Selim Abdelfattah M, Elhaig Mahmoud M, Moawed Sherif A, El-Nahas Ehab
Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, P.O. Box 13736, Toukh, Egypt.
Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt.
Vet World. 2018 Mar;11(3):259-267. doi: 10.14202/vetworld.2018.259-267. Epub 2018 Mar 2.
The present cross-sectional study was conducted to determine the seroprevalence and potential risk factors associated with Bovine viral diarrhea virus (BVDV) disease in cattle and buffaloes in Egypt, to model the potential risk factors associated with the disease using logistic regression (LR) models, and to fit the best predictive model for the current data.
A total of 740 blood samples were collected within November 2012-March 2013 from animals aged between 6 months and 3 years. The potential risk factors studied were species, age, sex, and herd location. All serum samples were examined with indirect ELIZA test for antibody detection. Data were analyzed with different statistical approaches such as Chi-square test, odds ratios (OR), univariable, and multivariable LR models.
Results revealed a non-significant association between being seropositive with BVDV and all risk factors, except for species of animal. Seroprevalence percentages were 40% and 23% for cattle and buffaloes, respectively. OR for all categories were close to one with the highest OR for cattle relative to buffaloes, which was 2.237. Likelihood ratio tests showed a significant drop of the -2LL from univariable LR to multivariable LR models.
There was an evidence of high seroprevalence of BVDV among cattle as compared with buffaloes with the possibility of infection in different age groups of animals. In addition, multivariable LR model was proved to provide more information for association and prediction purposes relative to univariable LR models and Chi-square tests if we have more than one predictor.
开展本次横断面研究,以确定埃及牛和水牛中牛病毒性腹泻病毒(BVDV)疾病的血清阳性率及相关潜在风险因素,使用逻辑回归(LR)模型对与该疾病相关的潜在风险因素进行建模,并为当前数据拟合最佳预测模型。
2012年11月至2013年3月期间,共采集了740份6个月至3岁动物的血液样本。所研究的潜在风险因素包括物种、年龄、性别和畜群位置。所有血清样本均通过间接ELISA试验检测抗体。数据采用不同的统计方法进行分析,如卡方检验、比值比(OR)、单变量和多变量LR模型。
结果显示,除动物物种外,BVDV血清阳性与所有风险因素之间无显著关联。牛和水牛的血清阳性率分别为40%和23%。所有类别的OR均接近1,牛相对于水牛的OR最高,为2.237。似然比检验表明,从单变量LR模型到多变量LR模型,-2LL显著下降。
有证据表明,与水牛相比,牛中BVDV的血清阳性率较高,且不同年龄组的动物都有感染的可能性。此外,如果有多个预测变量,相对于单变量LR模型和卡方检验,多变量LR模型被证明能为关联和预测目的提供更多信息。