Candidate ‘Avian orthoreovirus B’: An emerging waterfowl pathogen in Europe and Asia?

Abstract

A fusogenic virus was isolated from a flock of breeder Pekin ducks in 2019, Hungary. The affected flock experienced a marked decrease in egg production. Histopathological lesions were seen in the oviduct and in the lungs of birds sent for diagnostic investigation. The fusogenic agent was characterized as an orthoreovirus by viral metagenomics. The assembled viral genome was composed of 10 genomic segments and was 23,433 nucleotides (nt) in length. The study strain, designated Reo/HUN/DuckDV/2019, shared low‐to‐medium gene‐wise sequence identity with avian orthoreovirus strains from galliform and anseriform birds (nt, 38.90%–72.33%) as well as with representative strains of neoavian orthoreoviruses (nt, 40.07%–68.23%). On the contrary, the study strain shared 86.48%–95.01% pairwise nt sequence identities with recent German and Chinese reovirus isolates, D2533/6 and Ych, respectively. Phylogenetic analysis clustered all three unusual waterfowl pathogens on a monophyletic branch, indicating a common evolutionary origin of Reo/HUN/DuckDV/2019 with these enigmatic orthoreoviruses described over the past few years. The finding that a candidate new orthoreovirus species, tentatively called Avian orthoreovirus B, was isolated in recent years in Europe and Asia in moribund ducks seems an alarming sign that needs to be better evaluated by extending laboratory diagnosis of viral pathogens in countries where the waterfowl industry is important.

Development and Evaluation of a Monoclonal Antibody-Based Blocking Enzyme-Linked Immunosorbent Assay for the Detection of Antibodies against Novel Duck Reovirus in Waterfowl Species

“…The disease spread to China in 1997 and became widely prevalent in southern China’s major Muscovy duck production area ( 8 ). NDRV can infect almost all kinds of waterfowl species (domestic ducks and geese) ( 9 ). The main lesions are severe necrosis and hemorrhagic foci of the liver and spleen (known locally as hemorrhagic-necrotic hepatitis).…”

“…The main lesions are severe necrosis and hemorrhagic foci of the liver and spleen (known locally as hemorrhagic-necrotic hepatitis). The disease first occurred in 2000, spread quickly from south to north in eastern China, and eventually became an epidemic disease endangering the health of waterfowl worldwide ( 9 – 14 ).…”

“…It has been reported that the host range of NDRV has been enlarged. All species of ducklings (Muscovy duck, semi-Muscovy duck, Cherry Valley duck, Peking duck, Ma duck, and wild duck) and goslings can be infected ( 3 , 4 , 10 , 11 , 21 , 22 ), and genomic variation has already occurred ( 9 , 23 – 26 ). The disease has seriously hindered the healthy development of the waterfowl industry in China.…”

Distinct Whole Transcriptomic Profiles of the Bursa of Fabricius in Muscovy Ducklings Infected by Novel Duck Reovirus with Different Virulence

“…Duck reovirus (DRV) is a common waterfowl virus with various morbidities, belonging to the genus Orthoreovirus in the family Reoviridae [ 1 , 2 ]. DRV infection in waterfowl has been found in many parts of the world, mainly in Europe and Asia [ 2 , 3 ].…”

“…Duck reovirus (DRV) is a common waterfowl virus with various morbidities, belonging to the genus Orthoreovirus in the family Reoviridae [ 1 , 2 ]. DRV infection in waterfowl has been found in many parts of the world, mainly in Europe and Asia [ 2 , 3 ]. Based on biological and genetic properties, DRV can be classified into two genotypes: genotype I (Classical DRV, CDRV) and II (Novel DRV, NDRV) [ 2 , 4 ].…”