There is a high
incidence of hepatitis C virus (HCV) reinfection among gay men living with HIV in London, results of
a study published in the online edition of AIDS
show. The research involved men with HIV and HCV co-infection, who
cleared their primary HCV
infection spontaneously or after treatment. Approximately a quarter of
study participants were subsequently reinfected with HCV, a small number
of men
as many as three times.
The results were also presented at the 7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2013) in Kuala Lumpur, Malaysia last week.
“Our results
demonstrate a high risk of HCV re-infection among HIV-positive MSM [men who
have sex with men] who are either treated for or who spontaneously clear their
initial infection,” write the investigators. “These results emphasize the need
for effective sexual education for HIV-positive MSM presenting with primary HCV
infection and the implementation of preventative interventions to reduce the
risk of re-infection.”
Liver disease is
now an important cause of serious illness and death among people with HIV.
Much of this liver disease is due to co-infection with HCV. There are well-documented
epidemics of sexually transmitted HCV among gay men living with HIV in a number of
European cities, the US and Australia. Risk factors for transmission include
ulcerative sexually transmitted infections, unprotected anal sex, use of sex
toys, fisting and drug use.
A proportion of people clear HCV spontaneously and others are cured with treatment.
However, retrospective research in the Netherlands has shown a very high
incidence of HCV reinfection among gay men living with HIV.
Investigators at
the Chelsea and Westminster Hospital in London wanted to see if reinfection was
also occurring among the men in their care. The investigators also wished to see if
people who cleared HCV had protective immunity against the infection.
The investigators
designed a retrospective study involving gay men with HIV and HCV co-infection who received care
between 2004 and 2012. A total of 858 gay men with this co-infection received care at the
hospital in this period, and 191 of them cleared HCV infection but
were subsequently reinfected with the virus.
Analysis was
initially focused on the 145 men who had a documented date of initial HCV
infection.
These men
contributed a total of 400 person-years of follow-up, with a median follow-up
period of 2.1 years. There were 32 reinfections in this group, providing
a reinfection rate of 8 per 100 person-years. The incidence of reinfection
was 9.6 per 100 person-years among men who had been successfully treated
for their primary HCV infection. A quarter of them were reinfected
within two years.
There were five
reinfections among the 31 people who spontaneously cleared their initial
HCV
infection, a reinfection rate of 4.2 per 100 person-years. This rate was
not
significantly lower than that observed among people who had achieved a
sustained virological response (SVR, considered a cure) with
therapy. The authors therefore believe their results provide “only weak
evidence of protective immunity”.
In all, 17 of the
32 men who were reinfected spontaneously cleared or were successfully treated.
Over 32 person-years of follow-up, eight of these were reinfected
with HCV a second time. This yielded an incidence rate of 23.2 per 100
person-years. The median time to second reinfection was 1.5 years.
Analysis of the
entire cohort of 191 people and including those with an uncertain date of
primary HCV infection showed that a total of 44 individuals experienced
reinfection. The incidence rate was 7.8 per 100 person-years.
Seven men
spontaneously cleared their reinfection and 17 men achieved an SVR with a
second course of HCV therapy.
However, eight of
these patients were reinfected a second time, a second reinfection rate of
15.5 per 100 person-years. Four of these patients experienced spontaneous
clearance and three underwent another course of HCV therapy, the results of
which are pending. Two of the patients with spontaneous clearance had a third
reinfection.
Combining first,
second and third reinfections, there were a total of 54 reinfections. Most of
these (81%) involved the difficult-to-treat HCV genotypes 1 and 4.
Overall, 20% of
patients spontaneously cleared their reinfection. The treatment response rate
among patients undergoing therapy for reinfection was 73% for individuals with
genotypes 1 and 4 and 100% for genotypes 2 and 3.
“The majority of
re-infections were treated in the acute phase of the infection…and SVR rates
were consistent with studies treating acute HCV infection in HIV-positive MSM,”
explain the authors.
“We recommend
enhanced surveillance of patients who have cleared HCV infection to allow the
early detection and treatment of any re-infection,” the investigators conclude.
“In addition, we recommend directed education and prevention interventions to
HIV-positive MSM with HCV infection. Future work will include evaluation of
interventions and prospective studies to evaluate further protective immunity
in this population.”