Isolation and characterization of a Sagiyama virus from domestic pigs
Journal
Journal of Veterinary Diagnostic Investigation
Journal Volume
18
Journal Issue
2
Pages
156-161
Date Issued
2006
Author(s)
Abstract
In 2002, a strain of Sagiyama virus (SAGV) designated ML/Taiwan/02 was isolated from farmed pigs in Taiwan. The nsP1 and E1 gene sequences of the ML/Taiwan/02 strain shared 98.6 and 96.7% homology, respectively, with corresponding genes of a Japanese strain of SAGV. Nucleotide and amino acid sequence comparison revealed this strain of SAGV to be most closely related to Getah virus, as opposed to its current classification as a subtype of Ross River virus. To investigate the seroprevalence of SAGV infection in Taiwan, a total of 586 pig sera collected from 11 of 17 Taiwanese districts were tested for serum neutralizing antibodies (SNA) against SAGV. Results indicated that 51% of the samples had SNA titer ≥4, and 40% had SNA titer ≥48, indicative of repeated exposure to SAGV in the field. To study the pathogenicity of the ML/ Taiwan/02 strain, this strain was experimentally inoculated into 4-week-old specific-pathogen-free pigs that were seronegative for SAGV. Viremia was detected during postinoculation days (PID) 2-4, when the SNA titer was ≤16. By PID 7, viremia was no longer detectable, coinciding with the increase of SNA titer to ≥48. Clinical illnesses or remarkable lesions were not observed. To the authors' knowledge, this is the first reported isolation of a strain of SAGV from pigs in the field. The virus is experimentally nonpathogenic to pigs but is moderately widespread, most likely via repeated exposure to virus-carrying mosquitoes.
Subjects
Getah virus; Pigs; Ross River virus; Sagiyama virus
Other Subjects
Getah virus; Ross River virus; Sagiyama virus; Sus scrofa; Sus scrofa domestica
Type
journal article