Contact of birds with tick-borne encephalitis virus in the eastern part of the Russian plain.

A total of 706 native blood sera of birds representing 44 most common bird species in the southern parts of the Kirov region were examined for antibodies against tick-borne encephalitis virus. Some serologic tests were found positive, but the birds appeared to constitute a secondary and nonessential link in the circulation of virus in the natural environment of this area.