Fever of unknown origin in Taiwan

Background: Fever of unknown origin (FUO) is a challenging problem worldwide. There was no prospective study of FUO in the past two decades in Taiwan. A prospective study was conducted. Materials and Methods: The prospective study was undertaken from March 2001 to May 2002. All patients fulfilling the modified criteria for FU0, either admitted, referred or consulted in a medical center in southern Taiwan, were enrolled for analysis. Results: A total of 94 cases met the criteria of FU0. The final diagnoses of FUO consisted of 54 infectious diseases (57.4%), 8 hematologic/neoplastic (8.5%), 7 noninfectious inflammatory (7.4%), 8 miscellaneous (8.5%) and 17 undiagnosed (18.1%) cases. The single most common cause of FU0 was tuberculosis. Some infectious diseases, such as rickettsiosis and melioidosis, were rarely reported in western countries. Three patients with hemophagocytotic syndrome without ascertainable etiologies were present with FU0 in this study. Between the patients with and those without a final diagnosis, the short-term survival (3 months) was compared by the Kaplan-Meier analysis, which revealed no difference. Conclusions: Mycobacteriosis is still the leading cause of FUO in Taiwan and it is important to identify this treatable disease from all causes of FU0. This study has showed geographical variation among the studies of FUO.