Fever of unknown origin in China: evaluation of 918 cases during a ten-year-period of study

Background Fever of unknown origin (FUO) is a challenging problem worldwide. FUO, as defined by Petersdorf and Beeson in 1961 [1] , includes illness persisting for 3 weeks or more, occasional episodes of a fever 38.3°C or more, and an unclear cause upon examination after one week of hospitalization. Recently, only one retrospective study of FUO have been conducted in the south China, but there has been no good data about FUO in the north China, especially in the top-level general hospital. Based on these considerations, a 10-year retrospective study among patients with FUO in a 3100-bed teaching hospital in northern China was conducted to explore the geographic profile of FUO.