High Fever, Wide Distribution of Viral Pneumonia, and Pleural Effusion are More Critical Findings at the First Visit in Predicting the Prognosis of COVID-19: A Single Center, retrospective, Propensity Score-Matched Case-Control Study.

Introduction: Currently, infection control measures for SARS-COV2 are being relaxed, and it is important in daily clinical practice to decide which findings to focus on when managing patients with similar background factors. Methods: We retrospectively evaluated 66 patients who underwent blood tests (complete blood count, blood chemistry tests, and coagulation tests) and thin slice CT between January 1 and May 31, 2020, and performed a propensity score-matched case-control study. Cases and controls were a severe respiratory failure group (non-rebreather mask, nasal high-flow, and positive-pressure ventilation) and a non-severe respiratory failure group, matched at a ratio of 1:3 by propensity scores constructed by age, sex, and medical history. We compared groups for maximum body temperature up to diagnosis, blood test findings, and CT findings in the matched cohort. Two-tailed P-values <0.05 were considered statistically significant. Results: Nine cases and 27 controls were included in the matched cohort. Significant differences were seen in maximum body temperature up to diagnosis (p=0.0043), the number of shaded lobes (p=0.0434), amount of ground-glass opacity (GGO) in the total lung field (p=0.0071), amounts of GGO (p=0.0001), and consolidation (p=0.0036) in the upper lung field, and pleural effusion (p=0.0117). Conclusion: High fever, the wide distribution of viral pneumonia, and pleural effusion may be prognostic indicators that can be easily measured at diagnosis in COVID-19 patients with similar backgrounds.

Detection of silent infection of severe acute respiratory syndrome coronavirus 2 by serological tests.

BACKGROUND: To control COVID-19 pandemic is of critical importance to the global public health. To capture the prevalence in an accurate and timely manner and to understand the mode of nosocomial infection are essential for its preventive measure. METHODS: We recruited 685 healthcare workers (HCW's) at Tokyo Shinagawa Hospital prior to the vaccination with COVID-19 vaccine. Sera of the subjects were tested by assays for the titer of IgG against S protein's receptor binding domain (IgG (RBD)) or IgG against nucleocapsid protein (IgG (N)) of SARS-CoV-2. Together with PCR data, the positive rates by these methods were evaluated. RESULTS: Overall positive rates among HCW's by PCR, IgG (RBD), IgG (N) with a cut-off of 1.4 S/C (IgG (N)1.4), and IgG (N) with a cut-off of 0.2 S/C (IgG (N)0.2) were 3.5%, 9.5%, 6.1%, and 27.7%, respectively. Positive rates of HCW's working in COVID-19 ward were significantly higher than those of HCW's working in non-COVID-19 ward by all the four methods. Concordances of IgG (RBD), IgG (N)1.4, and IgG (N)0.2 against PCR were 97.1%, 71.4%, and 88.6%, respectively. By subtracting the positive rates of PCR from that of IgG (RBD), the rate of overall silent infection and that of HCW's in COVID-19 ward were estimated to be 6.0% and 21.1%, respectively. CONCLUSIONS: For the prevention of nosocomial infection of SARS-CoV-2, identification of silent infection is essential. For the detection of ongoing infection, periodical screening with IgG (RBD) in addition to PCR would be an effective measure. For the surveillance of morbidity in the population, on the other hand, IgG (N)0.2 could be the most reliable indicator among the three serological tests.

Longitudinal Analysis of Neutralizing Potency against SARS-CoV-2 in the Recovered Patients after Treatment with or without Favipiravir.

The effect of treatment with favipiravir, an antiviral purine nucleoside analog, for coronavirus disease 2019 (COVID-19) on the production and duration of neutralizing antibodies for SARS-CoV-2 was explored. There were 17 age-, gender-, and body mass index-matched pairs of favipiravir treated versus control selected from a total of 99 patients recovered from moderate COVID-19. These subjects participated in the longitudinal (>6 months) analysis of (i) SARS-CoV-2 spike protein's receptor-binding domain IgG, (ii) virus neutralization assay using authentic virus, and (iii) neutralization potency against original (WT) SARS-CoV-2 and cross-neutralization against B.1.351 (beta) variant carrying triple mutations of K417N, E484K, and N501Y. The results demonstrate that the use of favipiravir: (1) significantly accelerated the elimination of SARS-CoV-2 in the case vs. control groups (p = 0.027), (2) preserved the generation and persistence of neutralizing antibodies in the host, and (3) did not interfere the maturation of neutralizing potency of anti-SARS-CoV-2 and neutralizing breadth against SARS-CoV-2 variants. In conclusion, treatment of COVID-19 with favipiravir accelerates viral clearance and does not interfere the generation or maturation of neutralizing potency against both WT SARS-CoV-2 and its variants.

Longitudinal Analysis of Neutralizing Potency against SARS-CoV-2 in the Recovered Patients after Treatment with or without Favipiravir

The effect of treatment with favipiravir, an antiviral purine nucleoside analog, for coronavirus disease 2019 (COVID-19) on the production and duration of neutralizing antibodies for SARS-CoV-2 was explored. There were 17 age-, gender-, and body mass index-matched pairs of favipiravir treated versus control selected from a total of 99 patients recovered from moderate COVID-19. These subjects participated in the longitudinal (>6 months) analysis of (i) SARS-CoV-2 spike protein's receptor-binding domain IgG, (ii) virus neutralization assay using authentic virus, and (iii) neutralization potency against original (WT) SARS-CoV-2 and cross-neutralization against B.1.351 (beta) variant carrying triple mutations of K417N, E484K, and N501Y. The results demonstrate that the use of favipiravir: (1) significantly accelerated the elimination of SARS-CoV-2 in the case vs. control groups (p = 0.027), (2) preserved the generation and persistence of neutralizing antibodies in the host, and (3) did not interfere the maturation of neutralizing potency of anti-SARS-CoV-2 and neutralizing breadth against SARS-CoV-2 variants. In conclusion, treatment of COVID-19 with favipiravir accelerates viral clearance and does not interfere the generation or maturation of neutralizing potency against both WT SARS-CoV-2 and its variants.

Possibility of underestimation of COVID-19 prevalence by PCR and serological tests.

BACKGROUND: Exact comprehension of the prevalence of SARS-CoV-2 infection is essential for the preventive measures. In the clinical settings, however, patients infected with SARS-CoV-2 may not be fully detected by PCR. In the long-term prevalence study, cut-off of IgG assay may not be appropriate due to waning IgG titer. METHODS: 24 PCR-negative subjects suspected of COVID-19 were categorized into cohorts termed "presumed COVID-19 positive" and "presumed COVID-19 negative" by chest CT images. IgG against nucleocapsid protein of SARS-CoV-2 (IgG (N)) and IgG against receptor biding domain of SARS-CoV-2 (IgG (RBD)) were measured in sera of the subjects and the concordance with the cohort categorization was assessed by receiver operating characteristics (ROC) analyses. RESULTS: Area under the curves (AUC's) by the ROC analyses with the 24 subjects were 0.982 with IgG (N) and 0.854 with IgG (RBD). Even when we excluded the subjects whose initial PCR was performed after five days from symptom onset, the AUC's were 0.967 with IgG (N) and 0.800 with IgG (RBD). The ROC analysis indicated 0.2 S/C as the optimum cut-off forIgG (N). CONCLUSION: Both IgG (N) and IgG (RBD) titers were significantly elevated in subjects whose PCR never showed positive but suggestive of SARS-CoV-2 infection, which indicated the necessity of serological tests in complementing the shortcomings of PCR. For a long-term prevalence study, a cut-off lower than the one used in the ongoing infection phase (e.g. 0.2 S/C vs. 1.4 S/C) was indicated to be more appropriate for IgG (N).

Efficacy of Chest Radiography as a Primary Care Triage Tool in Severe Coronavirus Disease.

Objective Severe acute respiratory syndrome coronavirus 2 has spread globally, and it is important to utilize medical resources properly, especially in critically ill patients. We investigated the validity of chest radiography as a tool for predicting aggravation in coronavirus disease (COVID-19) cases. Methods A total of 104 laboratory-confirmed COVID-19 cases were referred from the cruise ship "Diamond Princess" to the Self-Defense Forces Central Hospital in Japan from February 11 to 25, 2020. Fifty-nine symptomatic patients were selected. Chest radiography was performed upon hospitalization; subsequently, patients were categorized into the positive radiograph (Group A) and negative radiograph (Group B) groups. Radiographic findings were analyzed with a six-point semiquantitative score. Group A was further classified into two additional subgroups: patients who required oxygen therapy during their clinical courses (Group C) and patients who did not (Group D). Clinical records, laboratory data, and radiological findings were collected for an analysis. Results Among 59 patients, 34 were men with a median age of 60 years old. Groups A, B, C, and D consisted of 33, 26, 12, and 21 patients, respectively. The number of patients requiring oxygen administration was significantly larger in Group A than in Group B. The consolidation score on chest radiographs was significantly higher in Group C than in Group D. When chest radiographs showed consolidation in more than two lung fields, the positive likelihood ratio of deterioration was 10.6. Conclusions Chest radiography is a simple and easy-to-use clinic-level triage tool for predicting the severity of COVID-19 and may contribute to the allocation of medical resources.

Efficacy and Safety of Favipiravir in Moderate COVID-19 Pneumonia Patients without Oxygen Therapy: A Randomized, Phase III Clinical Trial.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is an enveloped, single-stranded RNA virus. Favipiravir is an orally administrable antiviral drug whose mechanism of action is to selectively inhibit RNA-dependent RNA polymerase. A preliminary trial in COVID-19 patients reported significant improvements across a multitude of clinical parameters, but these findings have not been confirmed in an adequate well-controlled trial. We conducted a randomized, single-blind, placebo-controlled Phase III trial assessing the efficacy and safety of favipiravir in patients with moderate pneumonia not requiring oxygen therapy. METHODS: COVID-19 patients with moderate pneumonia (SpO2 ≥ 94%) within 10 days of onset of fever (temperature ≥ 37.5 °C) were assigned to receive either placebo or favipiravir (1800 mg twice a day on Day 1, followed by 800 mg twice a day for up to 13 days) in a ratio of 1:2. An adaptive design was used to re-estimate the sample size. The primary endpoint was a composite outcome defined as the time to improvement in temperature, oxygen saturation levels (SpO2), and findings on chest imaging, and recovery to SARS-CoV-2-negative. This endpoint was re-examined by the Central Committee under blinded conditions. RESULTS: A total of 156 patients were randomized. The median time of the primary endpoint was 11.9 days in the favipiravir group and 14.7 days in the placebo group, with a significant difference (p = 0.0136). Favipiravir-treated patients with known risk factors such as obesity or coexisting conditions provided better effects. Furthermore, patients with early-onset in the favipiravir group showed higher odds ratio. No deaths were documented. Although adverse events in the favipiravir group were predominantly transient, the incidence was significantly higher. CONCLUSIONS: The results suggested favipiravir may be one of options for moderate COVID-19 pneumonia treatment. However, the risk of adverse events, including hyperuricemia, should be carefully considered. TRIAL REGISTRATION: Clinicaltrials.jp number: JapicCTI-205238.

COVID-19 pneumonia and an indelible ground-glass nodule.

When a chest computed tomography (CT) scan is performed in the diagnosis and treatment of coronavirus disease 2019 (COVID-19) pneumonia, the possibility of lung neoplasm should be kept in mind if the ground-glass nodule (GGN) shows features that are non-specific for viral infection, such as solitary nature, relative roundness, well-defined borders, and distance from the pleura.

Two Cases of Severe COVID-19 Pneumonia Effectively Treated with Extracorporeal Membrane Oxygenation in Addition to Favipiravir and Corticosteroid.

Case 1: A 65-year-old man with novel coronavirus infection (COVID-19) complicated with acute respiratory failure. On admission, the patient was started on favipiravir and corticosteroid. However, due to a lack of significant improvement, he was introduced to mechanical ventilation and extracorporeal membrane oxygenation (ECMO). Although iliopsoas hematoma occurred as a complication, the patient recovered. Case 2: A 49-year-old man with COVID-19 had been started on favipiravir and corticosteroid. Due to progressive respiratory failure, the patient underwent mechanical ventilation and ECMO. The patient recovered without complications. We successfully treated these severe cases with a multimodal combination of pharmacological and non-pharmacological supportive therapy.

Clinical Features of 154 COVID-19 Patients and the Parameters for the Effective Detection of Pneumonia at the Time of the Initial Diagnosis in Japan.

Objective We aimed to clarify clinical and laboratory characteristics of coronavirus disease 2019 (COVID-19) patients, and further explore the features to detect COVID-19 pneumonia at the first visit to community-based hospitals. Methods Diagnoses of COVID-19 were based on positive results from real-time reverse-transcription polymerase chain reaction testing of nasopharyngeal-swab specimens. We retrospectively reviewed the medical records of patients showing positive results. The clinical characteristics and results of blood tests were compared between the patients with and without pneumonia. The risk factors associated with pneumonia were then evaluated by a multivariable analysis. Results The study cohort comprised 154 patients, including 117 patients (76.0%) with pneumonia at first visit. Significant differences were seen in age, the frequency of fever, tachycardia, desaturation (peripheral oxygen saturation ≤95%), any comorbidity, neutrocyte count and fraction, lymphocyte count and fraction, platelet count, lactate dehydrogenase (LDH), C-reactive protein (CRP), and fibrinogen between the patients with and without pneumonia. Using a multivariable analysis, CRP ≥0.3 mg/dL and fibrinogen >400 mg/dL were found to be associated with the presence of pneumonia. Conclusion Community-based settings for screening COVID-19 patients should perform chest X-ray and blood tests for white blood cell fractions, fibrinogen, LDH, and CRP. Of these, elevations in the CRP and fibrinogen levels could be critically associated with the presence of COVID-19 pneumonia.

A case of COVID-19 pneumonia successfully treated with favipiravir (Avigan) in which serum SARS-CoV-2 RNA detected by LAMP method was clinically useful.

A 49-year-old Japanese male was managed by mechanical ventilation due to coronavirus disease 2019 (COVID-19) pneumonia. Favipiravir as an antiviral therapy, and anti-inflammatory treatment were administered. SARS-CoV-2 RNA was detected in serum by the loop-mediated isothermal amplification (LAMP) method on Day 9; favipiravir treatment was continued. On Day 13, negative serum RNA was confirmed, followed by mechanical ventilation was removed. On Day 23, LAMP negative was confirmed in nasopharynx, after that the patient discharged on Day 27. We could treat successfully for severe COVID-19 pneumonia based on the LAMP method. We consider this method will be useful in COVID-19 treatment.

Comparison of COVID-19 disease between young and elderly patients: Hidden viral shedding of COVID-19.

OBJECTIVES: The symptoms of Coronavirus disease 2019 (COVID-19) vary among patients. The aim of this study was to investigate the clinical manifestation and disease duration in young versus elderly patients. METHODS: We retrospectively analyzed 187 patients (87 elderly and 100 young patients) with confirmed COVID-19. The clinical characteristics and chest computed tomography (CT) extent as defined by a score were compared between the two groups. RESULTS: The numbers of asymptomatic cases and severe cases were significantly higher in the elderly group (elderly group vs. young group; asymptomatic cases, 31 [35.6%] vs. 10 [10%], p < 0.0001; severe cases, 25 [28.7%] vs. 8 [8.0%], p = 0.0002). The proportion of asymptomatic patients and severe patients increased across the 10-year age groups. There was no significant difference in the total CT score and number of abnormal cases. A significant positive correlation between the disease duration and patient age was observed in asymptomatic patients (ρ = 0.4570, 95% CI 0.1198-0.6491, p = 0.0034). CONCLUSIONS: Although the extent of lung involvement did not have a significant difference between the young and elderly patients, elderly patients were more likely to have severe clinical manifestations. Elderly patients were also more likely to be asymptomatic and a source of COVID-19 viral shedding.

Serial serum SARS-CoV-2 RNA results in two COVID-19 cases with severe respiratory failure.

Coronavirus disease 2019 (COVID-19) is spreading worldwide and poses an imminent threat to public health. We encountered 2 cases of COVID-19 with progression resulting in severe respiratory failure and improvement without any specific treatment. To examine the course of infection, we performed reverse-transcription (RT) polymerase chain reaction assay with serum specimens, and serum SARS-CoV-2 RNA was detected in both cases when body temperature increased and respiratory status deteriorated. We, then examined, retrospectively and prospectively, the clinical course during hospitalization by performing serial examinations of serum SARS-CoV-2 RNA status. The findings from our cases suggest that not only is detection of viremia useful as a predictive marker of severity, but also serial serum SARS-CoV-2 RNA results can be helpful for predicting the clinical course.