RESUMO
The state of Rondônia in the Brazilian Amazon is prone to diseases transmitted by insect vectors because of the environmental and population changes resulting from large hydroelectric projects and the expansion of agricultural and livestock industries. The first case of Chagas disease by vectorial transmission was recorded in 2019 in a rural area in Rondônia, reinforcing the need for entomological surveillance. Hence, our goal was to estimate the abundance of Rhodnius spp. in palm trees located in rural and periurban areas and in Brazil-Bolivia border regions, perform domiciliary searches, and check for possible associations between triatomines and the presence/absence of palm-inhabiting fauna and outdoor farming, domestic animals, and buildings. The sampling took place in five municipalities of Rondônia in 2014 (June to August) and 2015 (April to June). Triatomines were collected by active searches during the selective pruning of palm tree crowns. Domiciliary inspections lasted from 30 to 60 min. A set of captured triatomines was analyzed for Trypanosoma cruzi and T. rangeli infection by PCR. Overall, 496 insects were captured during sampling of 150 palms in rural areas and 150 in periurban areas. No triatomine was found during active searches of 59 dwelling either indoors or outdoors. The majority of triatomines caught in the palm trees were identified as Rhodnius robustus (98.6%), and seven specimens were R. pictipes. Triatomine infestation was observed in only 20% of the sampled palms (61/300) in the vicinity of 26/59 households. Nearly half of the infested palm trees had only one or two triatomines, and few palms presented more than 15 triatomines. The municipality of Buritis had the highest triatomine abundance and percentage of infested palms; however, the highest triatomine density per infested palm was observed in Alvorada D'Oeste, where a quarter of the palms were infested. Ants, arachnids, termites, reptiles, and rodents were frequently found in palm trees. Dogs were the predominant domestic animals in households, whereas hens and cattle were the main farming animals. Model estimates showed that the number of triatomines was affected by the presence of henhouses and varied strongly between localities. No relationships were detected between the average number of triatomines and palm fauna and/or palm height. Overall, approximately half of the triatomines were infected with T. cruzi (51.4%) and/or T. rangeli (47.2%), reinforcing the need for continuous entomological surveillance and implementation of community-based approaches because the Brazilian state of Rondônia borders areas experiencing reinfestation by domiciled species and potential colonization of animal shelters by triatomines.
Assuntos
Arecaceae/parasitologia , Insetos Vetores/fisiologia , Doenças das Plantas/parasitologia , Rhodnius/fisiologia , População Rural , Trypanosoma cruzi/fisiologia , Trypanosoma rangeli/fisiologia , Animais , Brasil/epidemiologia , Bovinos , Doença de Chagas/transmissão , Cães , Doenças das Plantas/prevenção & controleRESUMO
Chagas disease is an anthropozoonosis, caused by a flagellated protozoan, Trypanosoma cruzi, in which the enzootic cycle occurs between mammals and triatomines. Two dogs with a history of sudden death were necropsied at the Federal University of Pará (UFPA). One dog had a pale area in the myocardium, which on histopathological examination showed a T. cruzi amastigote nest; immunohistochemistry (IHC) analysis characterized it as acute Chagas disease (ACD). The second dog showed no macroscopic changes. Microscopically, a few cardiomyocytes were replaced by adipocytes, and IHC result was negative for T. cruzi. However, results of polymerase chain reaction (PCR) of the cardiac tissue of both dogs was positive for T. cruzi DNA. After that, an epidemiological study was conducted in the region. For this study, we selected four areas in Castanhal. One of the four areas (Area 1) is where one of the dogs lived. The other three areas were chosen because they were recently deforested for housing. Blood samples were collected from dogs, cats, wild small mammals (marsupials and rodents), and the digestive tract of triatomines. Nested PCR was performed on all the blood samples and the triatomine digestive tracts. In Area 1, T. cruzi DNA was detected in 50% (12/24) of the tested dogs, in the only tested cat (1/1), 50% (1/2) of the tested marsupials (Didelphis marsupials), and 100% of the captured triatomines (Rhodnius pictipes) (2/2). In Area 2, T. cruzi DNA was not detected in any of the 11 (0/11) dogs and two marsupials tested (0/2), and no triatomines were found in this area. In Area 3, T. cruzi DNA was detected in 42.25% (30/71) of the dogs, in 66,6% (2/3) of the cats, the only captured marsupial (D. marsupialis) (1/1), and all three triatomines (3/3) (R. pictipes) tested. In Area 4, the two dogs tested were negative (0/2), 25% (1/4) of the captured marsupials (D. marsupialis) was positive, and no triatomine was captured in this area. The data demonstrate the importance of detecting T. cruzi in dogs, cats, small rodents, and marsupials in the Amazon metropolitan areas, where ecotopes carry reservoirs and vectors capable of participating in the Chagas disease cycle. The proximity between humans and T. cruzi vectors in these places might contribute to increased disease transmission risk and maintenance of agents. It was noted that high-standard condominiums, previously thought to reduce the risk for this disease, presented a new epidemiological risk. The presence of T. cruzi DNA in a dog who, a year earlier had tested negative, when another dog in the same house died of ACD, shows that the transmission cycle is present and active, with a high possibility of disease transmission to animals and humans.
Assuntos
Doença de Chagas/veterinária , Doenças do Cão/parasitologia , Trypanosoma cruzi/genética , Animais , Doenças do Gato/parasitologia , Gatos/parasitologia , Doença de Chagas/transmissão , DNA de Protozoário , Didelphis/parasitologia , Doenças do Cão/diagnóstico , Doenças do Cão/patologia , Cães/parasitologia , Insetos Vetores/parasitologia , Mamíferos/parasitologia , Marsupiais/parasitologia , Reação em Cadeia da Polimerase , Rhodnius/parasitologia , Fatores de Risco , Roedores/parasitologiaRESUMO
BACKGROUND: In recent decades some outbreaks of food-borne acute Chagas disease (ACD) in humans were identified by clinical and epidemiological characterization after association through the ingestion of açaí pulp probably contaminated with Trypanosoma cruzi. Whereas Belém and Abaetetuba stood out as important risk regions for disease transmission, the importance of Rhodnius pictipes, and Philander opossum for the biological cycle of T. cruzi, and data from agribusiness market of açaí, to study T. cruzi from vector and reservoir of the Brazilian Amazon region is critical for this context. Thus, the purpose of this study was to verify the infective capacity and the virulence of T. cruzi in açaí pulp from vector and reservoir at Pará State experimentally. METHODS: 105T. cruzi I in in natura açaí pulp from Belém at Pará State, at room temperature, after forced sieving, by intraperitoneal, gavage or oral route of inoculation in B6.129S7Rag1-/-tmMom/J Unib allowed food-borne ACD analysis using common light microscopy. PRINCIPAL FINDINGS: T. cruzi in in natura açaí pulp from R. pictipes (Val-De-Cans Forest, Belém, and Ajuaí River, Abaetetuba, Pará), and P. opossum (Combu Island, Belém, Pará) caused ACD and death between 17 and 52 days after experimental infections in murine immunodeficient hosts. CONCLUSIONS: T. cruzi from different sources and locations at Pará State in in natura açaí pulp retained its infective capacity and virulence, and can cause new outbreaks of ACD by oral transmission. Additionally, quality basic education will facilitate efficient hygiene practices throughout the açaí productive chain can eradicate food-borne ACD in the coming decades.
Assuntos
Doença de Chagas/transmissão , Euterpe/parasitologia , Parasitologia de Alimentos , Doenças Transmitidas por Alimentos/parasitologia , Trypanosoma cruzi/patogenicidade , Doença Aguda , Animais , Brasil/epidemiologia , Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Reservatórios de Doenças/parasitologia , Vetores de Doenças , Feminino , Doenças Transmitidas por Alimentos/epidemiologia , Insetos Vetores/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos , Gambás/parasitologia , Parasitemia/epidemiologia , Parasitemia/mortalidade , Rhodnius/parasitologia , VirulênciaRESUMO
Rhodnius amazonicus Almeida et al. (1973) is a triatomine of rare occurrence. This species was found for the third time in Breves city, Pará state, Brazil. Morphometric and morphological studies were carried out on one male and one female. Lent and Wygodzinsky (1979) considered this species as a synonym of R. pictipes, until its revalidation after 23 years by Bérenger and Pluot-Sigwalt (2002). Considering the synonym mentioned above, a comparative study between these two species was performed in order to report the third encounter of this species, and increase the number of morphological characters that distinguish R. amazonicus from R. pictipes. The dorsal side of the head, the dorsal and ventral portions of the thorax, the dorsal, ventral and posterior sides of the female genitalia, eggs and the median process of the pygophore were examined by scanning electronic microscopy (SEM). The head, thorax, abdomen and egg parameters of these two species were also measured. The identification of characters on the head, stridulatory sulcus, mesosternum, metasternum, scutellum, process of urotergite I, external female genitalia, pygophore and eggs made the distinction between R. amazonicus and R. pictipes possible. This study has shown the new characters recorded and described for the first time for R. amazonicus and R. pictipes by SEM here made it possible to confirm the morphological separation between these two species. The morphometric analysis also confirmed that the above two taxa are different at specific level.
Assuntos
Abdome/anatomia & histologia , Genitália Feminina/anatomia & histologia , Cabeça/anatomia & histologia , Rhodnius/anatomia & histologia , Tórax/anatomia & histologia , Animais , Brasil , Feminino , Genitália Feminina/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura , Óvulo/ultraestrutura , Rhodnius/ultraestrutura , Tórax/ultraestruturaRESUMO
A análise da distribuição de triatomíneos é essencial para a formulação de estratégias de controle da doença de Chagas na Região Amazônica. Neste trabalho, apresentam-se os resultados de capturas realizadas em ambientes silvestres e artificiais, em localidades rurais e urbanas de Manaus, Amazonas. Dos 115 triatomíneos coletados, 85 (73,9 por cento) são da espécie Rhodnius pictipes, 25 (21,7 por cento) de Rhodnius robustus e cinco (4,4 por cento) de Panstrongylus geniculatus. A taxa de infecção natural por flagelados foi de 5,9 por cento para Rhodnius pictipes e 8 por cento para Rhodnius robustus. Nenhum exemplar de Panstrongylus geniculatus estava infectado. Todos os exemplares infectados eram oriundos de fragmentos de matas da zona urbana. Verificou-se que 106 (92,2 por cento) triatomíneos foram coletados no ambiente silvestre e nove (7,8 por cento) nas unidades domiciliares pela busca ativa. O gênero Rhodnius predominou nitidamente no ambiente silvestre. Os exemplares de Panstrongylus geniculatus, todos adultos, foram coletados no intradomicílio. Não foram encontrados indícios de colonização domiciliar por triatomíneos.
Analysis of the distribution of triatomines is essential for formulating control strategies for Chagas disease in the Amazon region. In this paper, the results from trapping in wild and artificial environments in rural and urban localities in Manaus, Amazonas, are presented. Out of the 115 triatomines collected, 85 (73.9 percent) were of the species Rhodnius pictipes, 25 (21.7 percent) of Rhodnius robustus and five (4.4 percent) of Panstrongylus geniculatus. The rate of natural infection by flagellates was 5.9 percent for Rhodnius pictipes and 8 percent for Rhodnius robustus. None of the specimens of Panstrongylus geniculatus were infected. All of the infected specimens were from forest fragments in the urban zone. It was found that 106 insects (92.2 percent) were collected from the forest environment and nine (7.8 percent) in households, by means of the active search. The genus Rhodnius clearly predominated in the wild environment. The specimens of Panstrongylus geniculatus (all adults) were collected inside homes. There were no signs of domestic colonization by triatomines.