Reinfestation sources for Chagas disease vector, Triatoma infestans, Argentina

CECERE MC; VAZQUEZ-PROKOPEC GM; GURTLER RE; KITRON U

EMERGING INFECTIOUS DISEASES

Año: 2006 vol. 12 p. 1096 - 1102

1080-6040

Reinfestation by Triatoma infestans after insecticidespraying has caused elimination efforts in the dry Chacoregion to fail repeatedly. The sources and spatial extentthat need to be considered to understand the reinfestationpattern and to plan a comprehensive control program werestudied in 2 adjacent rural communities in northwesternArgentina from 1993 to 1997. The effects of external, residual,and primary sources on the reinfestation pattern wereevaluated by using geographic information systems, satelliteimagery, spatial statistics, and 5-year retrospective datafor 1,881 sites. The reinfestation process depended on primaryinternal sources and on surrounding infested communities.In the dry Chaco, successfully reducing the risk forreinfestation in a community depends on treating all communitiesand isolated sites within 1,500 m of the targetcommunity. In addition, during the surveillance phase,spraying all sites within 500 m of new foci will delay reinfestation.