Bovine babesiosis and anaplasmosis complex: diagnosis and evaluation of the risk factors from Bahia, Brazil

Abstract

Bovine babesiosis and anaplasmosis complex: diagnosis and evaluation of the risk factors from Bahia, BrazilComplexo tristeza parasitária bovina: diagnóstico e avaliação dos fatores de risco na Bahia, Brasil AbstractDirect diagnoses were made by using -blood smears and nested PCR (nPCR) tests on 309 blood samples from crossbred dairy cattle in the municipality of Ibicaraí, Bahia. From diagnostic blood smear slides, the observed parasitic frequencies were 31.1% for Anaplasma marginale and 20.4% for Babesia sp. From nPCR diagnoses, they were 63% for A. marginale, 34% for Babesia bigemina and 20.4% for Babesia bovis. There were significant differences (P < 0.01) between the two diagnostic methods (nPCR and blood smear slides). The compliance obtained from the kappa test was 0.41 and 0.48 for A. marginale and Babesia sp., respectively. The tick samples from the six farms analyzed using nPCR were only positive for A. marginale. Evaluation of the risk factors relating to the presence of ticks and the age of the animals showed that there was a significant association (P < 0.01) with the frequency of animals infected with both pathogens. Therefore, under the conditions studied, nPCR proved to be a good tool for diagnosing the agents of the bovine babesiosis and anaplasmosis complex because of its sensitivity and specificity in comparison with blood smears. The municipality of Ibicaraí is an area with endemic prevalence of bovine babesiosis and anaplasmosis confirmed by nPCR and A. marginale is the main agent of the disease.Keywords: Bovine Babesiosis and Anaplasmosis Complex, blood smear, nPCR, risk factors. ResumoRealizou-se o diagnóstico direto por esfregaço sanguíneo e nested PCR (nPCR) em 309 amostras de sangue de bovinos mestiços leiteiros provenientes do município de Ibicaraí, Bahia. A frequência observada no diagnóstico por lâminas de esfregaço sanguíneo foi 31,1% para Anaplasma marginale e 20,4% para Babesia sp. Enquanto que no diagnóstico por nPCR foi 63% para A. marginale, 34% para Babesia bigemina e 20,4% Babesia bovis. Verificaram-se diferenças significativas (P<0,01) na comparação entre os dois métodos de diagnósticos (nPCR e esfregaço sanguíneo). A concordância ao teste KAPPA obtida foi de 0,41 e 0,48 para A. marginale e Babesia sp., respectivamente. As amostras de carrapatos das seis propriedades analisadas por nPCR foram positivas apenas para A. marginale. Na avaliação dos fatores de risco verificou-se que a presença de carrapato e idade dos animais apresentaram associação significativa (P<0,01) com a frequência de animais infectados por ambos os patógenos analisados por nPCR. Portanto, nas condições estudadas, a nPCR revelou-se uma boa ferramenta para diagnóstico dos agentes do complexo tristeza parasitária bovina (TPB) devido a sensibilidade e especificidade, quando comparado ao esfregaço sanguíneo. O município de Ibicaraí

A Cross-Sectional Study of Bovine Babesiosis in Teltele District, Borena Zone, Southern Ethiopia

“…This result was in line with the finding of Ayaz et al [18] from Pakistan who reported high prevalence in old animals with 13.4% (61/452) followed by adult animals, 11.7% (48/409) while the lowest was found in young animals. However, the results of this paper disagree with Amorim et al [27] who identified that calves were more susceptible to Babesia spp. when compared to adult cows.…”

Dynamics of natural infection by Babesia bovis and Babesia bigemina in dairy cattle from an enzootic instability area in Northeastern Brazil

“…infection in the animals. Thus, according to with Brown et al (2006), Correia (2006) and Amorim et al (2014) with the absence of the etiological agent, the production of antibodies is limited, leaving the animals susceptible to clinical disease and even to death.…”

“…infection in calves at an early age further aggravates the productivity losses caused by the enzootic instability. Moreover, the producers' lack of knowledge exposes the animals to a high risk because the babesiose agents do not circulate in the environment; therefore, the animals do not develop protective antibodies and the matrices cannot transmit the passive immunity to the calves (SANTOS-JÚNIOR et al, 2000;BROWN et al, 2006;AMORIM et al, 2014).…”

“…In some situations, enzootic instability may be related to unsatisfactory passive immunity, stress, nutritional status, time of year, management, type of pasture or high infestation rates of pastures and cattle by a vector (BARROS et al, 2005;AMORIM et al, 2014). The primo-infection usually occurs between four and six months of life, with the peak of the parasitemia coinciding with the fall of the packed cell volume; in old age, primo-infection is usually severe and can be fatal (CARRIQUE MAS et al, 2000;SMITH et al, 2000).…”

Babesiose cerebral em bezerros

“…Babesiose cerebral é uma enfermidade causada pelo protozoário intraeritrocitário Babesia bovis, transmitido pelo carrapato Rhipicephalus (Boophilus) microplus (Amorim et al 2014 (Pereira 2006). A infecção por B. bovis pode induziro sequestro de eritrócitos parasitados nos capilares cerebrais resultando em sinais neurológicos como hiperexcitabilidade, incoordenação motora, opistótono, tremores musculares, paralisia dos membros pélvicos, movimentos de pedalagem, andar em círculos, cegueira e agressividade, sendo usualmente fatal.…”