and highlands of Mato Grosso do Sul, Brazil 1 (original) (raw)

Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil

Pesquisa Veterinária Brasileira, 2008

Pesq. Vet. Bras. 28(1):51-56, janeiro 2008 RESUMO.-[Dinâmica de infecção de Trypanosoma vivax em rebanho bovino mantido numa área de transição entre o Pantanal e o planalto de Mato Grosso do Sul.] Surtos de Trypanosoma vivax em bovinos de corte do Pantanal foram responsáveis por relevante impacto econômico, devido a perda de peso, abortos e mortalidade. Um manejo comum é o deslocamento de bovinos do Pantanal baixo para áreas adjacentes desse ecosistema para reprodução e engorda. Por essa razão, foi efetuado um estudo epidemiológico em rebanho de vacas movidas para uma área de transição entre Pantanal baixo e planalto do Estado de Mato Grosso do Sul para determinar a dinâmica de infec-Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil 1 Marques L.C. 2008. Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil. Pesquisa Veterinária Brasileira 28 :51-56. Trypanosoma vivax outbreaks in beef cattle in the Pantanal region of Mato Grosso do Sul state, Brazil, causes relevant economical impact due to weight loss, abortion and mortality. Cattle moved from the Pantanal to adjacent areas of this ecosystem for breeding and fattening is a common feature. Therefore an epidemiological study on breeding cows in the transition area between Pantanal lowland and adjacent highlands of Mato Grosso do Sul was performed to determine the T. vivax infection dynamics and outbreak risk. Three experimental groups were formed: Group 1 consisted of cows parasitologically negative by the Woo test and in the enzyme-linked immunosorbent assay for T. vivax antibody detection (Tv-ELISA-Ab); Group 2 parasitologically negative and positive in the Tv-ELISA-Ab; and in Group 3 cows were parasitologically positive and with positive reactions in the Tv-ELISA-Ab. During 24 months, the cows' dislodgment between the above established groups was monitored by Woo test and Tv-ELISA-Ab exams. The tabanid population was also monitored and the highest number occurred during the rainy season. Although parasitemias were detected only in the first four samplings of the experimental period, the cows could be considered as trypanotolerant, because no clinical signs were observed. Despite the higher T. vivax incidence during the dry season, no disease symptoms were seen. Even though T. vivax epidemiological situation in the herd was characterized as endemic with seasonal variation, the probability of outbreaks was null within the conditions of the study.

Epizootic Infection by Trypanosoma vivax in Cattle from the State of Minas Gerais, Brazil

The Korean Journal of Parasitology, 2019

Trypanosomiasis is caused by a pathogenic protozoan of the genus Trypanosoma, being Trypanosoma vivax the most important agent for cattle. The aim of the present study was to demonstrate the expansion of T. vivax infection in different mesoregions of Minas Gerais, Brazil, and describe the clinicopathological findings of trypanosomiasis in cattle. The diagnosis was based on visualization of the parasite in blood smears and DNA detection of T. vivax in the blood of live cows and tissues of necropsied animals by the polymerase chain reaction (PCR). Thirty suspected herds were tested, of which 11 were positive for T. vivax. The most frequent clinical signs were anemia, apathy, drop in milk production, weight loss, reproductive disorders, and nervous signs. Concomitant diseases, such as malignant edema, pneumonia and increased cases of mastitis were associated with T. vivax infection. Three cows were necropsied and the most significant findings were low body condition score, pale mucous and spleen with white pulp hyperplasia. The results demonstrated the expansion of T. vivax infection in Minas Gerais, that PCR-associated blood smears are promising for diagnosis, and that other diseases often occur concomitantly to T. vivax infection in regions with trypanosomiasis in cattle.

First report and molecular characterization of Trypanosoma vivax in cattle from state of Pernambuco, Brazil

Veterinary Parasitology, 2012

This paper describes an outbreak of Trypanosoma vivax for the first time in the state of Pernambuco, Brazil, affecting dairy cattle in the municipality of Itambé in the northern coastal zone of the state. Clinical signs compatible with infection by blood protozoa and epidemic miscarriages were observed. The diagnosis of T. vivax was confirmed through biometric microscopy and molecular analysis with PCR and DNA sequencing. The T. vivax isolate detected in the present study proved to be genetically very close to other Brazilian isolates of the protozoan despite being geographically distant.

Trypanosoma theileri in cattle herd of Rio Grande do Sul State, Brazil

Comparative Clinical Pathology, 2012

The aim of this study was to record the presence of Trypanosoma theileri in the blood of a cattle herd from a property placed in the municipality of Caçapava do Sul, Rio Grande do Sul State, Brazil. For this study, 37 samples of blood were collected from the herd and later analyzed by blood culture. After 20 days, 9 (24.3%) of 37 samples collected were positive for T. theileri, and each positive animal was asymptomatic and presented good nutritional status. This was the first property investigated, and these preliminary results already suggest that T. theileri presents high prevalence in the cattle herds from southern Brazil. Thus, an investigation may be worth due the economic losses caused by this silent disease.

Parasitological and clinical-pathological findings in twelve outbreaks of acute trypanosomiasis in dairy cattle in Rio de Janeiro state, Brazil

Veterinary Parasitology: Regional Studies and Reports, 2020

In Brazil, infection in cattle was first reported in the state of Pará, in 1944, and the presence of the parasite has already been recorded in several states. The purpose of this study was to report the clinical-pathological aspects of a natural infection by T. vivax in dairy cattle in the state of Rio de Janeiro. Twelve outbreaks of the infection were diagnosed in 11 municipalities from April 2016 to October 2018. All properties had acquired cattle from states where the disease had already been recorded and it was found that needles for oxytocin administration had been shared. These outbreaks were studied by visiting the properties to perform anamnesis, clinical exams and collection of material for laboratory diagnosis. Laboratory diagnosis was performed through parasitological, molecular and histopathological techniques. Animals with confirmed diagnosis for T. vivax showed anemia, lack of appetite, decreased milk production, weight loss, weakness, abortion, diarrhea and neurological signs. The main histological lesions found were meningoencephalitis and lymphohistiocytic myocarditis. In the central nervous system, the lesions were more severe in the brain compared to the spinal cord, being progressively more severe in the rostro-dorsal direction. Also, they were more accentuated in the white matter compared to the gray matter. Due to nonspecific clinical signs, laboratory tests were key for diagnosis. Trypanosomiasis in cattle herds in the state of Rio de Janeiro, Brazil, is of great concern because of its potential to cause economic losses. Southeast (São Paulo and Minas Gerais states), then T. vivax achieved in Rio de Janeiro. Trypanosoma vivax infection has also been reported in

Risk factors for trypanosomiasis by Trypanosoma vivax in cattle raised in Rio Grande do Norte state

Arquivos do Instituto Biológico, 2018

ABSTRACT: The objective of this study was to determine the prevalence of anti Trypanosoma vivax antibodies and the possible risk factors associated with the infection in cattle in Rio Grande do Norte, Northeastern Brazil, through a cross-sectional epidemiological study, with non-probabilistic convenience sampling. A total of 467 cattle’s serum samples were analyzed by indirect immunofluorescence. Forty-two samples tested positive for Trypanosoma vivax IgG antibodies, corresponding to the prevalence of 9%. Risk factors influencing the occurrence of trypanosomiasis were milk exploration, raising of European breeds, productivity category: lactation cow, purchase of new cattle, foraging habits near ponds and rivers, and the presence of mechanical vectors. So, high prevalence in beef animals (59.5%), females (95.2%), European breed (88.1%), lactating cows (85.7%), pasture at banks of dams and rivers (95.2%), in addition to the presence of mechanical vectors (81%) and acquisition of anima...

Bovine trypanosomosis in the Bolivian Pantanal

Veterinary Parasitology, 2007

Trypanosomosis caused by Trypanosoma vivax has been a constraint for cattle production in the Bolivian lowlands, since it was introduced in 1996. Flooded areas like the Bolivian Pantanal have a suitable environment for the presence and transmission of Salivarian trypanosomes and farmers from that region often report trypanosomosis-like problems on their farms. The objective of the present study, therefore, was to characterize the epidemiology of bovine trypanosomosis in the Bolivian Pantanal. In order to achieve this objective, 202 cattle from the province of Angel Sandoval and 209 cattle from the province of German Busch were randomly sampled (the Pantanal is located in both provinces). Twenty-nine farms in both provinces were visited, the farmers interviewed, and biologic samples collected from their cattle. Samples were submitted for parasitological and PCR evaluation and the prevalence of bovine trypanosomosis was estimated for each province. Laboratory results were correlated with the sampled animals packed cell volume (PCV) and body condition (BC) scores and the observed T. vivax parasites measured for morphometry analysis. Results from this study show differences in morphometric measures between T. vivax parasites from each province. Differences between provinces were also observed in the T. vivax-related disease situation. While in Angel Sandoval the PCV and BC of T. vivax-affected animals were significantly lower than those of the T. vivax-negative animals, in German Busch no differences were observed in the PCV and BC of T. vivax-positive or negative animals. Animal prevalence of T. vivax in Angel Sandoval was 27.79% (95% CI: 14.52-44.28) and in German Busch was 19.03% (95% CI: 9.19-30.75). The T. evansi animal prevalence in each province was 0.99% (95% CI: 0.27-2.99) and 5.71% (95% CI: 2.43-12.19), respectively. Based on questionnaire and laboratory results, it was concluded that trypanosomosis is a primary constraint for cattle production in the Bolivian Pantanal. #

Variables that modulate the spatial distribution of Trypanosoma cruzi and Trypanosoma evansi in the Brazilian Pantanal

Acta Tropica, 2007

An evaluation was made on how the landscape and cattle ranching affect the transmission cycles and the patterns of tripanosomatid infection (Trypanosoma cruzi and Trypanosoma evansi) of small wild mammals in the Pantanal. This region comprises a large natural environment with a multiplicity of habitats, wide variety of biodiversity besides the presence of livestock. T. cruzi and T. evansi infections were evaluated by parasitological and serological methods in one preserved and one cattle ranching area. The diversity of the small mammal fauna showed to be the same in the two studied areas, however, their relative abundance was different. Distinct enzootiological scenarios of both trypanosomatids could be observed. Transmission of T. cruzi occurred mainly in forested areas, in the two study areas, while T. evansi occurred dispersed among all habitats studied in the unpreserved area. The arboreal rodent Oecomys mamorae, the most abundant species in both areas, displayed high T. cruzi and T. evansi serum prevalence and parasitemias. Also, the caviomorph rodent Thrichomys pachyurus was shown to be an important host due to its expressive relative abundance, prevalence of infection by both trypanosomatid species and a broad range use of habitats. The role of the small mammal fauna in the transmission cycle of both trypanosomes species seems to be distinct according to land use since we found a broad range of T. evansi infected hosts in the preserved area in contrast to cattle ranching area and a half number of the rodents species infected with T. cruzi in unpreserved in comparison to protect area. The present study showed that cattle ranching in this study area did not enhance overall prevalence of T. cruzi infection among small wild mammals. Together with the observation that small mammals diversity in FA is similar to RN area suggest that ranching activity may also not necessarily conduct to biodiversity loss or risk of Chagas disease.

Outbreaks of trypanosomosis due to Trypanosoma vivax in cattle in Bolivia

Veterinary Parasitology, 1998

This paper reports the first occurrence of bovine trypanosomosis due to Trypanosoma ÕiÕax in Bolivia. T. ÕiÕax was identified in thin blood smears of 159 cattle from the Provinces of Velaco Ž. Ž. Ž. Ž. 57 , Nuflo de Chavez 20 , Guayaros 30 and Chiquitos 52 , and in 86.20% of 29 cattle from Laguna Concepcion examined by microhematocrit test. The clinical signs observed were fever, anemia, abortion, progressive weakness, loss of appetite, lethargy, substantial weight loss in a relatively short time, and progressive emaciation. q 1998 Elsevier Science B.V.