Current epidemiological trends of Chagas disease in Latin America and future challenges: Epidemiology, surveillance, and health policies

Abstract

Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi transmitted to humans by blood-sucking triatomine bugs and by blood transfusion.Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6-8 weeks. After several years of starting the chronic phase, 20-35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon, and the peripheral nervous system. Data on the prevalence and distribution of Chagas' disease improved in quality during the 1980s as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Brasilia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation.Thanks to a coordinated multicountry program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in 1997, in Chile in 1999, and in Brazil in 2006 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%.Similar multicountry initiatives have been launched in the Andean countries and in Central America and rapid progress has been reported to ensure the interruption of the transmission of Chagas disease as requested by a Resolution of the World Health Assembly approved in 1998.The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the Program is a health investment with very high return.The well-known research institutions in Latin America were the key elements of a worldwide network of laboratories that carried out basic and applied research that supported the planning and evaluation of national Chagas disease control programs. The present article reviews the current epidemiological trends of Chagas disease in Latin America and the future challenges in epidemiology, surveillance, and health policies.