Teagasc, Moorepark Research Centre, Animal and Bioscience Research Department, Fermoy P61P302, Ireland.
Department of Agriculture, Food and the Marine, Model Farm Road, Cork, Ireland.
Animal. 2023 May;17 Suppl 1:100774. doi: 10.1016/j.animal.2023.100774.
This review of bovine foetal mortality (>42 d gestation) concluded that while the majority of risk factors associated with sporadic loss operate at animal-level, e.g. foetal plurality, those that operate at herd-level, e.g. some foetopathogenic infections, are more likely to result in abortion outbreaks. While the causes of foetal mortality have traditionally been classified as infectious and non-infectious, in fact, the latter category is a diagnosis of exclusion, generally without determination of the non-infectious cause. This review has also established that the traditional dichotomisation of infectious agents into primary and secondary pathogens is based on a flawed premise and these terms should be discontinued. The delicate balance of the maternal gestational immune system between not rejecting the allograft (conceptus) but rejecting (attacking) foetopathogens is stage-of-pregnancy-dependent thus the timing of infection determines the clinical outcome which may result in persistent infection or foetal mortality. Utilisation of our knowledge of the materno-foetal immune responses to foetopathogenic infection has resulted in the development of numerous mono- and polyvalent vaccines for metaphylactic or prophylactic control of bovine foetal mortality. While some of these have been shown to significantly contribute to reducing the risk of both infection and foetal mortality, others have insufficient, or conflicting evidence, on efficacy. However, recent developments in vaccinology, in particular the development of subunit vaccines and those that stimulate local genital tract immunity, show greater promise.
本综述讨论了牛胎儿死亡（>42 天妊娠），得出的结论是，虽然与散发性损失相关的大多数风险因素在动物水平上起作用，例如胎儿多胎性，但在畜群水平上起作用的因素，例如某些胎儿病原体感染，则更有可能导致流产爆发。虽然胎儿死亡的原因传统上被分为传染性和非传染性，但实际上，后者是排除诊断，通常无法确定非传染性原因。本综述还证实，将传染性病原体传统上分为原发性和继发性病原体的二分法是基于一个有缺陷的前提，这些术语应停止使用。母体妊娠免疫系统在不排斥同种异体移植物（胚胎）但排斥（攻击）胎儿病原体之间的微妙平衡取决于妊娠阶段，因此感染的时间决定了临床结果，可能导致持续感染或胎儿死亡。利用我们对母体-胎儿对胎儿病原体感染的免疫反应的知识，已经开发出许多单价和多价疫苗，用于牛胎儿死亡的继发预防或预防控制。虽然其中一些疫苗已被证明可显著降低感染和胎儿死亡的风险，但其他疫苗在疗效方面证据不足或相互矛盾。然而，最近疫苗学的发展，特别是亚单位疫苗和刺激局部生殖道免疫的疫苗的发展，显示出更大的希望。
