ABSTRACT
During 1997 a seroepidemiological study on Chagas' disease was carried out in 18 localities of three provinces (Tocopilla,El Loa and Antofagasta) of Region II (20º 56'-26º south lat.; 70º 38'- 67º west long.), in order to asses the impact of the control program against triatoma infestans launched in 1988, based on insecticide spraying of dwellings. By means of ELISA and an indirect hemagglutination test for chagas' disease blood samples from 1,034 children under 10 years of age were examined, arising a 0.5 por ciento (3 cases) positivity. Test resulted positivite in 2 (0.9 percent) children from the locality of San Pedro de Atacama and 1 (0.4 percent) from Calama city, all in the age group 6-10 year -old. However, none of their dwellings were found infested with T.infestants. These result indicate that the control program has a good possibility to prevent new human infections. It is advisable to continue the seroepidemiological and entomological vigilance and remark the necessity of increasing the effort in the study of transmission through other routes, to adopt or reinforce the pertinent preventive measures
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Chagas Disease/epidemiology , Triatoma/pathogenicity , Trypanosoma cruzi/pathogenicity , Chagas Disease/transmission , Chile/epidemiology , Disease Vectors , Insect Control , Insect Vectors/drug effects , Insecticides/therapeutic use , Serologic Tests , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/isolation & purificationABSTRACT
In order to assess the impact of a control program against triatoma infestans launched in 1988, based on insecticide spraying of dwellings, a serological survey for chagasic infection was carried out during 1995 in three localities from San Pedro de Atacama county (22º55' south lat., 68º12' west long.), II Region of Antofagasta in northern Chile. Blood samples from 531 children and adolescents and 65 dogs were subjected to ELISA test and indirect inmunofluorescent test for Chagas's disease respectively. Tests resulted positive in 12 (2,3 percent) persons, all above 5 years old, in contrast with the 16,8 percent serological positivity observed in 1985. Three (4,6 percent) dogs (two 0-12 months old) resulted positive. These results indicate that dwellings sprayings with long-term activity insecticides against T. infestans is a good tool to prevent new human infections with T. cruzi. However, active vector transmissiom among domestic animals (canines) could be recently acquired.