Pilot study of aerosols visualized and evaluated in a radiotherapy room.

Health care institutions provide prevention strategies for coronavirus disease 2019 and non-infectious disease care. We investigated the characteristics of patient contamination in a radiotherapy room by examining the trajectory and number of airborne particles in the air when talking and coughing occurred and clarified the actual state of contamination in this closed space. Aerosols were visualized and evaluated in the vertical height and head-to-tail width directions when the participant was lying on the radiotherapy tabletop. Aerosol reach was significantly greater for loud voice and coughing both at vertical height and the head-to-tail width direction. The size and number of particles around the radiotherapy tabletop were also visualized and evaluated in the radiotherapy room. The radiotherapy staff who were in the presence of the participant sometimes had many particles adhering to their facial area; particle adhesion to the staff was dominated by small size particles. Particle adherence to the irradiation device surface near the ceiling had particles larger than 1 mm. Tabletop particles tended to have a wider size range, including bigger sizes and a larger count compared to the surrounding floor. The 0.7-m radius distance from the participant's mouth tended to be highly contaminated, and the smaller the particle size, the farther it reached. The capacity to estimate areas prone to contamination can be used to predict infection of other patients and medical staff in a radiotherapy room.

The Assessment of the Efficacy and Safety of Favipiravir for Patients with SARS-CoV-2 Infection: A Multicenter Non-randomized, Uncontrolled Single-arm Prospective Study.

Objective Among treatment options for coronavirus infectious disease 2019 (COVID-19), well-studied oral medications are limited. We conducted a multicenter non-randomized, uncontrolled single-arm prospective study to assess the efficacy and safety of favipiravir for patients with COVID-19. Methods One hundred participants were sequentially recruited to 2 cohorts: cohort 1 (Day 1: 1,600 mg/day, Day 2 to 14: 600 mg/day, n=50) and cohort 2 (Day 1: 1,800 mg/day, Day 2 to 14: 800 mg/day, n=50). The efficacy endpoint was the negative conversion rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the odds ratio (OR) of cohort 2 to cohort 1 for negative conversion on Day 10 was calculated. Characteristics of all participants and profiles of adverse events (AEs) were collected and analyzed. Results The mean age of participants was 62.8±17.6 years old. Thirty-four patients (34.0%) experienced worsening pneumonia, 7 (7.0%) were intubated, and 4 (4.0%) died during the observation period. Cohort 2 showed a higher negative conversion rate than cohort 1 [adjusted OR 3.32 (95% confidence interval (CI), 1.17 to 9.38), p=0.024], and this association was maintained after adjusting for the age, sex, body mass index, and baseline C-reactive protein level. Regarding adverse events, hyperuricemia was most frequently observed followed by an elevation of the liver enzyme levels (all-grade: 49.0%, Grade ≥3: 12.0%), and cohort 2 tended to have a higher incidence than cohort 1. However, no remarkable association of adverse events was observed between patients <65 and ≥65 years old. Conclusion The antiviral efficacy of favipiravir was difficult to interpret due to the limitation of the study design. However, no remarkable issues with safety or tolerability associated with favipiravir were observed, even in elderly patients with COVID-19.

Serological Screening of Immunoglobulin G against SARS-CoV-2 Nucleocapsid and Spike Protein before and after Two Vaccine Doses among Healthcare Workers in Japan.

This study sought to evaluate the effects of two vaccine doses and the extent of SARS-CoV-2 infection among healthcare workers. We measured immunoglobulin G antibody titers against SARS-CoV-2 nucleocapsid and spike protein among healthcare workers at Gunma University Hospital. In March 2021, prior to BNT-162b2 vaccination, two of 771 participants were seropositive for nucleocapsid and spike protein, whereas 768 were seronegative. The remaining one participant was seropositive for nucleocapsid protein but seronegative for spike protein. A total of 769 participants were seropositive for spike protein after two vaccination doses. The two seropositive participants prior to vaccination showed the highest antibody titers after the second vaccination. They were probably infected with SARS-CoV-2 without clinical symptoms before March 2021. Four weeks after the second vaccination, a younger age was associated with higher antibody titers against SARS-CoV-2 spike protein. Thirty-two weeks after the second vaccination, blood samples were collected from 342 of 769 participants. Antibody titers at 32 weeks after the second vaccination significantly decreased compared with those at 4 weeks after the second vaccination among all age groups. The rate of decrease in antibody titers between 4 and 32 weeks after the second vaccination was greater in the female participants. No sex differences were observed in the antibody titers within each age group. BNT-162b2 vaccination thus induced seroconversion in an age-dependent manner. Serological screening could further establish the likelihood of subclinical SARS-CoV-2 infection.

Erythema nodosum-like eruption in coronavirus disease 2019: A case report and literature review of Asian countries.

In the worldwide coronavirus disease 2019 (COVID-19) outbreak, skin manifestations were seen in COVID-19 patients. We report a case in which a COVID-19 patient developed cutaneous lesions that were diagnosed as erythema nodosum-like lesions, which were associated with COVID-19. Nasopharyngeal swab polymerase chain reaction (PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Histopathologically, extensive inflammation was seen from the epidermis to the fat tissue. An organized thrombus and disrupted inner elastic lamina were seen in an intradermal vessel. These findings suggest septal panniculitis with cutaneous polyarteritis nodosa. The results of PCR using the specimen of skin lesion was negative. The patient took non-steroidal anti-inflammatory drugs and the skin lesion improved in 3 weeks. To characterize the skin eruption, we reviewed previous reports on COVID-19 (confirmed by the detection of SARS-CoV-2 infection) from Asian countries. The type of eruption and timing of its appearance in this case seemed rare. Differences in skin manifestations between Western and Asian countries were noted.

Improvement of Severe COVID-19 in an Elderly Man by Sequential Use of Antiviral Drugs.

Although a variety of existing drugs are being tested for patients with coronavirus disease 2019 (COVID-19), no efficacious treatment has been found so far, particularly for severe cases. We report successful recovery in an elderly patient with severe pneumonia requiring mechanical ventilation and extracorporeal membrane oxygenation (ECMO). Despite administration of multiple antiviral drugs, including lopinavir/ritonavir, chloroquine, and favipiravir, the patient's condition did not improve. However, after administration of another antiviral drug, remdesivir, we were able to terminate invasive interventions, including ECMO, and subsequently obtained negative polymerase chain reaction results. Although further validation is needed, remdesivir might be effective in treating COVID-19.

[COVID-19 Pneumonia in a Patient in Her Seventies that Improved without Antiviral Drug Treatment：A Case Study]

As no specific therapeutic agents have been established yet for coronavirus disease 2019 (COVID-19), the illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), symptomatic therapy is the mainstay of treatment. Although the “Concept of antiviral treatment for COVID-19, First edition” published by the Japanese Association for Infectious Diseases recommends the use of antiviral medication for infected individuals over the age of 50 years, we have documented the case of a 73-year-old woman with COVID-19 pneumonia who improved without antiviral medication. The patient became infected with SARS-CoV-2 on the cruise ship, Diamond Princess, and first tested positive for SARS-CoV-2, by the RT-PCR test, on February 15, 2020. She was admitted to another hospital with fever and pneumonia on February 16, and on February, the pneumonia worsened in severity, she was transferred to our hospital. However, her condition improved spontaneously within a few days, without any antiviral medication. This report is very valuable for documenting the natural history of COVID-19 pneumonia and can be considered as a reference case for formulating strategies for antiviral drug administration for COVID-19 patients in the future.