The isolation and identification of further antigenic types of African horsesickness virus

Abstract

Two new strains of horsesickness virus were isolated m suckling mice by the intracerebral route. These strains were identified as horsesickness by:- (a) Demonstration of fixation of complement by the group specific complement fixation test. (b) Non-inactivation by sodium desoxycholate and diethyl ether under standard conditions. (c) Preliminary screen serum virus neutralisation tests. Detailed serum virus cross neutralisation tests showed that these virus strains belong to two new antigenic types, which have been designated Groups 8 and 9. The two strains were isolated from widely separated geographical regions and are regarded as the prototypes of the two new groups which have been shown to include other strains of virus. The significance of the finding is discussed in relation of control of horsesickness by mass immunisation.