An analysis of surveillance data on human plague in Qinghai Province

Objective To explore the causes associated with underdiagnosis and misdiagnosis for human plague,based on the analysis of surveillance data in Qinghai Province,providing reference for further prevention and control of it Methods Surveillance data on human plague were collected for the past 43 years in Qinghai Province and their quality,as well as distribution and dynamics of human plague,were analyzed Underdiagnosis was defined as death occurred in patients of plague without treatment,and misdiagnosis was defined as patients with plague diagnosed as other diseases and treated as non plague Results Most cases of human plague occurred in the areas around Qinghai Lake before 1980 and mainly in the southern part of Qinghai Province after 1980 Totally,there occurred 176 episodes of human plague epidemic with 423 definitely diagnosed cases from 1958 to 2000 in Qinghai,with 4 09 episodes and 9 84 case annually in average Ninety four cases were underdiagnosed in the index cases of 176 episodes of epidemic (53 41%) and 21 cases misdiagnosed (11 93%) In 423 reported cases of plague,165 were underdiagnosed (39 01%) and 34 misdiagnosed (8 04%) Number of the cases underdiagnosed and misdiagnosed accounted for 66 67% (110/165) and 61 76% (21/34),respectively,in 1960s,showing a gradually decreasing trend with time Conclusion Timely detection of suspect cases of human plague is crucial to its surveillance and control