title: Emergence of a highly pathogenic porcine reproductive and respiratory syndrome virus in the Mid-Eastern region of China.
abstract: Herds of pigs in the Mid-Eastern region of China have experienced recent outbreaks of a severe form of porcine reproductive and respiratory syndrome (PRRS) characterised by high fever and morbidity and mortality in animals of different ages. Eighty-one herds were diagnosed with PRRS virus (PRRSV) infection from June to December 2006 on the basis of clinical signs, pathological findings and reverse transcriptase polymerase chain reaction (RT-PCR). Twenty strains of PRRSV were isolated from 20 herds in six provinces. Following experimental inoculation, one isolate, designated SY0608, caused 100% morbidity and 25-50% mortality in 30-, 65- and 105-day-old pigs and the birth of stillborn and weak piglets from affected sows. The ORF5 gene had 99.5-99.8% nucleotide and 99-100% derived amino acid sequence identities among SY0608 and five other field isolates, but only 89.4% and 88.6% identities, respectively, with VR-2332, the prototypic North American isolate. The 2850bp Nsp2 gene of SY0608 had 79.4% nucleotide and 74.9% derived amino acid sequence identities with VR-2332; deletions of 1 and 29 amino acids corresponded to positions 480 and 531-559 of strain VR-2332, respectively. These findings demonstrated that a new highly pathogenic Northern American type PRRSV has spread widely in the Mid-Eastern region of China.
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Li
authors.forename: Xinglong
authors.initials: X
authors.lastname: Wang
authors.forename: Kuntao
authors.initials: K
authors.lastname: Bo
authors.forename: Xianwei
authors.initials: X
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
authors.forename: Baoshou
authors.initials: B
authors.lastname: Yang
authors.forename: Wenming
authors.initials: W
authors.lastname: Jiang
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D008969:Molecular Sequence Data; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000453:epidemiology / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000472:pathogenicity*; D011247:Pregnancy; D013552:Swine; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D014764:Viral Proteins