Risk factor assessment and molecular characterization of foot-and-mouth disease virus in buffaloes in Bangladesh

Foot-and-mouth disease (FMD) is a major infectious disease of cloven-hoofed animals that causes substantial economic losses. FMD in buffaloes was neglected in the surveillance program, therefore, this study aimed to identify and characterize the FMD virus (FMDV) and determine its associated risk factors in buffaloes in Bangladesh. A total of 150 tissue samples were purposively collected from 16 FMD-suspected buffalo farms, representing a study population of 501 buffaloes across three areas of Bangladesh. The samples were analyzed for FMDV and further tested for the serotypes (O, A, Asia 1) by RT-PCR test. The VP1 gene was sequenced and phylogenetic trees were studied. Epidemiological data were collected through a structured questionnaire. Logistic regression models were used to identify outbreak-associated risk factors. Overall, 29.94% (150/501) FMD prevalence and three serotypes, include O (n = 19), A (n = 7), and Asia 1(n = 4), were identified by RT-PCR. The case fatality, attack, and mortality rates of buffalo calves were 32.91%, 63.2%, and 20.8%, respectively. Potential risk factors identified for FMD in buffaloes including age (calves; AOR:14.07, 95%CI:6.37-31.07), grazing with cattle (yes; AOR:19.09, 95%CI:4.49-81.18), deworming practices (No, AOR:8.71, 95%CI:2.20-34.51), isolation shed (No; AOR:5.82, 95%CI:1.41-23.95), and grazing area (bush; AOR:20.78, 95%CI:5.07-85.12). Phylogenetic analysis of serotype O revealed a 95% sequence similarity with recent isolates from Bhutan and Nepal, while serotype A exhibited a 99% similarity with isolates from India and Bangladesh. Therefore, implementing appropriate control strategies is essential for reducing risk factors and minimizes the occurrence and spread of FMD.