Hepatitis C reinfection following treatment induced viral clearance among people who have injected drugs.
Although people who inject drugs (PWID) are an important group to receive Hepatitis C Virus (HCV) antiviral therapy, initiation onto treatment remains low. Concerns over reinfection may make clinicians reluctant to treat this group. We examined the risk of HCV reinfection among a cohort of PWID (encompassing all those reporting a history of injecting drug use) from Scotland who achieved a sustained virological response (SVR).



Clinical and laboratory data were used to monitor RNA testing among PWID who attained SVR following therapy between 2000 and 2009. Data were linked to morbidity and mortality records. Follow-up began one year after completion of therapy, ending on 31st December, 2012. Frequency of RNA testing during follow-up was calculated and the incidence of HCV reinfection estimated. Cox proportional hazards regression was used to examine factors associated with HCV reinfection.



Among 448 PWID with a SVR, 277 (61.8%) were tested during follow-up, median 4.5 years; 191 (69%) received one RNA test and 86 (31%) received at least two RNA tests. There were seven reinfections over 410 person years generating a reinfection rate of 1.7/100py (95% CI 0.7-3.5). For PWID who have been hospitalised for an opiate or injection related cause post SVR (11%), the risk of HCV reinfection was greater [AHR=12.9, 95% CI 2.2-76.0, p=0.002] and the reinfection rate was 5.7/100py (95% CI 1.8-13.3).



PWID who have been tested, following SVR, for HCV in Scotland appear to be at a low risk of reinfection. Follow-up and monitoring of this population are warranted as treatment is offered more widely.
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: amanda.weir@nhs.net.
Amanda
A
Weir
Health Protection Scotland, Glasgow, UK. Electronic address: allan.mcleod@nhs.net.
Allan
A
McLeod
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: hamish.innes@nhs.net.
Hamish
H
Innes
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: heather.valerio@nhs.net.
Heather
H
Valerio
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: esther.aspinall@nhs.net.
Esther J
EJ
Aspinall
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: david.goldberg2@nhs.net.
David J
DJ
Goldberg
Glasgow Royal Infirmary, Glasgow, UK. Electronic address: stephenbarclay@nhs.net.
Stephen T
ST
Barclay
Ninewells Hospital and Medical School, Dundee, UK. Electronic address: j.dillon@nhs.net.
John F
JF
Dillon
Gartnavel General Hospital, Glasgow, UK. Electronic address: Ray.Fox2@ggc.scot.nhs.uk.
Ray
R
Fox
Aberdeen Royal Infirmary, Aberdeen, UK. Electronic address: a.fraser2@nhs.net.
Andrew
A
Fraser
Royal Infirmary Edinburgh, Edinburgh, UK. Electronic address: peter.hayes@nhslothian.scot.nhs.uk.
Peter C
PC
Hayes
Monklands Hospital, Lanarkshire, UK. Electronic address: nicholas.kennedy@lanarkshire.scot.nhs.net.
Nicholas
N
Kennedy
Gartnavel General Hospital, Glasgow, UK. Electronic address: peter.mills@glasgow.ac.uk.
Peter R
PR
Mills
Glasgow Royal Infirmary, Glasgow, UK. Electronic address: Adrian.Stanley@ggc.scot.nhs.uk.
Adrian J
AJ
Stanley
West of Scotland Specialist Virology Centre, Glasgow, UK. Electronic address: Celia.Aitken@ggc.scot.nhs.uk.
Celia
C
Aitken
West of Scotland Specialist Virology Centre, Glasgow, UK. Electronic address: rory.gunson@nhs.net.
Rory
R
Gunson
East of Scotland Specialist Virology Centre, Edinburgh, UK. Electronic address: kate.templeton@nhs.net.
Kate
K
Templeton
Aberdeen Royal Infirmary, Aberdeen, UK. Electronic address: alison.hunt@nhs.net.
Alison
A
Hunt
Ninewells Hospital and Medical School, Dundee, UK. Electronic address: paul.mcintyre@nhs.net.
Paul
P
McIntyre
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Health Protection Scotland, Glasgow, UK. Electronic address: sharon.hutchinson2@nhs.net.
Sharon J
SJ
Hutchinson
D000328:Adult; D005260:Female; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000097:blood / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D012367:RNA, Viral / Q000097:blood; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000097:blood / Q000453:epidemiology*; D000072230:Sustained Virologic Response; D055815:Young Adult
D012367:RNA, Viral
Hepatitis C virus; People who inject drugs; Record linkage; Reinfection; Sustained viral response