Malaria is a vector-borne disease of significant public health concern. Despite widespread success of many elimination initiatives, elimination efforts in some regions of the world have stalled. Barriers to malaria elimination include climate and land use changes, such as warming temperatures and urbanization, which can alter mosquito habitats. Socioeconomic factors, such as political instability and regional migration, also threaten elimination goals. This is particularly relevant in areas where local elimination has been achieved and consequently surveillance and control efforts are dwindling and are no longer a priority. Understanding how environmental change, impacts malaria elimination has important practical implications for vector control and disease surveillance strategies. It is important to consider climate change when monitoring the threat of malaria resurgence due to socioeconomic influences. However, there is limited assessment of how the combination of climate variation, interventions and socioeconomic pressures influence long-term trends in malaria transmission and elimination efforts. In this study, we used Bayesian hierarchical mixed models and malaria case data for a 29-year period to disentangle the impacts of climate variation and malaria control efforts on malaria risk in the Ecuadorian province of El Oro, which achieved local elimination in 2011. We found shifting patterns of malaria between rural and urban areas, with a relative increase of Plasmodium vivax in urbanized areas. Minimum temperature was an important driver of malaria seasonality and the association between warmer minimum temperatures and malaria incidence was greater for Plasmodium falciparum compared to P. vivax malaria. There was considerable heterogeneity in the impact of three chemical vector control measures on both P. falciparum and P. vivax malaria. We found statistically significant associations between two of the three measures [indoor residual spraying (IRS) and space spraying] and a reduction in malaria incidence, which varied between malaria type. We also found environmental suitability for malaria transmission is increasing in El Oro, which could limit future elimination efforts if malaria is allowed to re-establish. Our findings have important implications for understanding environmental obstacles to malaria elimination and highlights the importance of designing and sustaining elimination efforts in areas that remain vulnerable to resurgence.

中文翻译：

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气候变化和控制干预措施对厄瓜多尔埃尔奥罗消除疟疾工作的相对作用：建模研究

疟疾是一种具有重大公共卫生问题的媒介传播疾病。尽管许多消除举措取得了广泛的成功，但世界某些地区的消除努力却停滞不前。消除疟疾的障碍包括气候和土地利用变化，例如气温升高和城市化，这可能会改变蚊子的栖息地。政治不稳定和区域移民等社会经济因素也威胁到消除目标。这在已经实现局部消除的地区尤为重要，因此监测和控制工作正在减少，不再是优先事项。了解环境变化如何影响消除疟疾对病媒控制和疾病监测策略具有重要的实际意义。在监测由于社会经济影响造成的疟疾卷土重来的威胁时，考虑气候变化很重要。然而，对气候变化、干预措施和社会经济压力的组合如何影响疟疾传播和消除工作的长期趋势的评估有限。在这项研究中，我们使用贝叶斯分层混合模型和 29 年的疟疾病例数据来分析气候变化和疟疾控制工作对厄瓜多尔埃尔奥罗省疟疾风险的影响，该省于 2011 年实现了局部消除。我们发现农村和城市地区之间的疟疾模式不断变化，城市化地区间日疟原虫的数量相对增加。最低气温是疟疾季节性的重要驱动因素，与间日疟相比，恶性疟原虫的最低气温升高与疟疾发病率之间的关联更大。三种化学媒介控制措施对恶性疟原虫和间日疟原虫疟疾的影响存在相当大的异质性。我们发现三项措施中的两项 [室内滞留喷洒 (IRS) 和空间喷洒] 与疟疾发病率降低之间存在统计学上的显着关联，这种关联因疟疾类型而异。我们还发现 El Oro 对疟疾传播的环境适应性正在增加，如果允许疟疾重新滋生，这可能会限制未来的消除工作。