Patrick D M, Tyndall M W, Cornelisse P G, Li K, Sherlock C H, Rekart M L, Strathdee S A, Currie S L, Schechter M T, O'Shaughnessy M V
University of British Columbia Centre for Disease Control, University of British Columbia, Vancouver, BC.
CMAJ. 2001 Oct 2;165(7):889-95.
Beginning in 1994, Vancouver experienced an explosive outbreak of HIV infection among injection drug users (IDUs). The objectives of this study were to measure the prevalence and incidence of hepatitis C virus (HCV) infection in this context and to examine factors associated with HCV seroconversion among IDUs.
IDUs recruited through a study site and street outreach completed interviewer-administered questionnaires covering subjects' characteristics, behaviour, health status and service utilization and underwent serologic testing for HIV and HCV at baseline and semiannually thereafter. A Cox proportional hazards model was used to identify independent correlates of HCV seroconversion.
As of Nov. 30, 1999, 1345 subjects had been recruited into the study cohort. The prevalence of anti-HCV antibodies was 81.6% (95% confidence interval [CI] 79.6% to 83.6%) at enrollment. Sixty-two HCV seroconversions occurred among 155 IDUs who were initially HCV negative and who returned for follow-up, for an overall incidence density rate of 29.1 per 100 person-years (95% CI 22.3 to 37.3). The HCV incidence remained above 16 per 100 person-years over 3 years of observation (December 1996 to November 1999), whereas HIV incidence declined from more than 19 to less than 5 per 100 person-years. Independent correlates of HCV seroconversion included female sex, cocaine use, injecting at least daily and frequent attendance at a needle exchange program.
Because of high transmissibility of HCV among those injecting frequently and using cocaine, the harm reduction initiatives deployed in Vancouver during the study period proved insufficient to eliminate hepatitis C transmission in this population.
自1994年起，温哥华注射吸毒者（IDU）中爆发了HIV感染疫情。本研究的目的是在此背景下测量丙型肝炎病毒（HCV）感染的患病率和发病率，并研究IDU中与HCV血清转化相关的因素。
通过一个研究点和街头外展招募的IDU完成了由访谈员填写的问卷，内容涵盖受试者的特征、行为、健康状况和服务利用情况，并在基线时以及此后每半年接受HIV和HCV血清学检测。使用Cox比例风险模型来确定HCV血清转化的独立相关因素。
截至1999年11月30日，1345名受试者被纳入研究队列。入组时抗HCV抗体的患病率为81.6%（95%置信区间[CI]79.6%至83.6%）。在155名最初HCV阴性且返回接受随访的IDU中发生了62例HCV血清转化，总体发病密度率为每100人年29.1例（95%CI 22.3至37.3）。在3年的观察期（1996年12月至1999年11月）内，HCV发病率保持在每100人年16例以上，而HIV发病率从每100人年超过19例降至不到5例。HCV血清转化的独立相关因素包括女性性别、使用可卡因、至少每天注射以及频繁参加针头交换项目。
由于HCV在频繁注射和使用可卡因者中具有高传播性，研究期间在温哥华实施的减少伤害措施被证明不足以消除该人群中的丙型肝炎传播。
