Estudo comparativo de três métodos de diagnóstico para detecção de anticorpos anti-Theileria equi em eqüinos de áreas endêmicas do estado do Rio de Janeiro

Roier

Rev. Bras. Parasitol. Vet.

et al. 2011

Self Cite

Serum samples from 714 equids of Itaguaí and Serrana microregions, Rio de Janeiro, southeastern Brazil, were examined by indirect fluorescent antibody test (titer 1:80) for Theileria equi. The prevalence in the microregions and factors associated with seropositivity were evaluated and the prevalence ratio (PR) calculated. The overall prevalence of T. equi infection was 81.09% (n = 579), with higher prevalence (p < 0.05) in the Itaguaí (85.43%) when compared to Serrana microregion (76.92%). The geographic area, altitude, farming condition and area of origin of equids were associated (p < 0.05) with seropositivity for T. equi. Equids reared in the Itaguaí microregion (PR = 1.11, p = 0.003) and at altitudes below 500 m (PR = 1.10; p = 0,014) were more likely to be seropositive for T. equi. Furthermore, when equids were born in the farm (PR = 1.10, p = 0.008) and reared with poor farming conditions (PR = 1.13, p = 0.018) they were more likely to be exposed to T. equi. The main ticks found on equids were Amblyomma cajennense and Dermacentor (Anocentor) nitens. The microregions studied are endemic areas for equine theileriosis and there exists enzootic stability for T. equi. Only factors related to the collection area of serum samples influenced the seropositivity of equids for T. equi in that region.Keywords: horses, equine theileriosis, IFAT, prevalence, epidemiology. ResumoAmostras de soro de 714 equídeos das microrregiões de Itaguaí e Serrana, Rio de Janeiro, Brasil, foram submetidas ao teste de imunofluorescência indireta (título 1:80) para Theileria equi. A prevalência entre as microrregiões e os fatores associados à soropositividade foram avaliados e a razão de prevalência (RP) calculada. A prevalência geral para T. equi foi de 81,09% (n = 579), com maior prevalência (p < 0,05) para microrregião de Itaguaí (85,43%), quando comparado a Serrana (76,92%). A região, altitude, nível da propriedade e origem dos equídeos foram associados (p < 0,05) com a soropositividade para T. equi. Equídeos criados na microrregião de Itaguaí (RP = 1,11; p = 0,003) e em altitudes abaixo de 500 m (RP = 1.10; p = 0,014) apresentaram maior chance de se tornarem soropositivos para T. equi. Além disso, quando são criados em propriedades de nível ruim (RP = 1,13; p = 0,018) e nascidos na propriedade (RP = 1,10; p = 0,008) apresentaram mais chance de terem contato com T. equi. As principais espécies de carrapatos encontradas parasitando os equídeos foram Amblyomma cajennense e Dermacentor (Anocentor) nitens. As microrregiões estudadas são endêmicas para theileriose equina e de estabilidade enzoótica para T. equi. Apenas os fatores relacionados à área de coleta das amostras de soro influenciaram a soropositividade dos equídeos para T. equi naquela região.Palavras-chave: equinos, theileriose equina, RIFI, prevalência, epidemiologia.

Section: Discussionsupporting

confidence: 89%

Factors associated to Theileria equi in equids of two microregions from Rio de Janeiro, Brazil

Roier

Rev. Bras. Parasitol. Vet.

et al. 2011

Self Cite

Rev. Bras. Parasitol. Vet.

“…In this study, a higher frequency of T. equi infection was observed in comparison with B. caballi infection corroborating the findings of previous studies on EP carried out in different regions of the world (BRÜNING, 1996;HEIM et al, 2007;RIBEIRO et al, 2013). Since the ticks Rhipicephalus microplus (BATTSETSEG et al, 2002), Amblyoma cajennense (= A.sculptum) (KERBER et al, 2009;MARTINS et al, 2016), and Dermacentor nitens (HEIM et al, 2007;SANTOS et al, 2009), which are the vectors of both T. equi and B. caballi, were present in the study area, differences in infection frequency between these two hemoparasitic infections is probably associated with the different forms of transmission and increased pathogenicity of T. equi (ALLSOPP et al, 2007), leading to higher and more persistent parasitaemias (DAVITKOV et al, 2016). In addition, the ability of equids to limit B. caballi infection (WEILAND, 1986) and/or the lower prevalence of B. caballi in the region (HAWKINS et al, 2015;ODUORI et al, 2015) may also explain the variations between the results of different surveys.…”

Section: Discussionsupporting

confidence: 91%

Frequency and factors associated with Theileria equi, Babesia caballi and Trypanosoma evansi in equids from Bahia (Northeast Brazil)

Costa

Freitas

Silva

et al. 2019

The aim of this study was to determine the frequency and factors associated to Babesia caballi, Theileria equi and Trypanosoma evansi in naturally infected equids from the northeast Brazil. Blood samples from 569 equids (528 horses, 8 mules, and 33 donkeys) were collected and tested for the presence of DNA of each of these protozoan parasites by PCR. Generalized linear models were used to evaluate risk factors associated with the infection. The frequency of T. equi infection was 83.5% (475/569) - 84.3% in horses, and 73.2% in donkeys and mules. The results of the final model indicated that age (senior group) and animal species (mule and donkey group) were protective factors against this pathogen. The frequency of B. caballi infection was 24.3% (138/569) - 23.5% in horses and 34.1% in donkeys and mules. Age (adult and senior group) was considered a protective factor against B. caballi infection whereas animal species (donkey and mule group) were considered a risk factor for the infection. Trypanosoma evansi infection was not detected in any of animals. Our results suggest that equids from the area studied may be infected earlier in life with the etiological agents of equine piroplasmosis and become asymptomatic carriers.

“…The classical routes of transmission are getting bitten by ixodidae ticks and the iatrogenic pathway. Transplacental transmission of T. equi has additionally been described in recent years (Allsopp et al 2007, Santos et al 2009, Chhabra et al 2012; however, the specific mechanism of transmission has not been elucidated (Wise et al 2014). Transplacental transmission can lead to abortion in the final trimester of gestation and to the birth of either stillbirths or foals that show clinical signs of piroplasmosis in the first few days after birth.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of humoral immune response in pregnant mares and foals vaccinated with Theileria equi recombinant EMA-2

et al. 2018

Theileria equi is an infectious hemoprotozoan agent of equine piroplasmosis, a disease that has severe economic and sanitary impact internationally. In addition to its common clinical features, piroplasmosis can cause gestational losses and neonatal damage, which makes neonates susceptible to this disease. The aim of this study was to evaluate the dynamics of humoral immune response to recombinant EMA-2 of T. equi in pregnant mares and foals, as well as the transfer of vaccine antibodies through the colostrum ingested by sucking foals. For vaccine production, the EMA-2 expression gene was cloned and expressed in the yeast species, Pichia pastoris. Thirty-six horses were used, of which 18 were pregnant mares and 18 were foals. The mares were divided into control and vaccinated groups, and the vaccinated group received three doses of rEMA-2 every 21 days starting at 300 days of gestation. Foals from vaccinated and control groups were evaluated until the sixth month of life. The production of antibodies by foals on the rEMA-2 vaccination schedule was also evaluated from the second month of life. Foals in the vaccinated group had received three doses of the vaccine every 21 days. The method used to evaluate serum and colostrum samples was indirect ELISA, and plates were sensitized with the rEMA-2 protein. At the end of the vaccination schedule, vaccinated mares showed a 2.3-fold increase in antibody levels when compared to baseline values. The colostrum of vaccinated mares presented antibody levels of 1.0432±0.33. Foals delivered by vaccinated mares presented levels of antibodies greater than those of foals delivered by control mares after their first time sucking (at about twelve hours after birth). Foals vaccinated in the second month of life showed an 8.3-fold increase in antibody levels when compared to baseline values. The vaccination schedule with rEMA-2 was able to stimulate humoral immunity in pregnant mares. Vaccine immunoglobins were concentrated in the colostrum of vaccinated mares and foals delivered by these mares showed an increase in serum levels of vaccine antibodies after the first-time sucking.