title: [Indications for the circulation of lentogenic Newcastle disease field virus in broiler chicks].
abstract: Haemagglutinin of nine out of eighteen lentogenic isolates from broilers showing respiratory problems was more stable than that of the La Sota strain (licensed for vaccination) and the Hitchner B1 strain (licensed for production but not for vaccination). This is indicative of the circulation of a lentogenic field virus during the period of isolation (1979-1981), the origin of which is not directly attributable to vaccination. The possible origin of this field virus is discussed.
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology*; D009522:Newcastle disease virus / Q000145:classification / Q000302:isolation & purification* / Q000472:pathogenicity; D014774:Virulence
vernacular_title: Aanwijzingen voor het circuleren van lentogeen NCD-veldvirus in slachtkuikens.