The increasing burden of tick-borne orthonairovirus infections, such as Crimean-Congo hemorrhagic fever, is becoming a global concern for public health. In the present study, we identify a novel orthonairovirus, designated Yezo virus (YEZV), from two patients showing acute febrile illness with thrombocytopenia and leukopenia after tick bite in Hokkaido, Japan, in 2019 and 2020, respectively. YEZV is phylogenetically grouped with Sulina virus detected in Ixodes ricinus ticks in Romania. YEZV infection has been confirmed in seven patients from 2014–2020, four of whom were co-infected with Borrelia spp. Antibodies to YEZV are found in wild deer and raccoons, and YEZV RNAs have been detected in ticks from Hokkaido. In this work, we demonstrate that YEZV is highly likely to be the causative pathogen of febrile illness, representing the first report of an endemic infection associated with an orthonairovirus potentially transmitted by ticks in Japan.

SYNOPSIS Respiratory viral infections may cause serious complications for older adults, including residents of long-term care facilities (LTCFs). While influenza is the most common cause of viral respiratory infections among older adults, several other respiratory viruses also cause significant morbidity and mortality, most notably respiratory syncytial virus. Other noninfluenza respiratory viral pathogens include human metapneumovirus, parainfluenza virus, rhinovirus, coronavirus, and adenovirus. All of these may cause outbreaks among LTCF residents. Recently developed rapid diagnostic molecular tests may clarify the epidemiology of these viruses and have potential, through early identification, to limit the severity of outbreaks among older adults living in LTCFs.

The coronavirus disease 2019 (COVID-19) pandemic has become an urgent global health issue. An older age and underlying conditions, such as diabetes, have been reported as risk factors, but whether or not autoimmune diseases increase the risk remains unknown. An 85-year-old man with Sjögren's syndrome developed a severe COVID-19 infection that required oxygen supplementation. After discussing the goals of care with him and his wife, off-label tocilizumab was given concomitantly, resulting in a rapid improvement in his symptoms and respiratory failure. This patient represents a supplementary case confirming the efficacy and safety of tocilizumab for COVID-19 in elderly patients with autoimmune diseases.

The ongoing spread of coronavirus disease (COVID-19) is a worldwide crisis. Hokkaido Prefecture in Japan promptly declared a state of emergency following the rapid increase of COVID-19 cases, and the policy became an example to mitigate the spread of COVID-19. We herein report 15 cases of COVID-19 including 3 cases requiring mechanical ventilation. Based on review of our cases, among patients over 50 years of age with underlying diseases such as hypertension and diabetes mellitus, and those who required oxygen administration tended to deteriorate. These cases highlight the importance of understanding the background and clinical course of severe cases to predict prognosis.