Species composition and spatial distribution of small mammals and their parasitic fleas in the Chongqing section of the Three Gorges Reservoir area
Objective To investigate the species composition and distribution of host animals and vector fleas of Yersinia pestis in Chongqing section of the Three Gorges Reservoir area,evaluate the presence of Y.pestis in these animals,and predict the potential risk of plague occurrence in the area.Methods From 2017 to 2022,an investigation was carried out in eight districts or counties along the Chongqing section of the Three Gorges Reservoir area,namely Fuling,Wanzhou,Kaizhou,Fengdu,Zhong County,Yunyang,Fengjie,and Wushan.Small mammals were captured by cage trapping method alongside the reservoir.The small animals and their parasitic fleas were identified and recorded.The data were used for descriptive analysis of their community structure characteristics.Chi-square test or Fisher's exact test was used to analyze differences between groups.Results A total of 403 small animals of 11 species were captured in 20123 cage traps.The total density was 1.92％.Rattus tanezumi was the dominant species (62.28％),followed by Mus musculus (14.14％),R.norvegicus (8.68％),Crocidura attenuate (4.47％),Apodemus agrarius (3.47％),Anourosorex squamipes (3.23％),Niviventer confucianus (1.99％),R.nitidus (0.74％),R.losea (0.50％),N.fulvescens (0.25％),and Leopoldamys edwardsi (0.25％).The species composition of small mammals in 8 districts and counties in Chongqing section of the Three Gorges Reservoir area showed significant differences (P<0.001).The small mammal density was relatively high in Fengdu County (2.88％),Fuling District (2.71％),Fengjie County (2.53％),and Yunyang County (2.52％).The density was relatively low in Zhong County (1.83％),Wanzhou District (1.38％),and Kaizhou District (1.00％).The small mammal density was significantly different among 8 districts and counties (x2=57.443,P<0.001).A total of 151 small mammals carried ectoparasitic fleas.A total of 1034 parasitic fleas in 3 species were captured.The total flea infection rate was 37.47％,and the total flea infection index was 2.57.In addition,the flea infection rates were significantly different among districts and counties (x2=54.534,P<0.001).Eight small animal species were infected with fleas,and their flea infection rates were significantly different (P=0.003).The vast majority of captured fleas were Leptopsylla segnis (1031 individuals),2 fleas were Monopsyllus anisus,and 1 flea was Ctenocephalides felis.Blood samples collected from all 403 live rodents tested negative for the serum antibody of Y.pestis F1.Conclusions The risk of plague epidemic among animals and humans is relatively low in the Chongqing section of the Three Gorges Reservoir area.However,continuous surveillance should be conducted to remain vigilant for the potential risk of plague and other rodent-borne diseases caused by the mixing of populations of domestic and wild small mammals and their ectoparasitic fleas,as well as the introduction of non-native species.
Three Gorges Reservoir areaPlagueVector fleaHost animal
万方数据
维普
