ASPECTOS DA SUSCETIBILIDADE DOS TRIATOMINEOS AO Trypanosoma cruzi NA BUSCA DE UM MODELO EXPERIMENTAL

Abstract

Estudou-se a suscelibilidade de diferenies espécies de iriaiomíneos cm relação à cepa Y de Trypanosoma cruzi, alravés da aplicação do xenodiagnóstico em camundongos com a infecção aguda. Uiílizarani-se 20 camundongos infectados e, em cada um, aplicaram-se 8 trialomíneos. um de cada espécie, para se alimentarem, simultaneamente. Cada triatomíneo foi examinado individualmente, pelo método das dejeções espontâneas. A ordern de suscetibilidade das espécies de trialomíncos em relação ao número de Iripanossomas excretados foi: 1° -Dipetalogaster máximas, 2" -Triatoma malogrosseitsis, 3° -Rhodiúits neglectus, 4° -T.infestans. Os experimentos foram realizados numa câmara biológica, a 28 ± 1°C, umidade relativa de 70 ± 5% e fotoperíodo de 12 horas. UNITERMOS: Suscetibilidade. Triatomíneos. Trypanosoma cruzi. Doença de Chagas. INTRODUÇÃOO xenodiagnóstico tem estimulado várias investigações com a finalidade de melhorar a sensibilidade deste exame, devido a sua utilização tanto para diagnosticar a tripanossomíase americana, no homem e em outros mamíferos, quanto para demonstrara parasitemia circulante, na experimentação com drogas tripaiiossomicidas. Dentre as investigações, a suscetibilidade de triatomíneos em relação ao Trypanosoma cruzi, tem sido objeto de estudo de diversos autores, tal como neste " Prof. do Dept." de Parasítologia -IPTSP/UFG. " Bolsista de iniciação científica do CNPq -Apoio financeiro: SENESU-PRPPG e FUNAP Recebido para publicação em 22/03/94

Triatominae fauna (Hemiptera: Reduviidae) in Mato Grosso do Sul, Brazil, and the influence of climatic elements on their populations.

“…matogrossensis has invades the home environment and presents a tendency to domiciliation. 30,31 In a previous work, 14 this species was not found naturally infected, but its infection rate (18.18%) in this study draws attention and is cause for concern. Despite being a kind of rocky environment and wild breeding sites, 32.32% of these insects were captured in the home environment, which is of concern because it is a species with good capacity vector for T. cruzi.…”

“…Despite being a kind of rocky environment and wild breeding sites, 32.32% of these insects were captured in the home environment, which is of concern because it is a species with good capacity vector for T. cruzi. 32 R. neglectus is predominantly wild, occurring in palm trees 29,30 and with low rates of T. cruzi infection. 33 Although P. diasi, R. neglectus, P. geniculatus and T. baratai not present major epidemiological importance, studies show that R. neglectus can form colonies domiciliary 33,34 exposing synanthropy highlighted in the Brazilian Midwest, 33 besides being the most frequent indoors, 7,35 which can lead to increased transmission capacity.…”

Experimental Hybrids of the Triatoma brasiliensis Species Complex Show Higher Susceptibility to the Trypanosoma cruzi Infection Than Their Parentals

“…Moreover, specimens that ingested very small amounts of blood (e.g., 91 mg) had a sufficient quantity of parasites to initiate and maintain the infection in their digestive tract for up to 30 days after feeding. Another study evaluating the susceptibility of four species of triatomines to infection with the Y strain also found the amount of blood ingested did not have any influence on the level of infection presented by the insects [55].…”

“…The host-parasite relationship drives triatomines to transmit T. cruzi to susceptible hosts, which involves several factors such as the morphogenesis process of the parasite [54]; the susceptibility of the insect vector to the parasite strain [55]; the average time between blood-feeding and infective defecation, which occurs when the triatomine is still in direct contact with the host's skin; and the number of blood meals at each stage during the insect developmental cycle [56]. These characteristics provide important information that enables us to evaluate the vector capacity of the triatomine species [57], which covers several biological, ecological, and behavioral parameters of the insect; also, we can evaluate their vector competence, which is estimated as the proportion of individuals susceptible to the etiological agent within the population [58].…”

“…The natural ecotope of the insects also needs to be considered since the specimens used in these experiments were all reared under laboratory conditions. Some studies have emphasized the superiority of wild vectors over domestic ones for studying T. cruzi infection [61], such as T. infestans and R. neglectus infected with the Y strain, which had a lower infection rate than Dipetalogaster maxima (Uhler, 1894) and Triatoma matogrossensis Leite & Barbosa, 1953, and which are typically wild species that invade domiciles [55].…”