DUCK VIRAL ENTERITIS IN EGYPT: ISOLATION AND DETECTION OF THE CIRCULATING VIRUS DURING OUTBREAKS FROM 2016-2018

Abstract

Abstract: Duck viral enteritis (DVE) is an acute and contagious herpes virus infection with a potential threat to domestic and wild waterfowl. In this study, 75% mortality rate with 40% drop in egg production was recorded among the examined flocks. Diagnosis of the disease was carried out based on the clinical signs, pathology and supported by laboratory confirmation. Microscopically, the presence of eosinophilic intranuclear inclusion bodies (IN/IB) in the hepatocytes revealed duck enteritis virus (DEV) infection. DEV was isolated in embryonated duck eggs; 42.6% of the samples showed evidence of infection. The nucleic acid of the DEV was detected by Polymerase Chain Reaction (PCR) in 19 out of 68 collected samples (27.9%) with positive amplification of the DNA polymerase gene. This investigation disclosed variation in the disease prevalence among the different ages, breeds, seasons, and immune status of ducks, as the disease was more prevalent among vaccinated flocks (34.8%) than in non-vaccinated ones (24.4%). Accordingly, control efforts can be done to reduce the further outbreaks of DVE in terms of adoption of good management practice, biosecurity measures and increasing awareness about the disease spread and application of proper vaccination regimens. Continuous studies of DEV at the molecular and immunological levels are important for the effectiveness of any control strategy of the disease including vaccination.Key words: DVE; duck plaque; histopathology; PCR; DNA polymerase gene; Egypt