H2N2 influenza viruses in domestic ducks.
D000818:Animals; D002988:Cloaca / Q000382:microbiology; D004372:Ducks / Q000382:microbiology*; D006723:Hong Kong; D053121:Influenza A Virus, H2N2 Subtype; D009980:Influenza A virus / Q000302:isolation & purification*; D009976:Orthomyxoviridae Infections / Q000382:microbiology*; D014132:Trachea / Q000382:microbiology