Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.
Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, Singapore.
PLoS Negl Trop Dis. 2020 Oct 29;14(10):e0008719. doi: 10.1371/journal.pntd.0008719. eCollection 2020 Oct.
An estimated 105 million dengue infections occur per year across 120 countries, where traditional vector control is the primary control strategy to reduce contact between mosquito vectors and people. The ongoing sars-cov-2 pandemic has resulted in dramatic reductions in human mobility due to social distancing measures; the effects on vector-borne illnesses are not known. Here we examine the pre and post differences of dengue case counts in Malaysia, Singapore and Thailand, and estimate the effects of social distancing as a treatment effect whilst adjusting for temporal confounders. We found that social distancing is expected to lead to 4.32 additional cases per 100,000 individuals in Thailand per month, which equates to 170 more cases per month in the Bangkok province (95% CI: 100-242) and 2008 cases in the country as a whole (95% CI: 1170-2846). Social distancing policy estimates for Thailand were also found to be robust to model misspecification, and variable addition and omission. Conversely, no significant impact on dengue transmission was found in Singapore or Malaysia. Across country disparities in social distancing policy effects on reported dengue cases are reasoned to be driven by differences in workplace-residence structure, with an increase in transmission risk of arboviruses from social distancing primarily through heightened exposure to vectors in elevated time spent at residences, demonstrating the need to understand the effects of location on dengue transmission risk under novel population mixing conditions such as those under social distancing policies.
据估计，每年有 1.05 亿例登革热感染发生在 120 个国家，这些国家的主要控制策略是传统的病媒控制，以减少蚊子媒介与人类的接触。由于社交距离措施，正在进行的 SARS-CoV-2 大流行导致人类流动性大幅下降；对虫媒传染病的影响尚不清楚。在这里，我们研究了马来西亚、新加坡和泰国登革热病例数的前后差异，并估计了社交距离作为治疗效果的影响，同时调整了时间混杂因素。我们发现，在泰国，社交距离预计每月将导致每 10 万人增加 4.32 例额外病例，相当于曼谷省每月增加 170 例（95%CI：100-242），全国增加 2008 例（95%CI：1170-2846）。还发现，泰国社交距离政策的估计值对模型的误设定、变量的添加和省略具有稳健性。相反，在新加坡或马来西亚没有发现社交距离对登革热传播有显著影响。报告的登革热病例的社交距离政策效果在国家间存在差异，这被认为是由于工作场所-居住地结构的差异造成的，社交距离主要通过增加在居住地的时间而增加了与病毒载体的接触，从而增加了虫媒病毒的传播风险，这表明需要了解在新型人群混合条件下（如社交距离政策下），位置对登革热传播风险的影响。
