[Zoonotic infections in the central and southern ulusy of the Republic of Sakha]. / Zoonoznye infektsii v tsentral'nykh i iuzhnykh ulusakh Respubliki Sakha.

The serological survey of humans, as well as agricultural animals and rodents, for the presence of zoonotic infections, was carried out. Local inhabitants were shown to have contacts with the causative agents of pseudotuberculosis, enteric yersiniosis, tularemia, leptospirosis, Q fever, tick-borne rickettsiosis, chlamydiosis, toxoplasmosis. The immune stratum with respect to enteric yersiniosis was found to have a greater index, while the immune strata with respect to chlamydiosis, Q fever, pseudotuberculosis had the least indices. However, the indices of immune strata perceptibly varied in individual regions. The highest occurrence of antibodies to all above-mentioned zoonotic infections was registered in Megino-Kangalasskii, Amga and Neriungrinskii ulusy [correction of regions]. The probable sources of leptospirosis, toxoplasmosis and Q fever were agricultural animals, while the probable sources of enteric yersiniosis and leptospirosis were rodents.

[Distribution of viruses from the Californian encephalitis serogroup (Bunyaviridae, Bunyavirus) in the northern expanses of Russia]. / Rasprostranenie virusov serogruppy Kaliforniiskogo éntsefalita (Bunyaviridae, Bunyavirus) v severnykh shirotakh Rossii.

The study was carried out in 1983-1991 and covered a territory of about 10 x 10(6) km2 in various physico-geographic areas (East Fennoscandia, Northern Russian Plain, West Siberia, Central Siberia, North-Eastern Siberia, and Northern Pacific Region) in the Arctic, Subarctic, Northern-Central-Southern taiga, forest-steppe, and steppe in Northern Russia. A total of 251 strains were isolated from 1391,900 mosquitoes, identified as the California group snowshoe hare (83), Inkoo (44), and Tahyna (2) viruses; 122 strains were not completely identified. Some of the strains with uncommon antigenic composition can be natural reassortants. Fifty-two percent of strains were isolated from Aedes communis and the associate species of mosquitoes, other hosts were A. excrucians (8%), A. cantans (6.25%), A. flavescens (6.25%), A. ciprius (6.25%), A. punctor (4.5%), A. vexans (4.5%), A. cataphylla (3.6%), A. nigripes (3.6%), and A. hexodontus (2.6%). The infection rate of mosquitoes was 0.009% in the tundra, 0.012% in forest-tundra, 0.01% in Northern taiga, 0.02% in Central taiga, 0.017% in Southern taiga, 0.026% in forest-steppe, and 0.097% in steppe. The epidemic season is one month in the tundra (from the beginning of July till the beginning of August), two months in Northern taiga (July-August), and three months in Central taiga (from the second half of June till the beginning of September). The highest infection rate of mosquitoes was observed at the end of the epidemic season in all regions. SSH strains prevailed to the East from the Enisei river, whereas to the West and in the Subarctic regions INK virus predominated, SSH being rare; in the taiga the distribution was quite the opposite. TAH virus was virtually absent. Human morbidity was observed in all territories studied. The immune stratum of adult population is about 30% in the tundra and forest-tundra and about 50% in Northern and Central taiga.

[The epidemiological and epizootiological characteristics of leptospirosis in the Republic of Sakha (Yakutia)]. / Epidemiologicheskaia i épizootologicheskaia kharakteristika leptospirozov v respublike Sakha (Iakutiia).

Among zoonotic infections with natural foci in the Republic of Sakha (Yakutia), leptospiroses have assumed greater importance. Their morbidity is sporadic, mainly afflicting rural adults. The serogroups pomona, grippotyphosa, and icterohaemorrhagiae are prevalent in the etiological structure of leptospiras. An epizootiological survey has revealed natural and anthropurgic leptospirosis foci which present a hazard primarily to rural inhabitants who deal with animal husbandry, fur-bearer breeding, hunting, and fishing. The vole (Microtis) and root vole (Microtis oeconomus) serve as the major reservoir and source of leptospiroses in the natural foci, while cattle and caged Arctic foxes do in the anthropurgic ones. High sizes of house and grey mice which are carriers of the Leptospira javanica and icterohaemorrhagiae, have been recorded in the residential and domestic constructions of localities. A complex of antileprospirotic measures that limits the influence of the leading factors of infection transmission and the risk of human infection is substantiated.