Autochthonous transmission of Chagas disease in Rio de Janeiro State, Brazil: a clinical and eco-epidemiological study

Abstract

BackgroundAfter the control of the main modes of Chagas disease (CD) transmission in most endemic countries, it is important to identify the participation of native sylvatic vectors in CD transmission. Although CD is not considered endemic in Rio de Janeiro State (RJ), Brazil, we identified patients with CD born in RJ and investigated the possible autochthonous transmission in the state.MethodsPatients born in RJ and followed in our institution between 1986 and 2011 were retrospectively analyzed. The cases identified as autochthonous transmission were submitted to epidemiological, clinical, serological, parasitological and molecular studies. Sectional field study with serological survey, research of sylvatic reservoirs and vectors was conducted in rural areas where patients were born.ResultsAmong 1963 patients, 69 (3.5%) were born in RJ. From these, 15 (21.7%) were considered to have acquired the infection by autochthonous transmission. Cardiac form was the commonest form of presentation (60%). In rural areas in RJ northern region, sylvatic cycles of Trypanosoma cruzi and domestic invasion by Triatoma vitticeps were identified, and CD prevalence among inhabitants was 0.74%.TcI genotype was identified in sylvatic reservoirs and vectors. The genotype (mixed infection TcI/TcVI) could be identified in one of the autochthonous cases.ConclusionsThe autochthonous vectorial transmission of CD occurs in RJ, probably due to wild cycles of T. cruzi and sylvatic vectors, such as T. vitticeps. Therefore, the health authorities should evaluate if RJ should be included in the original endemic area of CD and CD should be included in the diagnostic work out of cardiomyopathy of patients born in RJ. Moreover, control and educational measures should be put into place in the risk areas.

Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

“…More recently, Sangenis et al 42 identified TcI mixed with TcVI in an asymptomatic patient from the Rio de Janeiro State. Otherwise, in the Amazon region (Northern Brazil), TcI is the prevailing DTU found in humans as the agent of acute infections 6,7,21 , but this genotype was also identified in fourteen chronic patients with the indeterminate form of Chagas disease 22,40 .…”

Transmissão da doença de Chagas por consumo de carne de caça: revisão sistemática

“…Only six articles met the selection criteria for this systematic review 18,[30][31][32][33][34] . Three publications discussed the same infection episodes in Argentina, both involving children who had consumed raw or poorly cooked wild animal meat or blood [30][31][32] .…”

“…This habit may be a result of their contact with natives and Africans during the colonial period 20 . Recent research conducted in rural areas of Rio de Janeiro shows that consumption of wild animal meat was reported by 78% of residents and in the 15 cases of CD classified as autochthonous 18 . Armadillo and opossum, known reservoirs of T. cruzi, were the most cited animals 18,28 .…”

“…Recent research conducted in rural areas of Rio de Janeiro shows that consumption of wild animal meat was reported by 78% of residents and in the 15 cases of CD classified as autochthonous 18 . Armadillo and opossum, known reservoirs of T. cruzi, were the most cited animals 18,28 . Although hunting of wild animals was forbidden in Brazil in 1967, it still occurs in rural areas, and not only as a means of survival 29 .…”

“…T. cruzi infection has been identified in over a hundred species of wild mammals, in addition to domestic species like dogs, cats, pigs, goats, guinea pigs, and rabbits 2,3,[14][15][16][17] . [17][18][19] . Native populations had the habit of consuming meat from hunting, and this was an important source of food when animal husbandry techniques were not yet known 20 .…”