Coronaviruses in Avian Species – Review with Focus on Epidemiology and Diagnosis in Wild Birds

Milek, Justyna; Blicharz-Domanska, Katarzyna

Among the most abundant viruses infecting a wide variety of animals, including birds and humans are representatives of the large Coronaviridae family. Their virions contain the largest single-stranded positive sense RNA (ssRNA) genome, the feature which distinguishes them from other known viral RNA genomes (19) . Similarly to other RNA viruses, coronaviruses (CoVs) are characterised by high genetic diversity driven by mutation and recombination, which can lead to the emergence of new viruses. Such new pathogens can have new features which even enable them to switch to new hosts (49) . These newly created viruses can acquire zoonotic potential, as witnessed by the severe acute respiratory syndrome (SARS), the epidemic from Southern China in 2003 caused by SARS-CoVs. This disease, termed "atypical pneumonia", was diagnosed in humans in 29 countries and had a nearly 10% mortality rate. In 2012, there emerged a subsequent disease caused by a novel coronavirus, the so-called Middle East respiratory syndrome (MERS) with even higher mortality rates. Both SARS-and MERS-CoVs crossed the species barrier from bats to humans through civet cats and camels as intermediate organisms (17) .