Olias P, Dettwiler I, Hemphill A, Deplazes P, Steiner A, Meylan M
Institut für Tierpathologie, Vetsuisse-Fakultät, Universität Bern.
Wiederkäuerklinik, Vetsuisse-Fakultät, Universität Bern.
Schweiz Arch Tierheilkd. 2018 Jun;160(6):363-374. doi: 10.17236/sat00163.
Diarrhea in calves is one of the most important cattle diseases in Switzerland. The diagnosis and treatment of calf diarrhea represent a major challenge. Single-celled Cryptosporidium parasites are the most prevalent causative agents of calf diarrhea besides rotavirus in the first weeks of life, and are responsible for about 50% of diarrheal cases. Cryptosporidium parvum has been described as a cause of diarrhea in one to three weeks old calves since the 1970s. Oral ingestion of persistent environmental oocysts results in severe diarrhea lasting four to six days and shedding of large numbers of infectious oocysts. A tiny amount of 10 oocysts is already sufficient to cause disease. Detailed knowledge about the epidemiology and virulence of the different C. parvum strains is still lacking. In addition, current diagnostic tests cannot reliably distinguish between non-pathogenic (e.g. C. bovis) and pathogenic Cryptosporidium species. Until now, no effective therapeutic drug or vaccine against calf cryptosporidiosis has been found. Water-borne epidemics and the zoonotic potential of Cryptosporidium in immunodeficient patients are of great medical importance. The increasing number of cryptosporidiosis cases associated with high infant mortality in less industrialized and impoverished regions (including South-East Asia and sub-Saharan Africa) has intensified the research in recent years. The recent discoveries of new therapeutics against C. parvum may benefit calf medicine in the near future. This review article reports on these new developments, highlights calf cryptosporidiosis in Switzerland and draws attention to a new research project.
犊牛腹泻是瑞士最重要的牛病之一。犊牛腹泻的诊断和治疗是一项重大挑战。单细胞隐孢子虫寄生虫是犊牛出生后最初几周除轮状病毒外最常见的犊牛腹泻病原体，约占腹泻病例的50%。自20世纪70年代以来，微小隐孢子虫就被描述为1至3周龄犊牛腹泻的病因。经口摄入环境中持续存在的卵囊会导致严重腹泻，持续4至6天，并排出大量具有传染性的卵囊。仅10个卵囊的微量就足以致病。目前仍缺乏关于不同微小隐孢子虫菌株的流行病学和毒力的详细知识。此外，当前的诊断测试无法可靠地区分非致病性（如牛隐孢子虫）和致病性隐孢子虫物种。到目前为止，尚未发现针对犊牛隐孢子虫病的有效治疗药物或疫苗。水源性疫情以及隐孢子虫在免疫功能低下患者中的人畜共患病潜力具有重大医学意义。近年来，在工业化程度较低和贫困地区（包括东南亚和撒哈拉以南非洲），与高婴儿死亡率相关的隐孢子虫病病例不断增加，这加剧了相关研究。最近发现的针对微小隐孢子虫的新疗法可能在不久的将来使犊牛医学受益。这篇综述文章报道了这些新进展，突出了瑞士的犊牛隐孢子虫病，并提请关注一个新的研究项目。
