Kozasa Takashi, Tajima Motoshi, Yasutomi Ichiro, Sano Kimihiro, Ohashi Kazuhiko, Onuma Misao
Laboratory of Infectious Diseases, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Vet Microbiol. 2005 Mar 20;106(1-2):41-7. doi: 10.1016/j.vetmic.2004.12.009. Epub 2005 Jan 21.
The prevalence of bovine viral diarrhea virus (BVDV) in dairy herds in Hokkaido, Japan, was estimated by reverse transcription polymerase chain reaction (RT-PCR) using bulk tank milk samples. Sixteen out of 265 dairy herds were identified as BVDV positive, and at least one persistently infected (PI) cattle was recognized in each of the positive herds except for two herds of which, owners did not agree to examine individual cows. The proportion of positive herds with a history of BVDV PI was significantly higher than that with no history of BVDV PI (odds ratio (OR) 4.25, 95% confidence interval (CI) 1.471-12.278, p = 0.004). The herds examined for BVDV were divided into two groups, high and low disease incidence groups based on the occurrence of diseases such as diarrhea, pneumonia or abortion in the past 1 year. The BVDV positive herds in the high disease incidence group were significantly more than that in the low disease incidence group (OR 2.92, CI 1.110-7.683, p = 0.024). It was observed that there were significantly (p = 0.008) more PI calves or heifers in farms of high disease incidence group than in farms of low disease incidence group. These results suggested that bulk tank milk test was available method for the detection of PI animals in dairy herds, and the existence of PI non-lactating cows in herd correlated with the incidence of diseases of the diarrhea or respiratory disorders.
采用批量罐装牛奶样本，通过逆转录聚合酶链反应（RT-PCR）对日本北海道奶牛场牛病毒性腹泻病毒（BVDV）的流行情况进行了评估。265个奶牛场中有16个被鉴定为BVDV阳性，除了两个奶牛场主人不同意检查个体奶牛外，每个阳性奶牛场中至少识别出一头持续感染（PI）牛。有BVDV PI病史的阳性奶牛场比例显著高于无BVDV PI病史的奶牛场（优势比（OR）4.25，95%置信区间（CI）1.471 - 12.278，p = 0.004）。根据过去1年腹泻、肺炎或流产等疾病的发生情况，将接受BVDV检测的奶牛场分为高发病率和低发病率两组。高发病率组的BVDV阳性奶牛场显著多于低发病率组（OR 2.92，CI 1.110 - 7.683，p = 0.024）。观察到高发病率组农场的PI犊牛或小母牛明显多于低发病率组农场（p = 0.008）。这些结果表明，批量罐装牛奶检测是检测奶牛场PI动物的有效方法，且奶牛场中PI非泌乳奶牛的存在与腹泻或呼吸道疾病的发病率相关。
