Parham Paul E, Hughes Dyfrig A
Department of Public Health and Policy, University of Liverpool, London, EC2A 1AG, UK
Centre for Health Economics and Medicines Evaluation, Bangor University, Bangor, LL57 2PZ, UK.
Philos Trans R Soc Lond B Biol Sci. 2015 Apr 5;370(1665). doi: 10.1098/rstb.2013.0557.
Despite the dependence of mosquito population dynamics on environmental conditions, the associated impact of climate and climate change on present and future malaria remains an area of ongoing debate and uncertainty. Here, we develop a novel integration of mosquito, transmission and economic modelling to assess whether the cost-effectiveness of indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) against Plasmodium falciparum transmission by Anopheles gambiae s.s. mosquitoes depends on climatic conditions in low endemicity scenarios. We find that although temperature and rainfall affect the cost-effectiveness of IRS and/or LLIN scale-up, whether this is sufficient to influence policy depends on local endemicity, existing interventions, host immune response to infection and the emergence rate of insecticide resistance. For the scenarios considered, IRS is found to be more cost-effective than LLINs for the same level of scale-up, and both are more cost-effective at lower mean precipitation and higher variability in precipitation and temperature. We also find that the dependence of peak transmission on mean temperature translates into optimal temperatures for vector-based intervention cost-effectiveness. Further cost-effectiveness analysis that accounts for country-specific epidemiological and environmental heterogeneities is required to assess optimal intervention scale-up for elimination and better understand future transmission trends under climate change.
尽管蚊虫种群动态依赖于环境条件，但气候及气候变化对当前和未来疟疾的相关影响仍是一个存在持续争论和不确定性的领域。在此，我们开发了一种新颖的将蚊虫、传播和经济模型相结合的方法，以评估在低流行情况下，室内滞留喷洒（IRS）和长效驱虫蚊帐（LLINs）针对冈比亚按蚊传播恶性疟原虫的成本效益是否取决于气候条件。我们发现，尽管温度和降雨会影响IRS和/或扩大LLIN规模的成本效益，但这是否足以影响政策取决于当地的流行程度、现有干预措施、宿主对感染的免疫反应以及杀虫剂抗性的出现率。在所考虑的情景中，对于相同的扩大规模水平，发现IRS比LLIN更具成本效益，并且在较低的平均降水量以及降水量和温度的较高变异性情况下，两者都更具成本效益。我们还发现，传播高峰对平均温度的依赖性转化为基于病媒的干预成本效益的最佳温度。需要进行进一步的成本效益分析，以考虑各国特定的流行病学和环境异质性，从而评估消除疟疾的最佳干预扩大规模，并更好地了解气候变化下未来的传播趋势。
