The dominance indices and the probability to involve different fleas types in epizootic diseases on the example of Central-Caucasian high-mountain natural plague focus

The paper attempts to use an indicator of the number of fleas of different species in the natural focus of the plague to assess the intensity of epizootics. The correlation between the number of fleas of seven species and the number of isolated strains of plague microbe is established. It is shown for small species to be more often involved in epizootics during their intensive course, which corresponded to the first period of the focus activity. In the second period characterized the tendency to decrease the share of small species in the epizootic process. The third period demonstrated a significant difference with the first two previous ones. The detection in samples of field material of infected secondary carriers of these species or random carriers was indirect evidence of intense epizootics.