背景:自20世纪末以来,南美锥虫病引起了全球关注,以抑制病媒负担作为流行国家的主要控制策略。在中美洲,多国倡议成功地实现了估计的疾病流行率的显著降低,并在2012年消除了该地区的主要病媒物种。虽然过去十年见证了生态系统的重大变化,如城市化和主要媒介物种的更替,这可能会影响媒介的居住和残留传播,由于停止了主动病媒监测,该区域的最新病媒负担尚未得到彻底评估.这项研究的目的是更新萨尔瓦多媒介传播的克氏锥虫感染的风险,中美洲最大的查加斯病流行国家。
方法:于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媒介调查。检查房屋的选择是基于专家有目的的抽样。通过对昆虫粪便的显微镜观察检查克氏虫的感染,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epR软件包下提供的Jeffrey\'s方法推断具有95%置信区间的比例估计。
结果:从107所房屋中捕获了1529个Triatomadimidiata(侵染率,34.4%;107/311)在该期间访问的全国所有14个部门中;克氏锥虫感染的患病率高达10%(153/1529)。在国内,国内的双歧杆菌感染分布广泛,而克氏杆菌感染率在不同部门各不相同。十四个科室中有五个的感染率高于平均水平,表明该国零星的高风险地区。
结论:我们的综合研究表明,在全国范围内,T.cruzi感染严重。表明该疾病的潜在主动传播。因此,需要加强对病媒和人类感染的监测,以真正消除在中美洲传播克氏虫的风险。
BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.