ABSTRACT
ABSTRACT Background: An external quality assessment on the identification of triatomines within the laboratory network in the state of Rondônia. Methods: Seven laboratories participated in this evaluation. Each was provided with support materials and nine insects from the Hemiptera order for identification. Results: All samples were accurately identified at the species level. However, correct sex identification was achieved for only 79% of the samples. The most significant challenges were encountered in determining the sex of predators, phytophagous species, Rhodnius robustus, and Rhodnius pictipes. Conclusions: The identified shortcomings can inform enhancements in vector control programs for Chagas disease.
ABSTRACT
Objetivo: Avaliar a qualidade da identificação de triatomíneos na rede de laboratórios do estado de Pernambuco, Brasil. Métodos: Os nove laboratórios participantes receberam material de apoio com as chaves dicotômicas e um painel composto por sete insetos triatomíneos conhecidos no estado, para identificação da situação do espécime no recebimento (estrutura completa ou danificada), espécie e sexo. Resultados: Nove laboratórios de 12 aderiram ao estudo. A proporção de acerto para identificação do sexo foi de 56/63, e para espécie, 45/63, não apresentando relação direta com a ocorrência de danos nas estruturas morfológicas durante o transporte dos insetos. Para Panstrongylus megistus, houve acerto em todos os espécimes (9/9), enquanto para espécies do gênero Rhodnius a proporção foi menor (3/9). Conclusão: Apesar do bom desempenho na identificação entomológica, as fragilidades observadas poderão orientar ações para melhoria na rede de laboratórios e serão essenciais para os programas de controle vetorial da doença de Chagas.
Objetivo: Evaluar la calidad de la identificación de triatominos en la red de laboratorios del estado de Pernambuco, Brasil. Métodos: Los nueve laboratorios participantes recibieron material de apoyo con claves dicotómicas y un panel conformado por siete insectos triatominos conocidas en el estado, para identificar la situación del espécimen al recibirlo (estructura completa o dañada), especie y sexo. Resultados: La adherencia al laboratorio fue del 9/12. La proporción de aciertos para la identificación del sexo fue del 56/63, y para las especies 45/63, no mostraron relación directa con la ocurrencia de daños en las estructuras morfológicas durante el transporte de insectos. Solo Panstrongylus megistus logró el 9/9 de precisión, mientras que para las especies del género Rhodnius fue el más pequeño (3/9). Conclusión: A pesar del buen desempeño en identificación entomológica, la evaluación indicó debilidades que permitirán implementar acciones correctivas para mejorar la red de laboratorios, esenciales para los programas de control vectorial de la enfermedad de Chagas.
Objective: To assess the quality of triatomine identification in the laboratory network of the state of Pernambuco, Brazil. Methods: The participating laboratories received support material with dichotomous keys and a panel made up of seven triatomine insects known in the Pernambuco, in order to identify specimen status on receipt (intact or damaged structure), as well as species and sex. Results: Nine out of 12 laboratories took part of the study. The proportion of correct answers was 56/63 for sex identification, and 45/63, for species. The answers did not present a direct relationship with occurrence of damage to morphological structures during insect transportation. Panstrongylus megistus identification was correct for all specimens (9/9 laboratories), while correct identification of species of the Rhodnius genus was the lowest (3/9 laboratories). Conclusion: Despite the good performance in entomological identification, the weaknesses observed may guide improvements in the laboratory network and will be essential for Chagas disease vector control programs.
Subject(s)
Humans , Animals , Triatominae/parasitology , Entomology , Insect Vectors/parasitology , Trypanosoma cruzi/parasitology , Brazil/epidemiology , Chagas Disease/epidemiology , Laboratories/statistics & numerical dataABSTRACT
The first report of the occurrence of Panstrongylus geniculatus (Latreille) 1811 was reported in the state of Pernambuco. Therefore its distribution was amplified, and now, such as P. megistus, is the most widely distributed species in Brazil. P. geniculatus was found by health workers in intradomiciliary environments in Vitória de Santo Antão, testing positive for flagellates observed by direct examination of intestinal contents, and Giemsa staining
Subject(s)
Chagas Disease , Panstrongylus , TriatominaeABSTRACT
A new species of Rhodnius is described and illustrated from a male specimen from northeastern Brazil. The specimen was found died and dried. This species can be distinguished from its similar congener R. paraensis Sherlock, Guitton & Miles by the greater size, the general aspect of the color of the body, by the uniform color of the legs, different proportions between the morphological structures of the head and the segments of the rostrum; also, in the male genitalia by the aspect of median process of pygophore, dorsal phallotheca plate and phallotheca process.
Uma nova espécie de Rhodnius é descrita e ilustrada baseada em um exemplar macho do nordeste brasileiro. O espécime foi encontrado morto e ressecado. Esta espécie pode ser separada da espécie afim, R. paraensis Sherlock, Guitton & Miles, pelo seu maior tamanho, pelo aspecto geral de coloração do corpo, pela cor uniforme das pernas, pelas diferentes proporções entre as estruturas morfológicas da cabeça e dos segmentos do rostro; ainda, na genitália masculina, pelo aspecto do processo mediano do pigóforo, do falosoma e de seu processo.
Subject(s)
Hemiptera/anatomy & histology , Hemiptera/pathogenicity , Rhodnius/anatomy & histology , Rhodnius/classification , Rhodnius/pathogenicity , Triatominae/anatomy & histology , Triatominae/pathogenicityABSTRACT
Os autores utilizaram a técnica de precipitina para identificar as fontes alimentares de Panstrongylus lutzi (Neiva & Pinto, 1923) em 20 municípios do Estado do Ceará, Brasil. Os resultados detectaram a presença de sangue de oito diferentes fontes sanguíneas e alimentações mistas, demonstrando que Panstrongylus lutzi é uma espécie eclética. Altas taxas de infecção por tripanosomatídeos foram detectadas.
The authors used precipitin technique to detect the feeding sources of Panstrongylus lutzi (Neiva & Pinto, 1923) in 20 municipalities of Ceará State, Brazil. The results detected the presence of blood from eight different blood sources and mixed feedings, demonstrating that Panstrongylus lutzi is an eclectic species. High infection rates for Trypanosoma like-cruzi were detected.
Subject(s)
Humans , Animals , Male , Female , Gastrointestinal Contents , Insect Vectors/physiology , Panstrongylus/physiology , Trypanosoma cruzi , Brazil , Chagas Disease/transmission , Feeding Behavior/physiology , Insect Vectors/parasitology , Precipitin Tests , Panstrongylus/parasitologyABSTRACT
Eggs and all nymphs of these species were studied employing light microscopy (LM) and scanning electron microscopy (SEM). The major differences observed by LM in the eggs were related to the presence and the distribution of pores on the surface of their chorion. Morphological differences among three nymphal stages (1st, 3rd, and 5th) development of each species were observed. The differential characteristics are chromatic and in the shape of connexival spots. The ultrastructure of the ventral region of the head and the IX, X, and XI abdominal segments (anal tube) of the both species were described demonstrating morphological differences that can be used for diagnosis of the species.
Subject(s)
Animals , Triatoma/growth & development , Microscopy, Electron, Scanning , Nymph/anatomy & histology , Nymph/ultrastructure , Ovum/ultrastructure , Triatoma/anatomy & histology , Triatoma/ultrastructureABSTRACT
R. brethesi is a sylvatic species from the Amazon region; it has been incriminated as responsible for the transmission of Chagas disease in collectors of piaçaba in this region. The aim of present study was to investigate the efficiency of these insects as potential vectors of Trypanosoma cruzi. Aspects related with feeding and defecation patterns, life time, and mortality had been observed in each instar of R. brethesi. We use 5th instar nymphs to get adults virgins, after the moulting 3 groups with 6 females and 2 males each were created to obtain eggs. After hatching, 1st instar nymphs had been weighed and kept in bottles until the next moult. Insects were fed once a week in mice. Results showed that the average period of incubation was 17 days, the number of blood meal was increasing from the 1st to the 5th instar nymph with 7 (average) to become adult, a significative numbers of the defecations occurring immediately after the bloodmeals. The total percentual of mortality was 16 percent. This results suggests that this species presents a good exploitation of blood meals and a brief nymphal development in laboratory conditions reflecting its behavior in sylvatic environments.
Subject(s)
Animals , Male , Female , Insect Vectors , Life Cycle Stages , Rhodnius , Brazil , Chagas Disease , LaboratoriesABSTRACT
Belminus herreri, originally described from specimens collected in Panama, was considered entirely silvatic until to 2000 when it was found for the first time in a domestic habitat in Colombia. In 2001, during a new search of houses in the Department of Cesar, Colombia, 121 specimens were collected. Study of their feeding sources using an ELISA test revealed that 96 percent of these specimens had fed on cockroaches (Blattidae). However, a small proportion of these B. herreri specimens also showed the presence of Trypanosoma cruzi in their gut contents, suggesting a possible role for these insects in the epidemiology of Chagas disease.
Subject(s)
Animals , Male , Female , Gastrointestinal Contents , Insect Vectors , Triatominae , Chagas Disease , Colombia , Enzyme-Linked Immunosorbent Assay , Feeding Behavior , Housing , Insect Vectors , Polymerase Chain Reaction , Triatominae , Trypanosoma cruziABSTRACT
The subfamily Triatominae is actually represented by 137 species distributed among 6 tribes and 19 genera. Within this subfamily, the genus Panstrongylus, Berg 1879, is composed by 13 species widespread in sylvatic, peridomestic, and domestic habitats of Neotropical regions. These species are vectors of Chagas disease and consequently are found associated with its main hosts, such as birds and mammals. Interest in species of this genus has been increasing in the last few years. Reports of several authors indicate these Triatominae to invade and colonize houses, increasing their epidemiological significance. Morphometry was used in this study to investigate correlations among possible closely related species. We measured 224 specimens among 13 species through a set of metric variables of the head. The results indicated that the genus Panstrongylus seems to be homogeneous since 10 of the 14 species were shown to be closely related.
Subject(s)
Animals , Head , Insect Vectors , Panstrongylus , Insect Vectors , Panstrongylus , PhylogenyABSTRACT
There are several specific complexes belonging to the genus Triatoma Laporte, 1832, which are generally associated to specific geographic areas. Recent publications have linked the oliveirai complex to ecosystems of Mato Grosso, which are also present in other Brazilian states and even in other bordering countries as eastern Paraguay. The study of the abundant material collected during the last years allowed the description of several new species of the oliveirai complex: T. jurbergi Carcavallo, Galväo & Lent, 1998; T. baratai Carcavallo & Jurberg, 2000 and T. klugi Carcavallo, Jurberg, Lent & Galväo, 2001. Another new species belonging to the same complex is described here as T. vandae sp.n. It originates from the state of Mato Grosso, and has been reared in the insectary of the Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Departamento de Entomologia, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro
Subject(s)
Animals , Male , Female , Triatominae , Brazil , TriatominaeABSTRACT
Eggs and nymphs of Triatoma jurbergi were described using optical microscopy and scanning electron microscopy. T. jurbergi is a wild species, found in State of Mato Grosso (15ºS and 300 m.a.s.l), Brazil. Eggs showed the operculum and surface with pentagonal and hexagonal cells, with small fractures and punctuations randomly distributed. Differences were found in the five nymphal stages of T. jurbergi, that allow their to be distinguished from the similar species T. guazu. The diagnostic characters most useful for differentiation were the general color of the insect, abdomen shape and its length
Subject(s)
Animals , Triatoma , Microscopy, Electron, Scanning , Nymph , OvumABSTRACT
The flight initiation of T. infestans, the main vector of Chagas disease in the Southern Cone countries of Latin America, and of the closely-related species T. melanosoma was studied in laboratory. The results demonstrated that after the beginning of observations the peak of the flight activity was about 14 days after feeding in both species and it was usually more marked in the females than in the males, but there were no significant differences in the flight behaviour of the two species
Subject(s)
Animals , Male , Female , Flight, Animal/physiology , Triatoma/physiology , Behavior, Animal/physiology , Sex FactorsABSTRACT
Aborda os estágios ninfais da eclosäo do ovo até chegar à fase adulta
Subject(s)
Disease Vectors , Nymph/anatomy & histology , Triatominae/growth & developmentABSTRACT
Rhodnius pictipes (Hemiptera, Reduviidae) from Serra Norte, State of Para, Brazil, aclimatizes in an insectary at the Laboratorio Nacional e Internacional de Referencia em Taxonomia de Triatomineos, Departamento de Entomologia, Instituto Oswaldo Cruz, were fed through a silicone membrane. In order to know the viability and the efficiency of this membrane compared with insects fed on mice, the number of bloodmeals taken, period of development of the five nymphal instars, longevity of adults, average amount of blood intake in each meal and percent of mortality were observed. A total of 310 insects were used, comprising 50 nymphs of each instar, as well as 30 male and 30 female adults. Insects fed artificially had reduced minimal and maximal periods of development than the group fed on mice. The largest relative increase of body weight was observed in the 2nd instar followed by the 1st, and the amount of blood ingested increased during the development, to the 5th instar for both goups. There were no significant differences between the groups fed artificially and in vivo according to Tukey's test for p>0.05. The percent of mortality in the 1st instar was 18 per cent for artificially fed and 16 per cent for the group fed on mice; these percentages decreased as insects developed until the 4th instar, without mortality, returning to increase in the 5th instar. R. pictipes was shown to be easily adaptable to artificial feeding, and could be considered as an important and viable experimental model.
Subject(s)
Animals , Mice , Nutritional Support/methods , Rhodnius/growth & development , Mice/parasitology , SiliconesABSTRACT
Biology of Rhodnius pictipes Stal, 1872 under laboratory conditions (Hemiptera, Reduviidae, Triatominae) - Rhodnius pictipes Stal, 1872 is a silvatic species with a widespread distribution in South America, found in nine Brazilian states, naturally infected by Trypanosoma cruzi and T. rangeli. The individual rearing of this species under laboratory conditions, allowed the following biological aspects to be observed: incubation time, search for first meal after eclosion or moult, time - lapse between presentation of the blood meal and the beginning of feeding, duration of blood meal, time and place of defecation, number of blood meals, duration of each instar and adult longevity, and time required from egg to adult