A comparison of three methods of diagnosis of infectious laryngotracheitis

Three methods of isolation of ILT virus are compared. Examination of tracheas from sick birds by means of direct immunofluorescence detects about 60% of the cases detected by viral isolation in chick kidney cells or in embryonating eggs. The coupling of direct immunofluorescence on tracheal sections with viral isolation and immunofluorescence in CK cells is a good practical method to detect an ILT infection in sick birds.