[Diagnostic analysis of hospitalized patients with fever of unknown origin at department of infectious diseases].

Objective: To explore the etiology, diagnostic methods and procedures for patients with fever of unknown origin (FUO) at department of infectious diseases.

Methods: A total of 368 FUO patients admitted to department of infectious diseases from 2002 to 2009 were retrospectively reviewed. The correlations of etiologies and diagnostic methods with gender, age and progress of fever were analyzed.

Results: Among them, 112 (30.4%) cases were recognized in 2 weeks (diagnosis, n = 107; recovery with unknown causes, n = 5). A final diagnosis was established in 241 (94.1%) from the remaining 256 FUO patients (124 males, 132 females). Among them, the causes were infectious diseases (n = 193), rheumatologic/autoimmune diseases (n = 32) and hematological diseases/tumors (n = 16). The etiologies were infectious diseases (n = 95), rheumatologic/autoimmune diseases (n = 10), hematological diseases/tumors (n = 10) and unknown etiology (n = 9) in males respectively; infectious diseases (n = 98), rheumatologic diseases (n = 22), hematological diseases or tumors (n = 6) and unknown etiology (n = 6) in females respectively. Age of patients: < 14 yr (n = 10), 15 - 20 yr (n = 37), 21 - 50 yr (n = 110), 51 - 60 yr (n = 48) and > 61 yr (n = 51). Thermal process was < 4 weeks (n = 83) including 74 infectious diseases cases and > 8 weeks (n = 63), including infectious diseases (n = 21) and rheumatologic disease (n = 20).

Conclusion: Some FUO outpatients may be promptly confirmed by history taking, physical examination and routine examinations. The major cause is infection. Other causes of FUO are infectious diseases, rheumatological/autoimmune diseases and hematological diseases/tumors. For the diagnosis of FUO patients, gender, age and thermal process should be considered.