Sero-surveillance of Getah Virus among Thoroughbred Horses in Korea

Getah virus (GETV), which is transmitted by mosquitoes, causes lower limb edema and stiffness in horses. In this study, we investigated the sero-surveillance of GETV among Thoroughbred racehorses in Korea during 2013 and 2014. A total of 1,182 equine serum samples collected from Thoroughbred racehorses in four provinces (Gyeongnam, Gyeonggi, Jeonbuk and Jeju provinces) were analyzed using virus neutralization (VN) tests. An antibody titer of ≥ 1:2 was considered positive. Overall, the seropositivity rate for GETV was found to be 12.4% (146/1,182) among the racehorses; the annual seropositivity rates were 12.4% and 12.2% in 2013 and 2014, respectively. The seropositivity rates in April and September in 2013 turned out to be 8.6% and 15.2%, respectively. The regional distribution of seropositivity ranged from 5.0% to 22.3% in 2013 and from 0.0% to 15.0% in 2014, respectively. Gyeongnam province had the highest seropositivity rate than other provinces. By analyzing the distribution of VN titers according to horse age, we found that the highest GETV seropositivity rate was in horses over 6 years of age (22.4% and 28.1%, 2013 and 2014, respectively), and that the incidence of GETV was higher in geldings (17.6% and 18.6%, 2013 and 2014, respectively) than in males and females. These results indicate that Thoroughbred horses raised in Korea were bitten by mosquitoes harboring GETV.