Determinants of Foot and Mouth Virus in Eastern Algeria.

Foot and mouth disease (FMD) is a highly contagious viral disease affecting cattle with significant economic impact. This cross-sectional field study aims to determine the current serological status of FMD in Algerian cattle herds. The objectives were: to evaluate post-vaccination antibody responses to non-structural proteins (NSPs) in vaccinated cattle under the Algerian FMD control program, and to identify circulating Foot and Mouth Disease Virus (FMDV) strains while assessing vaccine efficacy. From September to November 2019, we collected 573 blood samples from clinically healthy, vaccinated cattle four weeks post-vaccination. Differentiation between infected and vaccinated animals was accomplished through detection of antibodies against NSPs using the FMDV 3ABC-AB ELISA assay for serotype determination. Results revealed that 112 samples (19.55%) tested positive for FMDV NSP antibodies, while 461 samples (80.45%) were negative. Only serotype O was identified among the positive samples. Sex (OR = 12.01; 95% CI: [5.60-25.75]) and age (OR = 9.38; 95% CI: [5.72-15.39]) were identified as significant risk factors for infection susceptibility. This study provides the first data on FMD prevalence and highlights the current serological status in Algeria. Our findings suggest the existing vaccination scheme requires optimization based on regional risk assessment and serological monitoring. We recommend implementing animal identification for traceability, cross-border surveillance, and molecular-spatial modeling to target interventions in high-risk areas.