Infectious laryngotracheitis (ILT), an acute infection of the upper respiratory tract of chickens, was absent before the end of 2013, in Tunisia. Severe respiratory signs were observed in 48 layer and broiler flocks (3 weeks to 80 weeks old) between June 2013 and June 2016, and characterized with dyspnea, bloody mucus excretion and decrease in egg production. Clinical signs were dominated by congestive and hemorrhagic inflammation of the upper respiratory tract. Histopathological analyses and PCR tests were performed on respiratory tissues of suspected birds. Suggestive lesions of ILT, such as epithelial necrosis, sero-fibrinous and sero-hemorrhagic exudates, syncytia and intranuclear inclusion bodies were observed in layers of the 25 flocks visited. ILTV was detected in 12 out of 31 flocks by conventional PCR, using specific primers for the gB gene of ILTV. Eight of these were positive in histopathology. Our findings confirmed the introduction for the first time of the ILT virus in commercial poultry farms, in Tunisia.
Key words: Infectious Laryngotracheitis, Histopathology, Molecular Diagnosis, Poultry, Tunisia