In June 2005, a low pathogenic H5N2 avian influenza occurred for the first time in layer chickens in Ibaraki Prefecture. Surveillance in trading restriction zones and epidemiologically related farms revealed 41 sero-positive farms, and 16 H5N2 viruses were isolated. That these viruses were genetically and antigenically similar to each other suggested that these isolates were derived from a common origin. Complete genomic characterization of all eight gene segments showed that these H5N2 isolates in Japan had high homology to the H5N2 strains prevalent in Central America since 1994. The virus was reisolated from tracheal and cloacal swabs of experimentally inoculated chickens and efficiently transmitted to sentinel chickens in adjacent cages. Long term antibody responses of chickens against the virus were observed with AGP and HI test.
(Research Team for Zoonotic Diseases, TEL +81-29-838-7708)
Reference:
- Okamatsu et al. (2007) Vet. Microbiol. 124(1-2) : 35-46.
- Okamatsu et al. (2007) Avian Dis. 51(1 Suppl) : 474-475.
