Epidemic analysis of human plague caused by Tibetan sheep in Qinghai Province

Abstract

Objective To analyze the epidemics and risk factors of human plague caused by Tibetan sheep in Qinghai Province. Methods The background data of human plague caused by Tibetan sheep in Qinghai Province from 1956 to 2014 were obtained from the plague surveillance reports and the information database of plague prevention and control in Qinghai Province. The data were analyzed, and area and time distributions were described. Results A total of 16 human plague cases caused by Tibetan sheep were found in Qinghai Province from 1956 to 1997, with 69 cases reported and 42 cases dead, the mortality rate was 60.9%. There was no human plague case caused by Tibetan sheep from 1998 to 2014. All of the initial cases were herdsman whose infection was due to eating or contacting Tibetan sheep died of plague. Ten human plague cases caused by Tibetan sheep occurred in Yushu Prefecture, accounted for 62.5%, 3 in Guoluo Prefecture, accounted for 18.8%, 2 and 1 in Haixi Prefecture and Haibei Prefecture, respectively, accounted for 12.5% and 6.2% each. The human plague cases caused by Tibetan sheep mainly occurred from May to November. Conclusions Tibetan sheep infected with the plague can spread it to humans. To reduce the risk of human plague caused by Tibetan sheep, the plague prevention and control departments need to increase the publicity of the plague and enhance herdsmen's knowledge on plague prevention. Key words: Plague; Tibetan sheep; Epidemiology; Risk factors