Anthropogenic effects on changing Q fever epidemiology in Russia.

In the northwestern region of Russia (Leningrad province) cattle is proved to be the main source of C. burnetii infection in humans, both in menaced professionals and in formally nonmenaced groups. Liquidation of specialized cattle-breeding complexes (with their well-organized veterinary surveillance) and broadening of the circle of non-professionals that contact with agriculture or domestic animals infected with C. burnetii provide the prerequisites to Q fever spreading among various groups of population.

Probabilistic evaluation of aspirating doses of a Q fever pathogen.

The process of biological aerosol penetration into respiratory organs is connected with the estimation of the amount of an aspiration dose of microorganisms (D) a human gets in the center of infection. Here we submit a probabilistic model describing the process of hits of a Q fever pathogen in a human respiratory tract. This approach makes it possible to get qualitatively different probabilistic estimations of doses received and corresponding values of critical time intervals of exposure at which the amount accumulated in the respiratory tract turns into an infecting dose. This permits one to approach the explanation of the infection process in the context of the absence of its absolute nature, which is connected both with the immune system responses and the irregularity with which the recipient receives aspiration doses under conditions of artificial distribution of the microbe-bearing aerosol.