, Brown University, Providence,
RI; Department of Medicine, Stanford University, Stanford, CA;
Statistical & Data Analysis Center, Harvard School of Public
Health, Boston, MA; Department of Medicine, University of California
San Diego, La Jolla, CA; Department of Medicine, Ohio State
University, Columbus, OH; Department of Medicine, University
of Cincinnati College of Medicine, Cincinnati, OH. Matthews
study: National Centre in HIV Epidemiology and Clinical Research,
Sydney, Australia; School of Biotechnology and Biomolecular
Sciences, University of New South Wales, Sydney, Australia;
Kirketon Road Centre; Virology Division, SEALS Microbiology,
Prince of Wales Hospital; Centre for Infection and Inflammation
Research, University of New South Wales, Sydney, University
of New South Wales; Burnet Institute, Melbourne, Australia.
Taylor, M Holubar, K Wu, and others. Incident hepatitis C virus
infection among US HIV-infected men enrolled in clinical trials.
Clinical Infectious Diseases (abstract).
January 31, 2011 (Epub ahead of print).
Matthews, and others. Patterns and characteristics of hepatitis
C transmission clusters among HIV-positive and HIV-negative
individuals in the Australian Trial of Acute Hepatitis C. Clinical
Infectious Diseases (abstract).
January 31, 2011 (Epub ahead of print).
Infectious Diseases. Study Examines Incident Hepatitis C Infection
in HIV-Infected Men. News release. February 1, 2011.