Injecting behaviours and prevalence of hepatitis B, C and D markers in New Zealand injecting drug user populations.
OBJECTIVE
To determine the seroprevalence of hepatitis C virus (HCV), hepatitis B virus (HBV) & hepatitis D virus (HDV) markers of infection among injecting drug user populations in New Zealand and to examine the relationship between demographic features, risk behaviours and infection.


METHODS
A total of 323 current injecting drug users completed a questionnaire that explored their needle and syringe using behaviours. Information was collected on injection pattern, sharing behaviours and methods of cleaning needles and syringes. Two hundred and forty-one respondents gave blood samples which were tested for hepatitis B, C and D markers.


RESULTS
Over half the respondents (59%) were male and 41% were female. Most (89%) identified as European. Sixty-four percent were anti-HCV positive. The likelihood of infection increased with age and duration of injecting. Forty-one percent (33/81) of those aged 25 or under, sixty-four percent (45/70) of those aged 26-30 and eighty-seven percent (78/90) over 30 were anti-HCV positive. Those who tested anti-HCV positive had been injecting for an average of 12.0 years compared to 6.0 years for those were anti-HCV negative. The results for hepatitis B are to be reported fully at a later date. Sharing behaviour was also a factor although this was less important as an independent factor. Comparisons with earlier surveys suggested that there has not been a significant decline in the rate of sharing needles and syringes since the initial period following introduction of the needle exchange programme.


CONCLUSIONS
The prevalence of hepatitis C infection is common among injecting drug users of all ages. Without a significant reduction in sharing behaviour, particularly among younger injecting drug users, it is unlikely that the prevalence of hepatitis C among injecting drug users will decline in the future. Evidence suggests that the carriage of hepatitis C is higher than that of hepatitis B which would help explain the differing rates of prevalence. However, the risk of future transmission of other parenterally transmitted diseases remains high without a further significant decline in sharing behaviour.
Kemp
R
R
Drugs and Health Development Project, Wellington.
Miller
J
J
Lungley
S
S
Baker
M
M
D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D004203:Disinfection / Q000706:statistics & numerical data; D005260:Female; D019694:Hepatitis B, Chronic / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D019698:Hepatitis C, Chronic / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D019701:Hepatitis D, Chronic / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016485:Needle Sharing / Q000706:statistics & numerical data; D009520:New Zealand / Q000453:epidemiology; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*