An outbreak of infectious Laryngeotracheitis (ILT) occured among a flock of laying hens (Lohmann's Mothers) of 34 weeks old at Kalama, Qualyobia governorate. Affected birds manifested symptoms of respiratory distress, gasping and bloody exudates from the nasal passages togther with a significant decrease in egg production and hatchability and a non significant decrease in fertility and abnormal dead embryos.
ILT virus could be isolated from samples collected during the course of the disease (nasal exudates as well as tracheal swabs and lung tissues). The isolated virus when inoculated in chicken embryos produc ed pock lesions on the CAM'S and it could be propagated in CER cells producing multinucleated giant cells and intranuclear inclusion bodies.
Susceptible birds of 16 weeks old could be experimentally infected with the isolated virus with re-isolation of ILT virus. Intranuclear inclusion bodies could be seen in epithelial cells lining the respiratory tract as early as 14 hours post-infection.
Specific antibodies could be detected in sera of recovered birds by using both the agar gel precipitation (AGP) and neutralization (SNT) tests.