Alvarado-Rybak Mario, Solano-Gallego Laia, Millán Javier
PhD Program in Conservation Medicine, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, República 252, Santiago, Chile.
Centro de Investigación para la Sustentabilidad, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello, República 252, Santiago, Chile.
Parasit Vectors. 2016 Oct 10;9(1):538. doi: 10.1186/s13071-016-1808-7.
Piroplasmids are tick-borne protozoan parasites that infect blood cells (erythrocytes, lymphocytes or other leukocytes) or endothelial cells of numerous wild and domestic vertebrates worldwide. They cause severe disease in livestock, dogs, cats, wild mammals and, occasionally, in humans. Piroplasmid infections are prevalent in wild carnivores worldwide although there is limited information about their clinical and epidemiological importance. There are currently nine recognized species of Babesia, two of Theileria, two of Cytauxzoon and one of Rangelia infecting captive and wild carnivores, including members of Canidae, Felidae, Mustelidae, Procyonidae, Ursidae, Viverridae, Hyaenidae and Herpestidae in the Americas, Eurasia and Africa. However, the number of piroplasmid species is likely higher than currently accepted due to the reported existence of DNA sequences that may correspond to new species and the lack of studies on many host species and biogeographical areas. Indeed, many species have been recognized in the last few years with the advancement of molecular analyses. Disease and mortality have been documented in some wild carnivores, whereas other species appear to act as natural, subclinical reservoirs. Various factors (e.g. unnatural hosts, stress due to captivity, habitat degradation, climate fluctuation or immunosuppression) have been associated with disease susceptibility to piroplasmid infections in some species in captivity. We aimed to review the current knowledge on the epidemiology of piroplasmid infections in wild carnivores and associated tick vectors. Emphasis is given to the role of wild carnivores as reservoirs of clinical piroplasmosis for domestic dogs and cats, and to the importance of piroplasmids as disease agents for endangered carnivores.
梨形虫是由蜱传播的原生动物寄生虫，可感染世界各地众多野生和家养脊椎动物的血细胞（红细胞、淋巴细胞或其他白细胞）或内皮细胞。它们会在牲畜、狗、猫、野生哺乳动物身上引发严重疾病，偶尔也会感染人类。梨形虫感染在全球野生食肉动物中普遍存在，不过关于其临床和流行病学重要性的信息有限。目前有9种公认的巴贝斯虫、2种泰勒虫、2种嗜吞噬细胞无形体和1种兰氏梨形虫感染圈养和野生食肉动物，包括美洲、欧亚大陆和非洲的犬科、猫科、鼬科、浣熊科、熊科、灵猫科、鬣狗科和獴科动物。然而，由于有报道称存在可能对应新物种的DNA序列，且许多宿主物种和生物地理区域缺乏研究，梨形虫物种的数量可能高于目前公认的数量。事实上，随着分子分析技术的进步，近年来已识别出许多物种。在一些野生食肉动物中已有疾病和死亡的记录，而其他物种似乎是自然的亚临床宿主。在圈养环境中，各种因素（如非自然宿主、圈养压力、栖息地退化、气候波动或免疫抑制）与某些物种对梨形虫感染的易感性有关。我们旨在综述目前关于野生食肉动物梨形虫感染流行病学及相关蜱传播媒介的知识。重点关注野生食肉动物作为家犬和家猫临床梨形虫病宿主的作用，以及梨形虫作为濒危食肉动物致病因子的重要性。
