[Endemic foci of hemorrhagic fever with renal syndrome in the North-Western region of the European part of the USSR].

For the detection of specific antigens of hemorrhagic fever with renal syndrome (HFRS) virus, examinations were carried out covering 8.061 animals of 23 species trapped in the Murmansk, Archangelsk, Vologda, Novgorod, Pskov, Leningrad regions, the Komi ASSR, Estonian SSR, Latvian SSR, and Lithuanian SSR in 1984-1987. Different activity and variable species-specific composition of animal virus carriers in the north, south, and west of the north-western region were demonstrated.

[Changes in the numbers of the causative agent of intestinal yersiniasis (Yersinia enterocolitica) in Xenopsylla cheopis (Aphaniptera) fleas in the process of blood digestion].

In infected fleas the agent of intestinal yersiniosis underwents a complex cycle of quantitative changes after each feeding. A species belonging of blood consumed greatly affected the dynamics of the agent abundance. The general peculiarity of the development of microbes in insects, which fed on various animals (white mice, Sirian hamsters, white rats and guinea pigs), is characterized by the decrease in the abundance of the agent during the first hours after feeding.