Non-injection drug use and Hepatitis C Virus: a systematic review

Abstract

This systematic review examined the evidence on the prevalence of the Hepatitis C Virus (HCV) in non-injecting drug users (NIDUs) who sniff, smoke or snort drugs such as heroin, cocaine, crack or methamphetamine. The search included studies published from January 1989 to January 2006. Twenty-eight eligible studies were identified and the prevalence of HCV in these NIDU populations ranged from 2.3 to 35.3%. There was substantial variation in study focus and in the quality of the NIDU data presented in the studies. The results of our systematic review suggested that there are important gaps in the research of HCV in NIDUs. We identified a problem of study focus; much of the research did not aim to study HCV in users of non-injection drugs. Instead, NIDUs were typically included as a secondary research concern, with a principal focus on the problem of transmission of HCV in IDU populations. Despite methodological issues, HCV prevalence in this population is much higher than in a non-drug using population, even though some IDUs might have inadvertently been included in the NIDU samples. These studies point to a real problem of HCV in NIDU populations, but the causal pathway to infection remains unclear.

Figure 1

Decision tree used to retrieve and select reports for synthesis of HCV infection in non-injection drug users.

Figure 2

Plots of prevalence by quality scores; medians and ranges by quality. The range is indicated by the horizontal bottom line or dot and the horizontal line or dot. The dot indicates that this lower or upper value is an outlier, while the line indicates that this lower or upper value is within the expected range. The median value for each quality score is indicated by the thick black line in the rectangle. Each rectangle encompasses the 25th - 75th percentile for the corresponding quality score.