Identification and genotyping of hepatitis C virus in injectable and oral drug users in New Zealand.

BACKGROUND: Hepatitis C virus infections are known to be common in injectable drug users (IDU) both in New Zealand and overseas. Little is known of the hepatitis C genotype frequency in this population. AIMS: To confirm the high incidence of hepatitis C virus infections in IDU and compare this with the frequency in oral drug users (ODU) as well as identify the pattern of hepatitis C genotypes present. METHODS: Use was made of an experimental nucleocapsid assay as well as a conventional anti-HCV assay. HCV-RNA was identified using a polymerase chain reaction (PCR) technique and a variation of this method was used for HCV genotyping. RESULTS: Seventy-four per cent of IDU were reactive for anti-HCV in both types of assay. PCR testing detected several more reactive samples. Dominant genotypes were Types I and V, but Type IV was not detected. Mixed infections were noted in some patients. There was a low frequency of anti-HCV in ODU. CONCLUSIONS: Hepatitis C virus infections are a problem in IDU in New Zealand, and additional public health measures may be required. The distribution of genotypes of HCV-RNA are similar to those seen in other Western countries.

Hepatitis C virus infections in oral and injectable drug users.

AIM: To assess the frequency of hepatitis C virus antibodies (anti HCV) and exposure to hepatitis B virus in injectable and oral drug users in Auckland. METHODS: Sera from 110 injectable drug users and 154 oral drug users were tested for anti HCV as well as hepatitis B and D virus markers. Liver function tests were also performed. RESULTS: 73% of injectable drug using persons and 4% of oral drug using persons were positive for anti HCV. Over half of persons with a positive anti HCV result had an abnormal elevation of the liver enzyme alanine aminotransferase (ALT). Total HBV exposure was similar in both injectable drug user and oral drug user groups at approximately 30%, with little difference between ethnic groups. There were no positive results for hepatitis D virus infection. CONCLUSIONS: Injectable drug users who are anti HCV positive may represent a potential source of HCV infection in the community. An upgraded educational programme, perhaps in conjunction with the needle/syringe exchange programme, may be required to ensure drug users are aware of the risks of HCV infection to both themselves and the community.