Integrated epidemiological and molecular investigation of foot-and-mouth disease in selected areas of central and Southern Ethiopia

Foot-and-mouth disease (FMD) is a highly contagious Transboundary animal disease that causes substantial production losses and constrains livestock trade. The study aimed to estimate FMDV seroprevalence, identify circulating serotypes, assess factors associated with seropositivity, and characterize FMDV detected during outbreaks in study areas of Ethiopia. A Cross-sectional study, questionnaire survey, and outbreak investigation were conducted from October 2023 to May 2025. Serum samples from 314 cattle in South Omo zone were tested using a competitive 3ABC-ELISA, and strongly positive samples were further analyzed by solid-phase competitive ELISA for serotypes-specific antibodies. Epithelial tissue and swab samples collected from clinically affected cattle in outbreak area were subjected to virus isolation in BHK-21 cells, real-time RT-PCR, and antigen-captured ELISA for serotyping. A semi-structured questionnaire was administered to 145 respondents to assess knowledge, attitudes, and practices regarding FMD. The overall FMDV seroprevalence was 80.9% (254/314). Seroprevalence differed significantly among districts ( p < 0.001) and herd size categories ( p < 0.001), while age, sex, and body condition were not significantly associated with seropositivity. In multivariable analysis, cattle from Daasanech had higher odds of seropositivity than those from Nyangatom (OR = 7.99; 95% CI: 3.12–20.49; p < 0.001), while cattle from medium and large herds had substantially higher odds of seropositivity than those from small herds (OR = 7.65; 95% CI: 3.50-16.68 and OR = 14.8; 95% CI: 6.46–33.94, respectively; p < 0.001). Antibody based serotyping identified four serotypes SAT2, O, SAT1, and A with SAT2 detected most frequently. Among 28 clinical specimens collected during outbreaks, 10 (35.7%) yielded CPE and were confirmed as FMDV positive by real time RT-PCR, with Ct values ranging from 19.8 to 32. Antigen based serotyping identified serotype O in 5/10 (50.0%) isolates, serotype A in 3/10 (30.0%), and mixed O/A in 2/10 (20.0%). Among questionnaire respondents, 81.4% reported awareness of FMD, whereas only 4.8% reported vaccination and quarantine practices. FMDV exposure was high in the study population, with substantial variation among districts and herd sizes and evidence of concurrent circulation of multiple serotypes. The detection of SAT2, O, SAT1, and A antibodies, and O and A viruses during outbreaks highlights the need for strengthened serotypes specific surveillance and improved vaccine strain selection. The low know how of vaccination and quarantine practices further emphasizes the need for community based disease awareness, biosecurity, and targeted FMD prevention and control measures in Ethiopia.