Monitoring of Five Bovine Arboviral Diseases Transmitted by Arthropod Vectors in Korea

ABSTRACT

A survey was performed in Korea to monitor the prevalence of five bovine arboviruses [Akabane virus, Aino virus, Chuzan virus, bovine ephemeral fever (BEF) virus, and Ibaraki virus] in arthropod vectors, such as Culicoides species. To determine the possible applications of survey data in annual monitoring and warning systems in Korea, we examined the prevalence of bovine arboviruses in arthropod vectors using RT-PCR. To compare the sensitivity and specificity of virus detection, nested PCR was also performed in parallel for all five viruses. Using the RT-PCR, the detection limits were at least up to 10(1.5), 10(2.8), 10(2.0), 10(1.8), and 10(4.0) TCID50/ml for Akabane virus, Aino virus, Chuzan virus, BEF virus, and Ibaraki virus, respectively. When nested PCR was performed using 1 micronl of PCR product, the detection limits were increased, to 10(0.05), 10(1.8), 10(1.0), 10(0.008), and 10(2.0) TCID50/ml for Akabane virus, Aino virus, Chuzan virus, BEF virus, and Ibaraki virus, respectively. Thus, nested PCR increased the sensitivity of the virus detection limit by 1~2 log. We pooled 30~40 mosquitoes in one sample. We collected 113 samples in 2006, 135 samples in 2007, and 100 samples in 2008. Among these samples, Chuzan virus and BEF virus genes were detected at a range between 0.82% and 1.19%, and Akabane virus, Aino virus, and Ibaraki virus genes were detected at less than 0.20%. These data may provide some insight into future epidemiological studies of bovine arboviral diseases in Korea.