Kwon Jisoo A, Iversen Jenny, Maher Lisa, Law Matthew G, Wilson David P
National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales, Sydney, New South Wales, Australia.
J Acquir Immune Defic Syndr. 2009 Aug 1;51(4):462-9. doi: 10.1097/QAI.0b013e3181a2539a.
We aim to estimate how changes in sterile syringe distribution through needle-syringe programs (NSPs) may affect HIV and hepatitis C virus (HCV) incidence among injecting drug users (IDUs) in Australia.
We develop a novel mathematical model of HIV and HCV transmission among IDUs who share syringes. It is calibrated using biological and Australian epidemiological and behavioral data. Assuming NSP syringe distribution affects the number of times each syringe is used before disposal, we use the model to estimate the relationship between incidence and syringe distribution.
HIV is effectively controlled through NSP distribution of sterile syringes {with the effective reproduction ratio below 1 [0.66 median, interquartile range (0.63-0.70)] under current syringe distribution}. In contrast, HCV incidence is expected to remain high and its control is not feasible in the foreseeable future. The proportion of injections that are shared and the number of times each syringe is used before disposal are the driving factors of HCV incidence. The frequency in which each syringe is used can potentially be influenced by changes in syringe distribution. We estimate that if syringe distribution or coverage doubled, then annual incidence is likely to reduce by 50%. However, if it was decreased to one third of the current level, then approximately 3 times the incidence could be expected.
This research highlights the large benefits of NSPs, puts forward a quantitative relationship between incidence and syringe distribution, and indicates that increased coverage could result in significant reductions in viral transmissions among IDUs.
我们旨在评估通过针头-注射器项目（NSPs）进行的无菌注射器分发变化如何影响澳大利亚注射吸毒者（IDUs）中的艾滋病毒和丙型肝炎病毒（HCV）发病率。
我们建立了一个关于共用注射器的注射吸毒者中艾滋病毒和丙型肝炎病毒传播的新型数学模型。该模型使用生物学以及澳大利亚的流行病学和行为学数据进行校准。假设NSP注射器分发会影响每个注射器在丢弃前的使用次数，我们使用该模型来估计发病率与注射器分发之间的关系。
通过NSP分发无菌注射器可有效控制艾滋病毒{在当前注射器分发情况下，有效繁殖率低于1[中位数为0.66，四分位间距（0.63 - 0.70）]}。相比之下，预计丙型肝炎病毒发病率仍将居高不下，并且在可预见的未来其控制是不可行的。共用注射的比例以及每个注射器在丢弃前的使用次数是丙型肝炎病毒发病率的驱动因素。每个注射器的使用频率可能会受到注射器分发变化的影响。我们估计，如果注射器分发或覆盖率翻倍，那么年发病率可能会降低50%。然而，如果降至当前水平的三分之一，那么发病率可能会增加约3倍。
本研究突出了NSPs的巨大益处，提出了发病率与注射器分发之间的定量关系，并表明增加覆盖率可显著减少注射吸毒者中的病毒传播。
