Serologic survey of cattle in the northeastern and north central United States, Virginia, Alaska, and Hawaii for antibodies to Cache Valley and antigenically related viruses (Bunyamwera serogroup virus).
Sudhir P Sahu
Sudhir P SahuU. S. Department of Agriculture, Animal and Plant Health Inspection Service, National Veterinary Services Laboratories, Ames, Iowa 50010, USA. Sudhir.P.Sahu@aphis.usda.gov
Bovine sera from northeastern states (Connecticut, Delaware, Maine, Maryland, Massachusetts, New York, Pennsylvania, Vermont, and West Virginia), north central states (Indiana, Illinois, Iowa, Kentucky, Michigan, Minnesota, North Dakota, Ohio, South Dakota, and Wisconsin), Virginia, Alaska, and Hawaii were examined for the presence of neutralizing antibodies to Cache Valley (CV), Lokern (LK), Main Drain (MD), Northway (NW), and Tensaw (TS) viruses. Microneutralization tests were performed using Vero cells. Ninety percent inhibition of the virus at a 1:10 serum dilution was considered positive for the presence of specific antibody. Sera having antibody to more than one virus were titrated from 1:10 to 1:640. The results indicated that 4-28% of the cattle per region had specific antibodies to CV virus. Neutralizing antibodies to NW, LK, and TS viruses were also detected, indicating possible exposure to these Bunyamwera serogroup viruses along with CV virus. Antibody titers measured against NW virus were very similar to those against CV virus. Antibodies to MD virus were present in low levels in bovine sera from Illinois, Maryland, and Ohio. Cattle from Alaska had only antibodies to NW virus. Antibodies to Bunyamwera serogroup viruses were not observed in sera from Hawaii.