Plague epidemic situation and surveillance on geography information system in regions along the Qinghai-Tibet railway

Abstract

Objective To evaluate the feasibility of using Qinghai-Tibet railway plague epidemic situation and surveillance on geography information in practical work in Naqu District and Anduo County on both sides of Qinghai-Tibet railway. Methods Applying Qinghai-Tibet railway plague epidemic situation and surveillance geography information system marmot density, distribution of blood collection sites, marmot caves, rate with fleas in marmot cave, index of fleas, geography distribution of epidemic situation and the greatest distance with positive serological results in epidemic areas in Naqu Area and Anduo County were investigated during construction of Qinghai-Tibet railway in 2005 and 2006. Results The areas investigated were 13 213.24 hm2, where 782 marmots were found, so the density of marmots were 0.059 single/hm2 on both sides of Qinghai-Tibet railway. There were 71 blood collection sites, covering 20 000 km2. Rate with fleas in marmot cave was 53.8%(7/13) and index of fleas was 1.23. During the period of 2005 and 2006, 61 reports were received on epidemic diseases. Among 3289 serum samples examined, 45 were positive for plague in Anduo County, Tibet, from July to November in 2005. Positive sera were mostly found on 3 days: 5 cases on September 23, with the distances away from the localities of sample collection reaching as far as 14.58 kin; 8 cases on October 30 with a distance of 6.00 km apart; and 5 cases on November 4, with a distances of 2.00～3.00 km apart. Conclusions The plague surveillance system is proven to be eonvenient and manipulable. Key words: Plague; Geographic information systems; Epidemiology; Epidemic situation