Gaspe María Sol, Provecho Yael Mariana, Piccinali Romina Valeria, Gürtler Ricardo Esteban
Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina.
Mem Inst Oswaldo Cruz. 2015 May;110(3):310-8. doi: 10.1590/0074-02760140376. Epub 2015 Apr 28.
House re-invasion by native triatomines after insecticide-based control campaigns represents a major threat for Chagas disease vector control. We conducted a longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa del Indio, northeastern Argentina, and used wing geometric morphometry to compare pre-spray and post-spray (re-infestant bugs) Triatoma infestans populations. The community-wide spraying with pyrethroids reduced the prevalence of house infestation by T. infestans from 31.9% to < 1% during a four-year follow-up, unlike our previous studies in the neighbouring Area I. Two groups of bug collection sites differing in wing shape variables before interventions (including 221 adults from 11 domiciles) were used as a reference for assigning 44 post-spray adults. Wing shape variables from post-spray, high-density bug colonies and pre-spray groups were significantly different, suggesting that re-infestant insects had an external origin. Insects from one house differed strongly in wing shape variables from all other specimens. A further comparison between insects from both areas supported the existence of independent re-infestation processes within the same district. These results point to local heterogeneities in house re-infestation dynamics and emphasise the need to expand the geographic coverage of vector surveillance and control operations to the affected region.
在基于杀虫剂的防治运动之后，本地锥蝽再次侵入房屋对恰加斯病病媒控制构成了重大威胁。我们在阿根廷东北部潘帕德尔印第奥的一个农村地区（第三区，407所房屋）开展了一项纵向干预研究，并使用翅几何形态测量法比较喷洒杀虫剂之前和之后（再次侵入的虫子）的侵扰锥蝽种群。与我们之前在邻近的第一区开展的研究不同，在为期四年的随访期间，全社区喷洒拟除虫菊酯使侵扰锥蝽的房屋侵扰率从31.9%降至<1%。两组在干预前翅形变量不同的虫子采集地点（包括来自11户住所的221只成虫）被用作分配44只喷洒杀虫剂之后成虫的参考。喷洒杀虫剂之后、高密度虫群和喷洒杀虫剂之前的组的翅形变量存在显著差异，这表明再次侵入的昆虫来自外部。来自一所房屋的昆虫在翅形变量方面与所有其他标本有很大差异。两个地区昆虫之间的进一步比较支持了同一地区内存在独立的再次侵扰过程。这些结果表明房屋再次侵扰动态存在局部异质性，并强调需要将病媒监测和控制行动的地理覆盖范围扩大到受影响地区。
