ABSTRACT
Equine piroplasmosis is the most important tick-borne disease to affect horses in Brazil. Theileria equi is one of the causative agents of equine piroplasmosis. Chronic cases are expected, in which the animals show no apparent signs of infection and remain asymptomatic but constitute a source of the infectious agent that ticks can spread. This study was conducted across 81 ranches located in the municipality of Sinop, State of Mato Grosso, Brazil. A sample calculation was performed to estimate the apparent prevalence of T. equi among horses. A total of 1,853 animals were included in the sampling analysis based on the information available from the Institute of Agricultural and Livestock Defense of Mato Grosso State. The serological analysis of 367 serum samples using an indirect enzyme-linked immunosorbent assay (ELISA) to detect anti-T. equi antibodies revealed that 337 animals were positive, representing a frequency of 90.70%. The molecular analysis to amplify the EMA-1 gene showed positivity in 20 of 89 tested samples. The fragments of four samples were sequenced and analyzed to determine their similarities to sequences from other species, based on sequences deposited at GenBank. All showed 100% similarity with T. equi. Our study represents the first report of T. equi antibodies among the equids in north-central region of Mato Grosso, revealing the widespread distribution of seropositive animals.
A piroplasmose equina é a doença transmitida por carrapatos mais importante em cavalos no Brasil. Theileria equi é um dos agentes causadores da piroplasmose equina. São esperados casos crônicos, nos quais os animais não apresentam sinais aparentes de infecção e permanecem assintomáticos, mas constituem uma fonte de infecção e disseminação por carrapatos. Este estudo foi realizado em 81 fazendas localizadas no município de Sinop, Estado de Mato Grosso, Brasil. Um cálculo amostral foi realizado para estimar a prevalência aparente de T. equi entre cavalos. No total, 1.853 animais foram incluídos na análise amostral com base nas informações disponíveis no Instituto de Defesa Agropecuária do Estado de Mato Grosso. A análise sorológica de 367 amostras de soro por meio de ensaio imunoenzimático indireto (ELISA) para detecção de anticorpos anti-T. equi revelou que 337 animais eram positivos, representando uma frequência de 90,70%. A análise molecular para o gene EMA-1 mostrou positividade em 20 das 89 amostras testadas. Os fragmentos de quatro amostras foram sequenciados e analisados para determinar suas semelhanças com sequências de outras espécies, a partir das sequências depositadas no GenBank. Todos mostraram 100% de similaridade com T. equi. Nosso estudo representa o primeiro relato de anticorpos contra T. equi entre os equídeos na região centro norte de Mato Grosso, revelando a ampla distribuição de animais soropositivos.
Subject(s)
Animals , Babesiosis/diagnosis , Horses/genetics , Pathology, Molecular , Serologic Tests , Theileria/pathogenicity , Theileriasis/diagnosis , Polymerase Chain ReactionABSTRACT
Babesiosis is a protozoal disease caused by members of the genus Babesia transmitted by the ixodid ticks. It is a parasite of various mammalian hosts as bovine [B. bovis], equine [B. equi], rodent [B. microti], canine [B. canis] and others. Human cases of babesiosis have been reported from several countries including Egypt. It is now well established that man may become infected [fulminating or subclinical] with several species of Babesia without prior splenectomy. In this paper, a total of 398 Rattus rattus and 90 R. norvegicus were trapped in Suez, Ismailia, Port-Said, North Sinai and South Sinai governorates. Blood films were taken from the tail after a simple cut of its end. The films were fixed in acetone free methyl alcohol and stained with Giemsa stain as usual. The results showed that all rats trapped in Ismailia had Babesia infection, then decreased in North Sinai, Port-Said, South Sinai and was zero in Suez. As double infection, Trypanosoma lewisi was found in rats trapped in Port-Said, North Sinai and South Sinai. But none had theileria infection. The medical and veterinary importance of these results was discussed