Smith D R, Fedorka-Cray P J, Mohan R, Brock K V, Wittum T E, Morley P S, Hoblet K H, Saif L J
Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691, USA.
Am J Vet Res. 1998 Aug;59(8):994-1001.
To test the association between exposure to bovine coronavirus (BCV) and outbreaks of winter dysentery (WD) in dairy herds and to examine other risk factors for outbreaks of WD in dairy herds.
12 dairy herds in Ohio affected with WD (case herds). For each case herd, 2 unaffected herds from the same area were concurrently used as control herds.
A case-control study was conducted, using herds as the unit of investigation. Multivariate logistic regression modeling was used to identify risk factors for contracting disease.
4 factors appeared to increase a herd's risk for WD: increase in herd prevalence of adult cows that had a fourfold or more increase in BCV serum IgG antibody titer; increase in herd prevalence of adult cows that had a fourfold or more increase in bovine viral diarrhea virus (BVDV) titer; housing cattle in tiestall or stanchion barns rather than free-stall facilities; and use of equipment to handle manure and subsequently handle feed. The adjusted population-attributable risk for these variables was 71, 43, 53, and 31%, respectively, and 99% overall, indicating that these variables had considerable impact on WD outbreaks for the study population.
In dairies in Ohio, recent herd exposure to BCV appeared to increase the risk for WD outbreaks. Some WD outbreaks might have been associated with acute BVDV infection. Certain housing and management practices may have increased the risk of an outbreak of WD.
检测奶牛群中接触牛冠状病毒（BCV）与冬季痢疾（WD）暴发之间的关联，并研究奶牛群中WD暴发的其他风险因素。
俄亥俄州12个受WD影响的奶牛群（病例群）。对于每个病例群，同时从同一地区选取2个未受影响的奶牛群作为对照群。
进行了一项病例对照研究，以奶牛群作为调查单位。采用多变量逻辑回归模型来确定患病的风险因素。
有4个因素似乎会增加奶牛群患WD的风险：成年母牛BCV血清IgG抗体滴度增加四倍或更多的奶牛群患病率增加；成年母牛牛病毒性腹泻病毒（BVDV）滴度增加四倍或更多的奶牛群患病率增加；将牛饲养在栓栏或固定栏牛舍而非自由栏设施中；以及使用处理粪便后再处理饲料的设备。这些变量调整后的人群归因风险分别为71%、43%、53%和31%，总体为99%，表明这些变量对研究人群的WD暴发有相当大的影响。
在俄亥俄州的奶牛场中，近期奶牛群接触BCV似乎会增加WD暴发的风险。一些WD暴发可能与急性BVDV感染有关。某些饲养和管理方式可能增加了WD暴发的风险。
