| newcastle disease outbreaks in western china were caused by the genotypes viia and viii. | twelve newcastle disease virus (ndv) strains were isolated from chickens involved in outbreaks of newcastle disease (nd) in western china (shaanxi, gansu, xinjiang, qinghai and guangxi provinces) between 1979 and 1999. all strains were determined to be velogenic by plaque formation, the mean death time (mdt) of embryonated eggs, and the intracerebral pathogenicity index (icpi). for preparation of virus rna, the acid guanidinium-thiocyanate method was used. a 908bp fragment of nucleotide was ampl ... | 2002 | 12052330 |