RESUMEN
Long-term annual monitoring of the natural foci of tularemia was first made on Wrangel Island. The objects of the investigation were pellets of birds-myophages, blood samples from rodents, and excrements from carnivorous mammals. A total of 2626 biological samples were examined in the period 2002 to 2011. A serological test was ascertained to be the most effective method for the detection of tularemia epizooties; polymerase chain reaction should be used as an additional technique to examine blood samples, as well as rodent tubular bone debris taken from the pellets. Tularemia epizooties were registered in the populations of two species of lemmings every year, except in 2003. An intensive diffuse tularemia epizooty was first detected in this area, which emerged in 2019, peaked by spring 2011, and covered most of the island. The antigen of tularemia pathogen was identified in 43.46% of the samples under examination,which is a high quantitative indicator of the intensity of an epizootic process. The fact that positive samples are annually found in the same areas of the island suggests that the causative agent is steadily and long preserved in the parasitic system. The availability of stable and active natural tularemia foci on Wrangel Island calls for preventive measures, particularly vaccination of risk groups coming to the island to conduct researches.
Asunto(s)
Anticuerpos Antibacterianos/sangre , ADN Bacteriano/genética , Infección Focal , Francisella tularensis/aislamiento & purificación , Tularemia/epidemiología , Tularemia/veterinaria , Animales , Regiones Árticas/epidemiología , Arvicolinae/microbiología , Heces/microbiología , Zorros/microbiología , Francisella tularensis/genética , Francisella tularensis/inmunología , Islas , Federación de Rusia/epidemiología , Estrigiformes/microbiología , Tularemia/microbiologíaRESUMEN
The subjects of the study were snowy owl castings (611 samples), polar fox litters (148 samples), and water samples of outdoor tundra water reservoirs. Tularemia antigen was sought in the castings and litters by the antibody neutralization test. The water was examined by bioassays. Tularemia antigen was annually detected in the study samples. Epizootically active autonomous natural foci of tundra-type tularemia were ascertained to continue to exist on the Wrangel island. The major vectors of the causative agent of tularemia were two types of lemmings (Siberian lemming and Vinogradov's one). The availability of epizootically active natural foci determines the need for vaccination against tularemia of persons who are long engaged in researches who are epidemiologically a risk group.