Molecular epidemiology of foot and mouth disease virus in Iran during 2019 and 2023.

Foot-and-mouth disease is an important transboundary animal disease with a significant economic impact. The high mutation rate of the foot-and-mouth disease virus leads to the emergence of new genotypes, which necessitate the detection, identification and surveillance of FMD. The current study was conducted to detect and characterize the circulating FMD viruses in Iran between November 2019 and September 2023, based on the VP1 sequence analysis. Three serotypes O, A and Asia 1 were detected. In this study, the first appearance of SA-2018 lineage in Iran was reported, along with the dominance of ANT-10 and PUN-16 sublineage of O/ME-SA/PanAsia-2 lineage. Meanwhile, the VP1 nucleotide sequences of serotype A viruses classified them to the A/ASIA/Iran-05/FAR-11; and sequences of Asia 1 viruses classified them to the Sindh-08 lineage. This study provided an update on the epidemiology of FMD virus in Iran and presented the emergence of the SA-lineage. Another finding was that even though the samples were taken from vaccinated animals, the positivity rate was high. Regarding the comparison results between field and vaccine nucleotide sequences, effective vaccination and the application of restrictions on the movement of animals are necessary.