The county of Morada Nova (State of Ceará, Brasil) wassprayed with BHCfrom 1972 to 1974, but during 1975, in the same zones, we have observed that the transmission of T. cruzi has continued in natural and artificial foci (domestic and peridomestic). In these ecctopes were captured triatomines that have sucked man, dog and chicken, showing ur that there is a relation between the cycles. But we have observed that the bugs of the region are less anthropophilic, so leading to small rates of infection (2,4%).