SARS-CoV-2 NSP13 interacts with host IRF3, blocking antiviral immune responses.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses an unprecedented threat to human health since late 2019. Notably, the progression of the disease is associated with impaired antiviral interferon (IFN) responses. Although multiple viral proteins were identified as potential IFN antagonists, the underlying molecular mechanisms remain to be fully elucidated. In this study, we firstly demonstrate that SARS-CoV-2 NSP13 protein robustly antagonizes IFN response induced by the constitutively active form of transcription factor IRF3 (IRF3/5D). This induction of IFN response by IRF3/5D is independent of the upstream kinase, TBK1, a previously reported NSP13 target, thus indicating that NSP13 can act at the level of IRF3 to antagonize IFN production. Consistently, NSP13 exhibits a specific, TBK1-independent interaction with IRF3, which, moreover, is much stronger than that of NSP13 with TBK1. Furthermore, the NSP13-IRF3 interaction was shown to occur between the NSP13 1B domain and IRF3 IRF association domain (IAD). In agreement with the strong targeting of IRF3 by NSP13, we then found that NSP13 blocks IRF3-directed signal transduction and antiviral gene expression, counteracting IRF3-driven anti-SARS-CoV-2 activity. These data suggest that IRF3 is likely to be a major target of NSP13 in antagonizing antiviral IFN responses and provide new insights into the SARS-CoV-2-host interactions that lead to viral immune evasion.

Management and implementation strategies of pre-screening triage in children during coronavirus disease 2019 pandemic in Guangzhou, China.

BACKGROUND: Emerging infectious diseases are a constant threat to the public's health and health care systems around the world. Coronavirus disease 2019 (COVID-2019), which was defined by the World Health Organization as pandemic, has rapidly emerged as a global health threat. Outbreak evolution and prevention of international implications require substantial flexibility of frontline health care facilities in their response. AIM: To explore the effect of the implementation and management strategy of pre-screening triage in children during COVID-19. METHODS: The standardized triage screening procedures included a standardized triage screening questionnaire, setup of pre-screening triage station, multi-point temperature monitoring, extensive screenings, and two-way protection. In order to ensure the implementation of the pre-screening triage, the prevention and control management strategies included training, emergency exercise, and staff protection. Statistical analysis was performed on the data from all the children hospitalized from January 20, 2020 to March 20, 2020 at solstice during the pandemic period. Data were obtained from questionnaires and electronic medical record systems. RESULTS: A total of 17561 children, including 2652 who met the criteria for screening, 192 suspected cases, and two confirmed cases without omission, were screened from January 20, 2020 to March 20, 2020 at solstice during the pandemic period. There was zero transmission of the infection to any medical staff. CONCLUSION: The effective strategies for pre-screening triage have an essential role in the prevention and control of hospital infection.