Mathematical Institute, Centre for Mathematical Biology, University of Oxford, 24-29 St Giles', Oxford, OX1 3LB, England.
Math Biosci Eng. 2009 Oct;6(4):779-813. doi: 10.3934/mbe.2009.6.779.
After two phases of AIDS control activities in India, the third phase of the National AIDS Control Programme (NACP III) was launched in July 2007. Our focus here is to predict the number of people living with HIV/AIDS (PLHA) in India so that the results can assist the NACP III planning team to determine appropriate targets to be activated during the project period (2007-2012). We have constructed a dynamical model that captures the mixing patterns between susceptibles and infectives in both low-risk and high-risk groups in the population. Our aim is to project the HIV estimates by taking into account general interventions for susceptibles and additional interventions, such as targeted interventions among high risk groups, provision of anti-retroviral therapy, and behavior change among HIV-positive individuals. Continuing the current level of interventions in NACP II, the model estimates there will be 5.06 million PLHA by the end of 2011. If 50 percent of the targets in NACP III are achieved by the end of the above period then about 0.8 million new infections will be averted in that year. The current status of the epidemic appears to be less severe compared to the trend observed in the late 1990s. The projections based on the second phase and the third phase of the NACP indicate prevention programmes which are directed towards the general and high-risk populations, and HIV-positive individuals will determine the decline or stabilization of the epidemic. Model based results are derived separately for the revised HIV estimates released in 2007. According to revised projections there will be 2.08 million PLHA by 2012 if 50 percent of the targets in NACP III are reached. We perform a Monte Carlo procedure for sensitivity analysis of parameters and model validation. We also predict a positive role of implementation of anti-retroviral therapy treatment of 90 percent of the eligible people in the country. We present methods for obtaining disease progression parameters using convolution approaches. We also extend our models to age-structured populations.
经过两阶段的艾滋病防治活动，印度于 2007 年 7 月启动了国家艾滋病控制计划（NACP III）的第三阶段。我们的重点是预测印度艾滋病毒/艾滋病患者（PLHA）的数量，以便结果可以帮助 NACP III 规划团队确定在项目期间（2007-2012）要激活的适当目标。我们构建了一个动态模型，该模型捕获了人群中低风险和高风险群体中易感人群和感染者之间的混合模式。我们的目的是通过考虑一般的易感人群干预措施以及其他干预措施（例如高危人群的针对性干预措施、提供抗逆转录病毒治疗以及 HIV 阳性个体的行为改变）来预测 HIV 估计值。在 NACP II 中继续进行当前水平的干预措施的情况下，该模型估计到 2011 年底将有 506 万 PLHA。如果在上述期间结束时，NACP III 的 50%目标得以实现，那么当年将避免约 80 万新感染。与 20 世纪 90 年代末观察到的趋势相比，目前的疫情状况似乎不太严重。基于 NACP 的第二阶段和第三阶段的预测表明，针对一般人群和高危人群的预防计划以及 HIV 阳性个体将决定疫情的下降或稳定。根据 2007 年发布的修订后的 HIV 估计值，分别得出基于模型的结果。根据修订后的预测，如果 NACP III 的 50%目标得以实现，到 2012 年将有 208 万 PLHA。我们对参数和模型验证进行了蒙特卡罗程序敏感性分析。我们还预测在该国实施 90%的合格人群接受抗逆转录病毒治疗将发挥积极作用。我们提出了使用卷积方法获得疾病进展参数的方法。我们还将我们的模型扩展到年龄结构人群。
