Theme: Epidemiology & Public Health Research Year: 2019
Background: Concern about reinfection after hepatitis C virus (HCV) treatment among People Who
Inject Drugs (PWID) is often reported as a barrier to initiating treatment, by both PWID and
physicians. The number of PWID receiving HCV treatment has increased since the introduction of
Direct Acting Antiviral (DAA) therapy, with concomitant increases in studies reporting reinfection
rates. To understand variation in measurement, reporting, and description of HCV reinfection rates,
we performed a critical review of conference abstracts.
Methods: All abstracts from four 2018 international conferences (AASLD, CROI, EASL & INHSU) that
reported on HCV reinfection after DAA treatment were reviewed, with 23 abstracts reporting
reinfections among PWID identified for analysis. Study design, definition of PWID, length of followup, frequency of post-treatment HCV RNA testing, rate/proportion of reinfection observed, and
characterization of reinfection rate were extracted.
Results: Of 23 abstracts reviewed, 20 were eligible for extraction. A quarter (5/20) only reported
reinfection proportions, ranging from 0% to 25.93%, without reporting person years (PY) of follow
up. Among abstracts reporting PY of follow up (15/20), reinfection rates ranged from 0.3 to 18.3/100
PY. Reinfection rates between 0-4/100 PY (n=12) were described as: ‘elevated’, ‘high’, ‘uncommon’,
‘similar to general population’, and ‘low’. Reinfection rates between 4-10/100 PY (n=2) were
described as; ‘relatively low’, and ‘possible’. Reinfection rates >10/100 PY (n=6) were described as;
‘high’, and ‘more common’.
Conclusion: Varying methods used to estimate reinfection rates, and inconsistent reporting may
obscure actual risk of HCV reinfection among PWID after receiving DAAs. Reinfection rates below
4/100 PY were subjectively described as ‘high’ or ‘elevated’, which may deter treatment providers
from treating PWID, or discourage PWID from engaging in HCV care. Inconsistent measurement and
careless description of HCV reinfection may contribute to stigma and discrimination experienced by
PWID living with HCV, hindering global HCV elimination.
Disclosure of Interest Statement: All inferences, opinions, and conclusions drawn are those of the
authors, and do not necessarily reflect the opinions or policies of the authors’ affiliated
organisations. SRB is supported by a CIHR and Michael Smith Foundation for Health Research Health
System Impact Postdoctoral Fellowship Award. MP is supported by a CIHR Health System Impact
Postdoctoral Fellowship Award.