X Zhang1, Z Wang2, G Mu3, T Wang4. 1. Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China. Electronic address: zhang_xd@jlu.edu.cn. 2. First Institute of Prevention and Treatment on Endemic Diseases of Jilin Province, Baicheng 137000, China. 3. Jilin Provincial Center for Animal Disease Control and Prevention, Changchun 130062, China. 4. Baicheng Normal University, Baicheng 137000, China; Military Veterinary Research Institute of Academy of Military Medical Sciences, Changchun 130122, China.