2Keffaber K K. Reproductive failure of unknown etiology[J]. Am Assoc Swine Pract Newslett,1989(1) : 1- 9.
3Biodeau R, Dea S, Sauvageau R A, et al. Porcine reproductive and respiratory syndrome in Quebec[J]. Vet Rec, 1991,129 (5):102-103.
4Tian K, Yu X L, Zhao T Z,et al. Emergence of fatal PRRSV variants: Unparalleled outbreaks of atypical PRRS in China and molecular dissection of the unique hallmark[J]. PLOS ONE,2007,2(6) :e526.
5Duan X, Nauwynck H J, Pensaert M B. Virus quantification and identification of cellular targets in the lungs and lymphoid tissues of pigs at different time intervals after inoculation with porcine reproductive and respiratory syndrome virus (PRRSV)[J].Vet Microbiol,1997,56:9- 19.
6Kim S,Kwang J,Joo H S,et al. Enhanced replication of porcine reproductive and respiratory syndrome (PRRS) virus in a homogenious subpopulation of MA 104 cell line[J]. ArchVirol,1993,33:477-483.
7Molitor T W, Choi C S, l.eitner G. Modulation of host immune response by SIRS virus[J]. Am Assoc Swine Pract Newsletter, 1992, 4:27-28.
8Zhou Y, Barghusen S, Choi C. Effect of SIRS virus infection on leukocyte populations in the peripheral blood and on cytokine expression in alveolar macrophage of growing pigs[J]. Am Assoc Swine Pract Newletter, 1992, 4:28.
