In a previous paper, the Vector Control Division of the Department of Health of the State of São Paulo, Brazil, presented the adopted criteria for transference of cleaned Triatoma infestans areas, the main vector of Chagas' disease in the region to a more advanced phase of its control program, called "Entomological Surveillance Phase". Among the areas where T. infestans was not found any longer there is a region of 2007 km², with an estimated population of 51000 people including six counties located in Region 7 - Bauru (São Paulo. State - Brazil), where the Pilot Area of Entomological Surveillance was installed. In this area, between May 1969 and June 1970, the following activities were performed: installation and functioning of a network of information Posts for Triatominae foci; investigation of Triatominae foci; estimation of the infestation in mud cottages, through special boxes for Triatominae (Gomez-Nuñez method); RIF (immunofluorescence reaction) serological survey in blood drop caught in filtering paper, carried through less than 8 years old children; research and capture of Triatominae bugs. As results there was not found T. infestans bugs in the area. Beside this, only few isolated specimens or small foci of other species (R. neglectus and T. sordida) that were not found infected by Trypanosoma cruzi. So, it was concluded that the changing of this area to the Entomological Surveillance Phase was correct, and that the methods used were satisfactory. By there this area was considered in condition to transfering the Chagas' disease control to the local Sanitary Units.
