Prevalence of avian metapneumovirus subtype B in live bird market in Gilan province, Iran

Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and swollen head syndrome in chickens. Four aMPV subgroups (A-D) have been reported previously based on their genetic and antigenic differences. Evidence suggests that the live bird markets (LBMs) play an important role in the epidemiology of the avian viral diseases. A total number of 450 oropharyngeal samples from eight different species of birds (migratory and local) were collected from LBMs of Gilan province, Iran, from October to December 2016. The presence of aMPV was determined by reverse transcription polymerase chain reaction (RT-PCR) based on nucleoprotein gene. The aMPV was detected in 30.60% of the examined birds including chickens (37.00%), turkey (33.00%), Eurasian teal (25.00%), common blackbird (33.00%), and Eurasian woodcock (25.00%). Bioinformatics analysis and a phylogenetic tree based on partial nucleotide sequences of the N gene showed that the detected aMPVs were belonged to subtype B. This is the first report of aMPV in non-commercial birds in Iran. Knowledge of the frequency and types of infected birds with pneumoviruses allow a better understanding of the epidemiology of aMPV in Iran.