Results from recent research demonstrate the high prevalence of EDS virus in wild and domestic ducks in South Korea and provide information on EDSV from ducks that showed variable adaptability in chickens, report S-Y. Cha of Chonbuk National University.

Together with co-authors at Kyungpook National University and the Animal, Plant and Fisheries Quarantine and Inspection Agency, they have a paper published in a recent issue of Poultry Science, in which they explain that EDS virus is an important pathogen of poultry that decreases egg production in chickens and causes respiratory disease in goslings.

In 2011, they obtained serum samples from 139 domestic Pekin ducks, 416 one-day-old Pekin ducklings and 75 wild ducks (67 mallards and eight pintails) to survey their exposure to the EDS virus.

A total of 123 of 139 sera (88.5 per cent) from Pekin ducks, 396 of the ducklings (95.2 per cent), and 16 of 67 mallards (23.9 per cent) were positive.

Field cases of EDS virus in wild and domestic ducks were investigated. Six cases from domestic Pekin ducks were identified by PCR detection and were used for virus isolation and molecular analysis.

Phylogenetic analyses of the partial hexon and full fibre genes showed that the D11-JW-012 and D11-JW-017 strains among six isolates belonged to different clusters compared with other known strains including the 127 strain.

The scientists assessed cell growth efficiency by haemagglutination (HA) titres and cytopathic effects in duck embryo liver cells and chicken embryo liver (CEL) cells to investigate host adaptation.

The D11-JW-017 strain propagated more in chicken embryo liver than the D11-JW-012 strain and the field isolate from chickens.

Reference

^{Cha S-Y., M. Kang, C-K. Park, K-S. Choi and H-K. Jang. 2013. Epidemiology of egg drop syndrome virus in ducks from South Korea. Poult. Sci. 92(7):1783-1789. doi: 10.3382/ps.2013-03067}