| dc.description | From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following
characteristics: (i) enzooty, maintained by wild animals and vectors, with broad occurrence from southern United
States of America (USA) to southern Argentina and Chile (42ºN 49ºS), (ii) anthropozoonosis, when man invades the
wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild
animals, especially marsupials, invade the human domicile and infect man, (iii) zoonosis-amphixenosis and exchanged
infection between animals and humans by domestic vectors in endemic areas and (iv) zooanthroponosis, infection that
is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for
Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are
seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species
of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra), Carnivora and Primata and
27 species of triatomines, most of which infected with T. cruzi. These conditions place the resident populations of this
area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction
- at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute
cases of Chagas disease in that region through oral transmission of T. cruzi, causing outbreaks of the disease. In four
seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas,
in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection.
The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were
stung by wild triatomines in that area. Finally, a characteristic that is greatly in evidence currently is the migration of
people with Chagas disease from endemic areas of Latin America to non-endemic countries. This has created a new
dilemma for these countries: the risk of transmission through blood transfusion and the onus of controlling donors and
treating migrants with the disease. As an enzooty of wild animals and vectors, and as an anthropozoonosis, Chagas
disease cannot be eradicated, but it must be controlled by transmission elimination to man. | |
