Epidemiological surveillance of animal plague in Jiuquan City,Gansu Province,2013-2023
Objective To investigate the dynamics and trends of animal plague in Jiuquan,Gansu Province,China for the possibility of human plague,so as to provide technical support for the prevention and control of animal plague and the emergency management of plague-related public health events in Jiuquan.Methods Animal plague was monitored according to the National Plague Surveillance Program.The plague surveillance data were collected from three counties(cities)in Jiuquan in 2013-2023,including host animal density,vector data,Yersinia pestis etiology and serology results.The data were analyzed using descriptive epidemiological methods.The Chi-square test was used to compare rates.The Chi-square test for linear trend and Spearman rank correlation test were used to analyze time series data changes.Results From 2013 to 2023,the average annual survey route length was 159.04 km;the average annual survey area of the foci was 1 747.86 hm2;the average annual number of marmots found was 297.73,with a density of 0.17 inds/hm2;the average annual infestation rate of rodent body vectors was 26.54%,with an average vector index of 1.50;and the average annual infestation rate of burrow vectors was 2.76%,with an average vector index of 0.06.Trend analyses revealed decreasing trends for the capture rate of wild nocturnal host animals(χ2trend=66.832,P<0.001),the pathogen-positive rate of host animals(χ2trend=9.260,P=0.020),the pathogen-positive rate of vector organisms(χ2trend=11.591,P<0.001),and the positive rate by serology(χ2trend=11.070,P<0.001)at the Marmota himalayana plague foci of Jiuquan from 2013 to 2023.Conclusions The dominant species of hosts and vectors at Jiuquan plague foci are prominent,and the composition and number of those species have changed over the years.Plague is still active among animals,so multiple surveillance methods should be adopted to improve the surveillance level to inform the trend of plague transmission.