Serological Survey of Infectious Laryngotracheitis in Broiler Flocks, Iran, 2018

Infectious Laryngotrachitis (ILT) is an acute respiratory disease with high morbidity and low mortality in poultry. ILT is caused by Gallid herpesvirus 1 (GaHV-1), a member of the Iltovirus genus and family Herpesviridae. It resulted in notable economic losses due to decreasing the growth rates, egg production, and increasing the mortality in commercial poultry, especially layer flocks, and usually, outbreaks are severe in older birds rather than younger flocks. However, Infectious Laryngotrachitis has been reported in broiler as well. Multicausal respiratory diseases are prevalent diseases in Iranian broiler flocks and caused a high rate of mortality and huge economic losses. Field and vaccine strains of Infectious Laryngotrachitis virus are circulating in layer flocks in some geographical locations. To detect seroprevalence of the Infectious Laryngotrachitis virus in broiler flocks, in this study, a total of 180 sera samples were collected in slaughterhouses from 15 broiler flocks (12 sera from each flock) of four provinces of Iran containing Golestan, West Azerbaijan, Qazvin and Tehran during autumn 2018. Infectious Laryngotrachitis virus antibodies were examined using a commercial ELISA test kit. Based on the results, the seroprevalence of the Infectious Laryngotrachitis virus was found to be 13 % of flocks. Also, our finding showed that 33% and 25% of flocks were seropositive to ILTV collected from Tehran and West Azerbaijan respectively. The results revealed that Infectious Laryngotrachitis viruses are circulating in broiler flocks in different parts of Iran.  This is the first report of ILT Seroprevalence in broiler flocks in Iran and in the future, the molecular studies on ILT would be nessaccery in respiratory disease syndrome