Staubli D, Iten C, Kneubühler J, Sager H, Müller N, Gottstein B
Institut für Parasitologie der Universität Bern.
Schweiz Arch Tierheilkd. 2006 Sep;148(9):483-9. doi: 10.1024/0036-7281.148.9.483.
Neospora caninum represents one of the most frequent abortifaciant organisms worldwide. The parasite is diaplacentally transmitted from the pregnant cow to the fetus, where it normally leads to the delivery of a healthy, however persistently infected calf. Abortion thus is a relative rare event. The transmission of bovine neosporosis occurs in more than 90% of the cases vertically due to the endogenous reactivation of a persistently infected mother. Exogenous infections are therefore responsible for less than 10% of the cases. The question arises about which infection sources may be relevant in this context. In Switzerland, the role of dogs as definitive hosts has been shown to be of low significance in that respect. Recently, discussion focused on the potential of infectious bull semen following natural or artificial insemination. Thus, a few years ago a report documented the detectability of N. caninum-DNA in the semen of naturally infected bulls by nested-PCR. As a consequence, we decided to gain own experience by investigating 5 separate semen specimens per animal, originating from 20 N. caninum-seropositive bulls used for artificial insemination in Switzerland. All probes turned out to be negative by nested PCR. Based upon our laboratory experiences, the potential bull semen-associated Neospora-problem seems not to affect the Swiss bull population, thus there is no evidence to include further respective means of control.
犬新孢子虫是全球最常见的导致流产的病原体之一。该寄生虫通过胎盘从怀孕母牛传播给胎儿，通常会产出健康但持续感染的小牛。因此，流产是相对罕见的事件。牛新孢子虫病超过90%的病例是由于持续感染的母牛内源性再激活而垂直传播的。因此，外源性感染导致的病例不到10%。由此产生的问题是，在这种情况下哪些感染源可能相关。在瑞士，狗作为终末宿主在这方面的作用已被证明意义不大。最近，讨论集中在自然或人工授精后感染性公牛精液的可能性上。因此，几年前一份报告记录了通过巢式PCR在自然感染公牛精液中可检测到犬新孢子虫DNA。因此，我们决定通过调查瑞士用于人工授精的20头犬新孢子虫血清阳性公牛，每头动物取5份单独的精液样本，以获取我们自己的经验。通过巢式PCR检测，所有样本结果均为阴性。根据我们的实验室经验，与公牛精液相关的新孢子虫潜在问题似乎不会影响瑞士公牛种群，因此没有证据表明需要采取进一步的相应控制措施。
