Fulminant myocarditis induced by SARS-CoV-2 infection without severe lung involvement:insights into COvID-19 pathogenesis

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection often leads to pulmonary complications.Cardiovascular sequelae,including myocarditis and heart failure,have also been reported.Here,the study presents two fulminant myocarditis cases infected by SARS-CoV-2 exhibiting remarkable elevation of cardiac biomarkers without significant pulmonary injury,as determined by imaging examinations.Immunohistochemical staining reveals the viral antigen within cardiomyocytes,indicating that SARSCoV-2 could directly infect the myocardium.The full viral genomes from respiratory,anal,and myocardial specimens are obtained via next-generation sequencing.Phylogenetic analyses of the whole genome and spike gene indicate that viruses in the myocardium/pericardial effusion and anal swabs are closely related and cluster together yet diverge from those in the respiratory samples.In addition,unique mutations are found in the anal/myocardial strains compared to the respiratory strains,suggesting tissue-specific virus mutation and adaptation.These findings indicate genetically distinct SARS-CoV-2 variants have infiltrated and disseminated within myocardial tissues,independent of pulmonary injury,and point to different infection routes between the myocardium and respiratory tract,with myocardial infections potentially arising from intestinal infection.These findings highlight the potential for systemic SARS-CoV-2 infection and the importance of a thorough multi-organ assessment in patients for a comprehensive understanding of thepathogenesisof COVID-19.

Co-existence and co-infection of influenza A viruses and coronaviruses: Public health challenges

Since the 20th century,humans have lived through five pandemics caused by influenza A viruses(IAVs)(H1N1/1918,H2N2/1957,H3N2/1968,and H1N1/2009)and the coronavirus(CoV)severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).IAVs and CoVs both have broad host ranges and share multiple hosts.Virus co-circulation and even co-infections facilitate genetic reassortment among IAVs and recombination among CoVs,further altering virus evolution dynamics and generating novel variants with increased cross-species transmission risk.Moreover,SARS-CoV-2 may maintain longterm circulation in humans as seasonal IAVs.Co-existence and co-infection of both viruses in humans could alter disease transmission patterns and aggravate disease burden.Herein,we demonstrate how virus-host ecology correlates with the co-existence and co-infection of IAVs and/or CoVs,further affecting virus evolution and disease dynamics and burden,calling for active virus surveillance and countermeasures for future public health challenges.

Isolation and characterization of Akabane virus Ib substrain and its pathogenesis in sulking mice

Dear Editor,Akabane disease is an arthropod-borne viral disease caused by the Akabane virus(AKAV)that can affect cattle,sheep,and goats.Inapparent infections in adults can lead months later to abortions,stillbirths,congenital defects,and death in newborns(Kurogi et al.,1976).Wild ruminants can also be affected,but abnormalities of the offspring in these species have not been reported.One report suggests that this virus can also cause clinical signs in pigs(Yanase et al.,2018).

Three Novel Avastroviruses Identified in Dead Wild Crows

Dear Editor,Astroviruses(AstVs)are non-enveloped,single-stranded RNA viruses with a diameter of approximately 35 nm(Madeley and Cosgrove 1975).The genomes of AstVs range in size from 6.8 to 7.9 kb(De Benedictis et al.2011),consisting of a 5'-untranslated region(UTR),three open reading frames(ORFs),a 3'-UTR,and a poly-adenylated(polyA)tail(Pantin-Jackwood et al.2006).In 1975,AstVs were first discovered in faeces of infants(Madeley and Cosgrove 1975).Until now,a variety of animal species,including cows,sheep,pigs,dogs,deer,rats,bats,chickens,ducks,turkeys,sea lions and seals have been reported to be infected with AstVs(Tzipori et al.1981;Cattoli et al.2007;Chu et al.2008,2010;Atkins et al.2009;Toffan et al.2009;Rivera et al.2010;Guix et al.2013;Kang et al.2012;Reuter et al.2012a,2012b;Li et al.2021).Currently,AstVs comprise two genera,Mamastrovirus(MAstV)and Avastrovirus(AAstV).Herein,we describe three novel AAstVs identified from dead crow tissues.To our knowledge,this is the first report for identification of AstVs in crows.