[Structure of the causative agents of shigellosis in areas of the USSR 1979-1981].

Summarized data on the specific structure of Shigella strains isolated in different territories of the USSR in 1979-1981 are presented. These data indicate that in the intra-specific structure of S. flexneri strains the proportion of serological subvariant 2a increased and that of serological variant 6 and subvariants 16 and 4a decreased during this period. Using one of the base territories of the All-Union Shigellosis Center as an example, the spread of an unusual serological variant of S. flexneri (IV:7,8) in the USSR is shown. The increase of the proportion of S. boydii strains, mainly S. boydii 4, is noted.