[Forest tick Ixodes ricinus (Ixodidae) in the foci of tick-borne borreliosis of the northwestern part of the Moscow region].

Monitoring studies during 1996-2001 have shown a natural foci of tick-borne borreliosis with high abundance of Ixodes ricinus and high infection rate with an agent: 19.5-38.4 tick individuals per 1 km of route, infection rate 18.0 +/- 1.7-22.5 +/- 1.5%. A risk to be infected with the Lyme disease in the ricinus focus of the tick-borne borreliosis during the epizootic season did not vary much during the period of study, 3.5-8.2 in different year, mean 6.0 infected ticks per 1 km of route.