Departamento de Medicina Veterinária, Universidade Federal do Paraná - UFPR, Curitiba, Paraná, Brazil.
Unidade de Vigilância em Zoonoses, Secretaria Municipal de Saúde, Foz do Iguaçu, Paraná, Brazil.
Vet Parasitol. 2019 Sep;273:71-79. doi: 10.1016/j.vetpar.2019.08.008. Epub 2019 Aug 18.
Tick-borne diseases (TBD) constitute an important group of illness affecting animals and humans worldwide. In Brazil, carthorses are frequently exposed to ticks and tick-borne pathogens, leading to impairment of horse performance and imposing restrictions by the international veterinary authorities for the importation of horses. Accordingly, this study has aimed to i) determine the prevalence of the TBD agents Theileria equi, Babesia caballi, Ehrlichia spp., and hemotropic mycoplasmas in carthorses, ii) identify the tick species parasitizing the animals, and iii) determine factors associated with exposure/infection in Foz do Iguaçu City, Parana state, southern Brazil. A total of 103 carthorses were screened for anti-T. equi and anti-Ehrlichia spp. antibodies by indirect fluorescent antibody assays (IFA). Samples were also tested by PCR assays targeting the 18S rRNA gene of T. equi and B. caballi, and 16S rRNA gene of hemoplasmas. Additionally, PCR assays targeting the 16S rRNA, disulfide bond formation protein (dsb) and tandem repeat proteins 36 (trp36) genes of Ehrlichia spp. were also performed. Antibodies to T. equi and Ehrlichia spp. were detected in 43/103 (41.75%; 95% CI: 32.10-51.88%) and 5/103 (4.85%; 95% CI: 1.59-10.97%) horses by IFA, respectively. DNA of T. equi and B. caballi were found in 25/103 (24.27%; 95% CI: 16.36-33.71%) and 10/103 (9.71%; 95% CI: 4.75-17.13%) carthorses, respectively, and all tested negative for Ehrlichia spp. and hemoplasmas. All sequences showed ≥99% identity with multiple T. equi and B. caballi 18S rRNA gene sequences deposited in GenBank. Overall, 191 Dermacentor nitens ticks were collected from 25/103 (24.27%) animals. Carthorses older than 5 years were more likely to be positive for T. equi (p < 0.05). In conclusion, equine piroplasmosis agents are highly prevalent in carthorses from Foz do Iguaçu City. The low prevalence of Ehrlichia spp. found may be due to the absence of Amblyomma ticks infesting animals, which should be further investigated.
蜱传疾病（TBD）构成了一组重要的影响全球动物和人类的疾病。在巴西，役马经常接触蜱和蜱传病原体，导致马的性能受损，并对国际兽医当局对马的进口施加限制。因此，本研究旨在：i）确定巴西福斯杜伊瓜苏市役马中东方马泰勒虫、马巴贝斯虫、埃立克体和血巴尔通体的 TBD 病原体的流行率，ii）确定寄生在动物身上的蜱种，iii）确定与暴露/感染相关的因素。通过间接荧光抗体检测（IFA）对 103 匹役马进行了抗东方马泰勒虫和抗埃立克体 spp. 抗体的筛查。还通过针对 T. equi 和 B. caballi 的 18S rRNA 基因和血巴尔通体的 16S rRNA 基因的 PCR 检测对样本进行了检测。此外，还对 Ehrlichia spp. 的 16S rRNA、二硫键形成蛋白（dsb）和串联重复蛋白 36（trp36）基因的 PCR 检测进行了检测。IFA 检测到 43/103（41.75%；95%CI：32.10-51.88%）和 5/103（4.85%；95%CI：1.59-10.97%）匹马的 T. equi 和 Ehrlichia spp. 抗体。在 103 匹役马中，发现 T. equi 和 B. caballi 的 DNA 分别为 25/103（24.27%；95%CI：16.36-33.71%）和 10/103（9.71%；95%CI：4.75-17.13%），所有样本均为 Ehrlichia spp. 和血巴尔通体检测均为阴性。所有序列与 GenBank 中多个 T. equi 和 B. caballi 18S rRNA 基因序列的相似度均≥99%。总的来说，从 25/103（24.27%）匹马中采集了 191 只硝皮蠹属蜱。年龄大于 5 岁的役马更有可能对 T. equi 呈阳性（p<0.05）。综上所述，福斯杜伊瓜苏市役马中东方马泰勒虫等血液原虫病病原体的流行率很高。发现的埃立克体 spp. 的低流行率可能是由于没有感染动物的 Amblyomma 蜱，这应该进一步调查。
