Evaluation of efficacy of cytology for the prompt diagnosis of infectious Laryngotracheitis in commercial chicken

In order to evaluate the efficacy of cytology technique for the prompt diagnosis of Infectious laryngotracheitis in commercial chicken, 100 commercial layer farms suspected for this disease were selected from which samples were subjected for both PCR confirmation of infectious laryngotracheitis virus and cytological diagnosis of the disease by observing intranuclear inclusion body of infectious laryngotracheitis virus. To locate the exact site of trachea to collect cytology smear, trachea was categorised as anterior one-third, middle and posterior one-third. Out of 70 positive cases confirmed by PCR technique, the anterior and posterior portions of the trachea revealed intranuclear inclusions of ILT virus only in 28 (40% positivity) and 31 (44% positivity) cases, respectively. The middle portions of the trachea depicted intranuclear inclusions in 51 cases (73% positivity). Cytology technique by taking smear from the middle portion of trachea was found efficient and would serve for prompt diagnostic tool for field level screening of the disease. This technique could also alleviate the usage of costly equipments involving high recurring costs for the diagnosis of this disease.