Surveillance based characterization of rodent density and seasonal variation in Nanchang,Jiangxi Province,China,2017-2022
Objective To investigate the rodent species composition,density,and seasonality in different habitats based on the rodent surveillance program in Nanchang,China,so as to provide a basis for scientifically formulating rodent control strategies in Nanchang.Methods Three types of surveillance habitats including urban residential area,rural natural village,and special industry were chosen from 2017 to 2022.Rodent density was investigated by the night snap-trapping method.Descriptive methods were used to perform a statistical analysis of rodent species composition and seasonal variation of rodent density in three different habitats in Nanchang.With SPSS 26.0 and Excel 2021 softwares,descriptive methods were used to perform a statistical analysis of surveillance data,and the Chi-square test was used for comparison of rodent density across different years and habitats.Results A total of 104121 effective traps were placed in Nanchang from 2017 to 2022,and 548 rodents were captured,with an average rodent density of 0.53%.The overall rodent density in the six years was statistically significant(χ2=34.857,P<0.001).A bimodal distribution with seasonal variation was found in the overall rodent density,the annual density of three dominant rodent species(Rattus norvegicus,Mus musculus,and R.tanezumi),and the rodent density in residential areas and special industry habitats,while the rodent density in rural natural village habitats showed a unimodal trend,with the peak in July.The rodent density in rural natural villages(1.56%)was significantly higher than that in special industries(0.45%)and than that in urban residential areas(0.30%)(χ2=304.340,P<0.001).The dominant rodent species in urban residential areas and rural natural village habitats were R.norvegicus and R.tanezumi,while M.musculus predominated in special industry habitats(47.47%).The composition ratio of R.norvegicus in special industry and rural natural village habitats was decreasing year by year;the composition ratio of R.tanezumi in urban residential areas showed a decrease after increasing,while it was generally increasing in special industry and rural natural village habitats;the composition ratio of M.musculus in three different habitats showed an overall increasing trend.Conclusions The rodent density varies greatly in Nanchang from 2017 to 2022.The rodent density showed a bimodal distribution with seasonal changes and was high in rural areas.Specific control measures should be taken according to the changes in rodent species in different habitats to reduce the rodent density and the risk of rodent-borne diseases.
RodentDensityRodent species compositionSeasonal variationSurveillance