A new subtype of type A influenzavirus isolated from turkeys.

A new subtype of avian influenzavirus A was isolated in January 1967 from an epizootic in a turkey hatchery in Ontario, Canada. The disease was fatal in 65 of 2 500 hens involved. Virus was isolated from lung and trachea tissue of three dead turkeys. Sera from convalescent birds contained antibody against the viruses isolated from the outbreak but not against other known type A avian influenzaviruses, Newcastle disease virus, Myxovirus Yucaipa, or Mycoplasma gallisepticum.The strain designated A/turkey/Ontario/6118/67 contained the influenza A type ribonucleoprotein. Haemagglutinin and neuraminidase antigens of the strain differed antigenically from the envelope antigens of other avian influenzaviruses isolated from birds, horses, pigs, or man. The designation of turkey/Ontario/6118/67 as containing haemagglutinin of avian subtype 8 (Hav 8) and neuraminidase of avian subtype 4 (Nav 4) is proposed.