Analysis of the plague epidemic characteristics in the natural foci of the Qilian Mountains-A-erh-chin Mountains Himalayan marmot plague in Gansu Province from 2011 to 2018 / 中华地方病学杂志

ABSTRACT

Objective:To understand the plague epidemic characteristics in the natural foci of the Qilian Mountains-A-erh-chin Mountains Himalayan marmot plague in Gansu Province, and to provide scientific basis for innovative prevention and control of the plague in combination with local conditions. Methods:A retrospective study was used to collect the monitoring data of the natural foci of plague in Gansu Province from 2011 to 2018 (from the epidemic surveillance files of the Center for Disease Control and Prevention of Gansu Province and direct network reporting information). Descriptive epidemiological method was used to analyze the plague epidemic characteristics of natural foci of the Qilian Mountains-A-erh-chin Mountains Himalayan marmot plague in Gansu Province from 2011 to 2018, including the distribution of host animals, pathogenic and serological testing of the plague bacteria, and the epidemic characteristics of human plague. Results:From 2011 to 2018, the total average marmot density in the natural foci of the Qilian Mountains-A-erh-chin Mountains Himalayan marmot plague in Gansu Province was 0.21/hm 2, of which Tianzhu County had the highest average marmot density of 0.58/hm 2, and Jiayuguan City had the lowest average marmot density of 0.01/hm 2. A total of 381 strains of Yersinia pestis were isolated in the foci, of which 4 were isolated from human corpses, 298 were host animals, and 79 were infectious vectors. Among them, the top 3 counties (cities) of isolated strains were Aksai County (38.85%, 148 strains), Subei County (31.50%, 120 strains) and Yumen City (16.27%, 62 strains). A total of 6 860 marmot serum, 1 769 dog serum were tested, the F1 antibody positive rates were 2.70% (185/6 860), 8.42% (149/1 769); and the F1 antigen positive rate of 814 animal materials was 4.30% (35/814), respectively. There were 4 times of human plague, 4 cases occurred and 4 cases died; 3 times occurred in Subei County and 1 time in Yumen City. The onset months were July, September, November and December. Active contact with infected animals such as shepherd dogs was the main route of infection, and migrant herders were the key occupation population. Conclusions:The animal epidemic situation in the natural foci of the Qilian Mountains-A-erh-chin Mountains Himalayan marmot plague in Gansu Province is active, and the plague presents different epidemic states in different regions. The prevention and control measures should be taken according to local conditions and guided by classification to strictly prevent the occurrence and transmission of the plague.