A seroepidemiologic survey of Chagas' disease in two Paraguayan villages

As in many Latin American countries, Chagas’ disease is a serious endemic public health problem in Paraguay. Vector studies conducted in various parts of the country through the mid-1970s found the principal Chagas’ disease vector, Triatoma infestans, to be present in all the areas surveyed, with the recorded house infestation indexes generally being in the 20-30 % range (I). More recently, surveys of 18 villages in or around 1979 found T. infestans present in 57 % of 451 homes inspected, and also found 23% of the captured vector insects to contain the Chagas’ disease agent, Ttypanosoma cmti. Similarly, 1980 surveys of 616 homes in ‘20 villages found a T. infestuns infestation index of 61% , with 25% of the captured insects testing positively for T. cruzi (2). Regarding human infections, during the 1970s sera from 140 Indians living in the Paraguayan Chaco were tested for T. crwi antibodies by the direct agglutination and indirect immunofluorescence methods. These two respective techniques obtained positive results with 72.9% and 73.6% of the test sera (3). It should be noted, however, that these are, the