The HITS study: modes of transmission, natural history and determinants of outcome from primary hepatitis C infection

丙型肝炎（HCV）影响了大约20万澳大利亚人，其中相当一部分人会出现长期并发症，包括肝硬化、肝衰竭和肝癌。这种病毒的主要传播方式是通过血液接触，特别是通过注射毒品。监狱似乎是社区丙型肝炎传播的一个关键焦点，因为大多数囚犯因与毒品有关的犯罪而被监禁，注射毒品在监狱中仍然很普遍。此外，由于近二分之一的囚犯在监禁时已经被感染，那些未感染的囚犯似乎面临通过其他（非注射）途径（例如纹身、打架和其他偶然的血液接触）感染的巨大风险。本申请寻求对HITS研究（监狱中丙型肝炎发病率和传播研究）的支持-这是一项对新南威尔士州监狱囚犯的前瞻性队列研究。在一个成功的试点项目中，大量的官僚主义和后勤障碍得到解决，此后，主要的一批学生自2000年底开始入学。初步数据证实，囚犯中的高危行为率很高，在监狱中获得的三种主要HCV感染已被记录为具有不寻常的抗体阴性模式，通常在HCV感染的筛查试验中未被发现。在暴露于HCV和原发感染的发展后，大约五分之一的人成功地解决了感染并清除了病毒，可能是通过有效的免疫反应或无毒病毒，或这些因素的组合。因此，除了HITS研究的公共卫生方面外，该研究还旨在确定允许清除HCV的免疫学和病毒学因素。这些研究将为指导丙型肝炎的治疗和免疫策略提供关键信息。

Hepatitis C (HCV) affects approximately 200,000 Australians, of whom a significant minority develop long term complications, including cirrhosis, liver failure and liver cancer. The dominant mode of transmission of this virus is via blood-to-blood contact, particularly via injecting drug use. Prisons appear to be a key focus of transmission of hepatitis C in the community as the majority of inmates are incarcerated for drug-related crimes, and injecting drug use remains prevalent whilst in prison. In addition, as almost one in two inmates are already infected at the time of incarceration, those who are uninfected appear to be at significant risk of becoming infected through other (non-injecting) routes such as tattooing, fights and other coincidental blood exposures. This application seeks support for the HITS study (Hepatitis C Incidence and Transmission in Prisons study) - a prospective cohort study of inmates of NSW prisons. Following a successful pilot in which the substantial bureaucratic and logistical hurdles were resolved, the main cohort has been enroling since late 2000. The initial data have confirmed a high rate of at risk behaviour amongst inmates and three primary HCV infections acquired in prison have been documented featuring an unusual antibody negative pattern which would typically pass undetected in screening assays for HCV infection. After exposure to HCV and the development of primary infection, approximately one in five individuals successfully resolves the infection and clears the virus, presumably via an efficient immune response or a non-virulent virus, or a combination of these factors. Therefore, in addition to the public health aspects of the HITS study, the research also aims to define the immunological and virological factors which allow clearance of HCV. These studies will provide key information to guide treatment and immunisation strategies against hepatitis C.