Analysis on epidemic factors of plague among animals in the natural plague focus of Meriones unguiculatus in Ningxia from 2005 to 2023

ZHOU Geng; LIU Yan; ZHANG Tao

doi:10.19821/j.1671-2781.2025.04.019

Abstract：Objective To investigate the factors of the incidence of plague among animals in the natural plague focus of Meriones unguiculatus in Ningxia,so as to provide scientific guidance for the control of animal plague.Methods The epidemic data of plague in Ningxia from 2005 to 2023 was collected from four plague surveillance sites.The data were analyzed by SPSS 25.0 software.The bilateral Spearman correlation analysis was performed to assess the correlation between the density of main host or secondary host or the flea index of main host and epidemic intensity of animal plague,respectively.Results From 2005 to 2023,the density of main host M.unguiculatus in the plague was from 0.29 rodents/hm2 to 5.09 rodents/hm2,with an average of 1.21 rodents/hm2.The capture rate of secondary host was between 3.95%and 9.38%,with an average of 6.65%.The flea index of main host was between 0.39 and 4.31,with an average of 0.93.In the past 19 years,a total of six years of spring inter-animal epidemics occurred in the natural plague focus of M.unguiculatus in Ningxia,and 120 strains of the plague bacteria detected.There was no correlation between the density of main host and epidemic intensity of animal plague(P=0.464).There was no correlation between the density of secondary host and epidemic intensity of animal plague(P=0.098).The flea index of main host(x)was correlated with epidemic intensity of plague(y)(P＜0.05),and the correlation coefficient was 0.476.By further regression analysis,the regression equation was obtained:y=0.107+0.154x.Conclusion The flea index of main host M.unguiculatus in spring was positively correlated with the epidemic intensity of plague in the natural plague focus of M.unguiculatus in Ningxia.The area bordering Ningxia and the natural plague focus in the Inner Mongolia Autonomous Region is an area where plague among gerbils is prevalent in spring.The key control strategies are timely detection of plague,elimination of rats and fleas,education of high risk group and grid administration.