上海市某区奶牛场结核病风险因素横断面研究

CROSS-SECTIONAL STUDY OF TUBERCULOUS RISK FACTORS IN DAIRY FARMS IN SHANGHAI

为了解某区奶牛场牛型结核分支杆菌的流行状况及风险因素。本研究于2016年9月~10月通过全群抽样策略,对某区27个奶牛场3月龄以上的所有牛只(15 903头)采用牛型结核分支杆菌PPD皮内变态反应试验对结核病感染状态进行检测,同步进行问卷调查,利用Epi info^TM 7软件对检测和问卷调查结果进行单因素分析,显著性水平为p <0.2,Fisher确切检验x^2;并将筛选出p<0.2的变量进行多因素Logistic回归分析,建立该区奶牛结核病Logistic预测模型。PPD皮内变态反应检测结果显示,结核病阳性牛(皮厚差≥4 mm)0头,可疑似牛(2 mm≤皮厚差<4 mm)37头,分布于9个奶牛场。单因素分析筛选出11个有统计学意义的风险因素,其中危害性风险因素9个,保护性风险因素2个,最终进入该区奶牛结核病Logistic预测模型的风险因素有病死牛深埋点位于场内、牛舍消毒频率≤3次/周和隔离结核病可疑牛只。结果表明,本市某区奶牛场结核病阳性率处于极低水平,未出现结核分支杆菌流行的状况,基本具备全面净化的条件。但该区部分奶牛场仍然存在牛只引进、生物安全措施执行不严格以及管理水平不高等高风险行为。

In order to investigate and evaluate the infection status and risk factors of Mycobacterium bovis(M.bovis)in Shanghai,the whole group sampling strategy was used to perform a survey on 27 dairy farms.Total 15903 cows were tested for M.bovis infection status using purified protein derivative(PPD)intradermal allergy.All the risk factors were analyzed using software Epi info^TM7 and p value<0.2 variables(Fisher exact test x^2)were used for multivariate logistic regression analysis.The survey found not M.bovis positive cow(skin thickness difference≥4 mm),but 37 suspicious cows(2 mm≤skin thickness difference<4 mm)that were raised on 9 dairy farms.Total 11 variables were significantly associated with M.bovis infection status.9 of which were risk factors and 2 were protective factors.Three risk factors contained in the final multivariable logistic regression model,which included"dead animal disposal site located on farm","frequency of cowshed disinfection≤3 times/week"and"quarantine tuberculosis suspicious cow".These results suggested that M.bovis infection in Shanghai was very low.However,some high risks were identified,such as cow introduction,low biological safety,low feed and management level,and so on.