Analysis of plague surveillance results and risk assessment in Yulin City, Shaanxi Province, 2011 - 2021 / 中华地方病学杂志

ABSTRACT

Objective:To analyze the epidemiological characteristics and related indicators of plague in Yulin City, Shaanxi Province, and to evaluate the risk of plague epidemic in the future and formulate scientific and reasonable prevention and control measures.Methods:The plague surveillance data of national (Dingbian County) and provincial (Yuyang District, Jingbian County, Hengshan District, Shenmu City, Fugu County) plague monitoring sites in Yulin City from 2011 to 2021 were collected through the China Disease Prevention and Control Information System Pestis Prevention and Control Management Information System, and the plague epidemic situation among humans and animals, the main host animals and their flea infection were analyzed by descriptive epidemiological methods. The expert consultation method and plague risk assessment tool V1.0 were used to assess the epidemic risk of the plague in Yulin City.Results:There was no human and animal plague epidemic in Yulin City from 2011 to 2021. In national monitoring site, the density of main host animal was 5.79/hm 2, ranging from 3.02/hm 2 to 9.08/hm 2,the dominant species was Mongolian gerbil, accounting for 98.21% (3 402/3 464); the capture rate of wild nocturnal rodents was 1.27% (350/27 600), ranging from 0.21% to 3.83%, the dominant species was Cricetulus barabensis, accounting for 44.86% (157/350); the flea infection rate of the rodent body was 16.91% (768/4 541), with a flea index of 0.40, the dominant flea species was the Nosopsyllus laeviceps kuzenkov, accounting for 66.54% (1 203/1 808). In provincial monitoring site, the density of main host animals was 0.49/hm 2, ranging from 0.31/hm 2 to 0.67/hm 2, the dominant species was Alashan ground squirrel, accounting for 63.61% (194/305); the capture rate of nocturnal rodents in the wild was 1.76% (560/31 795), ranging from 0.89% to 3.93%, the dominant species was Roborovski dwarf hamster, accounting for 26.61% (149/560); the capture rate of domestic rats was 2.37% (397/16 750), ranging from 1.48% to 3.10%, the rodents included Rattus norvegicus (47.36%, 188/397) and house mouse (52.64%, 209/397); the flea infection rate of the rat body was 13.26% (182/1 373), with a flea index of 0.40; the dominant flea species was Ophthalmopsylla jettmari, accounting for 45.23% (251/555). The 5 281 pathogenic culture samples and 2 110 serological test samples were all negative. The Pearson correlation analysis results showed that there was no correlation between rodent density and flea infection rate or flea index at national and provincial monitoring sites ( r = - 0.26, - 0.48, 0.09, 0.12, P > 0.05), while flea infection rate and flea index were positively correlated ( r = 0.67, 0.81, P < 0.05). In 2022, Yulin City, Shaanxi Province was not ruled out the possibility of human plague epidemic, and the risk of plague epidemic among animals was high. Conclusions:From 2011 to 2021, the density of the main host animals at the national and provincial monitoring sites in Yulin City has remained at a low level, and the flea index has increased. There is a risk of plague epidemic in Yulin City, so the monitoring work should be further strengthened, and emergency supplies and capacity reserves should be well prepared.