ABSTRACT
Objective:To analyze the dynamic characteristics of rodents population density distribution in plague foci of Yinchuan City, Ningxia, and to provide reference for early warning of the plague.Methods:The plague surveillance results and epidemic reports of Yinchuan City from 2015 to 2018 were collected retrospectively, and the data were obtained from the database of Yinchuan City Center for Disease Control and Prevention. Descriptive method was used to analyze the species, number, density, fleas, vector index, etiology and serology results of rodents in the plague foci.Results:From 2015 to 2018, 4 families, 8 genera, 13 species, and 8 843 rodents were captured in the plague foci of Yinchuan City, and Meriones unguiculatus (4 557 rodents) was the dominant species. The survey area of host animal density was 1 459 hm 2, 3 805 rodents were captured, and the average density was 2.61/hm 2, of which the Meriones unguiculatus density was 1.98/hm 2. A total of 41 488 traps of nocturnal rodents were investigated, and 2 660 rodents were captured, with an average capture rate of 6.41%. A total of 6 952 fleas were obtained, belonging to 4 families, 7 genera, and 8 species; Xenopsylla conformis conformis (4 597 fleas) and Nosopsyllus laeviceps kuzenkovi (1 761 fleas) were the dominant species. Among them, there were 2 286 flea-infected rodents, the body flea-infected rate was 25.85% (2 286/8 843), and the body flea-infected index was 0.76. A total of 220 gerbils nests were investigated, and the nest flea-infected rate was 34.55% (76/220), and the nest flea-infected index was 0.98. No plague bacterium was isolated by pathogen detection of rodents and fleas. The results of indirect hemagglutination test were all negative. Conclusion:The Meriones unguiculatus is the dominant species in the plague foci of Yinchuan City, the average density is still high, attention should be paid to the occurrence of plague outbreaks.
ABSTRACT
Objective To analyze the changes of gopher density and epidemic situations of animal plague in the natural plague foci of Yinchuan from 2004-2014,to sum up the epidemic regularity of the epidemic situation,and to provide a scientific basis for prevention and treatment of the plague.Methods Retrospective analysis was used in the study.The plague monitoring data were collected;the number of host animals,density of rat,media index,aetiological and serological test results were analyzed.Results From 2004 to 2014,a total of 15 664 rats in 14 species,4 families and 9 genera were captured.The dominant populations were Meriones unguiculatus and Meriones meridianus.The density of rats was 4 919 km2,the number of rats was 6 196,the density of each rat was 0.21 to 3.85/hm2,and the average density was 1.26/hm2.A total of 15 664 rats were examined,the number of positive rats was 33,and the positive rate was 0.21％ (33/15 664).Among them,gerbils were 29,accounted for 87.88％ (29/33);18 strains of Yersiniapestis were detected in dead rats,which accounted for 54.54％ (18/33).A total of 5 810 groups of 22 070 fleas were cultured,the number of positive fleas was 42,and the positive rate was 0.12％ (7/5 810).Plague fleas were 2 kinds,the same type cheopis subspecies in 6 groups of 37 fleas,Nosopsyllus laeviceps vole subspecies in 1 group of 5 fleas.The positive number of F1 antibody was 3,and the positive rate was 0.12％ (3/ 2 446).Conclusions Yinchuan City,the natural foci of plague epidemic,is in the active state.We should pay attention to the density changes of Meriones unguiculatus and strengthen the monitoring work to pick up the dead rats,and found the epidemic of animal plague as soon as possible,in order to prevent the occurrence of human plague.