Research on the Invading Process and Distribution of Duck Enteritis Virus in Artificially Infected Ducks by Indirect Immuno-Fluorescent Staining Method

Fifty adult ducks were inoculated with a virulence duck enteritis virus(DEV,strain CHv),and acute cases of duck viral enteritis(DVE) were duplicated.Tissue samples from heart,liver,spleen,lung,kidney,thymus,duodenum,bursa of Fabricius,brain,esophagus and the pancreas were collected after inoculation and paraffin slices of these samples were prepared.The method of indirect immuno-fluorescent staining(IFA) was applied to investigate the invading process and distribution of DEV.The results showed that DEV antigen can be detected in the spleen,thymus and bursa of Fabricius 4 hours after infection and in the liver,esophagus,duodenum,rectum and the lung 6 hours after infection.The positive rate of viral antigen in different tissues detected by IFA was 46/50 in the liver,48/50 in the spleen,46/50 in the lung,0/50 in the kidney,46/50 in the intestine,46/50 in the bursa of Fabricius,47/50 in the thymus,0/50 in the pancreas,0/50 in the brain,44/50 in the esophagus and 0/50 in the heart.The research suggested that the spleen,bursa of Fabricius,thymus,esophagus,intestine,liver and the lung are the main target organs of DEV in acute DVE cases.After infection,DEV appears in the spleen,the thymus and bursa of Fabricius first,then spreads to the liver,alimentary canal and the lung quickly.IFA is a sensitive and specific method in detecting DEV antigen in paraffin slices and it is a good method for diagnosis and antigen location of DEV.