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标题：Reduction in HCV Incidence Among Injection Drug Users Attending Needle and Syringe Programs in Australia: A Linkage Study
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作者：Jenny Iversen ; Handan Wand ; Libby Topp 等
期刊名称：American journal of public health
印刷版ISSN：0090-0036
出版年度：2013
卷号：103
期号：8
页码：1436-1444
DOI：10.2105/AJPH.2012.301206
语种：English
出版社：American Public Health Association
摘要：Objectives. We examined trends in HCV incident infection among injection drug users (IDUs) attending needle and syringe programs (NSPs) in Australia in 1995 to 2010. Methods. We created a passive retrospective cohort of 724 IDUs who tested negative for HCV antibodies by a simple deterministic method linking partial identifiers to find repeat respondents in annual cross-sectional serosurveillance. Results. We identified 180 HCV seroconversions over the study period, for a pooled incidence density of 17.0 per 100 person-years (95% confidence interval [CI] = 14.68, 19.66). Incidence density declined, from a high of 30.8 per 100 person-years (95% CI = 21.3, 44.6) in 2003 to a low of 4.0 (95% CI = 1.3, 12.3) in 2009. Conclusions. A decline in HCV incidence among Australian IDUs attending NSPs coincided with considerable expansion of harm reduction programs and a likely reduction in the number of IDUs, associated with significant changes in drug markets. Our results demonstrate the capacity of repeat cross-sectional serosurveillance to monitor trends in HCV incidence and provide a platform from which to assess the impact of prevention and treatment interventions. HCV infection is a major global cause of liver cirrhosis and cancer. 1,2 Transmission is believed to occur primarily through blood contact, with unsterile medical injections an important pathway, particularly in some developing countries. 2 In many industrialized nations, HCV is endemic among injection drugs users (IDUs), with prevalence exceeding 50%. 3,4 Mortality among HCV-infected persons is now higher than among HIV-infected persons in the United States. 5 Despite recent advances in the development of direct-acting antivirals for HCV, 6,7 treatment uptake among IDUs is low, 8 and monitoring of HCV incidence is critical to the planning, implementation, and evaluation of prevention programs targeting this group. HCV infection is acquired largely asymptomatically, and detection of incident cases requires repeat serological testing in at-risk populations. Globally, most estimates of HCV incidence among IDUs fall within the range of 20 to 40 seroconversions per 100 person-years. 9 In Australia, HCV incidence estimates derived from prospective cohort studies of IDUs in community settings have ranged from 10.7 to 15.5 per 100 person-years in Melbourne 10,11 and up to 45.8 per 100 person-years in Sydney. 12 However, because the logistics of identifying, recruiting, and retaining in follow-up large samples of HCV-negative IDUs necessitate significant resources, such studies are usually time limited, making it difficult to monitor trends in HCV incidence over extended periods. Several studies have estimated incidence of HIV infection by analyzing the serological results of people who have undergone repeat testing. 13–15 Major strengths of this method are lower cost (because data collected for other purposes are used) and the potential to create large retrospective cohorts across multiple years and wide geographic areas. Significant changes in Australia’s drug markets 16–18 and advances in therapeutic interventions for HCV over the past 2 decades have increased the importance of methods that enable the use of existing data to examine trends in incidence over time. In the late 1980s, bipartisan political support led to the establishment of publicly funded needle and syringe programs (NSPs) and the subsequent development of a widespread network of approximately 1000 public-sector NSPs in both metropolitan and regional areas. Since 1995, a national cross-sectional serosurvey of HCV prevalence and risk behavior has been conducted annually among people attending NSPs. We linked serological results of repeat respondents to investigate HCV incidence trends and correlates in 1995 to 2010.