title: The role of WHO in international studies on the ecology of influenza in animals.
mesh_terms: D000818:Animals; D001717:Birds / Q000382:microbiology; D006736:Horses / Q000382:microbiology; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification* / Q000502:physiology; D009976:Orthomyxoviridae Infections / Q000382:microbiology / Q000662:veterinary*; D013552:Swine / Q000382:microbiology; D014944:World Health Organization