Gay and bisexual men who acquire hepatitis C infection while
using pre-exposure prophylaxis (PrEP) for HIV prevention are part of the same sexual
networks and have the same risk factors as HIV-positive men who acquire
hepatitis C, a study of men in London reports in the Journal of Viral Hepatitis.
The research, carried out at five sexual health clinics in
England, recruited gay and bisexual men diagnosed with acute (recent) hepatitis
C infection during 2017. The study was designed to investigate whether HIV-negative
men who acquire hepatitis C have the same risk factors as HIV-positive men and
whether recently infected men formed part of a larger transmission network.
Although the rate of hepatitis C infection in HIV-negative
men has been much lower than in HIV-positive men, not only in England but in
other European countries, research in men using PrEP in France and the
Netherlands has shown an increasing rate of hepatitis C acquisition in recent
years.
In the PROUD study of PrEP carried out in the United Kingdom
between 2012 and 2014, two people were infected with hepatitis C for every 100
person-years of follow-up, and the incidence of hepatitis C appeared to rise
further during the post-trial follow-up period between 2014 and 2016,
indicating that hepatitis C acquisition among HIV-negative gay and bisexual men
is becoming a significant public health problem. (Desai)
Understanding how hepatitis C is being transmitted is
essential for achieving elimination of transmission among gay and bisexual men.
Recent research has shown that acute hepatitis C infections
have declined substantially among HIV-positive gay and bisexual men in the
United Kingdom, coinciding with increased access to direct-acting antiviral
treatment and very high rates of hepatitis cure among HIV-positive men.
A retrospective cohort study identified acute hepatitis C
infections among men attending HIV clinics between 2013 and 2018 and found that
hepatitis C incidence peaked among gay and bisexual men living with HIV in 2015
at 1.45 cases per 100 person-years of follow-up, falling to 0.46 cases per 100
person-years in 2018, a 68% reduction.(Garvey)
Viewed in this
context, the incidence rate observed in the PROUD study among HIV-negative men can
be recognised as high.
To investigate transmission
networks and risk factors for hepatitis C acquisition, researchers recruited 16
HIV-negative and 24 HIV-positive men with recently acquired hepatitis C (positive
antibody and HCV [hepatitis C virus] RNA test within 12 months and/or acute hepatitis). HIV-negative
men were younger (34 years vs 44 years, p = 0.021), all lived in London, almost
half were born outside the United Kingdom (43%) and 81% reported PrEP use in
the previous year. Thirty per cent were diagnosed with a sexually transmitted infection
at the same time as hepatitis C.
HIV-positive men had
well-controlled HIV infection (91% had an undetectable viral load) but also had
a high frequency of sexually transmitted infections. Twenty per cent had
syphilis and overall, 29% had an STI at hepatitis C diagnosis.
Although none of
the men reported sharing of injecting equipment, injecting drug use was common.
A third of men reported that they had been injected by a partner. Thirty-two
per cent reported injecting drug use within the previous year and in 94% of men
methamphetamine was the last drug injected. Overall, 52% reported methamphetamine
use. HIV-negative men were more likely to report use of GHB/GBL (75% vs 37%),
but with this exception, patterns of drug use did not differ according to HIV
status. Seventy-seven per cent reported nasal drug use and 42% reported rectal
drug use.
HIV-negative men
reported more sexual partners in the preceding year (36 vs 16), but in all
other respects, sexual histories did not differ according to HIV status. Sixty-two
per cent reported fisting, 79% reported group sex, 92% reported condomless anal
sex, 30% reported the sharing of douche equipment, 37% reported a history of
anal bleeding and the sharing of lubricant (67%) and sex toys (50%) was common.
Awareness of having
sex with partners with hepatitis C was low. Only one in four HIV-negative men
were aware of an HCV-positive partner in the previous 12 months and even fewer
HIV-positive men knew that they had sex with an HCV-positive partner (12%).
Two-thirds were infected with genotype 1a and 25% with
genotype 4. Genetic analysis of genotype 1a virus samples showed that 90% were
very closely related, forming four genetic clusters and several pairs indicating
transmission networks. All clusters included both HIV-negative and HIV-positive
men.
The study investigators conclude that awareness of hepatitis
C transmission routes should be promoted among gay and bisexual men, through
PrEP clinics, social networking apps and sex on premises venues. Three-monthly testing
using an antigen test or HCV RNA test is essential, as antibodies may take longer
than three months to emerge. Development of a home test for HCV may also
improve diagnosis.
Clinics providing PrEP and HIV treatment clinics should
ensure that they are talking about drug injecting during sex and harm reduction
with gay and bisexual men, as well as supplying sterile injecting equipment,
the study investigators recommend. Harm reduction and behaviour change are
likely to be essential for achieving microelimination of hepatitis C among gay
and bisexual men, even if very high levels of treatment coverage can be achieved,
they say.