Selim Abdelfattah, Megahed Ameer, Kandeel Sahar, Alanazi Abdullah D, Almohammed Hamdan I
Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt.
Department of Animal Medicine (Internal Medicine), Faculty of Veterinary Medicine, Benha University, Moshtohor-Toukh, Kalyobiya 13736, Egypt.
Animals (Basel). 2021 Apr 19;11(4):1165. doi: 10.3390/ani11041165.
Classification and Regression Tree (CART) analysis is a potentially powerful tool for identifying risk factors associated with contagious caprine pleuropneumonia (CCPP) and the important interactions between them. Our objective was therefore to determine the seroprevalence and identify the risk factors associated with CCPP using CART data mining modeling in the most densely sheep- and goat-populated governorates. A cross-sectional study was conducted on 620 animals (390 sheep, 230 goats) distributed over four governorates in the Nile Delta of Egypt in 2019. The randomly selected sheep and goats from different geographical study areas were serologically tested for CCPP, and the animals' information was obtained from flock men and farm owners. Six variables (geographic location, species, flock size, age, gender, and communal feeding and watering) were used for risk analysis. Multiple stepwise logistic regression and CART modeling were used for data analysis. A total of 124 (20%) serum samples were serologically positive for CCPP. The highest prevalence of CCPP was between aged animals (>4 y; 48.7%) raised in a flock size ≥200 (100%) having communal feeding and watering (28.2%). Based on logistic regression modeling (area under the curve, AUC = 0.89; 95% CI 0.86 to 0.91), communal feeding and watering showed the highest prevalence odds ratios (POR) of CCPP (POR = 3.7, 95% CI 1.9 to 7.3), followed by age (POR = 2.1, 95% CI 1.6 to 2.8) and flock size (POR = 1.1, 95% CI 1.0 to 1.2). However, higher-accuracy CART modeling (AUC = 0.92, 95% CI 0.90 to 0.95) showed that a flock size >100 animals is the most important risk factor (importance score = 8.9), followed by age >4 y (5.3) followed by communal feeding and watering (3.1). Our results strongly suggest that the CCPP is most likely to be found in animals raised in a flock size >100 animals and with age >4 y having communal feeding and watering. Additionally, sheep seem to have an important role in the CCPP epidemiology. The CART data mining modeling showed better accuracy than the traditional logistic regression.
分类与回归树（CART）分析是一种潜在的强大工具，可用于识别与山羊传染性胸膜肺炎（CCPP）相关的风险因素及其之间的重要相互作用。因此，我们的目标是在绵羊和山羊数量最多的省份，使用CART数据挖掘模型来确定CCPP的血清流行率并识别相关风险因素。2019年，在埃及尼罗河三角洲的四个省份对620只动物（390只绵羊、230只山羊）进行了一项横断面研究。从不同地理研究区域随机选取绵羊和山羊进行CCPP血清学检测，并从羊群管理人员和农场主那里获取动物信息。六个变量（地理位置、物种、羊群规模、年龄、性别以及共同饲养和饮水）用于风险分析。采用多步逻辑回归和CART模型进行数据分析。共有124份（20%）血清样本CCPP血清学检测呈阳性。CCPP患病率最高的是年龄大于4岁（48.7%）的动物，饲养在规模≥200只（100%）且有共同饲养和饮水的羊群中（28.2%）。基于逻辑回归模型（曲线下面积，AUC = 0.89；95%置信区间0.86至0.91），共同饲养和饮水显示CCPP的患病率比值比（POR）最高（POR = 3.7，95%置信区间1.9至7.3），其次是年龄（POR = 2.1，95%置信区间1.6至2.8）和羊群规模（POR = 1.1，95%置信区间1.0至1.2）。然而，更高准确性的CART模型（AUC = 0.92，95%置信区间0.90至0.95）显示，羊群规模大于100只动物是最重要的风险因素（重要性得分 = 8.9），其次是年龄大于4岁（5.3），然后是共同饲养和饮水（3.1）。我们的结果强烈表明，CCPP最有可能在饲养在规模大于100只动物且年龄大于4岁且有共同饲养和饮水的动物中发现。此外，绵羊似乎在CCPP流行病学中起着重要作用。CART数据挖掘模型显示出比传统逻辑回归更高的准确性。
