Antigenic types of bluetongue virus prevalent in Egypt

In an attempt to identify the antigenic types of bluetongue (BT) virus prevalent in Egypt 31 selected sheep sera from different parts of Egypt which had been screened by gel precipitation tests were examined by a plaque reduction test using 16 types of BT virus. Dilutions 1:5 of those screened sera reduced more than 50% of plaques of at least 1 of 16 types of BT virus. Two sera completely inhibited plaque formation with type 4 virus, 1 with type 13, another serum with type 15 and 2 other ser with type 16 virus. The significance of the above serological findings is discussed.