9261 HEPATITIS C REPORT GALLEY - North West Public Health ...

ehaviour at some stage in their drug using career (although the rates of injecting
among those attending SES and pharmacy SES are likely to be higher), giving a
conservative estimate of 30,200 IDUs. However, statistical estimations of the hidden
population of drug users in Merseyside (based on the overlap between the number of
people contacting drugs agencies and those arrested by the police for drug crime)
suggest that only about half of problematic heroin users are in contact with services
(Hardi & Bellis 1999). Although this would suggest that there may be twice as many
problematic drug users in the North West than we have estimated, the proportion of
the hidden population of drug users who are injectors cannot be determined.
In the North West of England, 67% of IDUs requesting a hepatitis test tested positive
for hepatitis C (Lamden et al. 1998). Since the sample was drawn from those requesting
a test, only a subset of the total population of IDUs was included. Little is known about
potential differences in patterns of injecting and sharing between groups attending
different agencies or none at all. A Scottish survey found little difference between
prevalence of hepatitis C among IDUs recruited from SES, treatment centres and on the
street (Taylor et al 2000). However, a survey of HIV prevalence among female IDUs in
London found a higher prevalence in those recruited from the community than in those
attending treatment agencies (Judd et al. 1999). Therefore, the assessment of the levels
of hepatitis C in the wider drug using communities requires sampling individuals
attending different services as well as those not in contact with services at all (Aim 1 of
this study).
Of the new agency episodes reported to the DMD, 73% were clients who reported
having injected at some stage previously, and of those, 48% reported ever having
shared injecting equipment (Birtles et al. 1999). A high proportion of those using drugs
have periods of imprisonment, where continued drug use and levels of sharing are
high (Eaton et al. 1998; section 1.3). However, estimations of sharing behaviour often
rely on a single question on sharing behaviour that may not measure the extent of
sharing (Hunter & Stimson 1998). In depth questions on sharing behaviour of IDUs in
the North West revealed that around 80% of IDUs had shared injecting equipment in
the previous four weeks (Speed & Bennet 1997). Moreover, there was a lack of
knowledge among IDUs as to the risks of sharing injecting paraphernalia compared to
the more well known risks of sharing needles and syringes (Speed & Bennett 1997).
The number of people in contact with services who share injecting equipment in the
North West can be estimated, assuming 80% of the estimated 30,200 IDUs share.
This leads to the prediction that there are around 24,100 current drug users who have
shared injecting equipment. Conservatively, this ignores those that have used drugs in
the past but now abstain from drugs and do not use drugs services.
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H EPATITIS C IN INJECTING DRUG USERS IN THE N ORTH W EST