Systematic review research on needle/syringe programs and opiate substitution programs in low- and middle-income countries

People who inject drugs (PWID) are at an elevated risk of infection by human immunodeficiency virus (HIV) or hepatitis C virus (HCV). In many high-income countries, needle and syringe exchange programs (NSPs) have been associated with reductions in bloodborne infections. However, there is not a good understanding of the effectiveness of NSP in low- and middle-income countries and transitional-economy countries. A systematic literature review, based on the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) guidelines, was utilized to collect primary study data on the coverage of NSP programs and the changes in HIV and HCV infection over time among PWID in lowand middle-income and transitional countries (LMICs). We included studies that reported laboratory measures of HIV or HCV and at least 50% coverage of the local injecting population (either through direct use or through secondary exchange). We also included national reports of newly reported HIV cases in countries that had national level data for PWID in conjunction with NSP scale-up and NSP implementation. Included in the review were studies of 11 NSPs with high-coverage from Bangladesh, Brazil, China, Estonia, Iran, Lithuania, Taiwan, Thailand, and Vietnam. In five studies, the HIV prevalence decreased (ranged from 3% to 15%) and in three studies the HCV prevalence decreased (ranged from 4.2% to 10.2%). In two studies, the HIV prevalence increased (ranged from 5.6% to 14.8%). The HCV incidence remained stable in one study. Of the four national reports of newly reported HIV cases, three studies reported decreases during the expansion of the NSP, and ranged from 30% to 93.3%; however, one national report documented an increase in HIV cases (37.6%). The estimated incidence among new injectors decreased in three studies with the reductions ranging from 11/100 person-years at risk to 16/100 person-years at risk. The data, although not fully consistent, generally support the effectiveness of NSP in reducing HIV and HCV infection in LMICs. If high coverage is achieved, NSP appears to be as effective in LMICs as in high-income countries. To identify and correct contributing problems, additional monitoring and evaluation research is needed for NSPs in which reductions in HIV/HCV infection among PWID are not occurring.