You are currently reviewing an older revision of this page.
No surface morphology is visible by EM.
Avihepatoviruses are both heat and acid stable.
Length of genome (Kim et al., 2006): up to 7,792 nt (5'-UTR: 625-655 nt, ORF: 6,750-6,756 nt, 3'-UTR: c. 318 nt). 5'-UTR contains a type IV IRES. The location of the cre has not been identified.
Genome layout: VPg+5'UTRIRES-IV[1AB-1C-1D-2A1npgp/2A2NTPase-2A3H-box/NC-2B-2C/3A-3B-3C-3D]3'UTR-poly(A)
The deduced polyproteins of the three types have lengths of 2,249-2,251 amino acids. There is no L protein. The 1AB polypeptide remains uncleaved and lacks a myristoylation signal. The genome sequences of all three DHAV types have three 2A motifs: i) NPGP; ii) AIG1-type guanine nucleotide-binding domain (GxxGxGKS NTP-binding motif); and iii) a H-box/NC motif. However, it is not clear if this genome region encodes one, two or three mature polypeptides. 3Dpol exhibits a CSG rather than PSG sequence motif.
Avihepatoviruses are divided into three genetic types, duck hepatitis A virus (DHAV) 1 to DHAV-3. DHAV-2 and DHAV-3 are not neutralized by DHAV-1 antiserum; however, the relationship between types 2 and 3 remains unstudied.
DHAV causes a highly fatal contagious disease of young ducklings, 1-28 days of age. The onset of the disease is very rapid, it spreads quickly through the flock and may cause up to 90% mortality. Sick ducklings develop spasmodic contractions of their legs and die within an hour in a typical "arched-backward" position. The liver is enlarged and shows hemorrhagic spots. A DHAV-1 live-attenuated vaccine is widely used.
Avihepato-: from avian and Greek hepatos, "liver"
Support for preparation of the Online Report and Report Summaries has been provided by: