Spatio-temporal analysis of reinfestation by Triatoma infestans (Hemiptera: Reduviidae) following insecticide spraying in a rural community in northwestern Argentina.

CECERE MC, VAZQUEZ-PROKOPEC GM, GÜRTLER RE, KITRON U.

Valencia-España

Congreso; 10. IX European Multicolloquium of Parasitology.; 2004

The spatio-temporal reinfestation patterns by Triatoma infestans following a blanket insecticide spraying in the rural community of Amamá, northwestern Argentina, were analyzed using geographic information system (GIS), satellite imagery, and spatial statistics. Domestic and peridomestic reinfestation by triatomine bugs was monitored from 1993 to 1997. T. infestans was detected at least once in 75% of 2110 sites evaluated. The  prevalence of sites positive at least once for T. infestans during the study period increased sharply from 1993-1995 (0.6-2.9%) to November 1997 (32%). The initial source of T. infestans was a pig corral in southern Amamá one year post-spraying. Subsequent infestations were clustered around this initial focus at a distance of ~400 m starting in 1995. In 1996, clustering was maximized in sites within the same or in neighboring compounds at distances of 25-175 m. The reinfestation process in the northern section apparently did not originate from this pig corral and was independent of the southern sources, as also supported by wing geometric morphometrics. Application of focal spatial statistics in this study allowed for the identification of T. infestans propagation epicenters. Targeted surveillance of key peridomestic sites, such as goat and pig corrals, using low-cost sensing devices and improved treatment regimes are recommended. An effective control program on the community level will be based on the spraying of actual epicenters and sites within a 450 m of these epicenters to prevent the propagation of T. infestans.