Background: Since the first report concerning the existence of avian influenza subtype H9N2 (AI
H9N2) in 2006 in Lebanon; a lot of pathological changes and mortalities were seen among chicken
flocks suggesting the influence of the AI H9N2 virus.
Objective: this study reports the circulation of H9N2 associated with mortalities in broiler sector and
decrease egg production in layer hens and breeders in Lebanon.
Methods: A total of 22 poultry flocks have been tested by real-time reverse transcription polymerase
chain reaction (rt-RT-PCR) for the presence of H9N2 in different types of chickens including broilers,
breeders, laying hens, backyard chickens and ducks. Tracheal swabs were collected from flocks raised
in different governorates in Lebanon.
Results:Testing of samples with rt-RT-PCR revealed that 6 flocks reared in 4 Lebanese governorates
were positive (CT ranged from 20.42 to 33.86). A Positive sample with CT 20.42 was tested and
partially sequenced and submitted to GenBank, acquired accessions number MH266696 and
designated A/chicken/Lebanon/21-E03/2018 (H9N2). Phylogenetic analysis of the obtained sequence
cluster the characterized strain along with (formerly) G1-like viruses’ subtype B like those circulating
in the Middle East.
Conclusion: the AI H9N2 avian influenza virus is circulating causing major problem among chickens.
More studies need to be addressed to understand the real effect of the H9 virus on chickens and
humans in Lebanon.