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Trypanosoma is a hemoflagellate capable of infecting a wide variety of invertebrates and vertebrates, such as Neotropical freshwater fish. The present study described and morphologically compared Trypanosoma spp., found in Platydoras armatulus, Valenciennes, 1840, in southwestern Amazon. Fish specimens were sampled in Ipixuna and Juruá rivers located in the states of Amazonas and Acre, Brazil. Fish blood samples were taken by cardiac puncture, and smears were prepared for quantification, morphometric measurements, and morphotyping (characterization of the trypanosomes according to their morphological variations) of trypanosomes found. Prevalence, mean abundance, and intensity of parasitism were estimated in the parasitized fish specimens. Five fish specimens were collected, showing a 100% prevalence of parasites in the host. We found two Trypanosoma morphotypes, A and B, in which A had the highest infection intensity in host specimens. Thus, the present study presented the first report of Trypanosoma parasitizing P. armatulus, with different morphological variations.

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The Amazon region may present a high diversity of endoparasites with a high degree of endemism. In this sense, this study describes the endoparasite fauna in freshwater fish from the Upper Juruá, in the Western Amazon. The study was carried out around the municipalities of Cruzeiro do Sul, state of Acre, and Guajará, state of Amazonas, Brazil. Fish were caught between periods of droughts and floods, using passive and active sampling methods. In the laboratory, specimens were biometrically analysed and necropsied. As a result, a total of 23,740 endoparasites were recorded, belonging to 62 species, with 91 new host reports and 91 new occurrences for the Western Amazon. Nematoda and Digenea were the most diverse and abundant groups, and the increase in host fish richness and diversity influenced the diversity and richness of endoparasites in the environments. In this sense, the present study expands the number of new reports, and contributes data on the distribution and richness of endoparasites for South America.

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To assess the incidence of anaemia iron deficiency and malaria in a malaria endemic community...

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Canine monocytic ehrlichiosis is a highly prevalent disease in Brazil, where the genetic diversity of Ehrlichia canis remains undefined. In this study, we used the TRP36 gene to examine the genetic diversity of E. canis strains from naturally infected dogs residing in five distinct geographic regions in Brazil. E. canis DNA was detected in 82/126 (65%) dogs by dsb-specific PCR and E. canis was isolated in cell culture from 13 dogs. Sequences obtained from dsb genes amplified from the isolates were identical to the US E. canis strain. An extended molecular characterization based on the TRP36 gene identified two major genogroups based on differences among eight isolates. Isolates with tandem repeat amino acid sequence (TEDSVSAPA) identical to the previously reported TRP36 sequence were found in the midwest, northeast and southeast regions of Brazil, and classified into the US genogroup. A novel Brazilian genotype with a different tandem repeat sequence (ASVVPEAE) was also identified in midwest, northern and southern regions. Similarity in the N-terminal sequence of a US genogroup member with the Brazilian genogroup suggested that genomic recombination between the two genogroups may have occurred. Other subtypes within the Brazilian genogroup were also identified using C-terminal amino acid divergence. We identified two distinct major Brazilian genogroups and several subtypes based on analysis of TRP36, and such information will be useful for further genotyping and possible associations with disease severity, understanding of the genetic and antigenic variability of E. canis, and for developing strain-specific vaccines and diagnostic methods based on TRP36.

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O presente estudo determinou a prevalência de anticorpos anti-Leptospira spp. em ovinos do Município de Monte Negro, RO. Foram examinados soros de 141 ovinos de raça, idade e sexo variados provenientes de 15 fazendas, pela técnica de Soroaglutinação Microscópica. Doze (80,0%) propriedades apresentaram pelo menos um animal reagente. Títulos de anticorpos iguais ou superiores a 100 foram detectados em 47 (33,3%) animais, e os sorovares mais frequentes foram Patoc (29,7%), Autumnalis (14,8%), Pyrogenes (10,6%), Australis (4,2%), Bratislava (4,2%), Hardjo (4,2%), Icterohaemorrhagiae (4,2%), Castellonis (2,1%) e Hebdomadis (2,1%). Em 11 (23,4%) soros não foi possível a determinação do provável sorovar envolvido na reação. Alerta-se também para a possibilidade de infecção no homem, tendo em vista as características regionais de fronteira agrícola amazônica.

The present study determined the prevalence of anti-Leptospira spp.antibodies in 141 ovines from 15 farms of the Monte Negro Municipality, Rondonia State, Brazil, by the microscopic agglutination test. Twelve (80.0%) farms presented at least 1 reactive animal. Antibodies titers of ? 100 were detected in 47 (33.3%) animals, the most frequent serovars being Patoc (29.7%), Autumnalis (14.8%), Pyrogenes (10.6%), Australis (4.2%), Bratislava (4.2%), Hardjo (4.2%), Icterohaemorrhagiae (4.2%), Castellonis (2.1%) and Hebdomadis (2.1%). In 11 (23.4%) sera it was not possible to determine the most frequent serovar involved. The results raise a warning as to the possibility of infection in the human being by Leptospira in light of the regional characteristics of the Amazon agricultural frontier.

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ABSTRACT The present study determined the prevalence of anti-Leptospira spp.antibodies in 141 ovines from 15 farms of the Monte Negro Municipality, Rondonia State, Brazil, by the microscopic agglutination test. Twelve (80.0%) farms presented at least 1 reactive animal. Antibodies titers of ? 100 were detected in 47 (33.3%) animals, the most frequent serovars being Patoc (29.7%), Autumnalis (14.8%), Pyrogenes (10.6%), Australis (4.2%), Bratislava (4.2%), Hardjo (4.2%), Icterohaemorrhagiae (4.2%), Castellonis (2.1%) and Hebdomadis (2.1%). In 11 (23.4%) sera it was not possible to determine the most frequent serovar involved. The results raise a warning as to the possibility of infection in the human being by Leptospira in light of the regional characteristics of the Amazon agricultural frontier.

RESUMO O presente estudo determinou a prevalência de anticorpos anti-Leptospira spp. em ovinos do Município de Monte Negro, RO. Foram examinados soros de 141 ovinos de raça, idade e sexo variados provenientes de 15 fazendas, pela técnica de Soroaglutinação Microscópica. Doze (80,0%) propriedades apresentaram pelo menos um animal reagente. Títulos de anticorpos iguais ou superiores a 100 foram detectados em 47 (33,3%) animais, e os sorovares mais frequentes foram Patoc (29,7%), Autumnalis (14,8%), Pyrogenes (10,6%), Australis (4,2%), Bratislava (4,2%), Hardjo (4,2%), Icterohaemorrhagiae (4,2%), Castellonis (2,1%) e Hebdomadis (2,1%). Em 11 (23,4%) soros não foi possível a determinação do provável sorovar envolvido na reação. Alerta-se também para a possibilidade de infecção no homem, tendo em vista as características regionais de fronteira agrícola amazônica.

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We standardized serodiagnosis of dogs infected with Trypanosoma cruzi using TESA (trypomastigote excreted-secreted antigen)-blot developed for human Chagas disease. TESA-blot showed 100% sensitivity and specificity. In contrast, ELISA using TESA (TESA-ELISA) or epimastigotes (epi-ELISA) as antigen yielded 100% sensitivity but specificity of 94.1% and 49.4%, respectively. When used in field studies in an endemic region for Chagas disease, visceral leishmaniasis and Trypanosoma evansi (Mato Grosso do Sul state, Central Brazil), positivities were 9.3% for TESA-blot, 10.7% for TESA-ELISA and 32% for epi-ELISA. Dogs from a non-endemic region for these infections (Rondonia state, western Amazonia) where T. cruzi is enzootic showed positivity of 4.5% for TESA-blot and epi-ELISA and 6.8% for TESA-ELISA. Sera from urban dogs from Santos, São Paulo, where these diseases are absent, yielded negative results. TESA-blot was the only method that distinguished dogs infected with T. cruzi from those infected with Leishmania chagasi and/or Trypanosoma evansi.

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Previous population dynamics data, generated for Amblyomma parvum Aragão and Amblyomma cajennense (Fabricius) in Argentina and southeastern Brazil, have indicated that these ticks complete 1 generation per year, with larvae predominating in autumn, nymphs in winter, and mostly adults during spring and summer. The present study reports population dynamics data for free-living Amblyomma spp. ticks in northern Brazil (Amazon forest, latitude 10 degrees S, 63 degrees W), and for Amblyomma spp. ticks collected on birds in southeastern Brazil (latitude 23 degrees S, 45 degrees W). In northern Brazil, adult ticks predominated from mid-spring to mid-autumn, larvae predominated in early winter, and nymphs from mid-winter to mid-spring. Seven Amblyomma spp. were identified, although A. cajennense predominated in 1 of the 2 sites sampled. In southeastern Brazil, larval infestations on birds peaked in autumn, followed by a nymphal infestation peak in late winter. At least 32% and 75% of these larvae and nymphs, respectively, were identified as Amblyomma longirostre (Koch). Similar to previous work, the present study showed that Amblyomma spp. larvae and nymphs predominated during autumn-winter months, and mostly adults during spring-summer months, a pattern compatible with 1 generation/yr, even at latitude 10 degrees S in northern Brazil.

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Foram testados, pela técnica de soroaglutinação microscópica aplicada à leptospirose, 329 cães provenientes do município de Monte Negro, RO, dos quais 156 eram da área urbana e 173 da área rural. Simultaneamente foi aplicado questionário para verificar a existência de possíveis fatores de risco pela regressão logística. Abordaram-se questões referentes a idade, sexo, dieta, tipo de criação, ambiente, contato com outras espécies e hábito de caça. Foram detectadas reações com títulos >100 em 27,3%, com 90 cães positivos ao agente, das quais 23,7% eram da área (37/156) urbana e 30,6% (53/173), da área rural (P>0,05). Os sorovares predominantes, reatores com títulos mais elevados, foram Autumnalis (22%), Pyrogenes (12%), Canicola (10%) e Shermani (7,5%). Cães com idade acima de 12 meses apresentaram maior ocorrência de anticorpos quando comparados aos cães mais jovens (P<0,05). Dentre os fatores de risco analisados, foram significativos a alimentação (dieta à base de ração comercial - odds ratio: 3,3; intervalo de confiança: 95%: 1,2 9,2; P=0,02) e o sexo (macho - odds ratio: 2,3; intervalo de confiança: 95%: 1,3 3,9; P=0,003). Ressalta-se a ocorrência de reações para sorovares mantidos na natureza por animais silvestres.(AU)

The microscopic agglutination test was applied to 329 samples taken from 156 dogs from urban area and 173 from rural areas of Monte Negro County, Rondônia State, Brazil, to determine anti-Leptospira spp. antibodies. A survey was concomitantly done to detect eventual risk factors thru the use of logistic regression. Studied variables were age, sex, diet, management, environment, contact with other species and hunting habit. Titers >100 were detected in 27.3% (90/329) of the dogs, being 23.7% (37/156) urban and 30.6% (53/173) rural dogs. The most frequent serovars were Autumnalis (22.0%), Pyrogenes (12.0%), Canicola (10.0%) and Shermani (7.5%). Dogs older than 12 months showed higher positive frequencies than younger animals (P<0.05). Risk factor were associated with commercial food as compared to homemade food (odds ratio: 3.3; 95% confidence interval : 1.3 3.9; P=0.02) and associated with sex, with higher occurrence in males than in females (odds ratio: 2.3; 95% confidence interval: 1.3 3.9; P=0.003). It was emphasized the serological occurrence of serovars kept and spread in nature by wild animals.(AU)

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Foram testados, pela técnica de soroaglutinação microscópica aplicada à leptospirose, 329 cães provenientes do município de Monte Negro, RO, dos quais 156 eram da área urbana e 173 da área rural. Simultaneamente foi aplicado questionário para verificar a existência de possíveis fatores de risco pela regressão logística. Abordaram-se questões referentes a idade, sexo, dieta, tipo de criação, ambiente, contato com outras espécies e hábito de caça. Foram detectadas reações com títulos >100 em 27,3 por cento, com 90 cães positivos ao agente, das quais 23,7 por cento eram da área (37/156) urbana e 30,6 por cento (53/173), da área rural (P>0,05). Os sorovares predominantes, reatores com títulos mais elevados, foram Autumnalis (22 por cento), Pyrogenes (12 por cento), Canicola (10 por cento) e Shermani (7,5 por cento). Cães com idade acima de 12 meses apresentaram maior ocorrência de anticorpos quando comparados aos cães mais jovens (P<0,05). Dentre os fatores de risco analisados, foram significativos a alimentação (dieta à base de ração comercial - odds ratio: 3,3; intervalo de confiança: 95 por cento: 1,2 - 9,2; P=0,02) e o sexo (macho - odds ratio: 2,3; intervalo de confiança: 95 por cento: 1,3 - 3,9; P=0,003). Ressalta-se a ocorrência de reações para sorovares mantidos na natureza por animais silvestres.

The microscopic agglutination test was applied to 329 samples taken from 156 dogs from urban area and 173 from rural areas of Monte Negro County, Rondônia State, Brazil, to determine anti-Leptospira spp. antibodies. A survey was concomitantly done to detect eventual risk factors thru the use of logistic regression. Studied variables were age, sex, diet, management, environment, contact with other species and hunting habit. Titers >100 were detected in 27.3 percent (90/329) of the dogs, being 23.7 percent (37/156) urban and 30.6 percent (53/173) rural dogs. The most frequent serovars were Autumnalis (22.0 percent), Pyrogenes (12.0 percent), Canicola (10.0 percent) and Shermani (7.5 percent). Dogs older than 12 months showed higher positive frequencies than younger animals (P<0.05). Risk factor were associated with commercial food as compared to homemade food (odds ratio: 3.3; 95 percent confidence interval : 1.3 - 3.9; P=0.02) and associated with sex, with higher occurrence in males than in females (odds ratio: 2.3; 95 percent confidence interval: 1.3 - 3.9; P=0.003). It was emphasized the serological occurrence of serovars kept and spread in nature by wild animals.

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