To the best of our knowledge, there are few reports on acquirement of medical skills of infection control using a scenario simulation program. We report the development of a education program using scenario-based simulation named Infection Control Training Course （ICTC）. The three main aims of this course are basic comprehension of standard precautions and contact precautions, acquirement of skills for wearing and removal of personal protective equipment （PPE）, and precise selection of PPE for various situations.
・For the materials and methods, 225 medical staff members taking part in the ICTC at TMU participated in the study. Investigations using a questionnaire about standard precaution, contact precaution and PPE selection were carried out for the pre-course and post-course of the day. In addition, the satisfaction level was evaluated using free score text.
・The return rates of the completed questionnaire for investigating these areas were 88.4% （pre-course） and 95.1% （post-course）. Among all the items investigated, improvements were verified statistically （Wilcoxon signed-rank test）. The satisfaction level was 94.7 ± 9.4 points.
・In conclusion, the ICTC was considered to be effective for acquiring medical skills of infection control, particularly basic comprehension regarding standard precaution, contact precaution and precise PPE selection using a scenario simulation program.

While the COVID-19 epidemic required the ability to confront infection prevention practices, its education for medical students remained inadequate. Herein, we have developed an infection practice simulation course for medical students, based on the simulation education method. The course is a compulsory part of the medical school curriculum. Features of the course include adoption of small group education by tutorial method, medical interviews of simulated patients, scenario simulation, supervised discussions and presentations between medical students, efficient point learning using worksheets, achievement assessment using OSCE, course direction by an infectious disease specialist, and university-wide educational participation from all clinical department doctors. The course was designed so that students could be guided to think carefully and be aware of their interactions. In addition, it was expected that participation in the course would have a lifelong educational effect on the medical doctors.

Objective: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported in China and subsequently spread worldwide. In Japan, many clusters occurred during the first wave in 2020. We describe the investigation of an early outbreak in a Tokyo hospital. Methods: A COVID-19 outbreak occurred in two wards of the hospital from April to early May 2020. Confirmed cases were individuals with laboratory-confirmed SARS-CoV-2 infection linked to Wards A and B, and contacts were patients or workers in Wards A or B 2 weeks before the index cases developed symptoms. All contacts were tested, and cases were interviewed to determine the likely route of infection and inform the development of countermeasures to curb transmission. Results: There were 518 contacts, comprising 472 health-care workers (HCWs) and 46 patients, of whom 517 were tested. SARS-CoV-2 infection was confirmed in 42 individuals (30 HCWs and 12 patients). The proportions of SARS-CoV-2 infections in HCWs were highest among surgeons, nurses, nursing assistants and medical assistants. Several HCWs in these groups reported being in close proximity to one another while not wearing medical masks. Among HCWs, infection was thought to be associated with the use of a small break room and conference room. Discussion Nosocomial SARS-CoV-2 infections occurred in two wards of a Tokyo hospital, affecting HCWs and patients. Not wearing masks was considered a key risk factor for infection during this outbreak; masks are now a mandated countermeasure to prevent the spread of SARS-CoV-2 infection in hospital settings.