Table 1. Results from virological investigation of birds in 1970-1972

          Bird species | No. examined | No. bioassays | No. * strains isolated | No. of TBE virus strain |
---------------------- | ------------ | ------------- | ---------------------- | ----------------------- |

         Gulls (Larus) |           78 |            12 |                      2 |                      -
                  Coot |           51 |             8 |                      1 |                      -
         Sandwich tern |            2 |             2 |                      1 |                      -
          Little egret |           16 |             4 |                      1 |                      -
         Squacco heron |            1 |             1 |                      1 |                      -
              Garganey |            1 |             1 |                      1 |                     54
                  Rook |          102 |            31 |                      7 |                      -
                  Lark |            7 |             5 |                      2 |                      -
          Tree sparrow |           23 |             3 |                      2 |                     59
              Pheasant |            3 |             3 |                      1 |                      -
         Other species |           41 |            23 |                      - |                      -
                 Total |          339 |            93 |                     19 |                      2

        IAF of poly -A |            0 |             0 |                      0 |                      0
        IAF of poly -B |           20 |            40 |                     20 |                     40
            IAF of TBE |           40 |            40 |                      0 |                     40
       Hyperimmune TBE |           80 |            80 |                      0 |                    160
             West Nile |            0 |             0 |                     20 |                      0
 Japanese encephalitis |            0 |             0 |                     80 |                      0
             Strain 54 |           40 |            40 |                      0 |                     40
             Strain 59 |           20 |            40 |                      0 |                     40
  * The data on antigenic group B arboviruses are cited in other reports.

Table 2. Results from identification of strains 54 and 59 by the CF test

         Serum Antigen | Strain 54 | Strain 59 | JE strain | TBE strain
---------------------- | --------- | --------- | --------- | ----------

        IAF of poly -A |         0 |         0 |         0 |         0
        IAF of poly -B |        20 |        40 |        20 |        40
            IAF of TBE |        40 |        40 |         0 |        40
       Hyperimmune TBE |        80 |        80 |         0 |       160
             West Nile |         0 |         0 |        20 |         0
 Japanese encephalitis |         0 |         0 |        80 |         0
             Strain 54 |        40 |        40 |         0 |        40
             Strain 59 |        20 |        40 |         0 |        40
   Footnote: O - negative result; numbers show reciprocal sera titers with 2-4 antigen units.

T730