Background: Many cases have been reported recently on multisystem inflammatory syndrome in children (MIS-C), a newly emerged disease that seemed to correlate with coronavirus disease 2019 . The aim of this review was to describe the clinical features, treatment and outcomes of MIS-C, as well as to assess the risk of bias of published case studies, analyzing their reporting quality. Methods:We searched all articles reporting on multisystem inflammatory condition in children and adolescents in the context of COVID-19 through MEDLINE (via PubMed), Web of Science, China Biology Medicine disc (CBM) and China National Knowledge Infrastructure (CNKI) from their inception to June 17, 2020. We used CARE and IHE checklists to evaluate the risk of bias and quality of the included studies.We combined the data of clinical manifestations, imaging findings, treatments and outcomes using STATA version 15.Results: Twenty-four studies were included, with a total of 270 participants. Most cases were from Europe and the United States, and the terms of MIS-C in different articles were varied. Fever and gastrointestinal symptoms were the most experienced symptoms. Shock, rash, conjunctivitis, lips or oral cavity changes, hand and feet anomalies, and lymphadenopathy were observed, while respiratory symptoms seemed relatively infrequent. Seventy-eight percent to 100% of patients had evidence of SARS-CoV-2 infection, and patients positive for SARS-CoV-2 by serology [86% (95% CI: 78%, 95%)] were more than those by RT-PCR [36% (95% CI: 26%, 46%)]. Most patients had one or more increased inflammatory markers including C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR), ferritin, interleukin-6 (IL-6), and D-dimer, accompanied by neutrophilia and lymphopenia. Impaired cardiac function was seen from elevated biomarkers and abnormal echocardiography. Intravenous immunoglobulin (IVIG), anticoagulants, inotropic agents and glucocorticoids were the main treatments, along with other intensive supportive care. Overall, the outcomes of MIS-C were favorable, and only one death was recorded. In terms of the quality assessment of included studies, most of the case studies did not follow the standard reporting checklist, so that they failed to get higher scores in the risk of bias assessment. Conclusions: Patients with MIS-C present with symptoms more severe than children with COVID-19, 122 Tang et al. A systematic review of MIS-C case studies

Background: Glucocorticoids are widely used in the treatment of various pulmonary inflammatory diseases, but they are also often accompanied by significant adverse reactions. Published guidelines point out that low dose and short duration systemic glucocorticoid therapy may be considered for patients with rapidly progressing coronavirus disease 2019 (COVID-19) while the evidence is still limited.Methods: We comprehensively searched electronic databases and supplemented the screening by conducting a manual search. We included randomized controlled trials (RCTs) and cohort studies evaluating the effectiveness and safety of glucocorticoids in children and adults with COVID-19, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), and conducted meta-analyses of the main indicators that were identified in the studies.Results: Our search retrieved 23 studies, including one RCT and 22 cohort studies, with a total of 13,815 patients. In adults with COVID-19, the use of systemic glucocorticoid did not reduce mortality [risk ratio (RR) =2.00, 95% confidence interval (CI): 0.69 to 5.75, I 2 =90.9%] or the duration of lung inflammation [weighted mean difference (WMD) =−1 days, 95% CI: −2.91 to 0.91], while a significant reduction was found in the duration of fever (WMD =−3.23 days, 95% CI: −3.56 to −2.90). In patients with SARS, glucocorticoids also did not reduce the mortality (RR =1.52, 95% CI: 0.89 to 2.60, I 2 =84.6%), duration of fever (WMD =0.82 days, 95% CI: −2.88 to 4.52, I 2 =97.9%) or duration of lung inflammation absorption (WMD =0.95 days, 95% CI: −7.57 to 9.48, I 2 =94.6%). The use of systemic glucocorticoid therapy prolonged the duration of hospital stay in all patients (COVID-19, SARS and MERS).

Artificial nuclease-dependent DNA cleavage systems (zinc-finger nuclease, ZFN; transcription activator like effectors, TALENs) and exogenous nucleic acid defense systems (CRISPR/Cas) have been used in the new era for genome modification. The most widely used toolbox for genome editing, modulation and detection contains Types II, V and VI of CRISPR/Cas Class 2 systems, categorized and characterized by Cas9, Cas12a and Cas13 respectively. In this review, we (1) elaborate on the definition, classification, structures of CRISPR/Cas Class 2 systems; (2) advance our understanding of new molecular mechanisms and recent progress in their applications, especially beyond genome-editing applications; (3) provide the insights on the specificity, efficiency and versatility of each tool; (4) elaborate the enhancement on specificity and efficiency of the CRISPR/Cas toolbox. The expanding and concerted usage of the CRISPR/Cas tools is making them more powerful in genome editing and other biotechnology applications.

Background: It is well-known that public health education plays a crucial role in the prevention and control of emerging infectious diseases, but how health providers should advise families and parents to obtain health education information is a challenging question. With coronavirus disease 2019 spreading around the world, this rapid review aims to answer that question and thus to promote evidencebased decision making in health education policy and practice. Methods: We systematically searched the literature on health education during COVID-19, severe acute respiratory syndrome (SARS) and middle east respiratory syndrome (MERS) epidemics in Medline (via PubMed), Cochrane Library, EMBASE, Web of Science, China Biology Medicine disc (CBM), China National Knowledge Infrastructure (CNKI), and Wanfang Data from their inception until March 31, 2020. The potential bias of the studies was assessed by Joanna Briggs Institute Prevalence Critical Appraisal Tool.Results: Of 1,067 papers found, 24 cross-sectional studies with a total of 35,967 participants were included in this review. The general public lacked good knowledge of SARS and MERS at the early stage of epidemics. Some people's knowledge, attitude and practice (KAP) of COVID-19 had been improved, but the health behaviors of some special groups including children and their parents need to be strengthened. Negative emotions including fear and stigmatization occurred during the outbreaks. Reliable health information was needed to improve public awareness and mental health for infectious diseases. Health information from nonprofit, government and academic websites was more accurate than privately owned commercial websites and media websites. Conclusions: For educating and cultivating children, parents should obtain information from the official websites of authorities such as the World Health Organization (WHO) and national Centers for Disease

Background: Glucocorticoids are widely used in the treatment of various pulmonary inflammatory diseases, but they are also often accompanied by significant adverse reactions. Published guidelines point out that low dose and short duration systemic glucocorticoid therapy may be considered for patients with rapidly progressing COVID-19 while the evidence is still limited. Methods:We comprehensively searched electronic databases and supplemented the screening by conducting a manual search. We included RCTs and cohort studies evaluating the effectiveness and safety of glucocorticoids in children and adults with COVID-19, SARS and MERS, and conducted meta-analyses of the main indicators that were identified in the studies. Results:Our search retrieved 23 studies, including one RCT and 22 cohort studies, with a total of 13,815 patients. In adults with COVID-19, the use of systemic glucocorticoid did not reduce mortality (RR=2.00, 95% CI: 0.69 to 5.75, I²=90.9%) or the duration of lung inflammation (WMD=-1 days, 95% CI: -2.91 to 0.91), while a significant reduction was found in the duration of fever (WMD=-3.23 days, 95% CI: -3.56 to -2.90). In patients with SARS, glucocorticoids also did not reduce the mortality (RR=1.52, 95% CI: 0.89 to 2.60, I²=84.6%), duration of fever (WMD=0.82 days, 95% CI: -2.88 to 4.52, I²=97.9%) or duration of lung inflammation absorption All rights reserved. No reuse allowed without permission.(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The purpose of this systematic review is to evaluate the efficacy and safety of using potential drugs: remdesivir and glucocorticoid in treating children and adolescents with COVID-19 and intravenous immunoglobulin (IVIG) in treating MIS-C. We searched seven databases, three preprint platform, ClinicalTrials.gov, and Google from December 1, 2019, to August 5, 2021, to collect evidence of remdesivir, glucocorticoid, and IVIG which were used in children and adolescents with COVID-19 or MIS-C. A total of nine cohort studies and one case series study were included in this systematic review. In terms of remdesivir, the meta-analysis of single-arm cohort studies have shown that after the treatment, 54.7% (95%CI, 10.3 to 99.1%) experienced adverse events, 5.6% (95%CI, 1.2 to 10.1%) died, and 27.0% (95%CI, 0 to 73.0%) needed extracorporeal membrane oxygenation or invasive mechanical ventilation. As for glucocorticoids, the results of the meta-analysis showed that the fixed-effect summary odds ratio for the association with mortality was 2.79 (95%CI, 0.13 to 60.87), and the mechanical ventilation rate was 3.12 (95%CI, 0.80 to 12.08) for glucocorticoids compared with the control group. In terms of IVIG, most of the included cohort studies showed that for MIS-C patients with more severe clinical symptoms, IVIG combined with methylprednisolone could achieve better clinical efficacy than IVIG alone.Conclusions: Overall, the current evidence in the included studies is insignificant and of low quality. It is recommended to conduct high-quality randomized controlled trials of remdesivir, glucocorticoids, and IVIG in children and adolescents with COVID-19 or MIS-C to provide substantial evidence for the development of guidelines. What is Known:• The efficacy and safety of using potential drugs such as remdesivir, glucocorticoid, and intravenous immunoglobulin (IVIG) in treating children and adolescents with COVID-19/MIS-C are unclear. What is New:• Overall, the current evidence cannot adequately demonstrate the effectiveness and safety of using remdesivir, glucocorticoids, and IVIG in treating children and adolescents with COVID-19 or MIS-C.• We are calling for the publication of high-quality clinical trials and provide substantial evidence for the development of guidelines.

Background: Existing recommendations on whether mothers with COVID-19 should continue breastfeeding are still conflicting. We aimed to conduct a rapid review of mother-to-child transmission of COVID-19 during breastfeeding.

Background: It is well-known that public health education plays a crucial role in the prevention and control of emerging infectious diseases, but how health providers should advise families and parents to obtain health education information is a challenging question. With COVID-19 (Coronavirus disease 2019) spreading around the world, this rapid review aims to answer that question and thus to promote evidence-based decision making in health education policy and practice. Methods:We systematically searched the literature on health education during COVID-19, SARS (severe acute respiratory syndrome) and MERS (middle east respiratory syndrome) epidemics in Medline (via PubMed), Cochrane Library, EMBASE,