Incidence of acute hepatitis C virus (HCV) among men who have sex with men (MSM) who use pre-exposure prophylaxis (PrEP) in
Lyon increased tenfold between 2016 and 2017, according to research
published in Clinical Infectious Diseases. There was also a
doubling of incidence among HIV-positive MSM, mainly as a result of
reinfection. There were distinct clusters of infections, over half
involving both HIV-positive and HIV-negative men.
study clearly demonstrates that the HCV epidemic has now spread in
HIV-negative MSM,” comment the authors. “The incidence of AHI [acute
hepatitis C incidence] was particularly high in PrEP-using MSM.”
The authors believe that measures to control the HCV epidemic among MSM
should include routine and frequent testing for all high-risk
individuals. For those diagnosed with acute infection, rapid initiation
of HCV therapy with direct-acting antivirals (DAAs) and harm reduction is
There’s now considerable evidence of sexual transmission
of HCV among HIV-positive MSM. Outbreaks are now being reported among
Investigators in Lyon wanted to further understand the dynamics of HCV
transmission among both HIV-positive and HIV-negative MSM, including
incidence, clustering and risk factors.
They therefore designed a study involving all cases of acute HCV among
MSM documented in the city between 2014 and 2017. HCV samples were
genetically analysed to see if infections were clustered and whether
there were distinct transmission networks.
During the study
period, there were a total of 108 acute HCV infections involving 96 MSM
(80 first infections and 28 reinfections). Risk factors for HCV
included injecting drug use (33%), snorting drugs (34%), group sex (69%)
and fisting (24%).
At least one risk factor was reported by 79% of HIV-positive and 96% of HIV-negative men.
patients were significantly younger than HIV-positive individuals
(median age, 37 vs 47 years, p = 0.02) and were more likely to report
drug use (96% vs 40%, p < 0.001) and fisting (50% vs 15%, p =
Two-thirds of HIV-negative men were receiving PrEP at the time of HCV
diagnosis. An additional 12% of HCV infections among HIV-negative MSM
were picked up at PrEP screening.
The number of acute HCV cases
diagnosed per year doubled from 20 cases in 2014 to 40 cases in 2017. By
2017, HIV-negative men represented 45% of acute diagnoses.
in HIV-positive MSM more than doubled, from 1.1 cases per 100
person-years in 2014 to 2.4 cases per 100 person-years in 2017. However,
this increase was only significant for reinfections, increasing from
4.8 per 100 person-years in 2014 to 11.8 cases per 100 person-years in
2017. The rate of first infections remained relatively stable,
increasing from 1.1 to 1.5 cases per 100 person-years over the same
In contrast, incidence of first infections among PrEP users increased
tenfold between 2016 and 2017, from 0.3 cases per 100 person-years to
3.0 cases per 100 person-years in 2017.
Spontaneous cure was
observed in 8% of cases. HCV therapy using DAAs was initiated by 94
patients, an average of five months after the estimated date of
infection. The overall sustained virological response rate was 96%.
most frequent HCV genotypes were 1a (55%), 4d (31%) and 3a (7%).
Phylogenetic analysis showed that 96% of acute infections belonged to a
cluster. Eight distinct clusters – involving between three and 27
sequences – were identified. All the clusters involved an individual
with HIV, with five also involving an HIV-negative man. Six clusters
involved an individual who was infected with HCV before 2014, though
acute infections were now driving the epidemic.
Analysis of the
five largest clusters showed that four were strongly associated with
drug use (45 to 85% of men), with fisting (50%) an additional risk
factor in one of them. Seventeen infections between January 2016 and
July 2017 involved closely related virus. These infections were in individuals sharing multiple risk factors. One cluster of patients diagnosed between June and August 2017 involved six patients, all
reporting nasal drug use and with a recent bacterial STI, possibly
suggesting HCV transmission between these individuals at a single event.
“This study reveals the changing epidemiology of AHI in MSM in
Lyon, France, in recent years, spreading from HIV-infected patients to
HIV-negative patients through sharing of high risk activities such as
chemsex and traumatic sexual practices,” write the authors. “All
clusters started with an HIV-infected MSM, suggesting that the epidemic
started in this population and later spread to HIV-negative MSM.”
authors believe their findings have important implications for the
control of sexually transmitted HCV in MSM. They urge that all MSM with
high-risk behaviour should be routinely and regularly screened for HCV.
DAA therapy and harm reduction should be provided early following
diagnosis of acute HCV, thus limiting the risk of onward transmission.
further analysis of the same group of patients was presented to CROI
2019. This showed the importance of rapid diagnosis, treatment and harm
reduction. Each MSM with acute HCV infection was estimated to pass on
the infection to 2.35 other MSM within five months.