Most mediastinal abscesses result from infections after thoracotomy, esophageal perforation or pene- trating chest trauma. This disease is rarely caused by closed blunt chest trauma. All previously reported such cases after closed blunt chest trauma presented with hematoma and sternal osteomyelitis resulting from sternal fracture. Here we report a 15-year-old sumo wrestler who presented with an anterior mediastinal abscess without any mediastinal fracture. The mediastinal abscess resulted from the hematogenous spread of Staphylococcus aureus to a hematoma that might have been caused by a closed blunt chest trauma incurred during sumo wrestling exercises.
Abscess ; diagnosis ; microbiology ; therapy ; Adolescent ; Anti-Bacterial Agents ; therapeutic use ; Combined Modality Therapy ; Debridement ; Diagnosis, Differential ; Drainage ; Humans ; Magnetic Resonance Imaging ; Male ; Mediastinal Diseases ; diagnosis ; microbiology ; therapy ; Staphylococcal Infections ; diagnosis ; microbiology ; therapy ; Thoracic Injuries ; diagnosis ; microbiology ; therapy ; Tomography, X-Ray Computed ; Wounds, Nonpenetrating ; diagnosis ; microbiology ; therapy ; Wrestling ; injuries

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.