Hepatitis C prevalence and needle/syringe sharing behaviours in recent onset injecting drug users

To investigate the prevalence of hepatitis C antibody (anti-HCV) in injecting drug users (IDU), particularly amongst those of recent onset beginning since the advent of the needle-exchange programme. Secondly this study sought information on needle-sharing practices.

The records of injecting drug users over 2 years from January 1992 were examined for anti-HCV results and needle-sharing reports on initial assessment at the Wellington drug dependency clinic.

Amongst 110 injecting drug users 92 (84%) were tested for anti-HCV, and 71 (77%) were positive. There was a significant (p = 0.02) association between the reported duration of intravenous drug misuse and the proportion of injecting drug users who were positive for anti-HCV. Of those injecting drug users who had reported use of less than 4 years, since the introduction of the New Zealand needle exchange programme, 53% were positive for anti-HCV. Needle-sharing was frequently reported to have ever occurred in 74% of these patients at some time, and in 64% of those who reported use of less than 4 years. These differences were not significant. However, in the period before presenting 67% had not shared over the last 3 months and 57% had not shared over the previous 1 year, which are improvements on previous studies of needle-sharing, considered to be the most important mode of transmission for blood-borne viruses in injecting drug users.

These results suggest considerable potential for HIV infection rates among injecting drug users in New Zealand to increase from the current low level. There needs to be continuing emphasis on public health programmes to eradicate needle-sharing, and to promote safe injecting techniques for injecting drug users.