How does the coronavirus differ from seasonal flu?

Coronavirus, as a source of pandemic pathogens

The coronavirus and the influenza virus have similarities and differences. In order to comprehensively compare them, their genome sequencing data were examined by principal component analysis. Variations in coronavirus were smaller than those in a subclass of the influenza virus. In addition, differences among coronaviruses in a variety of hosts were small. These characteristics may have facilitated the infection of different hosts. Although many of the coronaviruses were more conservative, those repeatedly found among humans showed annual changes. If SARS-CoV-2 changes its genome like the Influenza H type, it will repeatedly spread every few years. In addition, the coronavirus family has many other candidates for subsequent pandemics. One Sentence Summary The genome data of coronavirus were compared to influenza virus, to investigate its spreading mechanism and future status. Coronavirus would repeatedly spread every few years. In addition, the coronavirus family has many other candidates for subsequent pandemics.

Genome analyses help track coronavirus' moves

Genome analyses help track coronavirus' moves.

Detection of a coronavirus from turkey poults in Europe genetically related to infectious bronchitis virus of chickens.

Intestinal contents of 13-day-old turkey poults in Great Britain were analysed as the birds showed stunting, unevenness and lameness, with 4% mortality. At post mortem examination, the main gross features were fluid caecal and intestinal contents. Histological examination of tissues was largely unremarkable, apart from some sections that showed crypt dilation and flattened epithelia. Negative contrast electron microscopy of caecal contents revealed virus particles, which in size and morphology had the appearance of a coronavirus. RNA was extracted (turkey/UK/412/00) and used in a number of reverse transcription-polymerase chain reactions (RT-PCRs) with the oligonucleotides based on sequences derived from avian infectious bronchitis virus (IBV), a coronavirus of domestic fowl. The RT-PCRs confirmed that turkey/UK/412/00 was a coronavirus and, moreover, showed that it had the same partial gene order (S-E-M-5-N-3' untranslated region) as IBV. This gene order is unlike that of any known mammalian coronavirus, which does not have a gene analogous to the gene 5 of IBV.The gene 5 of the turkey virus had two open reading frames, 5a and 5b, as in IBV and the coronaviruses isolated from turkeys in North America. The turkey/UK/412/00 also resembled IBV, but not mammalian coronaviruses, in having three open reading frames in the gene encoding E protein (gene 3). The percentage differences between the nucleotide sequences of genes 3 and 5 and the 3' untranslated region of turkey/UK/412/00 when compared with those of IBVs were similar to the differences observed when different strains of IBV were compared with each other. No sequences unique to the turkey isolates were identified. These results demonstrate, for the first time, that a coronavirus was associated with disease in turkeys outside of North America and that it is a Group 3 coronavirus, like IBV.

A Multiscale and Comparative Model for Receptor Binding of 2019 Novel Coronavirus and the Implication of its Life Cycle in Host Cells

The respiratory syndrome caused by a new type of coronavirus has been emerging from China and caused more than 1000 death globally since December 2019. This new virus, called 2019 novel coronavirus (2019-nCoV) uses the same receptor called Angiotensinconverting enzyme 2 (ACE2) to attack humans as the coronavirus that caused the severe acute respiratory syndrome (SARS) seventeen years ago. Both viruses recognize ACE2 through the spike proteins (S-protein) on their surfaces. It was found that the S-protein from the SARS coronavirus (SARS-CoV) bind stronger to ACE2 than 2019-nCoV. However, function of a bio-system is often under kinetic, rather than thermodynamic, control. To address this issue, we constructed a structural model for complex formed between ACE2 and the S-protein from 2019-nCoV, so that the rate of their association can be estimated and compared with the binding of S-protein from SARS-CoV by a multiscale simulation method. Our simulation results suggest that the association of new virus to the receptor is slower than SARS, which is consistent with the experimental data obtained very recently. We further integrated this difference of association rate between virus and receptor into a mathematical model which describes the life cycle of virus in host cells and its interplay with the innate immune system. Interestingly, we found that the slower association between virus and receptor can result in longer incubation period, while still maintaining a relatively higher level of viral concentration in human body. Our computational study therefore provides, from the molecular level, one possible explanation that the new disease by far spread much faster than SARS.

Human coronaviruses: what do they cause?

SARS-CoV, human coronavirus NL63 (HCoV-NL63) and HCoV-HKU1 were first described in 2003, 2004 and 2005 respectively. Nevertheless, discovery of three new human coronaviruses does not necessary represent a sudden increase in emerging infections by new coronaviruses. Only SARS-CoV has recently been introduced to the human population; the other two have been circulating in humans for a long time. HCoV-HKU1 and HCoV-NL63 are respiratory coronaviruses, are frequently found during lower and upper respiratory tract infections, have spread worldwide, and prefer the winter season. These characteristics do not differ greatly from the symptoms described for the 'old' viruses HCoV-229E and HCoV-OC43. This report presents an overview of the current knowledge of the four human coronavirus that are now circulating in the human population.

Overview: The history and pediatric perspectives of severe acute respiratory syndromes: Novel or just like SARS

Many respiratory viral infections such as influenza and measles result in severe acute respiratory symptoms and epidemics. In the spring of 2003, an epidemic of coronavirus pneumonia spread from Guangzhou to Hong Kong and subsequently to the rest of the world. The WHO coined the acronym SARS (severe acute respiratory syndrome) and subsequently the causative virus as SARS-CoV. In the summer of 2012, epidemic of pneumonia occurred again in Saudi Arabia which was subsequently found to be caused by another novel coronavirus. WHO coined the term MERS (Middle East respiratory syndrome) to denote the Middle East origin of the novel virus (MERS-CoV). In the winter of 2019, another outbreak of pneumonia occurred in Wuhan, China which rapidly spread globally. Yet another novel coronavirus was identified as the culprit and has been named SARS-CoV-2 due to its similarities with SARS-CoV, and the disease as coronavirus disease-2019. This overview aims to compare and contrast the similarities and differences of these three major episodes of coronavirus outbreak, and conclude that they are essentially the same viral respiratory syndromes caused by similar strains of coronavirus with different names. Coronaviruses have caused major epidemics and outbreaks worldwide in the last two decades. From an epidemiological perspective, they are remarkably similar in the mode of spread by droplets. Special focus is placed on the pediatric aspects, which carry less morbidity and mortality in all three entities.

Coronavirus.

How coronavirus lockdowns stopped flu in its tracks.

Coronavirus

Coronavirus: the first three months as it happened

Why does the coronavirus spread so easily between people?

Coronavirus come of age

Prevalence and genetic diversity analysis of human coronaviruses among cross-border children

BACKGROUND: More than a decade after the outbreak of human coronaviruses (HCoVs) SARS in Guangdong province and Hong Kong SAR of China in 2002, there is still no reoccurrence, but the evolution and recombination of the coronaviruses in this region are still unknown. Therefore, surveillance on the prevalence and the virus variation of HCoVs circulation in this region is conducted. METHODS: A total of 3298 nasopharyngeal swabs samples were collected from cross-border children (<6 years, crossing border between Southern China and Hong Kong SAR) showing symptoms of respiratory tract infection, such as fever (body temperature > 37.5 °C), from 2014 May to 2015 Dec. Viral nucleic acids were analyzed and sequenced to study the prevalence and genetic diversity of the four human coronaviruses. The statistical significance of the data was evaluated with Fisher chi-square test. RESULTS: 78 (2.37%; 95%CI 1.8-2.8%) out of 3298 nasopharyngeal swabs specimens were found to be positive for OC43 (36;1.09%), HKU1 (34; 1.03%), NL63 (6; 0.18%) and 229E (2;0.01%). None of SARS or MERS was detected. The HCoVs predominant circulating season was in transition of winter to spring, especially January and February and NL63 detected only in summer and fall. Complex population with an abundant genetic diversity of coronaviruses was circulating and they shared homology with the published strains (99-100%). Besides, phylogenetic evolutionary analysis indicated that OC43 coronaviruses were clustered into three clades (B,D,E), HKU1 clustered into two clades(A,B) and NL63 clustered into two clades(A,B). Moreover, several novel mutations including nucleotides substitution and the insertion of spike of the glycoprotein on the viral surface were discovered. CONCLUSIONS: The detection rate and epidemic trend of coronaviruses were stable and no obvious fluctuations were found. The detected coronaviruses shared a conserved gene sequences in S and RdRp. However, mutants of the epidemic strains were detected, suggesting continuous monitoring of the human coronaviruses is in need among cross-border children, who are more likely to get infected and transmit the viruses across the border easily, in addition to the general public.

New Year and coronavirus

Will heat kill the coronavirus?

We don't know if changing seasons will help stem the outbreak, says Michael Le Page

Genetic evolution analysis of 2019 novel coronavirus and coronavirus from other species

The Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a Public Health Emergency of International Concern. However, so far, there are still controversies about the source of the virus and its intermediate host. Here, we found the novel coronavirus was closely related to coronaviruses derived from five wild animals, including Paguma larvata, Paradoxurus hermaphroditus, Civet, Aselliscus stoliczkanus and Rhinolophus sinicus, and was in the same branch of the phylogenetic tree. However, genome and ORF1a homology show that the virus is not the same coronavirus as the coronavirus derived from these five animals, whereas the virus has the highest homology with Bat coronavirus isolate RaTG13.

Coronavirus?

Will Coronavirus Disease 2019 Become Seasonal?

This manuscript explores the question of the seasonality of severe acute respiratory syndrome coronavirus 2 by reviewing 4 lines of evidence related to viral viability, transmission, ecological patterns, and observed epidemiology of coronavirus disease 2019 in the Southern Hemispheres' summer and early fall.

The infection with the novel SARS Cov-2 corona virus, the cause of severe acute respiratory distress syndrome, possessing its origin in the Chinese province Hubei, has reached the extent of a global pandemic within a few months. After aerosol infection, most people experience mild respiratory infection with cold symptoms such as cough and fever, and healing within two weeks. In about 5% of those infected, however, a severe course develops with the occurrence of multiple sub pleural bronchopulmonary infiltrates and even death as a result of respiratory failure. The corona virus pandemic has multiple impacts on social life that have not been seen before. For example, the government adopted measures to curb the exponential spread of the virus, which included a significant reduction in social contacts. Furthermore, the specialist societies recommended that no elective treatments be carried out during the pandemic period. This review article considers epidemiological aspects of novel corona virus infection and presents both the clinical as well the possible economic effects of the pandemic on gynaecology, obstetrics and reproductive medicine in Germany in the past, present and future. In addition, useful preventive measures for daily clinical work and the previously known scientific findings dealing with the impact of corona virus on pregnancy and birth are discussed.

Many respiratory viral infections such as influenza and measles result in severe acute respiratory symptoms and epidemics. In the spring of 2003, an epidemic of coronavirus pneumonia spread from Guangzhou to Hong Kong and subsequently to the rest of the world. The WHO coined the acronym SARS (severe acute respiratory syndrome) and subsequently the causative virus as SARS‐CoV. In the summer of 2012, epidemic of pneumonia occurred again in Saudi Arabia which was subsequently found to be caused by another novel coronavirus. WHO coined the term MERS (Middle East respiratory syndrome) to denote the Middle East origin of the novel virus (MERS‐CoV). In the winter of 2019, another outbreak of pneumonia occurred in Wuhan, China which rapidly spread globally. Yet another novel coronavirus was identified as the culprit and has been named SARS‐CoV‐2 due to its similarities with SARS‐CoV, and the disease as coronavirus disease‐2019. This overview aims to compare and contrast the similarities and differences of these three major episodes of coronavirus outbreak, and conclude that they are essentially the same viral respiratory syndromes caused by similar strains of coronavirus with different names. Coronaviruses have caused major epidemics and outbreaks worldwide in the last two decades. From an epidemiological perspective, they are remarkably similar in the mode of spread by droplets. Special focus is placed on the pediatric aspects, which carry less morbidity and mortality in all three entities.

Clinical implications and economic effects of the corona virus pandemic on gynaecology, obstetrics and reproductive medicine in Germany-learning from Italy.

A persistently infecting coronavirus in hibernating Myotis lucifugus, the North American little brown bat

Bats are important reservoir hosts for emerging viruses, including coronaviruses that cause diseases in people. Although there have been several studies on the pathogenesis of coronaviruses in humans and surrogate animals, there is little information on the interactions of these viruses with their natural bat hosts. We detected a coronavirus in the intestines of 53/174 hibernating little brown bats (Myotis lucifugus), as well as in the lungs of some of these individuals. Interestingly, the presence of the virus was not accompanied by overt inflammation. Viral RNA amplified from little brown bats in this study appeared to be from two distinct clades. The sequences in clade 1 were very similar to the archived sequence derived from little brown bats and the sequences from clade 2 were more closely related to the archived sequence from big brown bats. This suggests that two closely related coronaviruses may circulate in little brown bats. Sequence variation among coronavirus detected from individual bats suggested that infection occurred prior to hibernation, and that the virus persisted for up to 4 months of hibernation in the laboratory. Based on the sequence of its genome, the coronavirus was placed in the Alphacoronavirus genus, along with some human coronaviruses, bat viruses and the porcine epidemic diarrhoea virus. The detection and identification of an apparently persistent coronavirus in a local bat species creates opportunities to understand the dynamics of coronavirus circulation in bat populations.

Human Coronaviruses 229E and NL63: Close Yet Still So Far

HCoV-NL63 and HCoV-229E are two of the four human coronaviruses that circulate worldwide. These two viruses are unique in their relationship towards each other. Phylogenetically, the viruses are more closely related to each other than to any other human coronavirus, yet they only share 65% sequence identity. Moreover, the viruses use different receptors to enter their target cell. HCoV-NL63 is associated with croup in children, whereas all signs suggest that the virus probably causes the common cold in healthy adults. HCoV-229E is a proven common cold virus in healthy adults, so it is probable that both viruses induce comparable symptoms in adults, even though their mode of infection differs. Here, we present an overview of the current knowledge on both human coronaviruses, focusing on similarities and differences.

How coronavirus lockdowns stopped flu in its tracks

[Coronaviruses].

Coronaviruses contain positive-stranded RNA with ca. 30 kb as a genome, which is wrapped by the envelope, and constitute Nidovirales together with Arteriviridae. The feature of viruses in Nidovirales is the unique structure of the mRNA set, called 3' co-terminal nested set. Coronaviruses have several to more than 10 different species of subgenomic mRNA and generally only the OFR located in the 5' end of each mRNA is translated. The 5' 20 kb of the coronavirus genome or mRNA-1 consists of two ORFs, 1a and 1b, between that there is a unique RNA structure called pseudoknot. From mRNA-1, 1a as well as 1a+1b are translated; the latter 1a+1b results from the translation due to ribosomal frame-shifting facilitated by the pseudoknot structure. From those two proteins, totally 16 proteins are produced as a result of auto-cleavage by the proteases included in la protein. Those proteins exhibit different functions, such as RNA-dependent RNA polymerase, helicase, proteases and proteins that regulate cellular functions, mRNAs smaller than mRNA-2 translate in general the structural proteins, nucleocapsid (N) protein, spike (S) protein, integrated membrane (M) protein and envelope (E) proteins. Those proteins assemble to the vesicles located from ER to Golgi (ER Golgi intermediate compartment) and virions bud into the vesicles. Those virions are released from infected cells via exocytosis.

Comparison of the di- and trinucleotide frequencies from the genomes of nine different coronaviruses.

As an alternative to protein alignments for the comparison of sequences, the reiterations of mono- di- and trinucleotide frequencies were used for the comparison of coronavirus sequences. The relative abundance of the di- and trinucleotide frequencies within the 3' part from nine coronavirus genomes were determined. The patterns of dinucleotide frequencies and the trinucleotide frequencies showed some common features for all coronaviruses but also differences between the groups formerly defined on the base of antigenic relatedness. The normalised dinucleotide frequencies were further used to calculate the distances between coronavirus sequences. Based on the dinucleotide frequency distances, coronaviruses can be divided into two groups which roughly reflect the taxonomic groups. In this kind of evaluation, however, IBV occupies a position different to the one that it would take based on most protein sequence comparisons. Based on similarities within coding sequences and antigenic properties IBV occupies a place outside of both groups. Based on the dinucleotide frequencies IBV gained a position in between of the TGEV-related and the MHV-clustered coronaviruses.

Coronaviruses: General Features

Coronaviruses have the largest known RNA genomes (∼30kb), which are of positive sense. Together with toroviruses, they are classified in the family Coronaviridae, order Nidovirales. All coronaviruses have four common proteins, three in the envelope and one associated with the genome. Assembly of virus particles occurs at internal membranes. The genes for the structural proteins are at the 3′ end of the genome. Most of the genome (∼20kb) is gene 1, which encodes 15–16 proteins associated with RNA replication and transcription. Translation of gene 1 involves ribosomal frameshifting. Transcription is by a discontinuous process which results in a 3′ co-terminal nested set of mRNAs, each of which has a common leader sequence transcribed from the 5′ terminus of the genome. Only the most 5′-proximal gene of each mRNA is translated. Recombination is a feature of coronavirus evolution. The outbreak of severe acute respiratory syndrome (SARS) has resulted in the discovery of more coronaviruses in humans, other mammals, and avian species, and the realization that the host range of coronaviruses is wider than previously acknowledged. Coronaviruses are associated with a wide range of diseases, including the respiratory and enteric systems, though not necessarily restricted to these, for example, some coronaviruses affect the central nervous system, kidneys, and gonads. The most widely used coronavirus vaccine (billions of doses annually) is against infectious bronchitis virus, which affects chickens.

Uncertainty in the Time of Coronavirus

Generation coronavirus?

Coronavirus 2020.

Coronavirus can infect cats - dogs, not so much

[Seroepidemiological study of coronavirus infection in children and adults in St. Petersburg].

As the result of prolonged (17 years) observations of patients with acute respiratory infections hospitalized in basic departments of clinics of the Research Institute of Influenza, coronavirus infection was found to be the cause of respiratory diseases, on the average, in 12% of cases (in some years in 6.8% to 28.6% of cases). The analysis of extensive morbidity rates among different age groups of the population showed that children were affected by coronavirus infection 5-7 times more often than adults. Three year cycles of this infection were established. The periods of coronaviruses activation were accompanied by their detection in patient material by electron-microscopy, a sharp increase of immune response of patients as well as in the number of nosocomial infections and the proportion of the monoinfection of the coronavirus nature. Coronaviruses played the leading role among other viruses in the etiology of hospital respiratory infections. Mucosal antibodies to coronaviruses in the secretions of the nasal cavity proved to be more important than serum antibodies not only in protection from infection, but also in the pattern of clinical manifestations of the disease.

[Genomic characterization of SARS coronavirus: a novel member of coronavirus].

In March 2003, SARS-CoV, a novel coronavirus which has been proved to be a pathogen causing Severe Acute Respiratory Syndrome (SARS). The complete genome of SARS-CoV has been sequenced by international collaboration including China. In the present study, the genome sequences were collected from NCBI and genomic characterization was analyzed. SARS-CoV has a genome of 28-30 kb including 11 ORFs (Open Reading Frames), which is consistent with that of coronavirus family, and its genome organization is similar to those of other coronaviruses as well. SARS-CoV evolutionally closes to other coronavirus in their corresponding proteins, such as spike protein, small membrane protein and nucleocapsid protein. In some regions of the genome, the genomic sequence of SARS-CoV was significantly different from that of other coronavirus, and has a self-conservative genomic sequence. Moreover, its encoding protein sequences were greatly different from those of other coronavirus. The analysis indicated that SARS-CoV has lower redundancy, that is, it has a high variation possibility. It may not be a variant of other coronaviruses but a novel coronavirus, which existed independently in nature and was not recognized by human being before, although SARS-CoV is morphologically similar to other coronavirus and belongs to coronavirus family. The sequences of its genes and encoding proteins are substantially different from those of other coronavirus.

Understanding the Mosaic of COVID-19: A Review of the Ongoing Crisis

In late 2019, a queer type of pneumonia emerged in Wuhan city in the central part of China. On investigation, it was found to be caused by the coronavirus. Human coronaviruses were discovered in the 1960s. There are a total of seven types of coronaviruses that infect humans: 229E and NL63 are the alpha coronaviruses; OC43, HKU1, MERS-CoV, and SARS-CoV are beta coronaviruses, and SARS-CoV-2 or COVID-19 is a novel coronavirus. COVID-19 surfaced in China at the culmination of the year 2019. The pandemic then fanned out rapidly, involving Italy, Japan, South Korea, Iran, and the rest of the world.

Coronavirus can infect cats - dogs, not so much.

New coronavirus

Seasonality of infectious diseases and severe acute respiratory syndrome–what we don't know can hurt us

Summary The novel severe acute respiratory syndrome (SARS) coronavirus caused severe disease and heavy economic losses before apparently coming under complete control. Our understanding of the forces driving seasonal disappearance and recurrence of infectious diseases remains fragmentary, thus limiting any predictions about whether, or when, SARS will recur. It is true that most established respiratory pathogens of human beings recur in wintertime, but a new appreciation for the high burden of disease in tropical areas reinforces questions about explanations resting solely on cold air or low humidity. Seasonal variation in host physiology may also contribute. Newly emergent zoonotic diseases such as ebola or pandemic strains of influenza have recurred in unpredictable patterns. Most established coronaviruses exhibit winter seasonality, with a unique ability to establish persistent infections in a minority of infected animals. Because SARS coronavirus RNA can be detected in the stool of some individuals for at least 9 weeks, recurrence of SARS from persistently shedding human or animal reservoirs is biologically plausible.

Stop the coronavirus stigma now.

Another Decade, Another Coronavirus

Coronavirus-Pandemie – Erinnerungen an die Grippe-Epidemie von 1918 aus gynäkologisch-geburtshilflicher Sicht

From the medical reports on the flu epidemic in 1918, there is accordance with the present-day corona pandemic. The symptoms, course and outcome all seem to show parallels. Pregnant women in the last trimester are to be classified as being particularly vulnerable. Physicians in several disciplines, e.g. gynecology, general medicine and internal medicine are equally called upon to be particularly vigilant.

[Bats, viruses and humans: coronaviruses on the rise?].

The outbreak of the SARS coronavirus in 2002/2003 and the recent disease cases with a new human coronavirus (originally designated EMC-CoV, recently renamed MERS-CoV) have put the focus onto the virus family Coronaviridae. Both viruses appeared to have managed to jump over the species barrier from a bat reservoir to the human population. Bats are considered to serve as a natural reservoir for coronaviruses infecting mammals. An important factor for crossing the species-barrier is the adaptation to a new receptor on cells of the new host species. During evolution coronaviruses have developed a large diversity of binding specificities demonstrating the high flexibility of the coronaviral spike protein, which is responsible for binding to target cells.

Seasonality of Coronavirus 229E, HKU1, NL63 and OC43 from 2014-2020

Abstract The possibility of seasonality of Covid-19 is being discussed; here we show clinical microbiology laboratory data illustrating seasonality of coronaviruses 229E, HKU1, NL63 and OC43. The data shown are specific to the four studied coronaviruses, and may or may not generalize to Covid-19.

Transcription strategy of coronaviruses: fusion of non-contiguous sequences during mRNA synthesis.

MHV replicates in the cell cytoplasm and viral genetic information is expressed in infected cells as one genomic sized RNA ( mRNA1 ) and six subgenomic mRNAs. The seven RNAs were assumed to have common 3' ends of the size of RNA7 , the smallest RNA. The data reported here, show that this model is too simple and that the mRNAs are composed of a leader and body sequence. Electron microscopic analysis of hybrids formed between single stranded cDNA copied from mRNA7 and genomic RNA or mRNA6 shows that genomic RNA, mRNA6 and mRNA7 have common 5' terminal sequences. Furthermore, nucleotide sequence analysis shows that the nucleotide sequence of the 5' end of mRNA7 diverges from the corresponding region of the genome just upstream from the initiation codon of the nucleocapsid gene. Because the synthesis of each mRNA is inactivated by UV irradiation in proportion to its own length, the subgenomic mRNAs are apparently not produced by the processing of larger RNAs. The available data have to be explained by translocation of the polymerase/leader complex to specific internal positions on the negative strand. In this way the leader and body sequences are joined together by a mechanism completely different from conventional RNA splicing but nevertheless giving the same end result.

Does the coronavirus a global threat?

Why more coronavirus testing won't automatically help the hardest hit.

Forcing Seasonality of influenza-like epidemics with daily Solar resonance

Seasonality of acute viral respiratory diseases is a well-known and yet not fully understood phenomenon. Several models have been proposed to explain the regularity of yearly recurring outbreaks and the phase-differences observed at different latitudes on Earth. Such models take into account known internal causes, primarily the periodic emergence of new virus variants that evade the host immune response. Yet, this alone, is generally unable to explain the regularity of recurrences and the observed phase-differences. Here we show that seasonality of viral respiratory diseases, as well as its distribution with latitude on Earth, can be fully explained by the virucidal properties of UV-B and A Solar photons through a daily, minute-scale, resonant forcing mechanism. Such an induced periodicity can last, virtually unperturbed, from tens to hundreds of cycles, and even in presence of internal dynamics (host's loss of immunity) much slower than seasonal will, on a long period, generate seasonal oscillations.

Heat and coronavirus can be twin killers

Coronavirus controversy

Coronaviruses and immunosuppressed patients. The facts during the third epidemic.

Following the outbreak in China, the Lombardy region of Italy has become one of the areas of highest incidence of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). As the outbreak grew to a pandemic, many centres worldwide raised the concern that immunocompromised patients may be at high risk of developing a severe respiratory disease called COVID-19. Unlike common viral agents (such as Adenovirus, Rhinovirus, Norovirus, Influenza, Respiratory Syncytial Virus), Coronaviruses have not shown to cause a more severe disease in immunosuppressed patients. For this family of viruses the host innate immune response appears the main driver of lung tissue damage during infection.

Coronavirus: just imagine

Novel Coronavirus, Old Partisanship: COVID-19 Attitudes and Behaviours in the United States and Canada

The novel coronavirus reached the United States and Canada almost at the same time. The first reported American case was January 20, 2020, and in Canada it was January 15, 2020 (Canada, 2020; Holshue et al., 2020). Yet, the response to this crisis has been different in the two countries. In the US, President Donald Trump, prominent Republicans, and conservative media initially dismissed the dangers of COVID-19 (Stecula, 2020). The pandemic became politicized from the early days, and even though Trump and Republicans have walked back many of their initial claims, there continue to be media reports of partisan differences in public opinion shaped by that early response. At the same time, the response in Canada has been mostly characterized by across-the-board partisan consensus among political elites (Merkley et al., 2020).

Spatial modeling cannot currently differentiate SARS-CoV-2 coronavirus and human distributions on the basis of climate in the United States

The SARS-CoV-2 coronavirus is wreaking havoc globally, yet knowledge of its biology is limited. Climate and seasonality influence the distributions of many diseases, and studies suggest a link between SARS-CoV-2 and cool weather. One such study, building species distribution models (SDMs), predicted SARS-CoV-2 risk may remain concentrated in the Northern Hemisphere, shifting northward in summer months. Others have highlighted issues with SARS-CoV-2 SDMs, notably: the primary niche of the virus is the host it infects, climate may be a weak distributional predictor, global prevalence data have issues, and the virus is not in a population equilibrium. While these issues should be considered, climate still may be important for predicting the future distribution of SARS-CoV-2. To further examine if there is a link, we model with raw cases and population scaled cases for SARS-CoV-2 county-level data from the United States. We show that SDMs built from population scaled cases data cannot be distinguished from control models built from raw human population data, while SDMs built on raw data fail to predict the current known distribution of cases in the US. The population scaled analyses indicate that climate may not play a central role in current US viral distribution and that human population density is likely a primary driver. Still, we do find slightly more population scaled viral cases in cooler areas. This coupled with our geographically constrained focus make it so we cannot rule out climate as a partial driver of the US SARS-CoV-2 distribution. Climate's role on SARS-CoV-2 should continue to be cautiously examined, but at this time we should assume that SARS-CoV-2 can spread anywhere in the US.

Coronavirus-Pandemie  Erinnerungen an die Grippe-Epidemie von 1918 aus gynäkologisch-geburtshilflicher Sicht./ [Coronavirus pandemic-Memories of the flu epidemic from 1918 from a gynecological and obstetric perspective]

Early occurrence of influenza A epidemics coincided with changes in occurrence of other respiratory virus infections

BACKGROUND: Viral interaction in which outbreaks of influenza and other common respiratory viruses might affect each other has been postulated by several short studies. Regarding longer time periods, influenza epidemics occasionally occur very early in the season, as during the 2009 pandemic. Whether early occurrence of influenza epidemics impacts outbreaks of other common seasonal viruses is not clear. OBJECTIVES: We investigated whether early occurrence of influenza outbreaks coincides with shifts in the occurrence of other common viruses, including both respiratory and non‐respiratory viruses. METHODS: We investigated time trends of and the correlation between positive laboratory diagnoses of eight common viruses in the Netherlands over a 10‐year time period (2003–2012): influenza viruses types A and B, respiratory syncytial virus (RSV), rhinovirus, coronavirus, norovirus, enterovirus, and rotavirus. We compared trends in viruses between early and late influenza seasons. RESULTS: Between 2003 and 2012, influenza B, RSV, and coronavirus showed shifts in their occurrence when influenza A epidemics occurred earlier than usual (before week 1). Although shifts were not always consistently of the same type, when influenza type A hit early, RSV outbreaks tended to be delayed, coronavirus outbreaks tended to be intensified, and influenza virus type B tended not to occur at all. Occurrence of rhinovirus, norovirus, rotavirus, and enterovirus did not change. CONCLUSION: When influenza A epidemics occured early, timing of the epidemics of several respiratory winter viruses usually occurring close in time to influenza A was affected, while trends in rhinoviruses (occurring in autumn) and trends in enteral viruses were not.

Coronavirus receptor specificity.

Coronaviruses from pheasants (Phasianus colchicus) are genetically closely related to coronaviruses of domestic fowl (infectious bronchitis virus) and turkeys.

Reverse-transcriptase polymerase chain reactions (RT-PCRs) were used to examine RNA extracted from mouth/nasal swabs from pheasants exhibiting signs of respiratory disease. The oligonucleotides used were based on sequences of infectious bronchitis virus (IBV), the coronavirus of domestic fowl. A RT-PCR for the highly conserved region II of the 3' untranslated region of the IBV genome detected a coronavirus in swabs from 18/21 estates. Sequence identity with the corresponding region of IBVs and coronaviruses from turkeys was > 95%. A RT-PCR for part of the S1 region of the spike protein gene was positive with 13/21 of the samples. Sequence analysis of the RT-PCR products derived from nine of the pheasant viruses revealed that some of the viruses differed from each other by approximately 24%, similar to the degree of difference exhibited by different serotypes of IBV. Further analysis of the genome of one of the viruses revealed that it contained genes 3 and 5 that are typical of IBV but absent in both the transmissible gastroenteritis virus and murine hepatitis virus groups of mammalian coronaviruses. The nucleotide sequences of genes 3 and 5 of the pheasant virus had a similar degree of identity (approximately 90%) with those of coronaviruses from turkeys and chickens, as is observed when different serotypes of IBV are compared. This work: (a) confirms that coronaviruses are present in pheasants (indeed, commonly present in pheasants with respiratory disease); (b) demonstrates that their genomes are IBV-like in their organization; and (c) shows that there is sequence heterogeneity within the group of pheasant coronaviruses, especially within the spike protein gene. Furthermore, the gene sequences of the pheasant viruses differed from those of IBV to similar extents as the sequence of one serotype of IBV differs from another. On the genetic evidence to date, there is a remarkably high degree of genetic similarity between the coronaviruses of chickens, turkeys and pheasants.

Is the coronavirus airborne? Experts can't agree

Social stigma in the time of Coronavirus

Equine arteritis virus is not a togavirus but belongs to the coronaviruslike superfamily.

The nucleotide sequence of the genome of equine arteritis virus (EAV) was determined from a set of overlapping cDNA clones and was found to contain eight open reading frames (ORFs). ORFs 2 through 7 are expressed from six 3'-coterminal subgenomic mRNAs, which are transcribed from the 3'-terminal quarter of the viral genome. A number of these ORFs are predicted to encode structural EAV proteins. The organization and expression of the 3' part of the EAV genome are remarkably similar to those of coronaviruses and toroviruses. The 5'-terminal three-quarters of the genome contain the putative EAV polymerase gene, which also shares a number of features with the corresponding gene of corona- and toroviruses. The gene contains two large ORFs, ORF1a and ORF1b, with an overlap region of 19 nucleotides. The presence of a "shifty" heptanucleotide sequence in this region and a downstream RNA pseudoknot structure indicate that ORF1b is probably expressed by ribosomal frameshifting. The frameshift-directing potential of the ORF1a/ORF1b overlap region was demonstrated by using a reporter gene. Moreover, the predicted ORF1b product was found to contain four domains which have been identified in the same relative positions in coronavirus and torovirus ORF1b products. The sequences of the EAV and coronavirus ORF1a proteins were found to be much more diverged. The EAV ORF1a product contains a putative trypsinlike serine protease motif. Our data indicate that EAV, presently considered a togavirus, is evolutionarily related to viruses from the coronaviruslike superfamily.

[Morphology of coronaviruses from different species of monkeys in the Sukhumi nursery].

The ultrastructure of coronaviruses from 46 out of 111 monkeys examined (baboons, macaques, green monkeys, langurs) was studied by negative staining in homogenates of different parts of the intestinal tract, pancreatic gland, liver, kidneys, lungs, heart, and brain. Because of marked pleomorphism of coronaviruses it is suggested that morphological variants of the viruses may be distinguished. No relationship between pleomorphism of virus particles and species differences of monkeys and their organ pathology was established. Morphological signs distinguishing simian coronaviruses from those of man were noted.

Occupational health responses to COVID-19: What lessons can we learn from SARS?

On 31 December 2019, the World Health Organization (WHO) received reports of pneumonia cases of unknown etiology in the city of Wuhan in Hubei Province, China. The agent responsible was subsequently identified as a coronavirus-SARS-CoV-2. The WHO declared this disease as a Public Health Emergency of International Concern at the end of January 2020. This event evoked a sense of déjà vu, as it has many similarities to the outbreak of severe acute respiratory syndrome (SARS) of 2002-2003. Both illnesses were caused by a zoonotic novel coronavirus, both originated during winter in China and both spread rapidly all over the world. However, the case-fatality rate of SARS (9.6%) is higher than that of COVID-19 (<4%). Another zoonotic novel coronavirus, MERS-CoV, was responsible for the Middle East respiratory syndrome, which had a case-fatality rate of 34%. Our experiences in coping with the previous coronavirus outbreaks have better equipped us to face the challenges posed by COVID-19, especially in the health care setting. Among the insights gained from the past outbreaks were: outbreaks caused by viruses are hazardous to healthcare workers; the impact of the disease extends beyond the infection; general principles of prevention and control are effective in containing the disease; the disease poses both a public health as well as an occupational health threat; and emerging infectious diseases pose a continuing threat to the world. Given the perspectives gained and lessons learnt from these past events, we should be better prepared to face the current COVID-19 outbreak.

Coronavirus y personal de la salud

Who needs a Corona?

While the Western world now takes on a viral pandemic, the news-cycle and constant reminders to wash your hands and avoid touching your face might drive anyone to reach in the fridge for a beer. It is "Corona time," but unfortunately it is the virus of which we speak. At the time of this writing (early March 2020), there are many more questions than answers. It is clear that the virus is at least as transmissible as influenza, and it is likely that little or no pre-existing immunity exists within the world's population.

The Structure and Functions of Coronavirus Genomic 3’ and 5’ Ends

Coronaviruses (CoVs) are an important cause of illness in humans and animals. Most human coronaviruses commonly cause relatively mild respiratory illnesses; however two zoonotic coronaviruses, SARS-CoV and MERS-CoV, can cause severe illness and death. Investigations over the past thirty-five years have illuminated many aspects of coronavirus replication. The focus of this review is the functional analysis of conserved RNA secondary structures in the 5’ and 3’ of the betacoronavirus genomes. The 5’ 350 nucleotides folds into a set of RNA secondary structures which are well conserved, and reverse genetic studies indicate that these structures play an important role in the discontinuous synthesis of subgenomic RNAs in the betacoronaviruses. These cis-acting elements extend 3’ of the 5’UTR into ORF1a. The 3’UTR is similarly conserved and contains all of the cis-acting sequences necessary for viral replication. Two competing conformations near the 5’ end of the 3’UTR have been shown to make up a potential molecular switch. There is some evidence that an association between the 3’ and 5’UTRs is necessary for subgenomic RNA synthesis, but the basis for this association is not yet clear. A number of host RNA proteins have been shown to bind to the 5’ and 3’ cis-acting regions, but the significance of these in viral replication is not clear. Two viral proteins have been identified as binding to the 5’ cis-acting region, nsp1 and N protein. A genetic interaction between nsp8 and nsp9 and the region of the 3’UTR that contains the putative molecular switch suggests that these two proteins bind to this region.

Epidemiology of coronavirus respiratory infections.

Human coronaviruses were found by enzyme linked immunosorbent assay in upper respiratory tract secretions taken during 30% of 108 acute respiratory infections experienced by 30 children under age 6 years with recurrent respiratory infections (index group), and during 29% of 51 acute infections experienced by their siblings. Lower respiratory tract infection--predominantly wheezy bronchitis--occurred in 30% of the index children's coronavirus positive infections but in none of their siblings' infections. Reinfections were common. Two peaks of infection were seen each year in the late autumn/early winter and in the early summer.

The impact of the coronavirus outbreak on Macao. From tourism lockdown to tourism recovery

Macao was one of the first cities outside China to start a gradual tourism lockdown in January 2020 due to the coronavirus outbreak. Although critical to Macao’s economy, tourism had essentially ceased by March 2020, as the city closed its borders to regional and foreign arrivals. This paper presents the key policy and health measures since Macao’s first coronavirus case in January. The city had recorded no coronavirus cases in the city in early March, but saw a second wave of imported coronavirus cases mostly as residents and non-resident workers returned from overseas. At the request of government, over 10% of Macao’s hotel room inventory had been allocated as quarantine hotels. The ‘top-down’ approach by government meant stringent policy measures consisting of border closures and health advisories were actioned immediately to stem the spread of coronavirus. The economic consequences to the casino industry, which supplies 85% of the government’s total tax revenues, have been dramatic, as casino revenues continue to spiral downwards by over 80% in both February and March. This paper presents Macao’s reaction to the coronavirus in a three-wave analogy. It is argued that the recovery wave should move to public-private consolidation and collaboration.

Coronavirus: Stehen wir am Beginn einer neuen Pandemie?

Coronaviruses: Molecular Biology

Coronaviruses (CoVs) are enveloped, positive-strand RNA viruses with characteristic spike glycoproteins that project outward like the rays of the sun (corona – Latin for ‘crown’), when visualized by electron microscopy. CoV are classified, together with the toroviruses, in the family Coronaviridae and the order Nidovirales. All nidoviruses have a common genome organization and generate a nested set (nido – Latin for ‘nest’) of 3′ co-terminal mRNAs. CoVs have been isolated from a variety of species, including birds, livestock, domestic animals, and humans. CoV infections can cause respiratory, gastrointestinal, and neurologic disease, depending on the strain of the virus and the site of infection. Importantly, CoVs have been shown to cross species barriers and have emerged from animal reservoirs to infect humans and cause severe disease. The CoV responsible for an outbreak of severe acute respiratory disease (SARS-CoV) in 2002–03 likely originated as a bat coronavirus which, during replication in an intermediate host (such as the palm civet), evolved to be able to infect humans efficiently. SARS-CoV infected over 8000 people with approximately 10% mortality rate. The SARS-CoV outbreak was controlled by public health measures alone. However, emergence or re-emergence of CoV from animal reservoirs is a potential concern for public health.

Heat and coronavirus can be twin killers.

Differences in Clinical Characteristics of Covid-19 in Hispanic/Latino Population.

The Centers for Disease Control and Prevention (CDC) suggest several possible symptoms associated with coronavirus disease 2019 (COVID-19), including cough, shortness of breath (SOB), fever, chills, muscle pain, sore throats, new loss of taste or smell, nausea, vomiting, or diarrhea. ("Centers for Disease Control and Prevention. Symptoms of Coronavirus.,") The clinical characteristics from the study by Yu et al. published in Transboundary and Emerging Diseases and other Chinese studies were different from those we observe in the United States.

Coronavirus 2020

Autopsy slowdown hinders quest to determine how coronavirus kills.

Novel coronavirus spreads

Corona virus

Do Humidity and Temperature Impact the Spread of the Novel Coronavirus?

Direct Measurement of Rates of Asymptomatic Infection and Clinical Care-Seeking for Seasonal Coronavirus

The pandemic potential of the novel coronavirus (nCoV) that emerged in Wuhan, China, during December 2019 is strongly tied to the number and contagiousness of undocumented human infections. Here we present findings from a proactive longitudinal sampling study of acute viral respiratory infections that documents rates of asymptomatic infection and clinical care seeking for seasonal coronavirus. We find that the majority of infections are asymptomatic by most symptom definitions and that only 4% of individuals experiencing a seasonal coronavirus infection episode sought medical care for their symptoms. These numbers indicate that a very high percentage of seasonal coronavirus infections are undocumented and provide a reference for understanding the spread of the emergent nCoV.

Coronaviruses

Transmission via aerosols: Plausible differences among emerging coronaviruses

Nucleotide sequence and expression of the spike (S) gene of canine coronavirus and comparison with the S proteins of feline and porcine coronaviruses.

We have cloned, sequenced and expressed the spike (S) gene of canine coronavirus (CCV; strain K378). Its deduced amino acid sequence has revealed features in common with other coronavirus S proteins: a stretch of hydrophobic amino acids at the amino terminus (the putative signal sequence), another hydrophobic region at the carboxy terminus (the membrane anchor), heptad repeats preceding the anchor, and a cysteine-rich region located just downstream from it. Like other representatives of the same antigenic cluster (CCV-Insavc-1 strain, feline infectious peritonitis and enteric coronaviruses, porcine transmissible gastroenteritis and respiratory coronaviruses, and the human coronavirus HCV 229E), the CCV S polypeptide lacks a proteolytic cleavage site present in many other coronavirus S proteins. Pairwise comparisons of the S amino acid sequences within the antigenic cluster demonstrated that the two CCV strains (K378 and Insavc-1) are 93.3% identical, about as similar to each other as they are to the two feline coronaviruses. The porcine sequences are clearly more divergent mainly due to the large differences in the amino-terminal (residues 1 to 300) domains of the proteins; when only the carboxy-terminal parts (residues 301 and on) are considered the homologies between the canine, feline and porcine S polypeptides are generally quite high, with identities ranging from 90.8% to 96.8% . The human coronavirus is less related to the other members of the antigenic group. A phylogenetic tree constructed on the basis of the S sequences showed that the two CCVs are evolutionarily more related to the feline than to the porcine viruses. Expression of the CCV S gene using the vaccinia virus T7 RNA polymerase system yielded a protein of the expected M(r) (approximately 200K) which could be immunoprecipitated with an anti-feline infectious peritonitis virus polyclonal serum and which was indistinguishable from the S protein synthesized in CCV-infected cells.

[The differential diagnosis for novel coronavirus pneumonia and similar lung diseases in general hospitals].

Novel coronavirus pneumonia was novel coronavirus infection that has dominated pulmonary infection since December 2019. The main manifestations were fever, dry cough, shortness of breath, normal or leukopenia in peripheral blood and changes in chest CT and in severe cases, multiple organ failure might occur. The National Health Commission, PRC has revised the consensus on diagnosis and treatment seven times in a short period of time, indicating the growing understanding of the disease. Patients with novel coronavirus pneumonia usually had history of travelling or living in the epidemic area including Wuhan within 14 days before onset, or have been exposed to patients who had fever or respiratory symptoms from the epidemic area, or had clustering diseases. However, novel coronavirus pneumonia was becoming more and more blurred after vanishing epidemic. The diagnosis and differential diagnosis of novel coronavirus pneumonia was facing challenges not only because of large number of tourists increasing dramatically after the relieving of epidemic, but also patients with other diseases return from different areas to search for medical care. In this article, the clinical and chest imaging features of the novel coronavirus pneumonia were reviewed and compared with other infections and non-infectious diffuse pulmonary diseases. We were trying to find the similarities and differences among them, and to identify clues to the diagnosis of novel coronavirus pneumonia, so as to ensure accurate diagnosis and treatment.

Calling all coronavirus researchers: keep sharing, stay open.

The molecular biology of intracellular events during Coronavirus infection cycle

CoV-2 which is the causative agent of COVID-19 belongs to genus betacoronaviruses. The sequence analysis of S protein of CoV-2 has shown that it has acquired a 'polybasic cleavage site' consisting of 12 aminoacids that has been predicted to enable its cleavage by other cellular proteases possibly increasing its transmissibility. The aminoacids present in receptor binding domain of S protein of SARS CoV which are critical for its binding to cellular receptor are different in CoV-2. The presence of heptanucleotide slippery sequence in ORF1 resulting in ribosomal frameshifting, and presence of transcription regulatory sequences between ORFs resulting in discontinuous transcription, are peculiar features of Coronavirus infection cycle. The exonuclease activity of nsp14 provides possible proofreading ability to RNA polymerase makes coronaviruses different from other RNA viruses allowing coronaviruses to maintain their relatively large genome size. This mini-review summarizes the peculiar features of Coronaviruses genome and the critical events during the infection cycle with focus on CoV-2.

Concerns Over the Coronavirus Spread to the Oil Industry

On the global trends and spread of the COVID-19 outbreak: preliminary assessment of the potential relation between location-specific temperature and UV index

The novel coronavirus, since its first outbreak in December, has, up till now, affected approximately 114,542 people across 115 countries. Many international agencies are devoting efforts to enhance the understanding of the evolving COVID-19 outbreak on an international level, its influences, and preparedness. At present, COVID-19 appears to affect individuals through person-to-person means, like other commonly found cold or influenza viruses. It is widely known and acknowledged that viruses causing influenza peak during cold temperatures and gradually subside in the warmer temperature, owing to their seasonality. Thus, COVID-19, due to its regular flu-like symptoms, is also expected to show similar seasonality and subside as the global temperatures rise in the northern hemisphere with the onset of spring. Despite these speculations, however, the systematic analysis in the global perspective of the relation between COVID-19 spread and meteorological parameters is unavailable. Here, by analyzing the region- and city-specific affected global data and corresponding meteorological parameters, we show that there is an optimum range of temperature and UV index strongly affecting the spread and survival of the virus, whereas precipitation, relative humidity, cloud cover, etc. have no effect on the virus. Unavailability of pharmaceutical interventions would require greater preparedness and alert for the effective control of COVID-19. Under these conditions, the information provided here could be very helpful for the global community struggling to fight this global crisis. It is, however, important to note that the information presented here clearly lacks any physiological evidences, which may merit further investigation. Thus, any attempt for management, implementation, and evaluation strategies responding to the crisis arising due to the COVID-19 outbreak must not consider the evaluation presented here as the foremost factor.

Science in the time of coronavirus.

Changes in human nasal mucosa during experimental coronavirus common colds.

Twenty-four adult volunteers were inoculated with nasal drops containing a coronavirus of 229E serotype to determine the differences in the clinical and physiological reactions which occur between clinically infected, sub-clinically infected and non-infected individuals. Thirteen volunteers were clinically infected, 8 had sub-clinical infections and 3 were uninfected. Nasal airway resistance and the temperature of the nasal mucosa increased in all infected subjects both with and without symptoms: the core temperature increased also but to a lesser extent. Mucosal blood flow and nasal secretion increased only in those with symptoms. The albumin content of the nasal secretion increased in the clinically infected, suggesting that it was derived, partially at least, from the circulation. The nasal cycle of variation in airway resistance between the two sides of the nose was observed in all three groups but increased only in those clinically infected.

Why coronavirus death rate is so hard to pin down

Domestic abuse in the time of coronavirus.

Understanding the COVID19 Outbreak: A Comparative Data Analytics and Study

The Coronavirus, also known as the COVID-19 virus, has emerged in Wuhan China since late November 2019. Since that time, it has been spreading at large-scale until today all around the world. It is currently recognized as the world's most viral and severe epidemic spread in the last twenty years, as compared to Ebola 2014, MERS 2012, and SARS 2003. Despite being still in the middle of the outbreak, there is an urgent need to understand the impact of COVID-19. The objective is to clarify how it was spread so fast in a short time worldwide in unprecedented fashion. This paper represents a first initiative to achieve this goal, and it provides a comprehensive analytical study about the Coronavirus. The contribution of this paper consists in providing descriptive and predictive models that give insights into COVID-19 impact through the analysis of extensive data updated daily for the outbreak in all countries. We aim at answering several open questions: How does COVID-19 spread around the world? What is its impact in terms of confirmed and death cases at the continent, region, and country levels? How does its severity compare with other epidemic outbreaks, including Ebola 2014, MERS 2012, and SARS 2003? Is there a correlation between the number of confirmed cases and death cases? We present a comprehensive analytics visualization to address the questions mentioned above. To the best of our knowledge, this is the first systematic analytical papers that pave the way towards a better understanding of COVID-19. The analytical dashboards and collected data of this study are available online [1].

The coronavirus outbreak

CoV-2 which is the causative agent of COVID-19 belongs to genus betacoronaviruses. The sequence analysis of S protein of CoV-2 has shown that it has acquired a ‘polybasic cleavage site’ consisting of 12 aminoacids that has been predicted to enable its cleavage by other cellular proteases possibly increasing its transmissibility. The aminoacids present in receptor binding domain of S protein of SARS CoV which are critical for its binding to cellular receptor are different in CoV-2. The presence of heptanucleotide slippery sequence in ORF1 resulting in ribosomal frameshifting, and presence of transcription regulatory sequences between ORFs resulting in discontinuous transcription, are peculiar features of Coronavirus infection cycle. The exonuclease activity of nsp14 provides possible proofreading ability to RNA polymerase makes coronaviruses different from other RNA viruses allowing coronaviruses to maintain their relatively large genome size. This mini-review summarizes the peculiar features of Coronaviruses genome and the critical events during the infection cycle with focus on CoV-2.

A distinct name is needed for the new coronavirus

Occurrence and frequency of coronavirus infections in humans as determined by enzyme-linked immunosorbent assay.

The occurrence of human coronavirus (HCV) infections was analyzed by using sequential sera taken between 1976 and 1981 from adults working in the London area. Antibody rises to HCV 229E and HCV OC43 group viruses were measured in serum samples from these subjects by enzyme-linked immunosorbent assay. HCV infections were found throughout the year, although most occurred during two periods, from June through September and from December through February. There were no marked seasonal differences in either the range of antibody rises obtained or in the HCV groups to which these antibody rises were directed. However, there were more HCV antibody rises during the summer than in the winter. The antibody duration varied considerably, but had a mean of 3.5 months. Finally, the frequency of HCV infection per person was calculated to be 1 per 7.8 months.

Work Better From Home During the Coronavirus Quarantine

How Coronaviruses Cause Infection : from Colds to Deadly Pneumonia

The SARS-CoV-2 exerts a distinctive strategy for interacting with the ACE2 human receptor

The COVID-19 disease has plagued over 110 countries and has resulted in over 4,000 deaths within 10 weeks. We compare the interaction between the human ACE2 receptor and the SARS-CoV-2 spike protein with that of other pathogenic coronaviruses using molecular dynamics simulations. SARS-CoV, SARS-CoV-2, and HCoV-NL63 recognize ACE2 as the natural receptor but present a distinct binding interface to ACE2 and a different network of residue-residue contacts. SARS-CoV and SARS-CoV-2 have comparable binding affinities achieved by balancing energetics and dynamics. The SARS-CoV-2–ACE2 complex contains a higher number of contacts, a larger interface area, and decreased interface residue fluctuations relative to SARS-CoV. These findings expose an exceptional evolutionary exploration exerted by coronaviruses toward host recognition. We postulate that the versatility of cell receptor binding strategies has immediate implications on therapeutic strategies. One Sentence Summary Molecular dynamics simulations reveal a temporal dimension of coronaviruses interactions with the host receptor.

Why more coronavirus testing won't automatically help the hardest hit

Comparison of the morphology of three coronaviruses

The morphology of three coronaviruses; avian infectious bronchitis virus strain Connecticut (IBV Conn), human coronavirus strain 229E (HCV 229E) and mouse hepatitis virus strain 3 (MHV3), were examined by negative staining. Significant differences were found in the sizes of the three coronaviruses. Furthermore, three types of surface projection of the same lengths, but varying widths and morphology, were observed. Both IBV Conn and HCV 229E had bulbous projections characteristic of coronaviruses, although the projections of HCV 229E were somewhat thinner than those of IBV Conn. On the other hand, MHV3 particles had thin, cone-shaped surface projections, that were completely unlike typical coronavirus projections. The significance of these results is discussed.

Coronaviruses.