Sources for reinfestation by the Chagas disease vector, Triatoma infestans of neighboring communities in northwestern Argentina.

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

EMERGING INFECTIOUS DISEASES

Año: 2006 vol. 12 p. 1098 - 1102

1080-6040

Reinfestation by Triatoma infestans after insecticide spraying has caused elimination efforts in the dry Chaco region to fail repeatedly. The sources and spatial extent that need to be considered to understand the reinfestation pattern and to plan a comprehensive control program were studied in 2 adjacent rural communities in northwestern Argentina from 1993 to 1997. The effects of external, resid­ual, and primary sources on the reinfestation pattern were evaluated by using geographic information systems, satel­lite imagery, spatial statistics, and 5-year retrospective data for 1,881 sites. The reinfestation process depended on pri­mary internal sources and on surrounding infested commu­nities. In the dry Chaco, successfully reducing the risk for reinfestation in a community depends on treating all com­munities and isolated sites within 1,500 m of the target community. In addition, during the surveillance phase, spraying all sites within 500 m of new foci will delay reinfes­tation.