Centro de Investigación y Desarrollo en Salud, Universidad de El Salvador, San Salvador, El Salvador.
Department of Virology and Parasitology, Graduate School of Medicine, Osaka Metropolitan University, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan.
Infect Dis Poverty. 2022 Aug 9;11(1):89. doi: 10.1186/s40249-022-01008-5.
Since the late twentieth century, Chagas disease gained global attention to suppress the vector burden as a main control strategy in endemic countries. In Central America, multi-national initiative successfully achieved significant reduction in the estimated disease prevalence as well as elimination of the region's principal vector species at the time in 2012. While the last decade has witnessed significant changes in ecosystem-such as urbanization and replacement of the main vector species-that can possibly affect the vector's habitation and residual transmission, the up-to-date vector burden in the region has not been evaluated thoroughly due to the cessation of active vector surveillance. The aim of this study was to update the risk of vector-borne Trypanosoma cruzi infection in El Salvador, the top Chagas disease-endemic country in Central America.
A nationwide vector survey was conducted in the domestic environment of El Salvador from September 2018 to November 2020. The selection of the houses for inspection was based on expert purposeful sampling. Infection for T. cruzi was examined by microscopic observation of the insects' feces, followed by a species confirmation using PCR. The data were analyzed using R software version 4.1.3. Proportion estimates with 95% confidence intervals were inferred using the Jeffrey's method provided under the epiR package.
A total of 1529 Triatoma dimidiata was captured from 107 houses (infestation rate, 34.4%; 107/311) in all the fourteen departments of the country visited within the period; prevalence of T. cruzi infection was as high as 10% (153/1529). In the country, domestic T. dimidiata infestation was distributed ubiquitously, while T. cruzi infection rates varied across the departments. Five out of fourteen departments showed higher infection rates than the average, suggesting sporadic high-risk areas in the country.
Our comprehensive study revealed substantial T. cruzi infection of T. dimidiata across the country, indicating potential active transmission of the disease. Therefore, strengthened surveillance for both vector and human infection is required to truly eliminate the risk of T. cruzi transmission in Central America.
自 20 世纪后期以来，查加斯病引起了全球关注，以抑制病媒负担作为流行国家的主要控制策略。在中美洲，多国倡议成功地显著降低了该地区的疾病流行率，并在 2012 年消除了该地区当时的主要病媒物种。尽管过去十年中，生态系统发生了重大变化，如城市化和主要病媒物种的更替，这可能会影响病媒的栖息地和残留传播，但由于停止了主动病媒监测，该地区的最新病媒负担尚未得到全面评估。本研究旨在更新萨尔瓦多（中美洲查加斯病流行率最高的国家）的病媒传播克氏锥虫感染风险。
2018 年 9 月至 2020 年 11 月，在萨尔瓦多的国内环境中进行了全国性的病媒调查。检查房屋的选择基于专家有目的的抽样。通过显微镜观察昆虫粪便检查克氏锥虫感染，然后使用 PCR 进行物种确认。使用 R 软件版本 4.1.3 分析数据。使用 epiR 包提供的杰弗里方法推断具有 95%置信区间的比例估计值。
在全国范围内访问的 14 个地区的 107 所房屋中，共捕获了 1529 只三带喙库蚊（感染率为 34.4%；107/311）；克氏锥虫感染的流行率高达 10%（153/1529）。在该国，国内三带喙库蚊的感染分布广泛，而克氏锥虫感染率在各地区有所不同。14 个地区中有 5 个地区的感染率高于平均水平，表明该国存在一些高风险的点状地区。
我们的综合研究表明，该国三带喙库蚊感染克氏锥虫的情况相当普遍，表明该病存在潜在的活跃传播。因此，需要加强对病媒和人类感染的监测，以真正消除中美洲克氏锥虫传播的风险。
