Periurban Trypanosoma cruzi-infected Triatoma infestans, Arequipa, Peru

Abstract

In Arequipa, Peru, vectorborne transmission of Chagas disease by Triatoma infestans has become an urban problem. We conducted an entomologic survey in a periurban community of Arequipa to identify risk factors for triatomine infestation and determinants of vector population densities. Of 374 households surveyed, triatomines were collected from 194 (52%), and Trypanosoma cruzi-carrying triatomines were collected from 72 (19.3%). Guinea pig pens were more likely than other animal enclosures to be infested and harbored 2.38x as many triatomines. Stacked brick and adobe enclosures were more likely to have triatomines, while wire mesh enclosures were protected against infestation. In human dwellings, only fully stuccoed rooms were protected against infestation. Spatially, households with triatomines were scattered, while households with T. cruzi-infected triatomines were clustered. Keeping small animals in wire mesh cages could facilitate control of T. infestans in this densely populated urban environment.

Figure 1

High density of homes in the periurban community of Guadalupe, Arequipa, Peru, November 2004.

Figure 2

Map of households with Triatoma infestans and Trypanosmona cruzi–infected T. infestans in Guadalupe, a periurban community of Arequipa, Peru. Concentric circles are drawn around a house near the center of Guadalupe and represent parameters of T. infestans dispersal observed in rural areas (24,25). The nearest houses of neighboring communities are included for reference.

Figure 3

Clustering analysis of A) houses with Triatoma infestans and B) houses with Trypanosoma cruzi–infected T. infestans in a periurban community of Arequipa, Peru.