Isolation and characterization of duck viral enteritis (Duck plague) virus from ducks in field outbreaks in Bangladesh

Jahidul Islam; Md. Mohirul Islam; Md. Sadequl Islam; Md. Zaminur Rahman; Palash Bose; Mohammed Rafiqul Islam; Mst. Mianra Khatun; Md. Ariful Islam

doi:10.5455/JRVS.20240102065916

Abstract
Duck viral enteritis (DVE) also known as duck plague (DP) is a fatal viral disease of ducks globally that causes huge economic losses in the duck industries. The main objectives of the current study were: the isolation of the circulating duck viral enteritis virus (DVEV) from clinical specimens of field outbreaks, molecular identification of the virus and genetic characterization of DVEVThe natural outbreaks of duck plague (DP) were reported between February and June 2018 on three commercial duck farms located at Netrokona, Mymensingh and Nilphamari districts of Bangladesh. A total of 42 dead ducks were collected from the three farms. Postmortem examination of dead ducks was carried out and gross lesions of the visceral organs were recorded.Liver and spleen samples were collected aseptically and 10% viral inoculum was prepared from liver and spleen. Isolation of DVEV was done by injecting viral inoculum into 9-13 days old embryonated duck eggs through the chorioallantoic membrane (CAM) route.Molecular detection of DVEV in liver, spleen and CAM homogenate was performed by PCR targeting 446 bp fragment of DNA polymerase gene of DVEV. Phylogenetic analysis was carried out by comparing the amino acid sequence of field isolatesof DVEV with the amino acid sequence of global isolates of DVEV deposited in the GenBank. Enlargement of the liver and spleen, abdominal haemorrhage, and annular rings of the trachea were seen in the affected ducks which were characteristics gross lesions in DVE.18of 42 samples (42.85%) were found positive for DVEV by PCR assays. Embryos of duck experimentally inoculated with DVEV were found dead at 3-5 days post infection.Degenerated blood vessels of the CAM, dwarfism of the embryos was observed. The phylogenetic study revealed that the DVEV isolates causing disease outbreak in ducks in the current study were 100% similar to the isolates of DVEV thatpreviously reported from Bangladesh, Vietnam and China.

Key words: Duck, Duck viral enteritis, Bangladesh, Disease outbreaks, Phylogenetic analysis