The main sceneries of Chagas disease transmission. The vectors, blood and oral transmissions--a comprehensive review

Abstract

This review deals with transmission of Trypanosoma cruzi by the most important domestic vectors, blood transfusion and oral intake. Among the vectors, Triatoma infestans, Panstrongylus megistus, Rhodnius prolixus, Triatoma dimidiata, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma sordida, Triatoma maculata, Panstrongylus geniculatus, Rhodnius ecuadoriensis and Rhodnius pallescens can be highlighted. Transmission of Chagas infection, which has been brought under control in some countries in South and Central America, remains a great challenge, particularly considering that many endemic countries do not have control over blood donors. Even more concerning is the case of non-endemic countries that receive thousands of migrants from endemic areas that carry Chagas disease, such as the United States of America, in North America, Spain, in Europe, Japan, in Asia, and Australia, in Oceania. In the Brazilian Amazon Region, since Shaw et al. (1969) described the first acute cases of the disease caused by oral transmission, hundreds of acute cases of the disease due to oral transmission have been described in that region, which is today considered to be endemic for oral transmission. Several other outbreaks of acute Chagas disease by oral transmission have been described in different states of Brazil and in other South American countries.

Fig. 1:. Didelphis marsupialis and wild Panstrongylus megistus infected with Trypanosoma cruzi captured in Santa Teresa, state of Rio de Janeiro, Brazil (Coura 1966).

Fig. 2:. Rhodnius brethesi in palm tree and piassava’s gatherers and their families outside huts in the work place at the microregion of the Rio Negro, Brazilian Amazon.

Fig. 3:. distribution of the main vectors of Trypanosoma cruzi in the Americas (Scherlock 2000).

Fig. 4:. acute case of Chagas disease acquired by blood transfusion from a chronic case showing X ray with enlargement and sign of heart failure (A) and electrocardiogram showing myocardial ischaemia (B) (Coura 1966).

Fig. 5:. acute case of Chagas disease by oral transmission showing X ray heart enlargement (A) and oedema on the legs with skin necrosis (B) (Pinto et al. 2008).