Clinical Features of Spontaneous Remission in the Classic Fever of Unknown Origin:A Retrospective Study

Objective To summarize the clinical features of spontaneous remission in classic fever of unknown origin(FUO).Methods Medical records of 121 patients diagnosed with FUO at admission in Peking Union Medical College Hospital between January 2018 and June 2018 were reviewed retrospectively.Patients who were discharged without etiological diagnoses were followed for 2 years.The clinical features and outcomes of these patients were summarized.Multivariate logistic regression was used to analyze related factors of spontaneous remission of FUO.Results After excluding 2 patients who lost to follow-up,the etiology of 119 FUO patients were as follows:infectious diseases in 30(25.2%)cases,connective tissue diseases in 28(23.5%)cases,tumor diseases in 8(6.7%)cases,other diseases in 6(5.0%)cases,and unknown diagnoses in 47(39.5%)cases.Totally,41 patients experienced spontaneous remission of fever(the median time from onset to remission was 9 weeks,ranging from 4 to 39 weeks).In patients with spontaneous remission in FUO,lymphadenopathy was less common clinical manifestation,the levels of inflammatory markers including leukocyte count,neutrophil count,neutrophil ratio,C-reactive protein,and ferritin were lower,and the proportion of CD8 positive T lymphocytes expressing CD38 was lower.Multivariate logistic regression analysis of factors with a P-value<0.05 in univariate analysis shown that white blood cell count(OR:0.S45,95%CI:0.306-0.971,P=0.039),neutrophil count(OR:2.074,95%CI:1.004-4.284,P=0.049),and proportion of neutrophils(OR:0.928,95%Cl:0.871-0.990,P=0.022)were independent significant factors associated with spontaneous remission in FUO.Conclusions This study suggested that most patients discharged with undiagnosed classic FUO would remit spontaneously.Thus,for patients with stable clinical conditions,follow-up and observation could be the best choice.Patients with lower level of some inflammatory factors may have a high likelihood of spontaneous remission in classic FUO.

A Diagnostic Tool for Identification of Etiologies of Fever of Unknown Origin in Adult Patients

The diagnosis and treatment of fever of unknown origin (FUO) are huge challenges to clinicians.Separating the etiologies of FUO into infectious and non-infectious disease is conducive to clinical physicians not only on making decisions rapidly concerning the prescription of suitable antibiotics but also on further analysis of the final diagnosis.In order to develop and validate a diagnostic tool to efficiently distinguish the etiologies of adult FUO patients as infectious or non-infectious disease,FUO patients from the departments of infectious disease and internal medicine in three Chinese tertiary hospitals were enrolled retrospectively and prospectively.By using polynomial logistic regression analysis,the diagnostic formula and the associated scoring system were developed.The variables included in this diagnostic formula were from clinical evaluations and common laboratory examinations.The proposed tool could discriminate infectious and noninfectious causes of FUO with an area under receiver operating characteristic curve (AUC) of 0.83,sensitivity of 0.80 and specificity of 0.75.This diagnosis tool could predict the infectious and non-infectious causes of FUO in the validation cohort with an AUC of 0.79,sensitivity of 0.79 and specificity of 0.70.The results suggested that this diagnostic tool could be a reliable tool to discriminate between infectious and non-infectious causes of FUO.

Establishment of a Predictive Model Related to Pathogen Invasion for Infectious Diseases and Its Diagnostic Value in Fever of Unknown Origin

The present study aimed to establish a list of parameters indicative of pathogen invasion and develop a predictive model to distinguish the etiologies of fever of unknown origin (FUO) into infectious and non-infectious causes.From January 2014 to September 2017,431 patients with FUO were prospectively enrolled in the study population.This study established a list of 26 variables from the following 4aspects:host factors,epidemiological factors,behavioral factors,and iatrogenic factors.Predefined predicted variables were included in a multivariate logistic regression analysis to develop a predictive model.The predictive model and the corresponding scoring system were developed using data from the confirmed diagnoses and 9 variables were eventually identified.These factors were incorporated into the predictive model.This model discriminated between infectious and non-infectious causes of FUO with an AUC of 0.72,sensitivity of 0.71, and specificity of 0.63.The predictive model and corresponding scoring system based on factors concerning pathogen invasion appear to be reliable screening tools to discriminate between infectious and non-infectious causes of FUO.

Case Report: Fever of Unknown Origin <br/>—An Unusual Presentation for Diffuse Large B-Cell Lymphoma

A 61-year-old male initially presented with fever of unknown origin. He had extensive work-up over two years including an infectious diseases panel, autoimmune studies, and Rheumatology and Hematology evaluations. The patient was initially diagnosed with Adult Still’s disease and underwent an out-patient right nodal fine-needle aspiration that was indeterminate. After continued failure of treatment for Adult Still’s disease, the patient had surgical resection of a right axillary lymph node that yielded the diagnosis of diffuse large B-cell lymphoma. Further work-up revealed Epstein-Barr virus positivity, the possible trigger behind his mutation for diffuse large B-cell lymphoma and its uncommon presentation. The patient met criteria for central nervous system prophylaxis and received multiple administrations throughout his therapy. He ultimately expired following recurrence of his disease at its initial site but without central nervous system involvement. We report an uncommon presentation of a patient with diffuse large B-cell lymphoma. This lymphoma can have numerous, vague presentations requiring a broad differential diagnosis and may lead to multiple evaluations prior to an ultimate diagnosis. We will also discuss the need for central nervous system prophylaxis, how this patient is qualified for prophylaxis, and how central nervous system prophylaxis benefits, harms, or does not affect patients with diffuse large B-cell lymphoma.

Large renal carbuncle mimicking intra-abdominal neoplasm on Ga-67 scintigraphy: A case of fever of unknown origin

Fever of unknown origin is still a medical challenge. 67Ga single photon emission computed tomography/computed tomography images are commonly used to evaluate the final diagnosis of fever of unknown origin. We presented a case of fever of unknown origin undergone 67Ga scintigraphy and an intra-abdominal 67Ga avid tumor was detected which suspected to be a neoplasm. Further contrast enhanced computed tomography revealed that the lesion was a large renal carbuncle. We concluded that the contrast-enhanced CT or single photon emission computed tomography/computed tomography with contrast enhancement can be performed to further improve diagnostic performance.

Infectious causes of fever of unknown origin in developing countries: An international ID-IRI study

Background:Fever of unknown origin(FUO)in developing countries is an important dilemma and further research is needed to elucidate the infectious causes of FUO.Methods:A multi-center study for infectious causes of FUO in lower middle-income countries(LMIC)and lowincome countries(LIC)was conducted between January 1,2018 and January 1,2023.In total,15 participating centers from seven different countries provided the data,which were collected through the Infectious DiseasesInternational Research Initiative platform.Only adult patients with confirmed infection as the cause of FUO were included in the study.The severity parameters were quick Sequential Organ Failure Assessment(qSOFA)≥2,intensive care unit(ICU)admission,vasopressor use,and invasive mechanical ventilation(IMV).Results:A total of 160 patients with infectious FUO were included in the study.Overall,148(92.5%)patients had community-acquired infections and 12(7.5%)had hospital-acquired infections.The most common infectious syndromes were tuberculosis(TB)(n=27,16.9%),infective endocarditis(n=25,15.6%),malaria(n=21,13.1%),brucellosis(n=15,9.4%),and typhoid fever(n=9,5.6%).Plasmodium falciparum,Mycobacterium tuberculosis,Brucellae,Staphylococcus aureus,Salmonella typhi,and Rickettsiae were the leading infectious agents in this study.A total of 56(35.0%)cases had invasive procedures for diagnosis.The mean qSOFA score was 0.76±0.94{median(interquartile range[IQR]):0(0–1)}.ICU admission(n=26,16.2%),vasopressor use(n=14,8.8%),and IMV(n=10,6.3%)were not rare.Overall,38(23.8%)patients had at least one of the severity parameters.The mortality rate was 15(9.4%),and the mortality was attributable to the infection causing FUO in 12(7.5%)patients.Conclusions:In LMIC and LIC,tuberculosis and cardiac infections were the most severe and the leading infections causing FUO.

Giant cell arteritis in a patient with fever of unknown origin

Fever of unknown (FUO) origin challenging clinical condition. The causes of FUO are diverse: possible etiologies include infectious diseases, chronic granulomatous diseases, malignity, connective tissue disorders and vasculitis. Giant cell arteritis which affects the aorta and its main branches, contributes up to 17% of cases with fever of unknown origin above age 50. There is increasing evidence for a role for18F-FDG PET/CT in the diagnosis of vasculitis and18F-FDG PET/CT is a useful technic for evaluation of the FUO. Clinical studies show that FDG-PET is a useful diagnostic aid in obscure cases of fever of unknown origin. We report here a case of a 54-year-old woman who present to our clinic with FUO due to giant cell vasculitis.

Fever of unknown origin:a retrospective review of pediatric patients from an urban,tertiary care center in Washington,DC

Background Fever of unknown origin(FUO)continues to challenge clinicians to determine an etiology and the need for treatment.This study explored the most common etiologies,characteristics,and average cost of hospitalization for FUO in a pediatric population at an urban,tertiary care hospital in Washington,DC.Methods Records from patients admitted to Children's National Health System between September 2008 and April 2014 with an admission ICD-9 code for fever(780.6)were reviewed.The charts of patients 2-18 years of age with no underlying diagnosis and a temperature greater than 38.3℃for 7 days or more at time of hospitalization were included.Final diagnoses,features of admission,and total hospital charges were abstracted.Results 110 patients qualified for this study.The majority of patients(n=42,38.2%)were discharged without a diagnosis.This was followed closely by infection,accounting for 37.2%(n=41)of patients.Rheumatologic disease was next(n=16,14.5%),followed by miscellaneous(n=6,5.4%)and oncologic diagnoses(n=5,4.5%).The average cost of hospitalization was 40,295 US dollars.Conclusions This study aligns with some of the most recent publications which report undiagnosed cases as the most common outcome in patients hospitalized with FUO.Understanding that,often no diagnosis is found may reassure patients,families,and clinicians.The cost associated with hospitalization for FUO may cause clinicians to reconsider inpatient admission for diagnostic work-up of fever,particularly given the evidence demonstrating that many patients are discharged without a diagnosis.

Major causes of fever of unknown origin at Peking Union Medical College Hospital in the past 26 years

Background Despite the recent advances in medicine, fever of unknown origin （FUO） remains a diagnostic and therapeutic challenge even to expert physicians. To increase the knowledge of FUO, we conducted a retrospective study to investigate the causes of FUO and the change of major causes of FUO during the past 26 years. Methods The clinical data were retrospectively analyzed from 997 patients with FUO hospitalized at the Peking Union Medical College Hospital （PUMCH） between January 2004 and October 2010. Furthermore, the results were compared to that reported in previous studies of FUO in PUMCH since 1985. Results Of the 997 FUO cases, definite diagnosis was eventually achieved in 797 （79.9%） patients. The most common cause of FUO was infectious diseases （479 cases, 48.0%）, with tuberculosis accounting for 45.3% （217/479） of the cases of infections. One hundred and sixty-eight （16.9%） patients were diagnosed with connective tissue diseases, with Still＇s disease and vasculitis accounted for 31.5% （53/168） and 24.4% （41/168） of this category, respectively. Neoplasms and miscellaneous causes were found in 7.9% （79/997） and 7.1% （71/997）, respectively. However, no definite diagnosis had been made in the remaining 200 （20.1%） cases until they were discharged from the hospital. Conclusions During different periods, infectious diseases, especially tuberculosis, were the leading etiology of FUO and the proportion of tuberculosis had no significant difference. While the frequency of neoplasms was descending, the proportion of lymphoma in neoplasm was ascending; the frequency of undiagnosed＇cases was increasing, but in most FUO cases the causes can be diagnosed eventually after careful analysis of clinical data.

Malignant gastrointestinal melanomas of unknown origin: Should it be considered primary?

We read with interest the article entitled： ‘Jejuno-jejunal invagination due to intestinal melanoma’ by Resta , et al. They reported a rare clinical case of a young woman with a bleeding jejunal melanoma, whose early clinical presentation was an intestinal invagination. The article is also referred to the rarity of gastrointestinal melanomas as well as their possible primary nature.

Applied Value of Monitoring Serum Hepcidin in Differential Diagnosis of Infection versus Tumor Fevers

The applied value of serum hepcidin in differential diagnosis of infection fevers versus tumor fevers was explored.A total of 432 fever patients were selected according to the domestic fever of unknown origin（FUO） diagnostic criteria from our hospital between June 2010 and November 2013.Venous blood samples were taken on the day 1,5,10 after admission.The infection group（98 cases） and the tumor group（50 cases） were set up based on the clinical and laboratory findings.ELISA was used to determine the serum hepcidin and IL-6 levels.SPSS 13.0 was used for statistical analysis.Hepcidin showed obvious descending trend on the 10 th day in both the bacterial infection group（66 cases） and the virus infection group（32 cases）,and the descending trend was similar to that of inflammatory indexes such as procalcitonin（PCT）,hypersensitive C-reactive protein（h-CRP）,erythrocyte sedimentation rate（ESR）,white blood cell（WBC）,and ferritin.Serum hepcidin showed no obvious differences in the tumor group on the day 1,5,10 after admission.In the infection groups,serum hepcidin was positively correlated with IL-6（r=0.687,P=0.000） and CRP（r=0.487,P=0.026）,but had a poor correlation with blood sedimentation,ferritin,PCT and WBC（P〉0.05）.Monitoring dynamic changes of hepcidin and related inflammatory factors in patients with fever is expected to be used for clinical identification of infection fever and tumor fever.

SARS-CoV-2:Possible role in children with acute hepatitis of unknown origin

The UK raised an alert with the World Health Organization(WHO)in April 2022 concerning a significant surge in the num-ber of children diagnosed with acute hepatitis of unknown origin(AHUO).Despite an ongoing investigation attributing its etiology to adenovirus infection,the absence of adenovirus inclusions in liver biopsies and the remarkably low viral load raised doubts.Concurrently,reports of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infections in children coincided with the surge in acute hepatitis cases,prompting the need for a thorough examination of the poten-tial connection between current or past SARS-CoV-2 infections and pediatric hepatitis epidemics.Epidemiological data suggests that acute hepatitis is a notable manifestation of the multiple-system inflammatory syndrome in children following the global SARS-CoV-2 pandemic.However,the precise role of the SARS-CoV-2 virus in liver injury etiology remains uncertain.To shed light on the potential association between SARS-CoV-2 and AHUO in children,we conduct-ed a systematic review of epidemiological links,potential pathogenesis,and recent research findings,aiming to raise awareness and vigilance among clinicians.Convincing and definitive evidence will be essential in the future to confirm the direct impact of SARS-CoV-2 infection on children with AHUO.

Diagnosis and Clinical Management of Acute Severe Hepatitis of Unknown Origin: Operational Recommendation of Peking Union Medical College Hospital

Around 450 cases of acute severe hepatitis of unknown origin in children have been reported in 21 countries and region globally since April 2022,which has exceeded the past annual incidences of related regions,and has aroused wide concern.Affected patients were predominantly children under 16years of age,presented with symptoms of acute hepatitis with markedly elevated liver enzymes,and had been ruled out of common viral infections such as hepatitis A,B,C,D,and E.Similar cases have not been reported in China yet.However,considering that the severe acute hepatitis has involved worldwide areas,still with unknown origin,and incidences of severity is relatively high,we formulated this recommendation to standardize diagnosis and treatment of acute severe hepatitis of unknown origin in Peking Union Medical College Hospital,to get fully prepared to the possible public health events.

Severe Acute Hepatitis of Unknown Origin in Children: What Do We Know Today?

In May 2022, the UK International Health Regulations National Focal Point notified World Health Organization of 176 cases of severe acute hepatitis of unknown etiology in children under 10 years of age. From that moment on, cases of severe acute hepatitis of unknown origin in children began to be reported in several countries. As of June 17, 2022, a total of 991 cases had been reported in 35 countries worldwide, 50 children needed a liver transplant and 28 patients died. According to information published by ECDC, 449 cases have been detected in 21 EU countries. The children were between 1 month and 16 years of age. Adenovirus was detected in 62.2% of the analyzed samples. So far, the cause of these cases is unknown and many hypotheses remain open, but hepatitis A-E viruses and COVID-19 vaccines have been ruled out. A possible hypothesis has been published to explain the cause of these cases of severe hepatitis, according to which it could be a consequence of adenovirus infection in the intestine in healthy children previously infected with SARS-CoV-2. No other clear epidemiological risk factors have been identified to date. Thus, at this time, the etiology of the current cases of hepatitis remains under active investigation.

Squamous cell carcinoma metastatic to cervical lymph nodes from unknown primary origin:the impact of chemoradiotherapy

The management of cervical lymph node metastases of squamous cell carcinoma from an unknown primary site is still a therapeutic challenge.We report here our experience in treating these patients with chemoradiotherapy as a curative approach.Data from 40 patients were reviewed.In total,20(50%) patients underwent excisional biopsy.All patients underwent radiotherapy,which was delivered to both sides of the neck and pharyngeal mucosa(extensive field),and concurrent chemotherapy consisting of weekly cisplatin at a dose of 40 mg/m2.The clinical stage of the cervical nodes at presentation was N1 in 25%,N2 in 60%,and N3 in 15%.Most patients(75%) developed at least grade 3 mucositis.Eight patients(20%) had grade 3 xerostomia and 18 patients(45%) required esophageal dilation for stricture.The 5-year overall survival(OS) rate of all patients was 67.5%.The 5-year OS rates of patients with N1,N2,and N3 lesions were 100%,67%,and 41%,respectively(P = 0.046).The 5-year progression-free survival rate was 62.5%.In multivariate analysis,only N stage significantly affected OS(P = 0.022).Emergence of the occult primary was very limited(1 patient only).Our results suggest that extensive irradiation of both sides of the neck and pharyngeal mucosa with concurrent chemotherapy results in a lower emergence of primary tumor.Because the survival of patients with unknown primary is comparable to that of patients with known primary,an attempt at cure should always be made.

Hemophagocytic lymphohistiocytosis triggered by relapsing polychondritis:A case report

BACKGROUND Hemophagocytic lymphohistiocytosis(HLH)is a rare,life-threatening disorder caused by abnormal histiocytes and T cell activation.In adults,it is predominantly associated with infections,cancers,and autoimmune diseases.Relapsing polychondritis(RP),another rare disease,is diagnosed based on symptoms without specific tests,featuring cartilage inflammation characterized by swelling,redness,and pain,rarely inducing HLH.CASE SUMMARY A 74-year-old woman visited the emergency room with a fever of 38.6℃.Blood tests,cultures,and imaging were performed to evaluate fever.Results showed increased fluorescent antinuclear antibody levels and mild cytopenia,with no other specific findings.Imaging revealed lymph node enlargement was observed;however,biopsy results were inconclusive.Upon re-evaluation of the physical exam,inflammatory signs suggestive of RP were observed in the ears and nose,prompting a tissue biopsy for confirmation.Simultaneously,persistent fever accompanied by cytopenia prompted a bone marrow examination,revealing hemophagocytic cells.After finding no significant results in blood culture,viral markers,and tissue examination of enlarged lymph nodes,HLH was diagnosed by RP.Treatment involved methylprednisolone followed by azathioprine.After two months,bone marrow examination confirmed resolution of hemophagocytosis,with normalization of hyperferritinemia and pancytopenia.CONCLUSION Thorough physical examination enabled diagnosis and treatment of HLH trig gered by RP in patients presenting with fever of unknown origin.

基于双随机森林的发热待查智能诊断方法

在机器学习预测模型中,不平衡数据集会降低少数类的预测准确性。针对发热待查数据集的不平衡特性,该文提出了一种基于K-Means聚类欠采样的双随机森林病因预测方法。首先通过K-Means聚类欠采样构建一个平衡数据集,并在此基础上创建一个基于CART投票机制的随机森林预测模型。然后对初始数据集用同样的方法创建一个随机森林预测模型。最后将两个随机森林预测模型联合,使用两者的CART一起投票预测。该文提出的方法增加了CART的数量,在保持原有数据集特性的同时,提高了少数类的投票权重。在发热待查数据集上的实验表明,该文所提方法不仅改善了少数类的预测性能,对其他类别的预测性能也有一定程度的提升。

以伪装热为表现的儿童孟乔森综合征10例病例系列报告

背景以伪装热为表现的儿童孟乔森综合征病例常就诊于精神科、心理科以外的其他科室,这些科室医生对该病认识不足,患儿很难得到及时和正确的诊治,发病率可能被低估。目的 总结以伪装热为表现的孟乔森综合征儿童的临床资料,提高对该病的认识。设计病例系列报告。方法 回顾性纳入2022年1月至2024年1月在3个医院诊断以伪装热为表现的孟乔森综合征的连续住院病例。通过各医院管理信息系统采集病例性别、发病年龄、病程,就诊经历及治疗史,发热特征,体格检查,辅助检查等临床资料。主要结局指标发热特征。结果 10例患儿进入本文分析,均为女童,起病年龄12(10~14)岁,病程6.3(1~18)个月。门诊频次平均8(4~12)次,住院频次平均3.5(2~5)次,就诊医院数平均3.5(3~5)家。均有反复行糖皮质激素、抗菌药物治疗史且均无疗效。均在短时间内体温达到高热(39.0~40.2℃),约5 min内体温恢复正常;6例偶有头晕,其中伴头痛2例,伴腹痛1例;发热前均无畏寒及寒战,时间无规律性;体温恢复正常时无出汗反应。发热前后皮肤体感温度、脉搏、心率、呼吸频次均未见变化。精神和食欲均正常;体重轻度增加3例,余病例均未见下降;均无阳性体征。辅助检查均未见异常。单亲家庭环境4例,父母长期争执、吵闹5例,留守儿童1例。均转至心理科进行干预,随访时间8(5~12)个月,未见类似发热发作,也无因其他症状就诊者。结论 以伪装热为表现的儿童孟乔森综合征好发于女性儿童/青少年,多次反复求治于不同医院,体温可在3~8 min内达到高热,约5 min内恢复正常,发作时无发热时典型病理生理过程变化,实验室检验和辅助检查结果无异常;虽然病程较长,但无疾病状态改变。

李创鹏从“温少阴,通阳明”论治不明原因发热

不明原因发热是临床诊疗中的难点,患者常以发热为主诉就诊,伴随症状和体征一般不典型,现代医学对于不明原因发热发病机制的研究尚无统一定论,治疗仍以经验性抗炎为主,存在诊断延迟、治疗方案有限、治疗效果欠佳、不良反应明显等不足。中医认为,不明原因发热总属脏腑功能失调,阴阳失衡,具有病程长、病因不明、病情复杂、反复发作、缠绵难愈的特征。李创鹏主任医师基于六经辨证体系,指出不明原因发热的病机特点为少阴阳明合病,提出“温少阴,通阳明”的论治观点,即运用大黄附子汤合薏苡附子败酱散退热祛邪,以细辛引药直达少阴病所,同时健运脾胃、养阴生津、通调血脉,使邪去正安。

发热待查183例病因分析

目的了解183例发热待查(fever of unknown origin,FUO)患者的病因分布特点,比较其在不同医院、年龄段、性别、热程的病因构成,为临床诊治提供参考。方法回顾性分析郑州市第六人民医院及北京大学第一医院感染疾病科2022年8月至2023年10月收治的183例FUO住院患者的临床资料,按病因分为感染性疾病93例、非感染性炎症性疾病(non-infectious inflammatory diseases,NIID)42例、肿瘤性疾病14例、其他疾病21例、诊断不明13例,比较在不同医院、不同年龄段、不同性别、不同热程的病因分布差异。采用χ^(2)检验进行比较。结果纳入FUO患者中男性占61.20%(112/183),年龄(49.70±19.09)岁,细菌感染、成人Still病、淋巴瘤、坏死性淋巴结炎分别为各组确诊患者中常见病因。两家医院FUO患者中感染性疾病例数占比分别为64.29%(27/42)、46.81%(66/141),差异有统计学意义(χ^(2)=3.96,P<0.05);31~45岁患者感染性疾病数占比高于15~30岁患者[63.89%(23/36)比34.15%(14/41),χ^(2)=6.79,P<0.05];15~30岁患者其他疾病占比[29.27%(12/41)]高于其他各组患者(χ^(2)=4.10、6.35、9.51,均P<0.05);女性NIID占比高于男性[33.80%(24/71)比16.07%(18/112),χ^(2)=7.73,P<0.05];热程>3个月的感染性疾病患者占比[12.50%(3/24)]低于热程<1个月与热程1~3个月患者[61.33%(46/75)、52.38%(44/84)](χ^(2)=15.45、10.51,均P<0.05);热程>3个月的肿瘤性疾病患者占比高于热程<1个月的患者[20.83%(5/24)比4.00%(3/75);χ^(2)=4.86,P<0.05];热程>3个月的诊断不明病例数占比高于热程<1个月的患者[16.67%(4/24)比2.67%(2/75),χ^(2)=4.04,P<0.05]。结论对于FUO患者,应首先考虑感染性疾病。不同医院、年龄、性别、热程的FUO患者病因构成可能有所不同,应结合患者临床特点进行精确、快速的相关检验及检查以尽快明确病因。