Bluetongue in cattle : typing of viruses isolated from cattle exposed to natural infections

Abstract

Bluetongue viruses were isolated from five clinically healthy bovines exposed to natural infection over two consecutive bluetongue seasons. The isolated viruses were typed by serum-virus neutralization and found to represent 11 of the established antigenic groups. Two isolations failed to be neutralized and may represent further antigenic types of bluetongue virus. No single virus type could be found to occur in the same bovine for two consecutive seasons and in most instances the particular virus type occurred in the blood ·of a bovine for a period of less than 14 days.