Orbivirus

Viruses-10-00481-g001.BTV

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Orbivirus genome

Orbivirus is a genus of viruses belonging to the family Reoviridae. Orbiviruses are arthropod-borne viruses, meaning they are transmitted by insects such as mosquitoes and ticks. This genus includes several important pathogens that affect animals and, in some cases, humans. The most well-known orbiviruses include Bluetongue virus, which affects ruminants like sheep and cattle, and African horse sickness virus, which is deadly to horses.

Structure and Classification

Orbiviruses are characterized by their double-stranded RNA genome, which is segmented into ten to twelve segments. This segmentation allows for a high degree of genetic reassortment, leading to a wide variety of strains and serotypes within the genus. The viruses are non-enveloped and possess an icosahedral capsid structure, which is typical of the Reoviridae family.

Transmission and Disease

The transmission of orbiviruses is primarily through blood-feeding arthropod vectors. The virus replicates in both the vector and the host, causing disease in the latter. The specific disease symptoms depend on the virus species and the host, ranging from mild to severe. In animals, symptoms can include fever, hemorrhagic conditions, edema, and, in severe cases, death.

Diagnosis and Control

Diagnosis of orbivirus infections is typically based on the detection of the virus or its RNA in blood samples, using techniques such as polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA). Control measures are primarily focused on vector control to reduce transmission and vaccination of susceptible animals. For some orbiviruses, effective vaccines are available and widely used in endemic areas.

Research and Importance

Research on orbiviruses is crucial for understanding their biology, epidemiology, and interaction with hosts and vectors. This knowledge is essential for developing effective control strategies and vaccines. Orbiviruses are of significant concern in veterinary medicine due to their impact on livestock health and the economic losses they can cause. There is also interest in their potential threat to human health, although direct infections in humans are rare.