Subdirección de Sistemas Terrestres, Instituto Nacional de Técnica Aeroespacial (INTA)-Campus La Marañosa, Madrid, Spain.
Department of Pathology and infectious Diseases, University of Surrey, Guildford, UK.
Vet Med Sci. 2021 Nov;7(6):2234-2239. doi: 10.1002/vms3.587. Epub 2021 Aug 2.
Cutaneous forms of leishmaniosis due to Leishmania braziliensis have been reported in horses in the New World. Domestic animals play a role in the transmission of the disease. In Costa Rica, human cases of L. braziliensis, L. panamensis and L. infantum have been reported.
The present report describes five cases of equine cutaneous leishmaniosis in Costa Rica. The aetiological diagnosis was based on the presence of the parasite within the lesions.
Skin biopsies were used to perform histopathological analyses of the lesions. Immunohistochemistry was used to detect the presence of the Leishmania spp. antigens in tissue sections. Laser-capture micro-dissection and quantitative real-time PCR techniques were carried out to detect the pathogen nucleic acid within the microscopic lesions.
Histopathological analyses showed a granulomatous inflammation within the dermis, with multi-nucleated giant cells, macrophages, lymphocytes and few neutrophils and eosinophils. We detected the parasite by immunohistochemistry, using a rabbit polyclonal antibody raised against Leishmania spp. However, we could not identify Leishmania spp. by quantitative real-time PCR in formalin-fixed paraffin-embedded tissues, using specific primers for the conserved region in the minicircle of the Leishmania DNA kinetoplast.
Our results emphasise the importance of Leishmania spp. not only as a causative agent of equine cutaneous disease in the New World, but also as a possible emerging pathogen. Leishmaniosis is one of the most prevalent parasitic public health problems worldwide, and equines may have a role in the epidemiology of the disease.
新世界的马匹已报告有巴西利什曼原虫引起的皮肤利什曼病。家畜在疾病传播中起作用。在哥斯达黎加，已报告有人感染巴西利什曼原虫、巴拿马利什曼原虫和婴儿利什曼原虫病例。
本报告描述了哥斯达黎加的五例马皮肤利什曼病。病因学诊断基于病变内寄生虫的存在。
皮肤活检用于对病变进行组织病理学分析。免疫组织化学用于检测组织切片中利什曼原虫抗原的存在。激光捕获微切割和实时定量 PCR 技术用于检测微观病变内的病原体核酸。
组织病理学分析显示真皮内存在肉芽肿性炎症，有多核巨细胞、巨噬细胞、淋巴细胞和少量中性粒细胞和嗜酸性粒细胞。我们使用针对利什曼原虫属的兔多克隆抗体通过免疫组织化学检测到寄生虫。然而，我们无法使用针对利什曼原虫 DNA 动基体小环保守区的特异性引物在福尔马林固定石蜡包埋组织中通过实时定量 PCR 识别利什曼原虫属。
我们的结果强调了利什曼原虫属不仅是新世界马皮肤疾病的致病因子，而且可能是一种新兴病原体。利什曼病是全世界最普遍的寄生虫公共卫生问题之一，马可能在疾病的流行病学中起作用。
