Hirose Shizuka, Notsu Kosuke, Ito Satoshi, Sakoda Yoshihiro, Isoda Norikazu
Laboratory of Microbiology, Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Hokkaido, Japan.
Unit of Risk Analysis and Management, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 11, Kita-ku, Sapporo 001-00520, Hokkaido, Japan.
Pathogens. 2021 Jul 21;10(8):922. doi: 10.3390/pathogens10080922.
Bovine viral diarrhea (BVD) caused by BVD virus (BVDV) leads to economic loss worldwide. Cattle that are persistently infected (PI) with BVDV are known to play an important role in viral transmission in association with the animal movement, as they shed the virus during their lifetime. In this research, the "hot spot" for BVD transmission was estimated by combining phylogenetic and epidemiological analyses for PI cattle and cattle that lived together on BVDV affected farms in Tokachi district, Hokkaido prefecture, Japan. Viral isolates were genetically categorized into BVDV-1a, 1b, and 2a, based on the nucleotide sequence of the entire E2 region. In BVDV genotype 1, subgenotype b (BVDV-1b), cluster I was identified as the majority in Tokachi district. Network analysis indicated that 12 of the 15 affected farms had cattle movements from other facilities (PI-network) and farms affected with BVDV-1b cluster I consisted of a large network. It was implied that the number of cattle movements themselves would be a risk of BVD transmission, using the PageRank algorithm. Therefore, these results demonstrate that cattle movements would contribute to disease spread and the combination of virological and epidemiological analysis methods would be beneficial in determining possible virus transmission routes.
由牛病毒性腹泻病毒（BVDV）引起的牛病毒性腹泻（BVD）在全球范围内造成经济损失。已知持续感染（PI）BVDV的牛在与动物移动相关的病毒传播中起着重要作用，因为它们在一生中都会排出病毒。在本研究中，通过对日本北海道十胜地区受BVDV影响的农场中PI牛和共同生活的牛进行系统发育和流行病学分析，估计了BVD的传播“热点”。根据整个E2区域的核苷酸序列，将病毒分离株基因分类为BVDV-1a、1b和2a。在BVDV基因型1中，亚基因型b（BVDV-1b）的簇I在十胜地区被确定为大多数。网络分析表明，15个受影响的农场中有12个有来自其他设施的牛移动（PI网络），并且受BVDV-1b簇I影响 的农场构成了一个大网络。使用PageRank算法意味着牛移动的数量本身将是BVD传播的一个风险。因此，这些结果表明牛移动会导致疾病传播，并且病毒学和流行病学分析方法的结合将有助于确定可能的病毒传播途径。
