A Report of Some Investigations of Infectious Laryngotracheitis

THE investigations here reported deal with the influence of various agencies and factors on the pathogenicity of laryngotracheitis virus, and on some of the possible sources and modes of infection. They were instituted with the primary object of gaining information relative to the control of the disease which has become a major disease problem of the poultry industry. It has been shown by Gibbs (1931b) and Komarov and Beaudette (1931) that the etiological agent of infectious laryngotracheitis of the domestic fowl is harbored for long periods of time by certain “chronic carrier” individuals which have survived natural outbreaks of the disease. The possibility that the incitant is carried mechanically by non-susceptible species of birds and animals, or by contaminated equipment has been investigated (Gibbs, 1931a). That the virus of laryngotracheitis may be carried to the incubator upon the surface of hatching eggs from an actively infected flock or one harboring . . .