Diagnostic accuracy of a novel SARS CoV-2 rapid antigen test and usefulness of specimens collected from the anterior nasal cavity.

OBJECTIVES: We aimed to validate a newly developed antigen-detecting rapid diagnostic test (Ag-RDT) for SARS-CoV-2 using anterior nasal specimens. METHODS: Between February 12 and September 30, 2021, 16 patients (age range, <1 month-76 years) were enrolled, and samples were collected simultaneously from anterior nasal and nasopharyngeal sites continuously during hospitalization. The primary end points were the diagnostic accuracy of the Ag-RDT and utility of anterior nasal specimens. RESULTS: In total, 226 sets of paired samples were obtained. In 88.2% of specimens, the viral load was high at the nasopharyngeal site. The mean cycle threshold values for the anterior nasal and nasopharyngeal sites were 32.4 and 29.9, respectively. Using the real-time polymerase chain reaction results as a reference, the Ag-RDT showed a 100% sensitivity up to day 6 of the illness, using specimens with moderate or high viral load (cycle threshold <30) from either site. From day 7, the sensitivity was 70.4-90.6% and 83.9-84.6% for the anterior nasal and nasopharyngeal sites, respectively. The specificity remained at 100%. CONCLUSION: Our novel Ag-RDT meets the World Health Organization criteria and provides stable sensitivity and specificity and accurate results with anterior nasal specimens.

Acute Perimyocarditis in an Adolescent Japanese Male after a Booster Dose of the BNT162b2 COVID-19 Vaccine.

Perimyocarditis is a rare and serious cardiac complication following COVID-19 vaccination. Young males are most at risk after the second dose. With the introduction of the booster (third) dose, some reports have focused on the risk of perimyocarditis after a booster dose. However, no currently available report in Japan has comprehensively described this phenomenon. A healthy 14-year-old Japanese male, who had completed a two-dose primary series of the BNT162b2 (Pfizer-BioNTech) vaccine six months prior, developed fever and chest pain within 24 hours after a homologous booster dose. He was transferred to our institute because of worsening chest pain. A multiplex PCR test showed no evidence of active viral infections, including SARS-CoV-2. Electrocardiography revealed ST-segment elevation in almost all leads, suggesting pericarditis. Echocardiography showed normal systolic function. Laboratory data demonstrated C-reactive protein levels of 8.8 mg/dL and elevated cardiac damage markers (troponin T, 1.9 ng/mL; creatine phosphokinase, 1527 U/L; MB isoenzyme, 120 U/L), suggesting myocarditis. He was diagnosed with perimyocarditis associated with the booster dose, which was confirmed by cardiac magnetic resonance imaging four days after initial symptoms. Chest pain improved spontaneously along with a resolution of electrocardiographic findings and laboratory data within several days. He was discharged eight days after admission. Perimyocarditis is less frequent after a booster dose than after primary doses. In this case, the patient with booster-dose-associated perimyocarditis showed favorable clinical course without severe sequelae. The patient's clinical course was consistent with findings on previous large-scale reports on primary-dose-associated perimyocarditis and case series on booster-dose-associated perimyocarditis.

Case Report: Anterior Scleritis Presenting as a Primary Ocular Manifestation in Multisystem Inflammatory Syndrome in Children With COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) is a newly defined hyperinflammatory disease linked to antecedent coronavirus disease 2019. Patients with MIS-C present with various symptoms, and ocular findings such as mild bilateral conjunctivitis are relatively common. However, detailed descriptions of severe ocular reports associated with MIS-C are scarce in the current literature. Here we report a case of MIS-C in a Japanese boy, with severe eye manifestations in the form of anterior scleritis as the primary MIS-C symptom. Detailed ocular examinations by ophthalmologists may be key for clarifying the pathophysiology of MIS-C.

Diagnosis and treatment of influenza based on health insurance claims between the 2010-2011 and 2019-2020 influenza seasons in Japan.

Medical practices for influenza virus infection vary among countries. In Japan, treatment with anti-influenza drugs is recommended for patients diagnosed with influenza. This health claims database study provides quantitative information aimed at describing the actual medical practices, including diagnostic testing and medication use, for managing influenza in Japan. Most patients diagnosed with influenza underwent diagnostic tests and were prescribed anti-influenza drugs. Meanwhile, the majority of patients prescribed anti-influenza drugs had undergone diagnostic testing. However, an increase in the percentage of anti-influenza prescriptions without diagnostic testing was observed during the 2019-2020 influenza season, which may be associated with the COVID-19 pandemic.