Study On The Etiology And Prognosis Among 320 Patients With Fever Of Unknown Origin

Objective: Studying the variation of the etiology in patients with fever of unknown origin(FUO)over time and their prognosis to guide clinical diagnosis and treatment.Methods: Patients with FUO hospitalized in the Department of Infectious Diseases,the Second Hospital of Hebei Medical University from March 15,2016 to December 31,2019 were prospectively enrolled by using a structured diagnostic protocol.SPSS 22.0 software was applied to analyze the etiological distribution characteristics and prognosis of FUO,and we compared the etiological distribution in different years,gender,age,and duration of fever.Meanwhile,we analyzed the time of diagnosis,length of hospital stay,examination cost between infectious and non-infectious diseases in FUO.Results:1.A total of 320 patients with FUO were included,and the etiologic compositions were as follows: infectious diseases,69.3%;non-infectious inflammatory diseases,6.3%;other diseases,5.3%;neoplastic diseases,5.0%;multiple etiologies,1.3%;and undiagnosed,12.8%.The top two sites of infection were urinary tract infection(12.8%),and pulmonary infection(9.7%).The primary pathogen of infectious diseases was general bacteria(49.4%).And communicable diseases accounted for 8.4%,51.9% of which were brucellosis.2.The proportion of infectious diseases in 2018-2019 was higher than in2016-2017(P<0.05);the ratio of infectious diseases in male and elderly FUO was higher than in female,young,and middle-aged patients(P<0.05);the proportion of undiagnosed in young patients was higher than elderly(P<0.05).No statistical difference of etiological distribution in different duration of fever was observed(P>0.05).3.The time of diagnosis of non-infectious diseases was longer than that of infectious diseases(P<0.05).None of the differences in length of hospital stay and examination costs between infectious and non-infectious diseases achieved statistical significance(P>0.05).4.Of the 320 FUO cases,6(1.9%)died during hospitalization,314 were discharged,261(83.1%)were successfully followed up,with a median follow-up time of 18(8.5,28.5)months,and 53(16.9%)were lost.230(88.1%)of 261 cases survived,and 31 cases(11.9%)died.Among the dead patients,27 cases with definite diagnosis died,mostly due to the primary disease;and the remaining deaths were 4 undiagnosed cases,mostly due to cardiovascular and cerebrovascular diseases.Conclusions:1.The primary cause of FUO is infectious disease,with the urinary tract and lungs being the 2 most common sites,and the pathogen is predominantly general bacteria.Brucellosis is the most common communicable disease.2.The distribution of the etiology of FUO varies over time and varies among patients with FUO seen in different years.Infectious diseases are more common in male,elderly patients with FUO.Non-infectious diseases were more common in patients with FUO diagnosed for a long time.3.Patients with FUO have a low mortality rate of 1.9% during hospitalization,and most deaths after discharge are related to the primary disease.Also,undiagnosed patients are at risk of death,mostly from cardiovascular and cerebrovascular diseases,and follow-up monitoring is supposed to be strengthened.