Indications of pathogenic viruses in water of Lake Baikal and its tributaries

: The waters of 25 large rivers falling into the Baikal Lake, their mouth water areas and open Baikal Lake areas to a depth of 500 m were for the first time in the practice of researches on the Baikal Lake were investigated for markers of hepatitis A virus and rotaviruses. The investigations showed an insignificant contamination of surface waters with pathogenic viruses. The antigens of all studied viruses and high values of bacteria from the Escherichia coli group were recorded in the areas exposed to chronic man-made pollution. Data on the seasonal changes in the distribution of enteroviruses indicated their absence in the annual cycle in the pelagic area of the lake, which suggests that viral particle would not accumulate under the conditions of the Baikal Lake over a long period.