Birnaviridae

Birnaviridae is a family of viruses that infect a wide range of avian and piscine hosts. The family is divided into five genera: Aquabirnavirus, Avibirnavirus, Blosnavirus, Entomobirnavirus, and Gymnobirnavirus. The most well-known member of this family is the Infectious Bursal Disease Virus (IBDV), which causes a highly contagious disease in young chickens.

Structure

Viruses in the Birnaviridae family are non-enveloped, with icosahedral and Double-stranded RNA genomes. The virion size is around 60 nm in diameter. The genome is segmented and consists of two separate parts, each containing one large open reading frame (ORF).

Life Cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. The virus exits the host cell by monopartite non-tubule guided viral movement. Birds and fish serve as the natural host.

Pathology

The most significant disease associated with this family of viruses is Infectious Bursal Disease (IBD), also known as Gumboro disease. This disease, caused by the Infectious Bursal Disease Virus, is highly contagious and affects the immune system of young chickens, making them susceptible to secondary infections.

Prevention and Control

Control of Birnaviridae infections primarily involves biosecurity measures, vaccination, and culling of infected animals. Vaccines are available for some species and are an effective tool in preventing disease.

See Also

• Virus classification
• Infectious Bursal Disease
• Aquabirnavirus
• Avibirnavirus
• Blosnavirus
• Entomobirnavirus
• Gymnobirnavirus

References

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  ODR Birna Fig1 v1 c
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  ODR Birna Fig3 v3 (1)
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  ODR Birna Fig4 v7