5Li Y, Wang X, Bo K, et al. Emergence of a highly pathogenic porcine reproductive and respiratory syndrome virus in the Mid-Eastern region of China [J]. The Veterinary Journal, 2007, 174(3):577-584.
6Zhou L, Yang H. Porcine reproductive and respiratory syndrome in China [J]. Virus Research, 2010, 154(12):31-37.
7Lunney JK, Benfield DA, Rowland RRR. Porcine repro- ductive and respiratory syndrome virus: An update on an emerging and re-emerging viral disease of swine [J]. Virus Research, 2010, 154(1 2):1-6.
8Suarez P, Zardoya R, Prieto C, et al. Direct detection of the porcine reproductive and respiratory syndrome (PRRS) virus by reverse polymerase chain reaction (RT-PCR) [J]. Archives of virology, 1994, 135(1):89-99.
9Ramirez A, Wang C, Prickett JR, et al. Efficient surveil- lance of pig populations using oral fluids[J]. Preventive Veterinary Medicine, 2012, 104(3 4):292-300.
