Role of cervids in the epidemiology of bovine ephemeral fever virus infection in the Republic of Korea: A cross-sectional retrospective study.

Abstract

Bovine ephemeral fever (BEF) is a viral disease in cattle and buffaloes, with subclinical involvement in various ruminant species. This study aimed to investigate bovine ephemeral fever virus (BEFV) transmission in deer in the Republic of Korea (ROK) and the potential risk factors associated with seropositivity. We conducted a retrospective cross-sectional serological survey of neutralising antibodies against BEFV in cervid sera collected from the ROK. The seroprevalence of BEFV was estimated to be 10.8% (95% confidence interval [CI] = 8.5-14.1), demonstrating that exposure to this virus is prevalent among farmed and free-ranging cervids in the ROK. The results revealed that age class and geographic location affected seroprevalence. Older age and the presence of neighbouring ruminant farms were significant risk factors (odds ratio [OR] = 2.394, 95% CI = 1.195-4.796) and (OR = 1.533, 95% CI = 1.026-2.288), respectively. We also observed that the individual likelihood of positivity in the southern provinces was significantly higher than that in the northern provinces (OR = 1.744, 95% CI = 1.001-3.037). There were also significant differences in the seroprevalence of cervids between the western and eastern provinces (OR = 2.021, 95% CI = 1.047-3.900). Factors that were not significantly associated with BEFV antibody prevalence included herd size and species (p > 0.05). These results suggest that cervid species may serve as important reservoirs for the transmission of BEFV, highlighting the need for closer monitoring of BEFV infections in cervids in the ROK.