Center for Infectious Disease Research, Pontifical Catholic University of Ecuador, Quito, Ecuador.
J Med Entomol. 2010 Jan;47(1):80-8. doi: 10.1603/033.047.0111.
Chagas disease is a serious public health problem in Ecuador, where nearly 230,000 individuals show Trypanosoma cruzi infection. Sylvatic T. cruzi transmission is a threat to current control strategies. This is because of the possibility of house reinfestation by sylvatic triatomines after insecticide treatment. This work quantified the spatial distribution of triatomines in sylvatic habitats and its relationship with nearby human dwellings. A simple random sampling design using live-baited traps and manual searches for triatomines was used in areas near human communities in Manabi province, Ecuador, during June and July 2007. We identified risk factors associated with triatomine density using generalized linear models, and developed predictive maps for triatomine density interpolation. There were 345 triatomines belonging to the species Rhodnius ecuadoriensis and Panstrongylus howardi collected in sylvatic areas. Spatial analyses revealed an aggregated distribution pattern of the sylvatic triatomine populations (clustered mostly at a distance smaller than 100 m). Generalized linear models showed that the distance from the nearest house, nest type, and height from ground level were the main factors explaining triatomine densities. Squirrel nests (Sciurus stramineus), located in plants other than palms, above 5 m and close to the domicile presented higher infestation. Interpolation maps of triatomine microdistribution are presented as potential tools to predict triatomine occurrence. The presence of sylvatic populations and the synanthropic tendency of the vectors highlight the need for continuous active and passive entomological surveillance for the long-term control of Chagas disease.
恰加斯病是厄瓜多尔的一个严重公共卫生问题，那里有近 23 万人显示克氏锥虫感染。森林地带的克氏锥虫传播对当前的控制策略构成威胁。这是因为在使用杀虫剂处理后，森林地带的三锥虫有可能重新侵入房屋。这项工作量化了森林栖息地内三锥虫的空间分布及其与附近人类住区的关系。2007 年 6 月至 7 月期间，在厄瓜多尔马纳比省的人类社区附近，使用带有活诱饵的随机抽样设计和人工搜索来收集三锥虫。我们使用广义线性模型确定了与三锥虫密度相关的风险因素，并为三锥虫密度插值开发了预测图。在森林地区共收集到 345 只属于 Rhodnius ecuadoriensis 和 Panstrongylus howardi 种的三锥虫。空间分析显示，森林地带的三锥虫种群呈聚集分布模式（主要聚集在距离小于 100 米的地方）。广义线性模型表明，与最近的房屋的距离、巢穴类型和离地面的高度是解释三锥虫密度的主要因素。位于棕榈树以外的植物上、高于 5 米且靠近住所的松鼠巢穴（Sciurus stramineus）的感染率较高。三锥虫微观分布的插值图可作为预测三锥虫发生的潜在工具。森林地带种群的存在和媒介的拟生性突出表明，需要长期持续进行主动和被动的昆虫学监测，以长期控制恰加斯病。
