Theme: Epidemiology & Public Health Research Year: 2016
THE ROLE OF INCARCERATION IN HCV TRANSMISSION AMONGST PEOPLE WHO
INJECT DRUGS: A MODELLING ANALYSIS
Stone J1
, Martin NK2,1
, Altice FL3
, Azbel L
4
, Smyrnov P
5
, Hickman M1
, Hutchinson SJ,6,7
,
Aspinall E
6,7, Taylor A
8
, Munro A
8
, Dunleavy K
8
, Peters E
9
, Bramley P
10, Hayes PC11
,
Goldberg DJ6,7, Vickerman P1
1School of Social and Community Medicine, University of Bristol, UK,
2Division of Global
Public Health, University of California San Diego, US,
3Yale University School of Medicine,
Section of Infectious Diseases, New Haven, US,
4London School of Hygiene & Tropical
Medicine, London, UK,
5
International HIV/AIDS Alliance, Kyiv, Ukraine, 6School of Health
and Life Sciences, Glasgow Caledonian University, UK,
7Health Protection Scotland,
Glasgow, UK,
8School of Media, Culture and Society, University of the West of Scotland, UK
9Gartnavel General Hospital, Glasgow, UK,
10NHS Forth Valley Viral Hepatitis Service, UK
11Division of Health Sciences, Royal Infirmary Edinburgh, UK
Background: People who inject drugs (PWID) experience high incarceration rates, and
previous/recent incarceration is frequently associated with elevated HCV transmission risk.
We model the contribution of incarceration to HCV transmission amongst PWID in several
scenarios, mimicking four global settings.
Methods: We developed a dynamic model of incarceration and HCV transmission amongst
PWID. We first calibrated a Scotland-like scenario, with 3-fold elevated HCV acquisition risk
amongst recently released PWID (<6 months), lower HCV incidence in prison than the
community (attributed to high coverage of prison opiate substitution therapy, OST),
moderate levels of incarceration (61% PWID ever incarcerated), and short sentence lengths
(7 months).
Other scenarios were generated to be similar to Australia, Ukraine and Thailand through
altering the Scotland-like scenario, with different (re)incarceration rates, sentence lengths or
injecting durations, and higher HCV incidence in prison (double community incidence)
attributed to lower prison OST coverage.
Results: In Scotland, despite low HCV incidence while incarcerated the model suggests
incarceration elevates the overall endemic incidence among PWID by 25% due to elevated
transmission risk following release. Conversely, in settings with similar incarceration
dynamics but higher HCV incidence in prison (Australia), incarceration could be doubling
HCV incidence, whereas in settings that also have more incarceration (80% ever
incarcerated) and longer sentences (12 months; Thailand), incarceration could be increasing
HCV incidence 4-fold. In a setting with less incarceration and longer injecting durations (52%
ever incarcerated and 3.5x longer injecting; Ukraine) incarceration could be increasing HCV
incidence by only 16%. Removing the elevated risk post-release and reducing transmission
risk in prisons to that achieved in Scotland (through OST) could reduce incidence from 26%
in a Ukraine-like setting up to 98% in a Thailand-like setting.
Conclusion: Incarceration may contribute substantially to HCV transmission among PWID.
Reducing transmission risk in prison and following release may reduce this issue.
Disclosure of Interest Statement: Nothing to disclose