Ecology and molecular epidemiology of tick-borne rickettsioses and anaplasmoses with natural foci in Russia and Kazakhstan.

During our more than 20 years of monitoring, we have used epidemiological, field, and experimental methods for characterization of natural foci of tick-borne rickettsioses in Russia. The main results were obtained through genetic methods (PCR sequence) at the Université de la Mediterranée (Marseille, France). We describe considerable heterogeneity of tick-borne alpha(1)-proteobacteria: 16 microorganisms the of the order Rickettsiales were detected in Russia and Kazakhstan. R. sibirica-caused North Asiatic tick-borne rickettsiosis is the main tick-borne rickettsiosis in Russia, with wide distribution in Siberia and the Russian Far East and high epidemic activity of natural foci of different landscape types. Our results show circulation of different pathogenic rickettsiae in the same endemic territories. In the Far East region, R. sibirica subsp. R. sibirica, R. sibirica subsp. BJ-90, and R. heilongjiangensis were detected; in the Altay and Krasnojarsk regions, R. sibirica subsp. R. sibirica and R. heilongjiangensis; and in the Kurgan district of West Siberia, R. sibirica subsp. R. sibirica and R. slovaca. The roles of more than 15 new genotypes of alpha(1)-proteobacteria in infectious disease in Russia and Kazakhstan are in need of further study.