关键词: 鼠类监测, 鼠密度, 小型兽类, 种类构成, 病原体

Abstract:

Objective: To investigate the rodents species, density, and pathogens they carry in Zunyi, Guizhou Province, China. Methods: A total of 70 sampling points were set in 14 counties/districts of Zunyi, with five points in the east, south, west, north, and center of each county/district. Small mammals were monitored through night trapping in Zunyi from October 2021 to October 2022, followed by species identification and pathogen detection. Excel 2021 was used for data organization. SPSS 26.0 was used to analyze the density, species, and pathogen-carrying status of small mammals through rate or constituent ratio comparison with the Chi-square test (P < 0.05 indicates a statistically significant difference). Results: A total of 9 969 effective traps were placed at all the surveillance points, capturing 549 small mammals in total, of which 522 were rodents. The total density of small mammals was 5.51%. The total density of rodents was 5.24%. The rodent density was highest in Honghuagang District (12.94%), followed by Fenggang County (12.34%), and lowest in Chishui City (1.80%). There was a statistical difference in rodent density between the counties/districts (χ²=195.619, P < 0.001). Rattus norvegicus was the dominant rodent species in urban residential areas, rural residential areas, and key industries, while Apodemus agrarius was the dominant species in farming areas. The composition of rodent species statistically differed in different regions (the center, north, east, and west) of Zunyi (χ²=117.357, P < 0.001). Each small mammal was examined for Leptospira interrogans and Orientia tsutsugamushi in the liver, spleen, and kidney; Dabie bandavirus in the liver, spleen, and lung; and Hantavirus in the lung. Among 343 samples tested, 27 were positive, all for L. interrogans, with a pathogen detection rate of 7.87%. Shrews had the highest detection rate (16.00%), followed by A. agrarius (12.35%), and R. norvegicus had the lowest detection rate (1.64%). There was a significant difference in the detection rates of different species of small mammals (χ²=14.372, P=0.002). The detection rate was 9.66% (26/269) in farming areas, which was highest, and 2.94% (1/34) in key industries, with negative detection results in urban and rural residential areas. There were no differences in detection rates between different habitats (χ²=5.171, P=0.160). The detection rate was 27.03% in Meitan County, followed by 25.00% in Suiyang County, and zero in Renhuai City, Fenggang County, and Yuqing County, with a statistical difference between different counties/cities/districts (χ²=35.409, P=0.001). Conclusions: The density of rodents was relatively high in Zunyi. The detection of L. interrogans should be a warning of the possibility of related diseases. Local authorities should strengthen rodent control in spring and autumn and take comprehensive control measures according to actual situation and dominant rodent species and pathogen detection status in different habitats, so as to reduce the density of rodents and prevent the occurrence of rodent-borne diseases.

Key words: Rodent surveillance, Rodent density, Small mammal, Species composition, Pathogen