Foot-and-mouth disease in Armenia (1958-2003): Historical epidemiology, serotype dynamics, and evolving vaccination strategies.

Background and Aim: Foot-and-mouth disease (FMD) is a highly contagious transboundary animal disease affecting cloven-hoofed livestock, with significant economic and trade implications. Armenia lies within the West Eurasia and Middle East epidemiological pool, where serotypes O, A, Asia-1, and occasionally SAT-2 circulate. Despite decades of control efforts, the historical epidemiology of FMD in Armenia has not been comprehensively documented. This study aimed to conduct a 65-year retrospective analysis of FMD in Armenia to characterize serotype distribution, outbreak patterns, vaccination strategies, and diagnostic advancements, and to identify priorities for progression in the progressive control pathway (PCP-FMD). Materials and Methods: Data from 1958 to 2023 were compiled from the Union of Soviet Socialist Republics (USSR) agricultural archives, national veterinary records, World Organization for Animal Health/World Reference Laboratory for FMD reports, and peer-reviewed literature. Serotype identification, outbreak frequency, and species involvement were analyzed using descriptive statistics, heatmaps, and geographic information system (GIS) mapping. Diagnostic evolution from complement fixation testing to enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and viral protein 1 (VP1) sequencing was documented. Vaccination protocols were traced from early monovalent campaigns to current polyvalent strategies. Results: Between 1958 and 2023, Armenia recorded over 1 million FMD cases, with peaks in 1966 (591,820 cases) and 1973 (471,263 cases). Serotypes O, A, Asia-1, and SAT-1 were detected, with serotype O predominating. Outbreaks declined significantly after the 1980s, coinciding with mass vaccination, improved diagnostics, and targeted biosecurity measures. Notable milestones included integration of the A/Armenia/98 strain into vaccines (1999) and adoption of polyvalent vaccines containing the A/ASIA/G-VII lineage (2016). No outbreaks have been reported since 2016. Conclusion: Armenia's sustained control of FMD reflects adaptive vaccination strategies, early serotype detection, and regional cooperation. Progression from PCP-FMD Stage 2 to Stage 3 will require enhanced vaccination coverage, expanded surveillance, and strengthened veterinary infrastructure. Historical lessons from Armenia's control strategies may inform FMD management in similar transboundary risk zones.