Page 186 - Avian Virology: Current Research and Future Trends

Avian Reovirus

Frederick S.B. Kibenge *, Yingwei Wang , Molly J.T. Kibenge , Anil Kalupahana 6
1
2
3
1
and Scott McBurney 1

1 Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown,
PEI, Canada.
2 School of Mathematical and Computational Sciences, University of Prince Edward Island, Charlottetown, PEI, Canada.
3 Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya,
Peradeniya, Sri Lanka.
*Correspondence: kibenge@upei.ca

https://doi.org/10.21775/9781912530106.06

Abstract found in avian species that were clinically normal, with 80–95%
Avian reoviruses, including all orthoreoviruses of avian origin, of isolates being non-pathogenic (Jones, 2013), albeit reports
belong to the genus Orthoreovirus, one of 15 recognized genera of reoviruses in wild birds have been sporadic (Hollmén and
in the family Reoviridae, with a double-stranded RNA genome of Docherty, 2007; Styś-Fijoł et al., 2017).
ten segments and a non-enveloped double-layered icosahedral
capsid. Avian reoviruses are very common among commercial First discovered
poultry and other avian species and are also important avian Reovirus was first isolated in 1954 from a field outbreak of chronic
pathogens causing a variety of pathological conditions the most respiratory disease of chickens (and subsequently in ducks and
common being viral arthritis/tenosynovitis in commercial turkeys) and was named ‘Fahey-Crawley virus’ (Fahey and Craw-
broiler chickens and turkeys, and enteric disease and neurological ley, 1954). This isolate was subsequently characterized by Petek
disease in wild birds. These viruses have been extensively studied, et al. (1967) as a reovirus and was shown by Olson and Weiss
as evidenced by the extensive list of published literature reviewed (1972) to be serologically like the ‘viral arthritis agent’ of Olson
in this chapter. The application of the recently reported reverse and others (Olson and Kerr, 1966, 1967; Olson and Solomon,
genetics system using avian reoviruses will significantly increase 1968) that was isolated from synovitis in broiler chickens and
our understanding of avian reovirus biology and disease. its identity confirmed as a reovirus by using electron microscopy
(Walker et al., 1972). The name ‘reovirus’ is derived from reo:
sigla from ‘respiratory enteric orphan’ and was proposed by Sabin
Introduction and history (1959) for a subgroup of viruses (echovirus 10) isolated from
respiratory and gastrointestinal tracts but not known to be associ-
Origin of the virus ated with any known human disease state and hence considered
The term avian reovirus is used in this chapter to include all ‘orphan’ viruses.
orthoreoviruses of avian origin and not only isolates belonging
to the virus species Avian orthoreovirus (ARV). Avian reoviruses
are very common among commercial poultry and other avian Infectious agent
species. They have been isolated from various avian species with
a variety of pathological conditions (van de Zande and Kuhn, Classification
2007; Jones, 2013; Lu et al., 2015) including viral arthritis/teno- The family Reoviridae contains viruses with a wide host range,
synovitis, malabsorption syndrome, stunting-runting syndromes, including vertebrates, invertebrates, plants, protists, and fungi.
blue wing disease, osteoporosis, enteric disease, immunosuppres- Avian reoviruses belong to the genus Orthoreovirus, one of 15
sion, respiratory disease, neurological disease, and winter die-offs recognized genera in the family Reoviridae. The current classifica-
of wild birds. Of these, the most common and readily diagnosed tion of the Reoviridae family is detailed in the Ninth Report of
disease presentation is viral arthritis/tenosynovitis in commercial the International Committee on Taxonomy of Viruses (ICTV)
broiler chickens (Kibenge and Wilcox, 1983) and turkeys (Page (Attoui et al., 2012). Virions are non-enveloped, 60–80 nm in
et al., 1982), and enteric disease and neurological disease in free- diameter with one, two or three capsid shells depending on
ranging (wild) birds (Huhtamo et al., 2007; Kalupahana, 2017). the genus. The genome is segmented double-stranded RNA
By their very nature, avian reoviruses have most frequently been (dsRNA) with the number of genome segments varying from 10