Hepatitis C virus (HCV) infections in Switzerland are mainly related
to intravenous drug use. Since 2017, all patients with chronic
hepatitis C can be treated with direct-acting antivirals (DAAs)
irrespective of fibrosis stage. In March 2019, the Federal Office of
Public Health (FOPH) published guidelines for HCV management in
people who use drugs. To achieve HCV elimination by 2030, 80%
treatment uptake is necessary.
To evaluate the benefit of interferon-based and interferon-free HCV
treatment in patients on opioid agonist therapy (OAT) and monitor
HCV elimination, a 2-year study commissioned by the FOPH and
conducted within the Swiss Association for the Medical Management in
Substance Users (SAMMSU) cohort was performed.
Since 2014, the SAMMSU cohort has recruited OAT patients from eight
different centres throughout Switzerland. In addition to yearly
follow up, cross-sectional data were collected at the time-points 1
May 2017, 1 May 2018 and 1 May 2019. HCV treatment uptake, adherence
and success, as well as reinfection rates, the effect of early
versus late treatment and the efficacy of the
“treatment-as-prevention” approach were
Between 1 May 2017 and 1 May 2019, the number of patients enrolled
into the SAMMSU cohort increased from 623 to 900: 78% were male, the
median age was 45 years, 81% had ever used intravenous drugs, 13%
were human immunodeficiency virus (HIV) positive and 66% were HCV
antibody positive. HCV treatment up to 2012 was exclusively
interferon based (maximum 21 patients/year) and since 2016
exclusively interferon free (102 patients in 2017). Treatment
success increased from 57% (112/198; interferon based) to 97%
(261/268; interferon free) irrespective of cirrhosis or prior
non-response to interferon. Simultaneously, treatments became
shorter and better tolerated in the interferon-free era, resulting
in fewer preterm stops (17% vs 1%) and adherence problems (9% vs
2%). Between 2015 and 2018, the proportion of patients with no/mild
fibrosis (F0/F1) at first HCV treatment increased from 0% to 61%.
Earlier treatment reduced the duration of infectiousness. Between 1
May 2017 and 1 May 2019, the proportion of chronic hepatitis C
patients ever treated increased from 62% (198/321) to 80% (391/490).
In parallel, the HCV-RNA prevalence among HCV antibody-positive
patients declined from 36% (139/385) to 19% (113/593). The
reinfection rate after successful treatment was 2.7/100
person-years. The number of HCV first diagnoses per year decreased
from >20 up to 2015 to <10 in 2017 and 2018.
With nearly 100% DAA treatment success and a low reinfection rate,
treatment uptake directly translates into a reduction of HCV-RNA
prevalence. Eighty percent treatment uptake is feasible in OAT
patients, and adherence and treatment success are not worse than in
other populations. Duration of infectiousness and thus HCV
transmission can be reduced by early detection and treatment of
chronic hepatitis C.
Bregenzer A, Bruggmann P, Castro E, Moriggia A, Rothen M, Thurnheer
M C, Vernazza P, Scheidegger C. Hepatitis C virus elimination in
Swiss opioid agonist therapy programmes - the SAMMSU cohort. Swiss
Med Wkly 2021; 151:w20460.