Experience in controlling the effectiveness of barrier winter deratization on the territory of natural focus of hemorrhagic fever with renal syndrome in the Republic of Bashkortostan

The first experience of specialists of the Center for Hygiene and Epidemiology in the Republic of Bashkortostan to control the effectiveness of large-scale barrier winter deratization around settlements with high morbidity of hemorrhagic fever with renal syndrome (HFRS) is presented. For the first time in the territory of the Republic of Bashkortostan, barrier deratization was carried out in the winter period (February – March 2023) in order to improve the natural focus of HFRS on epidemic indications. Zoological, statistical, and epidemiological methods of research were used in the collection and analysis of data. According to zoological observations in the fall of 2022, the number of rodents in stationary points was 24.4 % per 100 trap-days, 2 times higher than in the fall of 2021. The peculiarity of weather conditions is high snow cover (up to 40 cm) and frost (up to minus 26 °C). The peculiarity of work: snowmobiles compacted snow in order to pass to the forest belt for spreading poisoned baits and setting traps. New data on the methodology of work – preliminary geocoding – determination of work sites (deratization and subsequent assessment of infestation after deratization) on the basis of mapping, according to the data of infection sites of patients with HFRS were presented. Features of the work are: participation of employees of different specialties (disinfectologists, biologists, zoologists, entomologist, assistants of medical epidemiologist), large-scale (4830 traps), compressed timing of work (February – March), 1030 days after winter deratization, interaction with the administration of the settlement. The technical complexity of setting traps to the level of "ground" in snow is described. Practical assistance of employees of research institutes, anti-plague institution, Reference centers for HFRS was noted. According to the results of external control of effectiveness after barrier deratization in winter, the number of small mammals in the farmsteads of settlements in 10–30 days after its completion did not exceed the normative index of 3 %, and in the forest belt around settlements did not exceed the normative index of 7 %. Keywords: small mammals, efficacy, trap-day, winter barrier deratization, hemorrhagic fever with renal syndrome, personal protective equipment.