Jawor Paulina, Król Dawid, Mee John F, Sołtysiak Zenon, Dzimira Stanisław, Larska Magdalena, Stefaniak Tadeusz
Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Theriogenology. 2017 Nov;103:130-136. doi: 10.1016/j.theriogenology.2017.07.044. Epub 2017 Jul 29.
The objective of this study was to determine the prevalence and types of infections in perinatal mortality (PM) cases from Polish dairy farms and the relevance of the presence of infection to the cause of death. This prospective longitudinal study was carried out on 121 PM and 21 control calves with a gestation of ≥260 days. Six control calves were euthanized and examined using the same protocol as for PM calves. Material was collected over a 20-month period between November 2013 and June 2015. The PM and control calves were collected from 29 to 5 herds, respectively. Blood samples from calves were tested for antibodies to Neospora caninum, glycoprotein B of BoHV-1, BVDV and SBV using ELISAs and Leptospira hardjo and Leptospira pomona with the microscopic agglutination test. Brain and kidney samples from all PM and six euthanized control calves were tested using real time PCR to detect Neospora caninum, pathogenic Leptospira spp., BoHV-1 and SBV; brain was examined histopathologically for detection of N. caninum cysts. Samples from eight inner organs from all PM and six control calves were cultured aerobically, anaerobically and microaerobically. Ear samples from all PM and control calves were tested for BVDV using an antigen ELISA. In total, 21.5% of PM calves were infected (antigen and/or antibody-positive) in utero; none of the control calves were infected. Direct evidence of infection (culture, Ag-ELISA, PCR, histopathology) was detected in 9.1% of PM calves. Gestation length in infected singletons was shorter than in uninfected singletons (274 ± 8 vs. 279 ± 7 days; P < 0.01). The odds ratio for diagnosis of infection in single pregnancies ≤275 days was 3.75 (95% CI:1.2-12.1), (P < 0.05). Infection was the cause of death in 10% of calves. The most common infections detected in these Polish PM calves were parasitic (11.6% of PM cases), viral (7.4%) and bacterial (5%). This study demonstrated that indirect evidence of infection is detected more frequently than direct, coinfection is rare, infection is rarely accompanied by gross lesions and is rarely a cause of death in cases of PM.
本研究的目的是确定波兰奶牛场围产期死亡（PM）病例中的感染患病率和类型，以及感染与死亡原因的相关性。这项前瞻性纵向研究对121头PM犊牛和21头妊娠≥260天的对照犊牛进行。对6头对照犊牛实施安乐死，并按照与PM犊牛相同的方案进行检查。在2013年11月至2015年6月的20个月期间收集材料。PM犊牛和对照犊牛分别从29个至5个牛群中采集。使用酶联免疫吸附测定法（ELISA）检测犊牛血液样本中的犬新孢子虫抗体、牛疱疹病毒1型（BoHV-1）糖蛋白B、牛病毒性腹泻病毒（BVDV）和 Schmallenberg病毒（SBV）抗体，并用显微镜凝集试验检测哈氏钩端螺旋体和波摩那钩端螺旋体。对所有PM犊牛和6头安乐死的对照犊牛的脑和肾样本进行实时聚合酶链反应（PCR）检测，以检测犬新孢子虫、致病性钩端螺旋体属、BoHV-1和SBV；对脑进行组织病理学检查以检测犬新孢子虫囊肿。对所有PM犊牛和6头对照犊牛的八个内脏样本进行需氧、厌氧和微需氧培养。使用抗原ELISA检测所有PM犊牛和对照犊牛的耳样本中的BVDV。总共，21.5%的PM犊牛在子宫内受到感染（抗原和/或抗体呈阳性）；对照犊牛均未感染。在9.1%的PM犊牛中检测到感染的直接证据（培养、抗原ELISA、PCR、组织病理学）。感染的单胎犊牛的妊娠期短于未感染的单胎犊牛（274±8天对279±7天；P<0.01）。妊娠≤275天的单胎妊娠中感染诊断的优势比为3.75（95%置信区间：1.2 - 12.1），（P<0.05）。感染是10%犊牛的死亡原因。在这些波兰PM犊牛中检测到的最常见感染是寄生虫感染（占PM病例的11.6%）、病毒感染（7.4%）和细菌感染（5%）。本研究表明，感染的间接证据比直接证据更频繁地被检测到，混合感染罕见，感染很少伴有肉眼可见病变，并且在PM病例中很少是死亡原因。
