Fever of unknown origin (FUO). I A. prospective multicenter study of 167 patients with FUO, using fixed epidemiologic entry criteria. The Netherlands FUO Study Group

Performance and value of 18F‑FDG PET/CT in patients with fever of unknown origin

Fever of unknown origin (FUO) is a common clinical and diagnostic challenge. The main aim of the present study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose (18FDG) positron emission tomography (PET)/CT in patients who present with FUO. Overall, 105 consecutive patients (61 men and 44 women) with a mean age of 51±35 years with FUO underwent 18FDG PET/CT scans. The performance of 18FDG PET/CT in determining the etiology of FUO was assessed. According to the PET/CT results, patients were classified into four groups: Group 1, patients with true-positive results (n=51; 49%), in whom abnormal 18FDG uptake identified the final diagnosis; group 2, patients with false-positive results (n=24; 23%), in whom 18FDG uptake was not consistent with the final diagnosis; group 3, patients with true-negative results (n=10; 9.5%), in whom the 18FDG uptake was normal and no final disease was established; and group 4, patients with false-negative results (n=20; 19%), in whom 18FDG uptake was normal and disease was finally established. Of the 51 patients with true-positive PET/CT results, 51% had infections, 35% had malignancies and 14% had inflammatory processes. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 72, 29, 68, 33 and 58%, respectively. In conclusion, the present results demonstrated that 18FDG PET/CT established the final diagnosis of FUO in the majority of patients (72%). These results support the use of 18FDG PET/CT in the initial evaluation and management of patients with FUO.

Metagenomic next-generation sequencing in patients with fever of unknown origin: A comprehensive systematic literature review and meta-analysis

Metagenomic Next-Generation Sequencing (mNGS) holds promise in diagnosing fever of unknown origin (FUO) by detecting diverse pathogens. We systematically reviewed the literature to evaluate mNGS's accuracy, clinical efficacy, and limitations in FUO diagnosis. Nine studies revealed mNGS's positivity rate ranging from 66.7% to 93.5% for bacterial bloodstream infections and systemic infections. Meta-analysis of three studies involving 857 patients, including 354 with FUO, showed a sensitivity of 0.91 (95% CI: 0.87-0.93) and specificity of 0.64 (95% CI: 0.58-0.70). Despite lower specificity, mNGS demonstrated a higher Diagnostic Odds Ratio (DOR) of 17.0 (95% CI: 4.5-63.4) compared to conventional microbiological tests (CMTs) at 4.7 (95% CI: 2.9-7.6). While mNGS offers high sensitivity but low specificity in identifying causative pathogens for FUO, its superior DOR suggests potential for more accurate diagnoses and targeted interventions. Further research is warranted to optimize its clinical application in FUO management.

Fever of Unknown Origin (FUO) Criteria Influences Diagnostic Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Criteria classifying fever of unknown origin (FUO) patients remains subject to discrepancies. A minimal standardized set of investigative tests serves as the foundation for the qualitative criteria, whereas quantitative incorporates the length of evaluation (7 or 3 days). A systematic review of studies would help physicians anticipate the frequency of illness types that could influence management.

METHODS

Prospective studies published in Medline (PubMed), Embase, Scopus, and Web of Science databases from January 1, 1997, to July 31, 2022, were included. A meta-analysis estimated associated pooled proportions between these criteria and diagnostic outcomes adjusted to the International Classification of Diseases, 10th edition (ICD-10) definitions.

RESULTS

Five qualitative studies corresponded to an increase of 15.3% (95% CI: 2.3-28.3%, p=0.021) in undiagnosed FUO proportions compared to eleven quantitative studies. Quantitative studies had 19.7% (95% CI: 6.0-33.4%, p=0.005) more in adjusted infectious disease proportions than qualitative studies. No significant differences in proportions between FUO defining criteria were noted for adjusted noninfectious inflammatory disorders (p=0.318), oncology (p=0.901), non-inflammatory miscellaneous disorders (p=0.321), diagnostic evaluation process, gross national income (GNI), or World Health Organization (WHO) geographic region.

CONCLUSIONS

Use of either qualitative or quantitative FUO criteria was associated with a statistically significant risk of over- or under-estimating infectious diseases and undiagnosed illnesses when using an ICD-10 adjusted FUO five-category system. Clinicians should anticipate differences depending on which criteria are used. While further research is warranted, qualitative criteria provide the best framework for study comparisons.

Recommendations for Updating Fever and Inflammation of Unknown Origin From a Modified Delphi Consensus Panel

Background

Fever of unknown origin (FUO) and inflammation of unknown origin (IUO) are syndromes commonly used as medical diagnoses. Since the existing literature has a mixture of diagnostic approaches, developing consensus-based recommendations would be helpful for clinicians, researchers, and patients.

Methods

A modified Delphi process was performed from October 2022 to July 2023, involving 4 rounds of online surveys and 2 live video conferences. The panel comprised international experts recruited based on peer-reviewed published publications and studies.

Results

Among 50 invited experts, 26 (52.0%) agreed to participate. Twenty-three panelists completed round 1 of the survey, 21 completed rounds 2 and 3, 20 completed round 4, and 7 participated in round 5 live video discussions. Of the participants, 18 (78.3%) were academic-based clinicians and researchers, 5 (21.7%) practiced in a community-based hospital, and 6 (26.1%) were female. Consensus was reached on 5 themes: (1) incorporating epidemiologic factors, such as geographic location and travel history; (2) updated criteria for classifying FUO or IUO; (3) initial evaluation approaches; (4) a classification system for diagnoses; and (5) recommendations for judicious limitation of empiric therapies. Experts strongly disagreed with using 2-deoxy-2-[18F] fluoro-D-glucose positron emission tomography/computed tomography as part of the diagnostic criteria for FUO. There were mixed opinions about the importance of the temperature measurement site, the 3-week minimum illness criterion, the need for a standard definition of relapsing fevers, and the use of similar evaluation strategies for FUO and IUO.

Conclusions

These Delphi-generated consensus-based recommendations offer potential improvements compared with earlier definitions and a guide for clinical practice and future research.

Unique clinical entity: Infective endocarditis with ruptured MCA mycotic aneurysm presented as fever of unknown origin: Case report and literature review

INTRODUCTION AND IMPORTANCE

Fever of unknown origin (FUO) in children poses a complex challenge for doctors. It involves a broad spectrum of potential diagnoses, with infectious diseases being the predominant culprits, followed by connective tissue disorders and malignancies.

CASE PRESENTATION

A 4-year-old boy with a prior diagnosis of a congenital bicuspid aortic valve was admitted to our hospital after experiencing two months of intermittent high-grade fever, severe nighttime headaches, and episodes of nausea and vomiting. His condition deteriorated rapidly with a drop in hemoglobin, elevated inflammatory markers, and the discovery of a large intracerebral hematoma. Further evaluation revealed infective endocarditis and a ruptured cerebral mycotic aneurysm associated with the bicuspid aortic valve infection. The aneurysm was successfully treated through cerebral endovascular catheterization, and the patient received six weeks of intravenous antibiotics. Cardiac surgery for valve repair was planned for a later date.

CLINICAL DISCUSSION

Among the infectious causes, infective endocarditis (IE) is a notable contributor, accounting for 1-5 % of all FUO cases. IE can lead to severe complications, with a small fraction of patients experiencing neurological issues such as stroke, encephalopathy, or the development of cerebral mycotic aneurysms.

CONCLUSION

The presented case serves as a stark reminder that FUO can be caused by serious underlying conditions, such as infective endocarditis. The rapid progression from fever and neurological symptoms to a ruptured cerebral mycotic aneurysm highlights the potentially life-threatening nature of these cases.

Microbial and Host Metabolites at the Backstage of Fever: Current Knowledge about the Co-Ordinate Action of Receptors and Molecules Underlying Pathophysiology and Clinical Implications

Fever represents an elevation of body temperature, that exerts a protective effect against pathogens. Innate immune cells and neurons are implicated in the regulation of body temperature. Pathogen-associated molecular patterns, i.e., lipopolysaccharides from Gram-negative bacteria and peptidoglycan and lipoteichoic acid from Gram-positive bacteria are exogenous pyrogens, that bind to Toll-like receptors on immune and non-immune cells. The subsequent release of pro-inflammatory cytokines [interleukin-1 (IL-1), IL-6 and Tumor necrosis factor-alpha] and their passage through the brain trigger the febrile response. In fact, neurons of the pre-optic area produce prostaglandin E2 (PGE2), that, in turn, bind to the PGE2 receptors; thus, generating fever. Apart from classical non-steroidal anti-inflammatory drugs, i.e., aspirin and acetaminophen, various botanicals are currently used as antipyretic agents and, therefore, their mechanisms of action will be elucidated.

Geographic Upon Noninfectious Diseases Accounting for Fever of Unknown Origin (FUO): A Systematic Review and Meta-analysis

Background

Diagnostic outcomes for fever of unknown origin (FUO) remain with notable numbers of undiagnosed cases. A recent systemic review and meta-analysis of studies reported geographic variation in FUO-related infectious diseases. Whether geography influences types of FUO noninfectious diagnoses deserves examination.

Methods

Medline (PubMed), Embase, Scopus, and Web of Science databases were searched systematically using medical subject headings published from January 1, 1997, to March 31, 2021. Prospective clinical studies investigating participants meeting adult FUO defining criteria were selected if they assessed final diagnoses. Meta-analyses were based on the random-effects model according to World Health Organization (WHO) geographical regions.

Results

Nineteen studies with significant heterogeneity were analyzed, totaling 2,667 participants. Noninfectious inflammatory disorders had a pooled estimate at 20.0% (95%CI: 17.0-23.0%). Undiagnosed illness had a pooled estimate of 20.0% (95%CI: 14.0-26.0%). The pooled estimate for cancer was 15.0% (95%CI: 12.0-18.0%). Miscellaneous conditions had a pooled estimate of 6.0% (95%CI: 4.0-8.0%). Noninfectious inflammatory disorders and miscellaneous conditions were most prevalent in the Western Pacific region with a 27.0% pooled estimate (95%CI: 20.0-34.0%) and 9.0% (95%CI: 7.0-11.0%), respectively. The highest pooled estimated for cancer was in the Eastern Mediterranean region at 25.0% (95%CI: 18.0-32.0%). Adult-onset Still’s disease (114 [58.5%]), systemic lupus (52 [26.7%]), and giant-cell arteritis (40 [68.9%]) predominated among the noninfectious inflammatory group. Lymphoma (164 [70.1%]) was the most common diagnosis in the cancer group.

Conclusions

In this systematic review and meta-analysis, noninfectious disease diagnostic outcomes varied among WHO-defined geographies. Evaluation of FUO should consider local variations in disease prevalence.

Rheumatic disorders among patients with fever of unknown origin: A systematic review and meta-analysis

OBJECTIVES

To conduct a systematic literature review and meta-analysis to estimate the proportion of fever of unknown origin (FUO) and inflammation of unknown origin (IUO) cases that are due to rheumatic disorders and the relative frequency of specific entities associated with FUO/IUO.

METHODS

We searched PubMed and EMBASE between January 1, 2002, and December 31, 2021, for studies with ≥50 patients reporting on causes of FUO/IUO. The primary outcome was the proportion of FUO/IUO patients with rheumatic disease. Secondary outcomes include the association between study and patient characteristics and the proportion of rheumatic disease in addition to the relative frequency of rheumatic disorders within this group. Proportion estimates were calculated using random-effects models.

RESULTS

The included studies represented 16884 patients with FUO/IUO. Rheumatic disease explained 22.2% (95%CI 19.6 - 25.0%) of cases. Adult-onset Still's disease (22.8% [95%CI 18.4-27.9%]), giant cell arteritis (11.4% [95%CI 8.0-16.3%]), and systemic lupus erythematosus (11.1% [95%CI 9.0-13.8%]) were the most frequent disorders. The proportion of rheumatic disorders was significantly higher in high-income countries (25.9% [95%CI 21.5 - 30.8%]) versus middle-income countries (19.5% [95%CI 16.7 - 22.7%]) and in prospective studies (27.0% [95%CI 21.9-32.8%]) versus retrospective studies (20.6% [95%CI 18.1-24.0%]). Multivariable meta-regression analysis demonstrated that rheumatic disease was associated with the fever duration (0.011 [95%CI 0.003-0.021]; P=0.01) and with the fraction of patients with IUO (1.05 [95%CI 0.41-1.68]; P=0.002).

CONCLUSION

Rheumatic disorders are a common cause of FUO/IUO. The care of patients with FUO/IUO should involve physicians who are familiar with the diagnostic workup of rheumatic disease.

Optimal use of the FDG-PET/CT in the diagnostic process of fever of unknown origin (FUO): a comprehensive review

Numerous studies have clarified the usefulness of ¹⁸F-fluorodeoxyglucose (FDG)-PET/CT (positron emission tomography) for diagnosing the cause of fever of unknown origin (FUO). Various types of disease can cause FUO, but the cause remains unknown in a certain proportion of FUO, even when the advanced diagnostic methodologies are used. FDG-PET/CT is regarded as a second-line modality in the diagnostic process of FUO, and its potential to identify the cause of FUO will be maximized when the appropriate clinical considerations are understood. Accordingly, this review presents basic knowledge regarding FUO, and reports the current status of FDG-PET/CT applied to diagnosing the cause of FUO, including diagnostic performance, test protocols, possible factors influencing the diagnostic result, outcomes, and cost-effectiveness. This knowledge will enable effective future use of FDG-PET/CT to improve outcomes in patients with FUO.

Prospective Studies Comparing Structured vs Nonstructured Diagnostic Protocol Evaluations Among Patients With Fever of Unknown Origin: A Systematic Review and Meta-analysis

Importance

Patients meeting the criteria for fever of unknown origin (FUO) can be evaluated with structured or nonstructured approaches, but the optimal diagnostic method is unresolved.

Objective

To analyze differences in diagnostic outcomes among patients undergoing structured or nonstructured diagnostic methods applied to prospective clinical studies.

Data Sources

PubMed, Embase, Scopus, and Web of Science databases with librarian-generated query strings for FUO, PUO, fever or pyrexia of unknown origin, clinical trial, and prospective studies identified from January 1, 1997, to March 31, 2021.

Study Selection

Prospective studies meeting any adult FUO definition were included. Articles were excluded if patients did not precisely fit any existing adult FUO definition or studies were not classified as prospective.

Data Extraction and Synthesis

Abstracted data included years of publication and study period, country, setting (eg, university vs community hospital), defining criteria and category outcome, structured or nonstructured diagnostic protocol evaluation, sex, temperature threshold and measurement, duration of fever and hospitalization before final diagnoses, and contribution of potential diagnostic clues, biochemical and immunological serologic studies, microbiology cultures, histologic analysis, and imaging studies. Structured protocols compared with nonstructured diagnostic methods were analyzed using regression models.

Main Outcomes and Measures

Overall diagnostic yield was the primary outcome.

Results

Among the 19 prospective trials with 2627 unique patients included in the analysis (range of patient ages, 10-94 years; 21.0%-55.3% female), diagnoses among FUO series varied across and within World Health Organization (WHO) geographic regions. Use of a structured diagnostic protocol was not significantly associated with higher odds of yielding a diagnosis compared with nonstructured protocols in aggregate (odds ratio [OR], 0.98; 95% CI, 0.65-1.49) or between Western Europe (Belgium, France, the Netherlands, and Spain) (OR, 0.95; 95% CI, 0.49-1.86) and Eastern Europe (Turkey and Romania) (OR, 0.83; 95% CI, 0.41-1.69). Despite the limited number of studies in some regions, analyses based on the 6 WHO geographic areas found differences in the diagnostic yield. Western European studies had the lowest percentage of achieving a diagnosis. Southeast Asia led with infections at 49.0%. Noninfectious inflammatory conditions were most prevalent in the Western Pacific region (34.0%), whereas the Eastern Mediterranean region had the highest proportion of oncologic explanations (24.0%).

Conclusions and Relevance

In this systematic review and meta-analysis, diagnostic yield varied among WHO regions. Available evidence from prospective studies did not support that structured diagnostic protocols had a significantly better rate of achieving a diagnosis than nonstructured protocols. Clinicians worldwide should incorporate geographical disease prevalence in their evaluation of patients with FUO.

Geographic Variation of Infectious Disease Diagnoses Among Patients with Fever of Unknown Origin (FUO) – A Systematic Review and Meta-analysis

Background

Fever of unknown origin (FUO) investigations yield a substantial number of patients with infectious diseases. This systematic review and meta-analysis aimed to quantify more common FUO infectious diseases etiologies and to underscore geographic variation.

Methods

Four databases (PubMed, Embase, Scopus, and Web of Science) were searched for prospective studies reporting FUO rates among adult patients from 1 January 1997 to 31 March 2021. The pooled proportion for infectious diseases etiology was estimated using the random-effects meta-analysis model.

Results

Nineteen prospective studies were included with 2667 total cases. No studies were available for Africa or the Americas. Overall, 37.0% (95.0% confidence interval [CI], 30.0%–44.0%) of FUO patients had an infectious disease etiology. Infections were more likely from Southeastern Asia (pooled proportion, 0.49 [95% CI, .43–.55]) than from Europe (pooled proportion, 0.31 [95% CI, .22–.41]). Among specifically reported infectious diseases (n = 832), Mycobacterium tuberculosis complex predominated across all geographic regions (n = 285 [34.3%]), followed by brucellosis (n = 81 [9.7%]), endocarditis (n = 62 [7.5%]), abscesses (n = 61 [7.3%]), herpesvirus (eg, cytomegalovirus and Epstein-Barr virus) infections (n = 60 [7.2%]), pneumonia (n = 54 [6.5%]), urinary tract infections (n = 54 [6.5%]), and enteric fever (n = 40 [4.8%]).

Conclusions

FUO patients from Southeastern Asia were more likely to have an infectious diseases etiology when compared to other regions. The predominant factor for this finding appears to be differences in disease prevalence among various geographical locations or other factors such as access to timely care and diagnosis. Noting epidemiological disease factors in FUO investigations could improve diagnostic yields and clinical outcomes.

Evaluation of the implantation of transpedicular screws in spinal instrumentation with free-hand technique and navigation-assisted with intraoperative computed tomography: An analytical-positional study

BACKGROUND

Spinal instrumentation using transpedicular screws has been used for decades to stabilize the spine. In October 2018, an intraoperative CT system was acquired in the Neurosurgery service of the University Hospital Complex of Vigo, this being the first model of these characteristics in the Spanish Public Health System, so we began a study from January 2015 to December 2019 to assess the precision of the transpedicular screws implanted with this system compared with a control group performed with the classical technique and final fluoroscopic control.

METHODS

The study was carried out in patients who required transpedicular instrumentation surgery, in total 655 screws were placed, 339 using the free-hand technique (Group A) and 316 assisted with intraoperative CT navigation (Group B) (p>0.05). Demographic characteristics, related to surgery and the screw implantation grades were assessed using the Gertzbein-Robbins classification.

RESULTS

92 patients were evaluated, between 12 and 86 years (average: 57.1 years). 161 thoracic screws (24.6%) and 494 lumbo-sacral screws (75.4%) were implanted. Of the thoracic screws, 33 produced a pedicle rupture. For the lumbo-sacral screws, 71 have had pedicle violation. The overall correct positioning rate for the free-hand group was 72.6% and for the CT group it was 96.5% (p<0.05).

CONCLUSION

The accuracy rate is higher in thoracic-lumbar instrumentation in the navigation group versus free-hand group with fluoroscopic control.

Fever of Unknown Origin: The Workup and Diagnosis of Pel-Ebstein Fever

The clinical and diagnostic workup of fever of unknown origin (FUO) is key in the treatment of patients on the internal medicine service. In this article, the authors present a case of fever of unknown origin, walk through the differential diagnosis, explain the laboratory testing ordered in the workup of the patient as well as the resulting values of said testing, and discuss the pathophysiology and diagnostic criteria for the diagnosis of Pel-Ebstein fever. The authors also discuss a clinical pearl when working with electronic health records to ensure that the needs of the patient in question are met.

Fever of Unknown Origin (FUO) - A Call for New Research Standards and Updated Clinical Management

Prolonged fever of 38.3°C or higher for at least 3 weeks' duration has been termed fever of unknown origin if unexplained after preliminary investigations. Initially codified in 1961, classification with subgroups was revised in 1991. Additional changes to the definition were proposed in 1997, recommending a set of standardized initial investigations. Advances in diagnosis and management and diagnostic testing over the last 3 decades have prompted a needed update to the definition and approaches. While a 3-week fever duration remains part of the criteria, a lower temperature threshold of 38°C and revised minimum testing criteria will assist clinicians and their patients, setting a solid foundation for future research.

Diagnostic Value of 18F-FDG PET/CT vs. Chest-Abdomen-Pelvis CT Scan in Management of Patients with Fever of Unknown Origin, Inflammation of Unknown Origin or Episodic Fever of Unknown Origin: A Comparative Multicentre Prospective Study

Fluorodesoxyglucose Positron Emission Tomography (PET/CT) has never been compared to Chest-Abdomen-Pelvis CT (CAPCT) in patients with a fever of unknown origin (FUO), inflammation of unknown origin (IUO) and episodic fever of unknown origin (EFUO) through a prospective and multicentre study. In this study, we investigated the diagnostic value of PET/CT compared to CAPCT in these patients. The trial was performed between 1 May 2008 through 28 February 2013 with 7 French University Hospital centres. Patients who fulfilled the FUO, IUO or EFUO criteria were included. Diagnostic orientation (DO), diagnostic contribution (DC) and time for diagnosis of both imaging resources were evaluated. One hundred and three patients were included with 35 FUO, 35 IUO and 33 EFUO patients. PET/CT showed both a higher DO (28.2% vs. 7.8%, p < 0.001) and DC (19.4% vs. 5.8%, p < 0.001) than CAPCT and reduced the time for diagnosis in patients (3.8 vs. 17.6 months, p = 0.02). Arthralgia (OR 4.90, p = 0.0012), DO of PET/CT (OR 4.09, p = 0.016), CRP > 30 mg/L (OR 3.70, p = 0.033), and chills (OR 3.06, p = 0.0248) were associated with the achievement of a diagnosis (Se: 89.1%, Sp: 56.8%). PET/CT both orients and contributes to diagnoses at a higher rate than CAPCT, especially in patients with FUO and IUO, and reduces the time for diagnosis.

Ferritin, fever, and frequent visits: Hyperferritinemic syndromes in the emergency department

Fever of unknown origin (FUO) is defined as persistent fevers without an identifiable cause despite extensive medical workup. Emergency physicians caring for patients reporting a persistent, nonspecific, febrile illness should carefully consider potentially serious non-infectious causes of FUO. We present a case of a 35-year-old man who presented to the emergency department (ED) three times over a 10-day period for persistent febrile illness and was ultimately diagnosed with Adult-Onset Still's Disease (AOSD) after a serum ferritin level was found to be over 42,000 μg/L. AOSD, along with macrophage activation syndrome, catastrophic antiphospholipid syndrome, and septic shock comprise the four hyperferritinemic syndromes. These are potentially life-threatening febrile illnesses that characteristically present with elevated ferritin levels. In this article, we highlight the value of a serum ferritin level in the workup of a patient with prolonged febrile illness and its utility in facilitating early diagnosis and prompt treatment of hyperferritinemic syndromes in the ED.

The diagnostic value of 18F-FDG PET/CT in identifying the causes of fever of unknown origin

BACKGROUND

This study investigated the clinical significance of ¹⁸F-fluorodeoxyglucose positron emission tomography / computed tomography (¹⁸F-FDG PET/CT) in identifying the causes of fever of unknown origin (FUO).

METHODS

Patients with a fever who received an ¹⁸F-FDG PET/CT examination were retrospectively selected. The means of the two groups were compared using an independent-samples t-test.

RESULTS

Among the 89 included patients, 66 were diagnosed using ¹⁸F-FDG PET/CT. The sensitivity, specificity and diagnostic accuracy of ¹⁸F-FDG PET/CT for the diagnosis of patients with FUO were 84.5%, 25.8%, and 64.0%, respectively. The detection rates of ¹⁸F-FDG PET/CT for neoplastic diseases, infectious diseases and non-infectious inflammatory diseases were 100%, 61.3%, and 75%, respectively. The difference in C-reactive protein (CRP) levels between the two groups was statistically significant.

CONCLUSIONS

¹⁸F-FDG PET/CT has great clinical importance in diagnosing and identifying causes of FUO and improves the accuracy of FUO diagnosis when combined with serum CRP levels.

Evaluation of the implantation of transpedicular screws in spinal instrumentation with free-hand technique and navigation-assisted with intraoperative computed tomography: An analytical-positional study

BACKGROUND

Spinal instrumentation using transpedicular screws has been used for decades to stabilize the spine. In October 2018, an intraoperative CT system was acquired in the Neurosurgery service of the University Hospital Complex of Vigo, this being the first model of these characteristics in the Spanish Public Health System, so we began a study from January 2015 to December 2019 to assess the precision of the transpedicular screws implanted with this system compared with a control group performed with the classical technique and final fluoroscopic control.

METHODS

The study was carried out in patients who required transpedicular instrumentation surgery, in total 655 screws were placed, 339 using the free-hand technique (Group A) and 316 assisted with intraoperative CT navigation (Group B) (p>0.05). Demographic characteristics, related to surgery and the screw implantation grades were assessed using the Gertzbein-Robbins classification.

RESULTS

92 patients were evaluated, between 12 and 86 years (average: 57.1 years). 161 thoracic screws (24.6%) and 494 lumbo-sacral screws (75.4%) were implanted. Of the thoracic screws, 33 produced a pedicle rupture. For the lumbo-sacral screws, 71 have had pedicle violation. The overall correct positioning rate for the free-hand group was 72.6% and for the CT group it was 96.5% (p<0.05).

CONCLUSION

The accuracy rate is higher in thoracic-lumbar instrumentation in the navigation group versus free-hand group with fluoroscopic control.

Progress Report: Next-Generation Sequencing (NGS), Multiplex Polymerase Chain Reaction (PCR), and Broad-Range Molecular Assays as Diagnostic Tools for Fever of Unknown Origin (FUO) Investigations in Adults

Even well into the 21st century, infectious diseases still account for most causes of fever of unknown origin (FUO). Advances in molecular technologies, including broad-range PCR of the 16S rRNA gene followed by Sanger sequencing, multiplex PCR assays, and more recently, next-generation sequencing (NGS) applications, have transitioned from research methods to more commonplace in some clinical microbiology laboratories. They have the potential to supplant traditional microbial identification methods and antimicrobial susceptibility testing. Despite the remaining challenges with these technologies, publications in the past decade justify excitement about the potential to transform FUO investigations. We discuss available evidence using these molecular methods for FUO evaluations, including potential cost-benefits and future directions.

Exploring Fever of Unknown Origin Intelligent Diagnosis Based on Clinical Data: Model Development and Validation

Background

Fever of unknown origin (FUO) is a group of diseases with heterogeneous complex causes that are misdiagnosed or have delayed diagnoses. Previous studies have focused mainly on the statistical analysis and research of the cases. The treatments are very different for the different categories of FUO. Therefore, how to intelligently diagnose FUO into one category is worth studying.

Objective

We aimed to fuse all of the medical data together to automatically predict the categories of the causes of FUO among patients using a machine learning method, which could help doctors diagnose FUO more accurately.

Methods

In this paper, we innovatively and manually built the FUO intelligent diagnosis (FID) model to help clinicians predict the category of the cause and improve the manual diagnostic precision. First, we classified FUO cases into four categories (infections, immune diseases, tumors, and others) according to the large numbers of different causes and treatment methods. Then, we cleaned the basic information data and clinical laboratory results and structured the electronic medical record (EMR) data using the bidirectional encoder representations from transformers (BERT) model. Next, we extracted the features based on the structured sample data and trained the FID model using LightGBM.

Results

Experiments were based on data from 2299 desensitized cases from Peking Union Medical College Hospital. From the extensive experiments, the precision of the FID model was 81.68% for top 1 classification diagnosis and 96.17% for top 2 classification diagnosis, which were superior to the precision of the comparative method.

Conclusions

The FID model showed excellent performance in FUO diagnosis and thus would be a potentially useful tool for clinicians to enhance the precision of FUO diagnosis and reduce the rate of misdiagnosis.

Aetiology of pyrexia of unknown origin in north India

The aetiology of pyrexia of unknown origin (PUO) varies dramatically according to epidemiology. We studied the cause and spectrum of PUO in Indian adults. A total of 152 patients (112 prospectively and 40 retrospectively) met Petersdorf and Beeson's criteria. The diagnostic evaluation was guided by potentially diagnostic clues, based on a 'step-wise' approach. The five main categories, i.e. infectious, neoplastic, non-infectious inflammatory, miscellaneous and undiagnosed comprised 43.4%, 21.5%, 19.7%, 2.0% and 12.5%, respectively. The top three causes were tuberculosis (n = 43, 28.3%), lymphoma (n = 19, 12.5%) and adult-onset Still's disease (n = 12, 7.9%). Tuberculosis predominated in all age groups, and about 70% of cases had the extrapulmonary form, the most common being gastrointestinal. Hodgkin and non-Hodgkin lymphomas were equally distributed, but solid malignancies were uncommon. Adult-onset Still's disease was the second commonest cause in adults aged ≤ 40 years. Fever resolved spontaneously in 12/19 cases of undiagnosed cause. Extrapulmonary tuberculosis remains the most prevalent PUO in India.

Diagnostic Value of 18F-FDG-PET/CT in Patients with FUO

Conventional diagnostic imaging is often ineffective in revealing the underlying cause in a considerable proportion of patients with fever of unknown origin (FUO). The aim of this study was to assess the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) in patients with FUO. We retrospectively reviewed ¹⁸F-FDG-PET/CT scans performed on 50 consecutive adult patients referred to our department for further investigation of classic FUO. Final diagnosis was based on histopathological and microbiological findings, clinical criteria, or clinical follow-up. Final diagnosis was established in 39/50 (78%) of the patients. The cause of FUO was infection in 20/50 (40%), noninfectious inflammatory diseases in 11/50 (22%), and malignancy in 8/50 (16%) patients. Fever remained unexplained in 11/50 (22%) patients. ¹⁸F-FDG-PET/CT scan substantially contributed to the diagnosis in 70% of the patients, either by identifying the underlying cause of FUO or by directing to the most appropriate site for biopsy. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of ¹⁸F-FDG-PET/CT for active disease detection in patients with FUO were 94.7%, 50.0%, 84.0%, 85.7%, and 75.0%, respectively. In conclusion, whole-body ¹⁸F-FDG-PET/CT is a highly sensitive method for detection of the underlining cause of FUO or for correctly targeting suspicious lesions for further evaluation.

Classic fever of unknown origin: analysis of a cohort of 87 patients according to the definition with qualitative study criterion

OBJECTIVES

The aim of this study was to evaluate the characteristics of fever of unknown origin (FUO) according to the definition with qualitative study criterion and of patients without diagnosis.

MATERIALS AND METHODS

Prospective observational study performed from 2009 to 2017 of all patients who were diagnosed with FUO according to the extended definition with qualitative study criterion. Demographic, clinical, diagnostic and evolving variables were evaluated.

RESULTS

Of the 87 patients registered, 17.3% presented criteria of inflammation of unknown origin (IUO). The diagnoses were: non-infectious inflammatory diseases (NIID) in 19 patients (21.8%), infections in 15 (17.2%), miscellaneous in 14 (16.1%), malignant diseases in 13 (15%) and without diagnosis in 26 (29.9%). In 17.6% of the cases, a potentially diagnostic clue (PDC) was identified. The patients without diagnosis were characterized by a lower number of total PDC (5.9±3.3 vs. 8.7±3.4; P=.000), fewer clinical signs (.4±.6 vs. .9±.8; P=.001), a smaller number of tests in the previous study (2.7±2.1 vs. 4.6±2; P=.000), a shorter diagnostic interval (14.6±7.7 days vs. 21.4±9.5 days; P=.029) and less alteration of erythrocyte sedimentation rate (52.3±41.3mm/h vs. 89.8±42.7mm/h; P=.000), haemoglobin (12.9±1.7g/dl vs. 11.7±1.6g/dl; P=.003) and albumin (36.9±6.4g/l vs. 33.2±7.2g/l; P=.025). ¹⁸F-fluorodeoxyglucose positron-emission tomography combined with computed tomography (¹⁸F-FDG-PET/TC) proved to be helpful in 37% of the cases. Mortality was 6.8%.

CONCLUSIONS

The definition of FUO with qualitative study criterion incorporates a diagnostic protocol that provides clear benefits in terms of cost-effectiveness.

Fever and Fever of Unknown Origin: Review, Recent Advances, and Lingering Dogma

Fever has preoccupied physicians since the earliest days of clinical medicine. It has been the subject of scrutiny in recent decades. Historical convention has mostly determined that 37.0°C (98.6°F) should be regarded as normal body temperature, and more modern evidence suggests that fever is a complex physiological response involving the innate immune system and should not be characterized merely as a temperature above this threshold. Fever of unknown origin (FUO) was first defined in 1961 by Petersdorf and Beeson and continues to be a clinical challenge for physicians. Although clinicians may have some understanding of the history of clinical thermometry, how average body temperatures were established, thermoregulation, and pathophysiology of fever, new concepts are emerging. While FUO subgroups and etiologic classifications have remained unchanged since 1991 revisions, the spectrum of diseases, clinical approach to diagnosis, and management are changing. This review considers how newer data should influence both definitions and lingering dogmatic principles. Despite recent advances and newer imaging techniques such as 18-fluorodeoxyglucose-positron emission tomography, clinical judgment remains an essential component of care.

Key diagnostic characteristics of fever of unknown origin in Japanese patients: a prospective multicentre study

OBJECTIVE

To identify the key diagnostic features and causes of fever of unknown origin (FUO) in Japanese patients.

DESIGN

Multicentre prospective study.

SETTING

Sixteen hospitals affiliated with the Japanese Society of Hospital General Medicine, covering the East and West regions of Japan.

PARTICIPANTS

Patient aged ≥20 years diagnosed with classic FUO (axillary temperature≥38.0°C at least twice within a 3-week period, cause unknown after three outpatient visits or 3 days of hospitalisation). A total of 141 cases met the criteria and were recruited from January 2016 to December 2017.

INTERVENTION

Japanese standard diagnostic examinations.

OUTCOME MEASURES

Data collected include usual biochemical blood tests, inflammatory markers (erythrocyte sedimentation rate (ESR), C reactive (CRP) protein level, procalcitonin level), imaging results, autopsy findings (if performed) and final diagnosis.

RESULTS

The most frequent age group was 65-79 years old (mean: 58.6±9.1 years). The most frequent cause of FUO was non-infectious inflammatory disease. After a 6-month follow-up period, 21.3% of cases remained undiagnosed. The types of diseases causing FUO were significantly correlated with age and prognosis. Between patients with and without a final diagnosis, there was no difference in CRP level between patients with and without a final diagnosis (p=0.121). A significant difference in diagnosis of a causative disease was found between patients who did or did not receive an ESR test (p=0.041). Of the 35 patients with an abnormal ESR value, 28 (80%) had causative disease identified.

CONCLUSIONS

Age may be a key factor in the differential diagnosis of FUO; the ESR test may be of value in the FUO evaluation process. These results may provide clinicians with insight into the management of FUO to allow adequate treatment according to the cause of the disease.

Fever of unknown origin - a literature review

Fever of undetermined origin (FUO) is a challenging entity with a striking presence in hospitals around the world and can be associated with a myriad of differential diagnoses. It is defined as axillary temperature ≥ 37.8 ° C on several occasions, lasting ≥ three weeks, in the absence of diagnosis after three days of hospital investigation or three outpatient visits. The main etiologies are: infectious, neoplastic, and rheumatic. The diagnosis is based on the detailed clinical history and physical examination of these patients, in order to direct the specific complementary tests to be performed in each case. Empirical therapy is not recommended (with few exceptions) in patients with prolonged fever, as it may disguise and delay the diagnosis and conduct to treat the specific etiology. The prognosis encompasses mortality of 12% - 35%, varying according to the underlying etiology. In this sense, the objective of this study is to review the main topics about fever of undetermined origin, bringing historical and scientific aspects, national and international.

The impact of global budgeting in Taiwan on inpatients with unexplained fever

Unexplained fever is one of the most common and difficult diagnostic problems faced daily by clinicians. This study evaluated the differences in health service utilization, health care expenditures, and quality of care provided to patients with unexplained fever before and after global budget (GB) implementation in Taiwan.The National Health Insurance Research Database was used for analyzing the health care expenditures and quality of care before and after implementation of the GB system. Patients diagnosed as having unexplained fever during 2000-2001 were recruited; their 2000-2001 and 2004-2005 data were considered baseline and postintervention data, respectively.Data of 259 patients with unexplained fever were analyzed. The mean lengths of stay (LOSs) before and after GB system implementation were 4.22 ± 0.35 days and 5.29 ± 0.70 days, respectively. The mean costs of different health care expenditures before and after implementation of the GB system were as follows: the mean diagnostic, drug, therapy, and total costs increased respectively from New Taiwan Dollar (NT$) 1440.05 ± NT$97.43, NT$3249.90 ± NT$1108.27, NT$421.03 ± NT$100.03, and NT$13,866.77 ± NT$2,114.95 before GB system implementation to NT$2224.34 ± NT$238.36, NT$4272.31 ± NT$1466.90, NT$2217.03 ± NT$672.20, and NT$22,856.41 ± NT$4,196.28 after implementation. The mean rates of revisiting the emergency department within 3 days and readmission within 14 days increased respectively from 10.5% ± 2.7% and 8.3% ± 2.4% before implementation to 6.3% ± 2.2% and 4.0% ± 1.7% after implementation.GB significantly increased LOS and incremental total costs for patients with unexplained fever; but improved the quality of care.

Fever of unknown origin (FUO): which are the factors influencing the final diagnosis? A 2005-2015 systematic review

BACKGROUND

The differential diagnosis of Fever of Unknown Origin (FUO) is very extensive, and includes infectious diseases (ID), neoplasms and noninfectious inflammatory diseases (NIID). Many FUO remain undiagnosed. Factors influencing the final diagnosis of FUO are unclear.

METHODS

To identify factors associated with FUO diagnostic categories, we performed a systematic review of classical FUO case-series published in 2005-2015 and including patients from 2000. Moreover, to explore changing over time, we compared these case-series with those published in 1995-2004.

RESULTS

Eighteen case-series, including 3164 patients, were included. ID were diagnosed in 37.8% of patients, NIID in 20.9%, and neoplasm in 11.6%, FUO were undiagnosed in 23.2%. NIIDs significantly increased over time. An association exists between study country income level and ID (increasing when the income decreases) and undiagnosed FUO (increasing when the income increases); even if not significant, the use of a pre-defined Minimal Diagnostic Work-up to qualify a fever as FUO seems to correlate with a lower prevalence of infections and a higher prevalence of undiagnosed FUO. The multivariate regression analysis shows significant association between geographic area, with ID being more frequent in Asia and Europe having the higher prevalence of undiagnosed FUO. Significant associations were found with model of study and FUO defining criteria, also.

CONCLUSIONS

Despite advances in diagnostics, FUO still remains a challenge, with ID still representing the first cause. The main factors influencing the diagnostic categories are the income and the geographic position of the study country.

Long-term prognosis, treatment, and outcome of patients with fever of unknown origin in whom no diagnosis was made despite extensive investigation: A questionnaire based study

In 30-50% of patients with fever of unknown origin (IUO) no explanation for the fever can be found. Prognosis and effects of empirical treatment of these patients are largely unknown.With this retrospective, questionnaire based corort study in all unexplained FUO patients in an expert center between 2003 and 2014 we studied mortality and outcome.In 131 of 274 FUO patients, FUO remained unexplained. Ninety-nine of them responded to the long-term follow up questionnaire. Adter a median duration of follow-up of 60 months, spontaneous remission of fever occured in 47.3%. Empirical treatment was effective in 66.7% of patients. Mortality was 6.9%. The cause of death was considered not to be related to the febrile disease in five out of six patients. Ten out of 99 responders reported to have received a final explanation for FUO after evaluation in the expertise center, but this diagnosis could not be confirmed in six cases and was considered to be an unlikely explanation for FUO in four out of six cases.We conclude that mortality in unexplained FUO is low en mostly unrelated to the febrile disease. Spontaneous resolution of fever is common. Empirical treatment prescribed by an expert physician is often effective, but should be avoided untill all diagnostic possibilities have been exhaused.

Fever of Unknown Origin: the Value of FDG-PET/CT

Fever of unknown origin (FUO) is commonly defined as fever higher than 38.3°C on several occasions during at least 3 weeks with uncertain diagnosis after a number of obligatory investigations. The differential diagnosis of FUO can be subdivided in four categories: infections, malignancies, noninfectious inflammatory diseases, and miscellaneous causes. In most cases of FUO, there is an uncommon presentation of a common disease. FDG-PET/CT is a sensitive diagnostic technique for the evaluation of FUO by facilitating anatomical localization of focally increased FDG uptake, thereby guiding further diagnostic tests to achieve a final diagnosis. FDG-PET/CT should become a routine procedure in the workup of FUO when diagnostic clues are absent. FDG-PET/CT appears to be a cost-effective routine imaging technique in FUO by avoiding unnecessary investigations and reducing the duration of hospitalization.

Referral of patients with fever of unknown origin to an expertise center has high diagnostic and therapeutic value

BACKGROUND

up to 50% of patients with fever of unknown origin (FUO) remain undiagnosed despite extensive evaluation. In expertise centers, at least 25-63% of these patients are referred after evaluation in another hospital. The diagnostic and therapeutic yields of referral to an expertise center are currently unknown.

AIM

To determine the diagnostic and therapeutic yield of referral of patients with fever of unknown origin (FUO) that remain undiagnosed in non-expertise hospitals.

DESIGN

Data on workup, outcome, treatment and prognosis were extracted from medical records of all 236 patients referred to the Radboud university medical center's department of internal medicine because of FUO between January 2005 and June 2014.

RESULTS

A final diagnosis could be made in 110 of 192 tertiary referred FUO patients. The rate of diagnosis did not differ between patients referred for first opinion or after tertiary referral (68.2 vs. 57.3%, P = 0.234). Over half of undiagnosed tertiary referred patients were treated, and fever resolved in half of these patients. Of 96 undiagnosed patients, two died (2.1)% and in both death was considered unrelated to the febrile disease.

CONCLUSION

The diagnostic rate in patients with FUO does not differ between patients that are tertiary referred and patients that have not been previously evaluated in another hospital. With a total diagnostic value of 57.3% and an additional therapeutic yield of 10.9% in undiagnosed patients, tertiary referral should therefore be considered in patients that remain undiagnosed in a non-expertise center.

Fever of unknown origin and splenomegaly: A case report of blood culture negative endocarditis

RATIONALE

Fever of unknown origin (FUO) can be determined by different conditions among which infectious diseases represent the main cause.

PATIENT CONCERNS

A young woman, with a history of aortic stenosis, was admitted to our unit for a month of intermittent fever associated with a new diastolic heart murmur and splenomegaly. Laboratory tests were negative for infectious screening. The total body computed tomography (CT) scan excluded abscesses, occulted neoplasia, or lymphadenopathy.

DIAGNOSES

The transthoracic and transesophageal echocardiogram showed an aortic valve vegetation. Three sets of blood cultures were negative for all microorganisms tested. According to these findings, Bartonella endocarditis was suspected and the serology tests performed were positive. Finally, real-time polymerase chain reaction (RT-PCR) detected Bartonella henselae DNA on tissue valve.

INTERVENTIONS

The patient underwent heart valve surgery and a treatment of Ampicillin, Gentamicin, and oral Doxycycline was prescribed for 16 days and, successively, with Doxycycline and Ceftriaxone for 6 weeks.

OUTCOMES

After surgery and antibiotic therapy, patient continued to do well.

LESSONS

Bartonella species are frequently the cause of negative blood culture endocarditis. Molecular biology techniques are the only useful tool for diagnosis. Valvular replacement is often necessary and antibiotic regimen with Gentamicin and either Ceftriaxone or Doxycycline is suggested as treatment.Echocardiogram and blood cultures must be performed in all cases of FUO. When blood cultures are negative and echocardiographic tools are indicative, early use of Bartonella serology is recommended.

Radionuclide Imaging of Infection and Inflammation in Children: a Review

With the exception of radiolabeled monoclonal antibodies, antibody fragments and radiolabeled peptides which have seen little application in the pediatric population, the nuclear medicine imaging procedures used in the evaluation of infection and inflammation are the same for both adults and children. These procedures include (1) either a two- or a three-phase bone scan using technetium-99m methylene diphosphonate; (2) Gallium 67-citrate; (3) in vitro radiolabeled white blood cell imaging (using ¹¹¹Indium-oxine or ^99mTechnetium hexamethyl-propylene-amine-oxime-labeled white blood cells); and (4) hybrid imaging with ¹⁸F-FDG. But children are not just small adults. Not only are the disease processes encountered in children different from those in adults, but there are developmental variants that can mimic, but should not be confused with, pathology. This article discusses some of the differences between adults and children with osteomyelitis, illustrates several of the common developmental variants that can mimic disease, and, finally, focuses on the increasing use of ¹⁸F-FDG PET/CT in the diagnosis and response monitoring of children with infectious and inflammatory processes. The value of and need for pediatric specific imaging protocols are reviewed.

Neglected Australian Arboviruses and Undifferentiated Febrile Illness: Addressing Public Health Challenges Arising From the 'Developing Northern Australia' Government Policy

The Australian Government is currently promoting the development of Northern Australia, with an associated increase in the local population. Consequent to this is the public health threat posed by heightened human exposure to many previously neglected arboviruses that are indigenous to the region. This initiative to support economic activity in the tropical north of the continent is leading to the accelerated expansion of an infection-naïve human population into hitherto un-encountered ecosystems inhabited by reservoir animals and vectors for these arboviruses. Combined with an apparent rise in the number and impact of dramatic climate events, such as tropical cyclones and floods caused by torrential monsoonal rainfall, this heightens the potential for viral transmission to humans. More than 75 arboviruses have been identified in Australia, some of which are associated with human disease but for which routine tests are not available to diagnose infection. Here, we describe briefly the neglected Australian arboviruses that are most likely to emerge as significant agents of human disease in the coming decades. We also advocate the establishment of a thorough surveillance and diagnostic protocol, including developing new pan-viral rapid tests for primary care use to assist in the early diagnosis and correct treatment of affected patients. We propose that the implementation of these activities will enhance our understanding of the geographical range, prevalence, identification and control of neglected Australian arboviruses. This would minimise and limit the possibility of large-scale outbreaks with these agents as population and economic growth expands further into Australia's tropical north.

Confronting the Emerging Threat to Public Health in Northern Australia of Neglected Indigenous Arboviruses

In excess of 75 arboviruses have been identified in Australia, some of which are now well established as causative agents of debilitating diseases. These include Ross River virus, Barmah Forest virus, and Murray Valley encephalitis virus, each of which may be detected by both antibody-based recognition and molecular typing. However, for most of the remaining arboviruses that may be associated with pathology in humans, routine tests are not available to diagnose infection. A number of these so-called 'neglected' or 'orphan' arboviruses that are indigenous to Australia might have been infecting humans at a regular rate for decades. Some of them may be associated with undifferentiated febrile illness-fever, the cause of which is not obvious-for which around half of all cases each year remain undiagnosed. This is of particular relevance to Northern Australia, given the Commonwealth Government's transformative vision for the midterm future of massive infrastructure investment in this region. An expansion of the industrial and business development of this previously underpopulated region is predicted. This is set to bring into intimate proximity infection-naïve human hosts, native reservoir animals, and vector mosquitoes, thereby creating a perfect storm for increased prevalence of infection with neglected Australian arboviruses. Moreover, the escalating rate and effects of climate change that are increasingly observed in the tropical north of the country are likely to lead to elevated numbers of arbovirus-transmitting mosquitoes. As a commensurate response, continuing assiduous attention to vector monitoring and control is required. In this overall context, improved epidemiological surveillance and diagnostic screening, including establishing novel, rapid pan-viral tests to facilitate early diagnosis and appropriate treatment of febrile primary care patients, should be considered a public health priority. Investment in a rigorous identification program would reduce the possibility of significant outbreaks of these indigenous arboviruses at a time when population growth accelerates in Northern Australia.

Miliary tuberculosis: Epidemiologicaland clinical analysis of large-case series from moderate to low tuberculosis endemic Country

The aim of this study was to determine the clinical features, and outcome of the patients with miliary tuberculosis (TB).We retrospectively evaluated 263 patients (142 male, 121 female, mean age: 44 years, range: 16-89 years) with miliary TB. Criteria for the diagnosis of miliary TB were at least one of the followings in the presence of clinical presentation suggestive of miliary TB such as prolonged fever, night sweats, anorexia, weight loss: radiologic criterion and pathological criterion and/or microbiological criterion; pathological criterion and/or microbiological criterion.The miliary pattern was seen in 88% of the patients. Predisposing factors were found in 41% of the patients. Most frequent clinical features and laboratory findings were fever (100%), fatigue (91%), anorexia (85%), weight loss (66%), hepatomegaly (20%), splenomegaly (19%), choroid tubercules (8%), anemia (86%), pancytopenia (12%), and accelerated erythrocyte sedimentation rate (89%). Tuberculin skin test was positive in 29% of cases. Fifty percent of the patients met the criteria for fever of unknown origin. Acid-fast bacilli were demonstrated in 41% of patients (81/195), and cultures for Mycobacterium tuberculosis were positive in 51% (148/292) of tested specimens (predominantly sputum, CSF, and bronchial lavage). Blood cultures were positive in 20% (19/97). Granulomas in tissue samples of liver, lung, and bone marrow were present in 100% (21/21), 95% (18/19), and 82% (23/28), respectively. A total of 223 patients (85%) were given a quadruple anti-TB treatment. Forty-four (17%) patients died within 1 year after diagnosis established. Age, serum albumin, presence of military pattern, presence of mental changes, and hemoglobin concentration were found as independent predictors of mortality. Fever resolved within first 21 days in the majority (90%) of the cases.Miliary infiltrates on chest X-ray should raise the possibility of miliary TB especially in countries where TB is endemic. Although biopsy of the lungs and liver may have higher yield rate of organ involvement histopathologicaly, less invasive procedures including a bone marrow biopsy and blood cultures should be preferred owing to low complication rates.

Fever of unknown origin, giant cell arteritis, and aortic dissection

Giant cell arteritis is one of the most frequent causes of pyrexia of unknown origin after infectious or malignant causes have been ruled out. In this case report we describe a 66-year old female patient, who after five weeks of remitting fever developed a life-threatening, painless severe aortic dissection. The timely use of modern imaging technologies such as magnetic resonance angiography or positron emission computed tomography could in the future be of help to recognize aortic involvement early and to avoid this devastating complication in patients with fever of unknown origin.

Laboratory surveillance of arboviral infections in a southern France region colonized by Aedes albopictus

The establishment of Aedes albopictus in southern France, a recognized competent vector for several arboviruses, represents a new threat for the local transmission and spread of what were until recently considered as tropical diseases. A preparedness and response plan, based on vigilance of both clinicians and laboratories, has introduced significant changes in guidelines and behaviour regarding patients' care specifically during the activity period of mosquitoes. In the present study, we report the results of a 1-year activity in arboviral infection diagnosis. A total of 141 patients were included in this retrospective study. The number of suspected imported and autochthonous cases was 69 and 72, respectively. A diagnosis of arboviral infection was confirmed for 15 (21·7%) suspected imported cases, with identification of 13 dengue viruses, one chikungunya virus and one Zika virus. No autochthonous cases were detected. This report illustrates the increase in requests for arboviral infection diagnosis and confirms the challenge with identifying autochthonous arboviral infection cases in many unspecific febrile syndromes.

Endocarditis: the great mimic of rheumatic diseases

Rheumatic manifestations may be prevalent in more than 30% of patients with infective endocarditis (IE), often predating this diagnosis by several months. A case series of five patients recorded at a tertiary care Rheumatology and Clinical Immunology unit over a period of 1 year emphasises that varied presentations of endocarditis may mimic uncommon rheumatic diseases.

Fever of unknown origin (FUO) revised

Fever of unknown origin (FUO) was originally characterised in 1961 by Petersdorf and Beeson as a disease condition of temperature exceeding 38.3 °C on at least three occasions over a period of at least three weeks, with no diagnosis made despite one week of inpatient investigation. However, since underlying diseases are often reported for classical FUO, these presentations may not be considered to be of “unknown origin”. Rather, the aetiology of prolonged fever may resolve, or not resolve. The definition of fever with unresolved cause (true FUO) is difficult, as it is a moving target, given the constant advancement of imaging and biomarker analysis. Therefore, the prevalence of fever with unresolved cause (FUO) is unknown.

In this review, we report such a case of prolonged fever, which initially has presented as classical FUO, and discuss current literature. Furthermore, we will give an outlook, how a prospective study on FUO will allow to solve outstanding issues like the utility of different diagnostic investigations, and the types and prevalence of various underlying diseases.

Contribution of (18)F-FDG PET in the diagnostic assessment of fever of unknown origin (FUO): a stratification-based meta-analysis

PURPOSE

The aim of this study was to quantify the contribution of FDG PET to the diagnostic assessment of fever of unknown origin (FUO), taking into account the diagnostic limitations resulting from the composite nature of this entity.

METHODS

The PubMed/MEDLINE database was searched from 2000 to September 2015. Original articles fulfilling the following criteria were included: (1) FUO as the initial diagnosis, (2) no immunosuppressed or nosocomial condition, (3) final diagnosis not based on PET, (4) a follow-up period specified, (5) adult population, and (6) availability of adapted data for calculation of odds ratios (ORs). ORs were computed for each study and then pooled using a random effects model. Stratification-based sensitivity analyses were finally performed using the following prespecified criteria: (a) study design, (b) PET device, (c) geographic area, and (d) follow-up period.

RESULTS

A meta-analysis of the 14 included studies showed that normal PET findings led to an increase in the absolute final diagnostic rate of 36 % abnormal PET findings to an increase of 83 %, corresponding to a pooled OR of 8.94 (95 % CI 4.18 - 19.12, Z = 5.65; p < 0.00001). The design of the studies influenced the results (OR 2.92, 95 % CI 1.00 - 8.53 for prospective studies; OR 18,57, 95 % CI 7.57 - 45.59 for retrospective studies; p = 0.01), whereas devices (dedicated or hybrid), geographic area and follow-up period did not.

CONCLUSION

Abnormal PET findings are associated with a substantially increased final diagnostic rate in FUO. Consequently, FDG PET could be considered for inclusion in the first-line diagnostic work-up of FUO. Further randomized prospective studies with standardized FDG PET procedures are warranted to confirm this first-line position.

Recurrent Fever in Children

Children presenting with recurrent fever may represent a diagnostic challenge. After excluding the most common etiologies, which include the consecutive occurrence of independent uncomplicated infections, a wide range of possible causes are considered. This article summarizes infectious and noninfectious causes of recurrent fever in pediatric patients. We highlight that, when investigating recurrent fever, it is important to consider age at onset, family history, duration of febrile episodes, length of interval between episodes, associated symptoms and response to treatment. Additionally, information regarding travel history and exposure to animals is helpful, especially with regard to infections. With the exclusion of repeated independent uncomplicated infections, many infective causes of recurrent fever are relatively rare in Western countries; therefore, clinicians should be attuned to suggestive case history data. It is important to rule out the possibility of an infectious process or a malignancy, in particular, if steroid therapy is being considered. After excluding an infectious or neoplastic etiology, immune-mediated and autoinflammatory diseases should be taken into consideration. Together with case history data, a careful physical exam during and between febrile episodes may give useful clues and guide laboratory investigations. However, despite a thorough evaluation, a recurrent fever may remain unexplained. A watchful follow-up is thus mandatory because new signs and symptoms may appear over time.

Whole-body MRI: non-oncological applications in paediatrics

Whole-body magnetic resonance imaging (WBMRI) is a fast and accurate method for detecting and monitoring of diseases throughout the entire body without exposure to ionizing radiation. Among emerging non-oncological potential applications of WBMRI, rheumatological diseases play an important role. Rheumatological WBMRI applications include the evaluation of chronic multifocal recurrent osteomyelitis, dermatomyositis, fever of unknown origin, arthritis, and connective tissue diseases. Aim of this review is to give an overview of the use of WBMRI in rheumatological field.