Respiratory Enteric Orphan Viruses (referred to as REO viruses) are a diverse group of viruses that primarily infect animals, particularly birds and mammals. They belong to the family Reoviridae, which includes a variety of double-stranded RNA viruses. The term "orphan" in their name indicates that these viruses were initially identified and characterized as having unknown or uncertain disease associations.
REO viruses are known to infect the respiratory and gastrointestinal tracts of their hosts, causing respiratory and enteric diseases with varying degrees of severity. They can lead to clinical symptoms such as respiratory distress, diarrhea, weight loss, reduced growth, and in some cases, death. In birds, REO viruses have been implicated in causing avian respiratory infections, as well as enteritis and hepatitis. In mammals, they have been associated with enteric diseases in livestock, including pigs, cattle, and sheep.
The genetic material of REO viruses is composed of segmented double-stranded RNA, which encodes for various proteins required for viral replication and infectivity. This unique genetic structure makes REO viruses capable of genetic reassortment, leading to the emergence of new strains with altered pathogenic properties.
Although primarily affecting animals, there have been reports of REO viruses infecting humans, particularly in individuals with weakened immune systems. However, human infections are considered rare and usually result in mild disease.
Given the potential economic impact on livestock health and the potential zoonotic threat to humans, the study and surveillance of REO viruses are of significant importance in veterinary and public health fields.
