Family: Caliciviridae

Genus: Nacovirus


Distinguishing features

The strains in this genus form a distinct clade within the family Caliciviridae (Figure 4. Caliciviridae)


See discussion under family description

Genome organization and replication

The genome of nacovirus is 7.6 kb and contains two ORFs (ORF1 and ORF2). ORF1 encodes a polyprotein with a calculated molecular weight of 250.6 kDa and a VP1 protein with a calculated molecular weight of 61.6 kDa. ORF2 encodes a polypeptide with a calculated molecular weight of 21.5 kDa. 


Nacoviruses are novel avian caliciviruses that were detected in intestinal contents of turkeys, chickens and geese from the United States, Germany, Netherlands and China (Wolf et al., 2012, Day et al., 2010, Liao et al., 2014). In turkeys, weight loss, enteritis and liver enlargements with foci of intrahepatic necrosis and inflammation was reported. 

Species demarcation criteria 

Not defined as there is only one species in the genus. 

Related, unclassified viruses

Virus name

Accession number

Virus abbreviation

goose calicivirus strain N



chicken calicivirus F10026n



Virus names and virus abbreviations are not official ICTV designations.