The comprehensive diagnosis and prevention of duck plague in northwest Shandong province of China.

Here, we report the first outbreak of duck plague (DP) confirmed in 4 tissue samples that were collected since August 2012 from the northwestern region of Shandong province, China. Among these, 3 were collected from commercial Jin-ding variety layer ducks and one from Cherry Valley meat-breeding ducks. The sick ducks (7 to 49 wk old) were characterized by typical DP symptoms and necroscopic features. The flocks experienced high morbidity and mortality rates, and decreased production performance, which led to tremendous economic losses. The diagnosis of DP infection was confirmed by comprehensive analyses of epidemiological data, clinical signs, necroscopic features, histopathological examinations, and viral isolation and identification. According to the laws of the People's Republic of China on Animal Epidemic Prevention, emergency measures were implemented to control the outbreak, which included slaughter of the infected flocks and proper disposal of the bodies, manure, and other wastes, disinfection and thorough cleaning of the duck facilities, fields, tools, utensils, and devices, as well as emergency vaccination of the threatened flocks and the implementations of revised immunization procedures. Possible causes of the DP outbreak and the prevalence of the virus in Shandong province were also analyzed and are discussed herein.