Akabane and bovine ephemeral fever (BEF) viruses cause vector-borne diseases. In this study, inactivated Akabane virus (AKAV)+Bovine ephemeral fever virus (BEFV) vaccines with or without recombinant vibrio flagellin (revibFlaB) protein were expressed in a baculovirus expression system to measure their safety and immunogenicity. Blood was collected from mice, guinea pigs, sows, and cattle that had been inoculated with the vaccine twice. Inactivated AKAV+BEFV vaccine induced high virus neutralizing antibody (VNA) titer against AKAV and BEFV in mice and guinea pigs. VNA titers against AKAV were higher in mice and guinea pigs immunized with the inactivated AKAV+ BEFV vaccine than in animals inoculated with vaccine containing revibFlaB protein. Inactivated AKAV+BEFV vaccine elicited slightly higher VNA titers against AKAV and BEFV than the live AKAV and live BEFV vaccines in mice and guinea pigs. In addition, the inactivated AKAV+BEFV vaccine was safe, and induced high VNA titers, ranging from 1 : 64 to 1 : 512, against both AKAV and BEFV in sows and cattle. Moreover, there were no side effects observed in any treated animals. These results indicate that the inactivated AKAV+BEFV vaccine could be used in cattle with high immunogenicity and good safety.
Animals ; Antibodies, Neutralizing ; Baculoviridae ; Cattle ; Cattle* ; Ephemeral Fever* ; Flagellin ; Guinea Pigs ; Mice ; Vaccines ; Vibrio

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.
Animals ; Arboviruses ; Arthropod Vectors ; Arthropods ; Cattle ; Ceratopogonidae ; Culicidae ; Ephemeral Fever ; Epidemiologic Studies ; Korea ; Limit of Detection ; Organothiophosphorus Compounds ; Palyam Virus ; Polymerase Chain Reaction ; Prevalence ; Sensitivity and Specificity ; Viruses

Arthropod-borne viruses (Arboviruses) are transmitted by arthropods such as Culicoides biting midges and cause abortion, stillbirth, and congenital malformation in ruminants, apparently leading to economic losses to farmers. To monitor the distribution of Culicoides and to determine their relationship with different environmental conditions (temperature, humidity, wind speed, and altitude of the farms) on 5 cattle farms, Culicoides were collected during summer season (May-September) in 2016 and 2017, and analyzed for identification of species and detection of arboviruses. About 35% of the Culicoides were collected in July and the collection rate increased with increase in temperature and humidity. The higher altitude where the farms were located, the more Culicoides were collected on inside than outside. In antigen test of Culicoides against 5 arboviruses, only Chuzan virus (CHUV) (2.63%) was detected in 2016. The Akabane virus (AKAV), CHUV, Ibaraki virus and Bovine ephemeral fever virus (BEFV) had a positive rate of less than 1.8% in 2017. In antigen test of bovine whole blood, AKAV (12.96%) and BEFV (0.96%) were positive in only one of the farms. As a result of serum neutralization test, antibodies against AKAV were generally measured in all the farms. These results suggest that vaccination before the season in which the Culicoides are active is probably best to prevent arbovirus infections.
Agriculture ; Altitude ; Animals ; Antibodies ; Arbovirus Infections ; Arboviruses ; Arthropods ; Cattle ; Ceratopogonidae ; Ephemeral Fever Virus, Bovine ; Farmers ; Humidity ; Jeollabuk-do ; Korea ; Neutralization Tests ; Palyam Virus ; Ruminants ; Seasons ; Stillbirth ; Vaccination ; Wind

Vector-borne arboviruses produce mild to severe symptoms in domestic animals. Bovine ephemeral fever (BEF), Akabane, Aino, and Chuzan virus have been primarily attributed to reproductive disorders or febrile diseases in cattle, and Japanese encephalitis virus (JEV) is mainly associated with reproductive failures in swine. We investigated antibody titers from domestic swine against four bovine arboviruses (BEF, Akabane, Aino, and Chuzan virus) and from cattle against JEV in Korea. While the positive rates for Akabane and BEF were 37.4% and 15.7%, the positive incidence of Chuzan and Aino were relatively low, with positive rates of 3.04% and 0.4%, respectively, based on a virus neutralization assay. Antibody titers against more than one virus were also frequently detected in domestic swine. The incidence of JEV was 51.3% among domestic cattle. In addition, one positive case was detected in the thoracic fluids from 35 aborted calves, based on the hemagglutination inhibition test. Our results indicate that swine are susceptible hosts of bovine arboviruses without showing clinical symptoms in a natural environment. Moreover, we confirmed that JEV could be associated with reproductive failure in pregnant cattle, as were other vector-borne bovine arboviruses assessed in this study.
Animals ; Antibodies, Viral/blood ; Cattle ; Cattle Diseases/*epidemiology/*virology ; Encephalitis Virus, Japanese/*immunology ; Encephalitis, Japanese/blood/epidemiology/*veterinary/virology ; Ephemeral Fever/blood/*epidemiology/virology ; Ephemeral Fever Virus, Bovine/*immunology ; Hemagglutination Tests ; Incidence ; Korea/epidemiology ; Neutralization Tests ; Swine ; Swine Diseases/*epidemiology/*virology