Analysis of plague monitoring results in natural focus of Marmota sibirica plague in Hulunbuir Plateau from 2009 to 2020 / 中华地方病学杂志

ABSTRACT

Objective:To analyze the plague monitoring results of Marmota sibirica plague natural focus in Hulunbuir Plateau, and to study the characteristics of development and variation of the plague focus. Methods:From 2009 to 2020, monitoring was conducted in Manzhouli City, Prairie Chenbarhu Banner, Xin Barag Left Banner, and Xin Barag Right Banner from May to September each year. The one-day bow-clip method was used to investigate the density of the Spermophilus dauricus, and the 5-meter clamp method was used to investigate other small rodents. The classification and identification of ectoparasite fleas were done by using low power microscope. According to "Diagnostic Criteria for Plague" (WS 279-2008), the detectable materials of rats and fleas were tested, and Yersinia pestis was isolated and cultured. The serums of collected rats were detected by indirect hemagglutination test. Results:From 2009 to 2020, the average density of dauricus in Marmota sibirica plague natural focus of Hulunbuir Plateau was 0.45/hm 2, and the capture rate of other small rodents was 1.25% (787/63 091). A total of 9 species, 8 genera and 4 families of rodents were captured. The total flea infection rate of Spermophilus dauricus was 28.37% (1 945/6 856) and the fleas index was 1.04. A total of 3 species, 3 genera and 2 families of fleas were collected. A total of 6 674 Spermophilus dauricus were dissected and 6 787 fleas were cultured in 2 537 groups. The Yersinia pestis test was negative. A total of 6 795 serum samples from Spermophilus dauricus were detected, of which 11 were positive with a positive detection rate of 0.16%. The highest titer of positive serum was 1∶1 280. Indirect hemagglutination test positive materials were found for 5 consecutive years from 2010 to 2014; the positive serums were found in Manzhouli City and Xin Barag Right Banner. Conclusions:The Yersinia pestis antibady positive serum of Spermophilus dauricus has been detected in Marmota sibirica plague focus of Hulunbuir Plateau for many years, which is worthy of high vigilance. In the future, continuous surveillance should be carried out, bacterial detection should be strengthened, possible plague outbreaks should be detected in time, and various plague prevention and control should be done well.