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

Milek, Justyna; Blicharz-Domanska, Katarzyna

Taxonomic classification. CoVs belong to the family Coronaviridae, subfamily Coronavirinae, and order Nidovirales. Initially, classification of members of this subfamily was based on their serological relationships as opposed to the new taxonomic revision based on a threshold level of sequence identity of a few replicase regions (the pp1ab polyprotein and the ORF1ab gene). According to these criteria, Coronavirinae are divided into four genera: alpha-, beta-, gamma-, and deltacoronavirus, replacing the traditional division into antigenic groups 1, 2, and 3 (4) . The final list of species proposed by the International Committee on Taxonomy of Viruses (ICTV) including the genus identified in birds, is presented in Table 1 . Generally, alpha-and betaCoVs infect humans and domestic animals, while gamma-and deltaCoVs are largely associated with avian hosts although they were also detected in marine mammal species as well as in some Asian carnivores (32, 52) .