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.

A New Influenza-Tracking Smartphone App (Flu-Report) Based on a Self-Administered Questionnaire: Cross-Sectional Study.

BACKGROUND: Influenza infections can spread rapidly, and influenza outbreaks are a major public health concern worldwide. Early detection of signs of an influenza pandemic is important to prevent global outbreaks. Development of information and communications technologies for influenza surveillance, including participatory surveillance systems involving lay users, has recently increased. Many of these systems can estimate influenza activity faster than the conventional influenza surveillance systems. Unfortunately, few of these influenza-tracking systems are available in Japan. OBJECTIVE: This study aimed to evaluate the flu-tracking ability of Flu-Report, a new influenza-tracking mobile phone app that uses a self-administered questionnaire for the early detection of influenza activity. METHODS: Flu-Report was used to collect influenza-related information (ie, dates on which influenza infections were diagnosed) from November 2016 to March 2017. Participants were adult volunteers from throughout Japan, who also provided information about their cohabiting family members. The utility of Flu-Report was evaluated by comparison with the conventional influenza surveillance information and basic information from an existing large-scale influenza-tracking system (an automatic surveillance system based on electronic records of prescription drug purchases). RESULTS: Information was obtained through Flu-Report for approximately 10,094 volunteers. In total, 2134 participants were aged <20 years, 6958 were aged 20-59 years, and 1002 were aged ≥60 years. Between November 2016 and March 2017, 347 participants reported they had influenza or an influenza-like illness in the 2016 season. Flu-Report-derived influenza infection time series data displayed a good correlation with basic information obtained from the existing influenza surveillance system (rho, ρ=.65, P=.001). However, the influenza morbidity ratio for our participants was approximately 25% of the mean influenza morbidity ratio for the Japanese population. The Flu-Report influenza morbidity ratio was 5.06% (108/2134) among those aged <20 years, 3.16% (220/6958) among those aged 20-59 years, and 0.59% (6/1002) among those aged ≥60 years. In contrast, influenza morbidity ratios for Japanese individuals aged <20 years, 20-59 years, and ≥60 years were recently estimated at 31.97% to 37.90%, 8.16% to 9.07%, and 2.71% to 4.39%, respectively. CONCLUSIONS: Flu-Report supports easy access to near real-time information about influenza activity via the accumulation of self-administered questionnaires. However, Flu-Report users may be influenced by selection bias, which is a common issue associated with surveillance using information and communications technologies. Despite this, Flu-Report has the potential to provide basic data that could help detect influenza outbreaks.

Performance Evaluation of a Novel Fully Automated Real-Time Reverse Transcriptase-Polymerase Chain Reaction Kit for the Detection of Norovirus.

OBJECTIVE: Rapid and accurate detection of norovirus is essential for the prevention and control of the out- breaks. The aim of this study is to compare the fully automated real-time reverse transcriptase-polymerase chain reaction method (EV-kit) with the conventional immunochromatography method (IC) for diagnosis of norovirus, using one-tube reverse transcriptase-polymerase chain reaction (RT-PCR) analysis as the gold standard. METHODS: Between November 2013 and March 2014, clinical data and fecal specimens (53 bulk stools, 41 rectal swabs) were collected from 94 patients who visited the Department of General Medicine, Juntendo University Hospital for acute diarrhea. The sensitivity and specificity of each study test was determined by comparing with RT-PCR, and reproducibility was analyzed by determining Cohen's kappa coefficients. RESULTS: Of 94 specimens, 35(37%, 26 bulk stools, 9 rectal swabs) were positive for norovirus antigen by RT-PCR. The sensitivity, specificity, and Cohen's kappa coefficient of the EV-kit were 91% (32/35), 88% (52/59), and 0.778, respectively; those of the IC were 54% (19/35), 90% (53/59), and 0.468, respectively. For rectal swab testing, the sensitivity was 89% (8/9) for the EV-kit and 33% (3/9) for IC, ana that for bulk stool testing was 92% (24/26) for the EV-kit and 62% (16/26) for IC. CONCLUSIONS: Use of the EV-kit was significantly more sensitive than was IC testing, taking RT-PCR analy- sis as the gold standard. Rectal swab or bulk stool specimens may be adequate for the detection of norovirus antigen when the EV-kit is used. [Original].

Relationships between Causes of Fever of Unknown Origin and Inflammatory Markers: A Multicenter Collaborative Retrospective Study.

OBJECTIVE: Although inflammatory markers, such as the white blood cell (WBC) count, erythrocyte sedimentation rate (ESR) and levels of C-reactive protein (CRP) and procalcitonin, are widely used to differentiate causes of fever of unknown origin (FUO), little is known about the usefulness of this approach. We evaluated relationships between the causes of classical FUO and the levels of inflammatory markers. METHODS: A nationwide retrospective study including 17 hospitals affiliated with the Japanese Society of Hospital General Medicine was conducted. PATIENTS: This study included 121 patients ≥18 years old diagnosed with "classical FUO" (axillary temperature ≥38.0°C at least twice over a ≥3-week period without elucidation of the cause on three outpatient visits or during three days of hospitalization) between January and December 2011. RESULTS: The causative disease was infectious diseases in 28 patients (23.1%), non-infectious inflammatory disease (NIID) in 37 patients (30.6%), malignancy in 13 patients (10.7%), other in 15 patients (12.4%) and unknown in 28 patients (23.1%). The rate of malignancy was significantly higher for a WBC count of <4,000/µL than for a WBC count of 4,000-8,000/µL (p=0.015). Among the patients with a higher WBC count, the rate of FUO due to NIID tended to be higher and the number of unknown cases tended to be lower. All FUO patients with malignancy showed an ESR of >40 mm/h. A normal ESR appeared to constitute powerful evidence for excluding a diagnosis of malignancy. In contrast, the concentrations of both serum CRP and procalcitonin appeared to be unrelated to the causative disease. CONCLUSION: The present study identified inflammatory markers that should be considered in the differential diagnosis of classical FUO, providing useful information for future diagnosis.

Relationship between public subsidies and vaccination rates with the 23-valent pneumococcal vaccine in elderly persons, including the influence of the free vaccination campaign after the Great East Japan Earthquake.

Low vaccination rates with pneumococcal vaccine in elderly persons in Japan are thought to be related to low levels of public subsidy. To identify strategies to increase future pneumococcal vaccination rates, we examined the relationship between public subsidies and vaccination rates. We also investigated the influence of free vaccinations after the 2011 Great East Japan Earthquake on vaccination rates in the three Tohoku prefectures of Japan. We surveyed a total of 1742 municipalities in Japan about whether public subsidies were available and their monetary amount. Vaccination rates with the 23-valent pneumococcal vaccine were calculated as the "cumulative amount shipped to each municipality divided by the population aged ≥65 years." There were no subsidies in 773 municipalities (44.4%). In those municipalities with public subsidies, larger subsidies were significantly associated with elevated vaccination rates (p < 0.0001). Compared to a mean vaccination rate of 25.4% throughout Japan, the vaccination rate was 52.1% in municipalities where the full cost was subsidized. The three prefectures (Iwate, Miyagi, and Fukushima) most affected by the Great East Japan Earthquake ranked as the top three prefectures for vaccination rates in Japan, presumably as a result of the free vaccination campaign for disaster victims. Our findings show that public subsidies play an important role in increasing the vaccination rate. The free vaccinations given to disaster victims after the Great East Japan Earthquake helped to achieve extremely high vaccination rates in the three Tohoku prefectures. We suggest that such public subsidies should be promoted throughout Japan.

Factors influencing the diagnostic accuracy of the rapid influenza antigen detection test (RIADT): a cross-sectional study.

OBJECTIVE: To evaluate the diagnostic accuracy of the rapid influenza antigen detection test (RIADT) and determine which symptoms are relevant to results. DESIGN: Single-centre, cross-sectional study. SETTING: Primary care centre, Tokyo, Japan. PARTICIPANTS: 82 consecutive outpatients presenting with upper respiratory symptoms and fever ≥37°C at any time from symptom onset, between December 2010 and April 2011. MAIN OUTCOME MEASURES: Results of history and physical examination including age, sex, temperature, time of test from symptom onset, vaccination record and current symptoms (sore throat, arthralgia and/or myalgia, headache, chills, cough and/or throat phlegm, nasal discharge) were recorded. The RIADT and a fully automated respiratory virus nucleic acid test (Verigene Respiratory Virus Plus; VRV), the latter being the gold standard, were performed. Patients were divided into four groups: false negative (FN), RIADT- and VRV+; true positive (TP), RIADT+ and VRV+; true negative (TN), RIADT- and VRV-; and false positive, RIADT+ and VRV-. Groups were compared regarding age, sex, temperature, time of test from symptom onset, vaccination record and symptoms. RESULTS: RIADT sensitivity, specificity, positive predictive value and negative predictive value were 72.9% (95% CI 61.5% to 84.2%), 91.3% (79.7% to 102.8%), 95.6% (89.5% to 101.6%) and 56.8% (40.8% to 72.7%), respectively. Time from symptom onset to test was shorter for the FN group than the TP group (p=0.009). No significant differences were detected for the other factors assessed. Results revealed higher temperatures for FN than TN patients (p=0.043), and more FN than TN patients had chills (p=0.058). CONCLUSIONS: The RIADT sensitivity was low, due to early administration of the test. In the epidemic season, the RIADT should not be used for suspected influenza until 12 h after symptom onset. A positive RIADT firmly supports the influenza diagnosis; a negative result does not confirm its absence. High fever and chills might indicate influenza, but additional tests are sometimes necessary.

Near point-of-care administration by the attending physician of the rapid influenza antigen detection immunochromatography test and the fully automated respiratory virus nucleic acid test: contribution to patient management.

Rapid influenza antigen detection tests (RIADTs) using immunochromatography are the most readily available tools for the diagnosis and management of influenza. This study was designed to assess whether near point-of-care administration by primary care physicians of the RIADT and a fully automated respiratory virus nucleic acid test (Verigene Respiratory Virus Plus®; RV+) would contribute to improved patient management. When viral culture and RT-PCR/bi-directional sequencing were used as the gold standard, sensitivities and specificities for RIADT and RV+ were 58.3% and 90.9%, and 97.2% and 100%, respectively. Within 12 hours from onset of fever, sensitivities were 44.4% and 94.4%, respectively, for RIADT and RV+. In clinical situations where a higher-sensitivity test is needed, such as during pre-admission evaluations, for testing of hospital employees during the prodromal phase of infection, during the therapeutic decision-making process, and during outbreaks, we suggest that patients testing negative by the RIADT can be reassessed with the RV+ test to achieve maximal diagnostic accuracy.