94 research outputs found

    Revisão e análise cladística dos gêneros Cerqueirellum (Py-Daniel, 1983) e Coscaroniellum (Py-Daniel, 1983) (Diptera: Simuliidae)

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    Os insetos da família Simuliidae são hematófagos e vetores de diversos patógenos dentre os quais destacam-se os vermes filarióides Mansonella ozzardi e a Onchorcerca volvulus. Dentre os grupos supraespecíficos que são vetores de mansonelose e oncocercose na América do Sul, destaca-se gênero Cerqueirellum (Py-Daniel). O gênero Coscaroniellum (Py-Daniel) é um genêro filogeneticamente muito próximo a Cerqueirellu. Não existia concordância quanto à validade de Cerqueirelum e Coscaroniellum como clados supraespecíficos, sendo ambos os gêneros incluídos por uma escola taxonômica como grupos de espécies em Psaroniocompsa (Enderlein). Devido aos problemas nomenclaturais quanto aos clados supraespecíficos das espécies que compõem Cerqueirellum, Coscaroniellum e Psaroniocompsa, foi feita uma revisão e estabelecidas as relações filogenéticas entre as espécies envolvidas em Cerqueirellum e Coscaroniellum. Foi elaborada, primeiramente, uma lista preliminar das espécies de simulídeos incluídos nos gêneros Cerqueirellum e Coscaroniellum, sendo reunidas informações sobre localidade tipo, formas descritas, distribuição geográfica e dados biológicos. Em seguida foi examinado o material entomológico que se encontra depositado na coleçãode Simuliidae do INPA. Os espécimes examinados foram montados em lâminas e feito um quadro analítico com base filogenética e montado chaves de identificação e distribuição geográfica para cada gênero estudado. Foram incluídas na análise algumas espécies de simulídeos próximos de Cerqueirellum, sendo caracterizado e apresentado e apresentado um novo gênero, denominado de Shelleyellum gen. nov. Os gêneros Cerqueirellum, Coscaroniellum e Shelleyellum gen. nov. Apresentaram-se como entidades basais válidas, consistentes e mononfiléticas

    Importância do método de gota espessa de sangue no diagnóstico de filárias simpátricas no Amazonas, Brasil

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    In this work, the visual diagnostic methods for human filarias in the blood are evaluated. The thick blood film method is more faithful to identify the microfilariae species if compared to policarbonate membrane filtration and Knott methods, especially in areas where more than one species occur, as in Amazon basin. Slides with Mansonella ozzardi microfilariae were mounted and photographed by different diagnosis methods. The thick blood film method is much easier to see the diagnostic morphological characters as cephalic and caudal space, pattern of nucleation of the tail and tail shape that can separate the blood Amazonian microfilariae species

    Description of two new species of Palpomyia Meigen (Diptera: Ceratopogonidae) from the Brazilian Amazon

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    Resumo. Duas novas espécies de insetos predadores e bioindicadores da qualidade da água do gênero Palpomyia, grupo distincta, são descritas e ilustradas baseadas em espécimes machos. Os imaturos das espécies Palpomyia amazonensis sp. nov. e Palpomyia lanceolata sp. nov. foram coletados em armadilhas ovitrampas e criados em laboratório até adultos. Ambas novas espécies são semelhantes a Palpomyia guyana Clastrier, 1992 e Palpomyia turnbowi Grogan et al., 2013 e diferem de Palpomyia versicolor Macfie, 1939, única espécie do grupo distincta descrita na Amazônia Brasileira. Com as duas descrições, foram aumentadas para três o número de espécies para a Amazônia e 32 para o Brasil. Descrição de duas novas espécies de Palpomyia Meigen (Diptera: Ceratopogonidae) da Amazônia brasileira Abstract. Two new Amazonian predaceous midge of the genus Palpomyia, from the distincta group, were described based on male specimens. This genus is an important bioindicator of aquatic environments. The immatures of Palpomyia amazonensis sp. nov. and Palpomyia lanceolata sp. nov. were collected with ovitraps and reared in laboratory until adulthood. Both new species are similar with Palpomyia guyana Clastrier, 1992 and Palpomyia turnbowi Grogan et al., 2013 but differs from Palpomyia versicolor Macfie, 1939, the unique species described in Brazilian Amazon until now. With the description of these new species we increase to three the representative species of the distincta group in the Brazilian Amazon and to 32 the number of Brazilian species of Palpomyia

    Comparative biology of two populations of Lutzomyia umbratilis (Diptera: Psychodidae) of Central Amazonia, Brazil, under laboratory conditions.

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    Lutzomyia umbratilis is the main vector of cutaneous leishmaniasis due to Leishmania guyanensis in northern South America. It has been found naturally infected with this species of Leishmania only east of the Rio Negro and north of the Rio Amazonas. However, populations of this sand fly species are also present in areas south of the Amazon river system, which may act as a geographical barrier to the Leishmania guyanensis cycle. With the aim of looking for possible biological differences between populations of L. umbratilis from each side of this river system, their biology in the laboratory was investigated. Progenitors collected on tree bases in Manaus and Manacapuru (east and west, respectively, of the Rio Negro) were reared in the laboratory. Results from observations of the life cycle, fecundity, fertility, and adult longevity at 27 degrees C and 92% RH were analyzed by descriptive statistics and z, t, U, and chi2 tests. Although the Manaus and Manacapuru colonies showed a longer developmental time than most Lutzomyia species reared at similar temperatures, length of time of egg and 4th instar larva of the two populations differed significantly (p < 0.01). Females of the latter retained significantly (p < 0.001) less mature oocytes, and the general productivity (% adults from a known number of eggs) of the colony was significantly (p < 0.01) higher than that of the former. These results show that the L. umbratilis population of Manaus is more productive, and thus a better candidate for future mass-rearing attempts. The two populations differ in their life cycle, fecundity, fertility, adult longevity, and emergence. These differences may reflect some divergence of intrinsic biological features evolved as a result of their geographical isolation by the Rio Negro. It is expected that further investigations on morphometry, cuticular hydrocarbon, isoenzyme, molecular and chromossomal analyses, infection, and cross-mating experiments with these and other allopatric populations of both margins of the Amazon river system will help reveal whether or not L. umbratilis has genetically diverged into two or more reproductively isolated populations of vectors or non-vectors of Leishmania guyanensis

    Mansonella ozzardi in the municipality of Tefé, Amazonas, Brazil, 60 years after the first report: An epidemiologic study

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    The prevalence of mansonelliasis was studied in the municipality of Tefé, state of Amazonas, Brazil. The prevalence (thick blood smear method) was 13.6% (147/1,078), higher in the Solimões River region (16.3%) than in the Tefé River region (6.3%). In the sampled communities in the Solimões River region, a higher density of cases was observed, as indicated by a kernel analysis (odds ratio 0.34; 95% confidence interval: 0.20-0.57). Males had a higher prevalence (χ2 = 31.292, p &lt; 0.001) than women. Mansonella ozzardi prevalence was higher in retirees and farmers (28.9% and 27%, respectively). Prevalence also significantly increased with age (χ2 = -128.17, p &lt; 0.001), with the highest numbers occurring in persons older than 67 years

    Hematophagous biting midges (Diptera: Ceratopogonidae) from Tefé municipality, Amazonas state, Brazil

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    Some species of biting midges are vectors of pathogens that cause disease in vertebrates, including humans. The aim of this study was to survey the biting midge fauna in Tefé, Amazonas, Brazil. Culicoides were collected using HP light traps during January, February, and April 2013. Midges collected included one species from the genus Lectoconops that bites humans. A total of 248 Culicoides individuals were collected, representing 19 species from two subgenera (Haematomyidium and Hoffmania) and four informal species groups (carpenteri, leoni, fluvialis, and reticulatus). Twelve individuals of L. brasiliensis were also collected, and this is the first record of L. brasiliensis in Amazonas. Three species of Culicoides were also recorded for the first time in Amazonas, including Culicoides aitkeni, C. glabellus and C. ocumarensis. The most abundant species were C. hylas (81 individuals), and C. foxi (27). The Culicoides fauna in Tefé is diverse, and proven vectors such as C. paraensis and C. insignis were found

    Mansonella ozzardi in Amazonas, Brazil: Prevalence and distribution in the municipality of Coari, in the middle Solimões River

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    This study investigated some epidemiological aspects of the Mansonella ozzardi in municipality of Coari, Amazonas. Clinical symptoms were correlated with the filarial infection and the parasitic infection rates (PIR) were estimated in simuliid vectors. The general M. ozzardi human prevalence rate was 13.3% (231/1733), of which 10.2% (109/1069) were from the urban area and 18.4% (122/664) from the rural area. The prevalence rates were higher in men (14.5% urban and 19.7% rural) than in women (6.7% urban and 17.2% rural) and occurred in most age groups. The indices of microfilaremics were higher in people ≥ 51 years old (26.9% urban and 61.5% rural). High prevalence rates were observed in retired people (27.1% urban area), housewives and farmer (41.6% and 25%, respectively, in rural area). The main clinical symptoms were joint pains and sensation of leg coldness. Only Cerqueirellum argentiscutum (Simuliidae) transmits M. ozzardi in this municipality (PIR = 5.6% urban and 7.1% rural). M. ozzardi is a widely distributed parasitic disease in Coari. Thus, temporary residency in the region of people from other localities involved with the local gas exploitation might be a contributing factor in spreading the disease

    A field trial of a PCR-based Mansonella ozzardi diagnosis assay detects high-levels of submicroscopic M. ozzardi infections in both venous blood samples and FTA® card dried blood spots

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    BACKGROUND: Mansonella ozzardi is a poorly understood human filarial parasite with a broad distribution throughout Latin America. Most of what is known about its parasitism has come from epidemiological studies that have estimated parasite incidence using light microscopy. Light microscopy can, however, miss lighter, submicroscopic, infections. In this study we have compared M. ozzardi incidence estimates made using light microscopy, with estimates made using PCR. METHODS: 214 DNA extracts made from Large Volume Venous Blood Samples (LVVBS) were taken from volunteers from two study sites in the Rio Solimões region: Codajás [n = 109] and Tefé [n = 105] and were subsequently assayed for M. ozzardi parasitism using a diagnostic PCR (Mo-dPCR). Peripheral finger-prick blood samples were taken from the same individuals and used for microscopic examination. Finger-prick blood, taken from individuals from Tefé, was also used for the creation of FTAcard dried blood spots (DBS) that were subsequently subjected to Mo-dPCR. RESULTS: Overall M. ozzardi incidence estimates made with LVVBS PCRs were 1.8 times higher than those made using microscopy (44.9% [96/214] compared with 24.3% [52/214]) and 1.5 times higher than the PCR estimates made from FTAcard DBS (48/105 versus 31/105). PCR-based detection of FTAcard DBS proved 1.3 times more sensitive at diagnosing infections from peripheral blood samples than light microscopy did: detecting 24/105 compared with 31/105. PCR of LVVBS reported the fewest number of false negatives, detecting: 44 of 52 (84.6%) individuals diagnosed by microscopy; 27 of 31 (87.1%) of those diagnosed positive from DBSs and 17 out of 18 (94.4%) of those diagnosed as positive by both alternative methodologies. CONCLUSIONS: In this study, Mo-dPCR of LVVBS was by far the most sensitive method of detecting M. ozzardi infections and detected submicroscopic infections. Mo-dPCR FTAcard DBS also provided a more sensitive test for M. ozzardi diagnosis than light microscopy based diagnosis did and thus in settings where only finger-prick assays can be carried-out, it may be a more reliable method of detection. Most existing M. ozzardi incidence estimates, which are often based on light microscope diagnosis, are likely to dramatically underestimate true M. ozzardi parasitism incidence levels.Jansen Fernandes de Medeiros had financial support from edital PPSUS FAPEAM/SUSAM/MS/CNPq 007/2009. FAPEAM also provided finical support for the work of: Tatiana Amaral Pires de Almeida; Lucyane Bastos Tavares da Silva and J. Lee Crainey. The authors would like to thank Ricardo Mota and personal at Tefé for their technical assistance and two referees for their useful comments, which have helped to improve the manuscript. This paper is contribution number 23 of the Research Programme on Infectious Disease Ecology in the Amazon (RP-IDEA) of the Instituto Leônidas and Maria Deane—Fiocruz Amazônia.S

    Posterior Spiracles of Fourth Instar Larvae of Four Species of Phlebotomine Sand Flies (Diptera: Psychodidae) under Scanning Electron Microscopy

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    In the present study, posterior spiracles of laboratory-reared fourth instar larvae of Lutzomyia longipalpis, L. migonei, L. lenti, and L. whitmani (Diptera: Psychodidae) of the State of Ceará, Brazil, were examined under scanning electron microscopy. The number of papillae of spiracles examined varied according to the species examined, but no intraspecific differences were found. The importance of this structure to sand fly larva identification and phylogeny is commented
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