Mexico: Chagas Disease 1986

Chagas’ disease, caused by a parasite similar to that responsible for African sleeping sickness, is transmitted by the triatomine insect, found in several parts of Guerrero. Human infection with Trypanosoma cruzi is found in every country in South and Central America. The disease is endemic in communities living in wooden and thatched dwellings, where the bugs live in close contact with humans. In 1986, CIET initiated a project to measure the prevalence of Chagas disease in the State of Guerrero. Blood samples were taken from 20 representative communities, and household searches for the bugs were carried out. Using the portable plastic microscope, faeces of infected bugs were shown to the communities to explain the nature of the disease. A survey of every household in the 20 communities was carried out to measure local knowledge of the disease and to familiarize them with the triatomine bug. From 4,372 blood samples collected in these communities, 75 tested strongly positive for the infection, with the incidence being as high as 15% in some areas. A further study was carried out on the populations of the two communities whose blood samples showed the greatest number of cases of infection. The aim was to find a correlation between Chagas’ disease and coronary complications. The electrocardiographs of 15% of the 145 people tested, were compatible with Chagas’ disease.
For further information see:
Andersson, N., Morales, A., Nava, E. Trypanosoma cruzi infection in the Mexican State of Guerrero: a seroepidemiological (ELISA) survey of 20 communities. Journal of Tropical Medicine and Hygiene 1990; 93:341-346.