A system of surveillance for Chagas' disease aiming at a systematic investigation of the occurrence of triatominae in human dwellings in S. Paulo, Brazil was proposed. It included a serological survey of residents in house considered to be potencial breeding places for blood-sucking triatomines. Serologically positive cases were observed to be distributed in age groups from 19 years of age upwards. Case-investigation revealed that the infection had been acquired either in S. Paulo in the past or recently in other States. A serologically positive (titre - 128 - IgG) case of an 8-year-old male child, was detected by the Indirect Fluorescent Antibody Technique (IFAT). In S. Paulo State natural transmission is now of low probability. An epidemiological investigation disclosed the fact that this was a case of blood transfusion infection. The donor was found to be serologically positive (IFAT, titre = 1024 - IgG). His case-history was typical of vector transmitted infection. It is worthy of note that blood had been donated by this patient in four instances, without his condition having been diagnosed. The necessity of organizing an integrated Public Health Service to take more efficient care of such cases is stressed.
Trypanosomiasis South American; Blood transfusion