Transmission of Hepatitis C Virus Infection among Younger & Older People Who Inject Drugs in Vancouver, Canada
BACKGROUND & AIMS:
Understanding
HCV transmission among people who inject drugs (PWID) is important for
designing prevention strategies. This study investigated whether HCV infection
among younger injectors occurs from few or many transmission events from older
injectors to younger injectors among PWID in Vancouver, Canada.
METHODS:
HCV
antibody-positive participants at enrolment or follow-up (1996-2012) were
tested for HCV RNA and sequenced (Core-E2). Time-stamped phylogenetic trees
were inferred using Bayesian Evolutionary Analysis Sampling Trees (BEAST).
Association of age with phylogeny was tested using statistics implemented in
the software Bayesian Tip Significance (BaTS) testing. Factors associated with
clustering (maximum cluster age: five years) were identified using logistic
regression.
RESULTS:
Among 699
participants with HCV subtype 1a, 1b, 2b and 3a infection (26% female, 24%
HIV+): 21% were younger (<27 years), and 10% had recent HCV seroconversion.
When inferred cluster age was limited to <5 years, 15% (n=108) were in
clusters/pairs. Although a moderate degree of segregation was observed between
younger and older participants, there was also transmission between age groups.
Younger age (<27 vs. >40, AOR: 3.14, 95% CI:1.54, 6.39),HIV (AOR: 1.97,
95%-CI: 1.22, 3.18) and subtype 3a (AOR: 2.12, 95% CI: 1.33, 3.38) were
independently associated with clustering.
CONCLUSIONS:
In
this population of PWID from Vancouver, HCV among young injectors was seeded
from many transmission events between HCV-infected older and younger injectors.
Phylogenetic clustering was associated with younger age and HIV. These data
suggest that HCV transmission among PWID is complex, with transmission
occurring between and among older and younger PWID.
By: Jacka B1, Applegate T2, Poon AF3, Raghwani J4, Harrigan PR3, DeBeck K5, Milloy MJ6, Krajden M7, Olmstead A7, Joy JB8, Marshall BD9, Hayashi K8, Pybus OG4, Lima VD3, Magiorkinis G10, Montaner J3, Lamoury F2, Dore GJ2, Wood E3, Grebely J2.
- 1Viral Hepatitis Clinical Research Program, The Kirby Institute, UNSW Australia, Sydney NSW, Australia. Electronic address: bjacka@kirby.unsw.edu.au.
- 2Viral Hepatitis Clinical Research Program, The Kirby Institute, UNSW Australia, Sydney NSW, Australia.
- 3BC Centre for Excellence in HIV/AIDS, St Paul's Hospital, Vancouver BC; Division of AIDS, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
- 4Department of Zoology, University of Oxford, Oxford, UK.
- 5BC Centre for Excellence in HIV/AIDS, St Paul's Hospital, Vancouver BC; School of Public Policy, Simon Fraser University, Vancouver, BC, Canada.
- 6BC Centre for Excellence in HIV/AIDS, St Paul's Hospital, Vancouver BC; Department of Family Practice, Faculty of Medicine, University of British Columbia, Vancouver, BC.
- 7BC Centre for Disease Control, Vancouver BC.
- 8BC Centre for Excellence in HIV/AIDS, St Paul's Hospital, Vancouver BC.
- 9Department of Epidemiology, Brown University, Providence, RI, USA.
- 10Department of Zoology, University of Oxford, Oxford, UK; Virus Reference Department, Public Health England, London, United Kingdom.
- J Hepatol. 2016 Feb 25. pii: S0168-8278(16)00165-3. doi: 10.1016/j.jhep.2016.02.031.
No comments:
Post a Comment