Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
Harry Butler Institute, Vector- and Water-Borne Pathogen Research Group, Murdoch University, Murdoch, Western Australia, 6150, Australia.
Parasitol Res. 2021 Dec;120(12):4189-4198. doi: 10.1007/s00436-021-07116-9. Epub 2021 Mar 13.
Sheep and goats are commonly infected with three Cryptosporidium species, including Cryptosporidium parvum, Cryptosporidium ubiquitum, and Cryptosporidium xiaoi, which differ from each in prevalence, geographic distribution, and public health importance. While C. parvum appears to be a dominant species in small ruminants in European countries, its occurrence in most African, Asian, and American countries appear to be limited. As a result, zoonotic infections due to contact with lambs and goat kids are common in European countries, leading to frequent reports of outbreaks of cryptosporidiosis on petting farms. In contrast, C. xiaoi is the dominant species elsewhere, and mostly does not infect humans. While C. ubiquitum is another zoonotic species, it occurs in sheep and goats at much lower frequency. Host adaptation appears to be present in both C. parvum and C. ubiquitum, consisting of several subtype families with different host preference. The host-adapted nature of C. parvum and C. ubiquitum has allowed the use of subtyping tools in tracking infection sources. This has led to the identification of geographic differences in the importance of small ruminants in epidemiology of human cryptosporidiosis. These tools have also been used effectively in linking zoonotic transmission of C. parvum between outbreak cases and the suspected animals. Further studies should be directly elucidating the reasons for differences in the distribution and public health importance of major Cryptosporidium species in sheep and goats.
绵羊和山羊通常感染三种隐孢子虫，包括微小隐孢子虫、微小隐孢子虫 ubiquitum 和小隐孢子虫xiaoi，它们在流行程度、地理分布和公共卫生重要性方面存在差异。虽然微小隐孢子虫似乎是欧洲国家中小反刍动物的主要种，但在大多数非洲、亚洲和美洲国家的发生似乎受到限制。因此，由于与羔羊和山羊幼崽接触而导致的人畜共患感染在欧洲国家很常见，导致宠物农场经常爆发隐孢子虫病。相比之下，小隐孢子虫xiaoi 是其他地方的主要种，主要不感染人类。虽然微小隐孢子虫 ubiquitum 是另一种人畜共患病种，但它在绵羊和山羊中的发生频率要低得多。宿主适应性似乎存在于微小隐孢子虫和微小隐孢子虫 ubiquitum 中，包括具有不同宿主偏好的几个亚型家族。微小隐孢子虫和微小隐孢子虫 ubiquitum 的宿主适应性使得在追踪感染源时可以使用亚分型工具。这导致了在人类隐孢子虫病流行病学中小反刍动物重要性的地理差异的鉴定。这些工具还在将微小隐孢子虫 between between outbreak cases 和疑似动物之间的人畜共患传播联系起来方面发挥了有效作用。进一步的研究应直接阐明绵羊和山羊中主要隐孢子虫种分布和公共卫生重要性差异的原因。
