Presence of Recombinant Bat Coronavirus GCCDC1 in Cambodian Bats.

Bats have been recognized as an exceptional viral reservoir, especially for coronaviruses. At least three bat zoonotic coronaviruses (SARS-CoV, MERS-CoV and SARS-CoV-2) have been shown to cause severe diseases in humans and it is expected more will emerge. One of the major features of CoVs is that they are all highly prone to recombination. An extreme example is the insertion of the P10 gene from reoviruses in the bat CoV GCCDC1, first discovered in Rousettus leschenaultii bats in China. Here, we report the detection of GCCDC1 in four different bat species (Eonycteris spelaea, Cynopterus sphinx, Rhinolophus shameli and Rousettus sp.) in Cambodia. This finding demonstrates a much broader geographic and bat species range for this virus and indicates common cross-species transmission. Interestingly, one of the bat samples showed a co-infection with an Alpha CoV most closely related to RsYN14, a virus recently discovered in the same genus (Rhinolophus) of bat in Yunnan, China, 2020. Taken together, our latest findings highlight the need to conduct active surveillance in bats to assess the risk of emerging CoVs, especially in Southeast Asia.

Modeling SARS-CoV-2 propagation using rat coronavirus-associated shedding and transmission.

At present, global immunity to SARS-CoV-2 resides within a heterogeneous combination of susceptible, naturally infected and vaccinated individuals. The extent to which viral shedding and transmission occurs on re-exposure to SARS-CoV-2 is an important determinant of the rate at which COVID-19 achieves endemic stability. We used Sialodacryoadenitis Virus (SDAV) in rats to model the extent to which immune protection afforded by prior natural infection via high risk (inoculation; direct contact) or low risk (fomite) exposure, or by vaccination, influenced viral shedding and transmission on re-exposure. On initial infection, we confirmed that amount, duration and consistency of viral shedding, and seroconversion rates were correlated with exposure risk. Animals were reinfected after 3.7-5.5 months using the same exposure paradigm. 59% of seropositive animals shed virus, although at lower amounts. Previously exposed seropositive reinfected animals were able to transmit virus to 25% of naive recipient rats after 24-hour exposure by direct contact. Rats vaccinated intranasally with a related virus (Parker's Rat Coronavirus) were able to transmit SDAV to only 4.7% of naive animals after a 7-day direct contact exposure, despite comparable viral shedding. Cycle threshold values associated with transmission in both groups ranged from 29-36 cycles. Observed shedding was not a prerequisite for transmission. Results indicate that low-level shedding in both naturally infected and vaccinated seropositive animals can propagate infection in susceptible individuals. Extrapolated to COVID-19, our results suggest that continued propagation of SARS-CoV-2 by seropositive previously infected or vaccinated individuals is possible.

Reflexões acerca da "infodemia" relacionada à covid-19 / Reflexiones sobre la "infodemia" relacionada con covid-19 / Reflections about covid-19 "infodemic"

RESUMO Este estudo tem o objetivo de refletir sobre os impactos negativos que a disseminação desenfreada de notícias sobre a COVID-19 pode trazer para a saúde e para a sociedade. Desse modo, destaca-se a necessidade de ações e intervenções que previnam ou minimizem esses impactos e que sensibilizem a população quanto ao correto manejo das informações, de forma a diminuir as repercussões prejudiciais da infodemia acerca dessa nova afecção. Trata-se de uma análise reflexiva sobre as consequências que a "infodemia" pode causar à saúde e à sociedade, devido à divulgação desenfreada de notícias relacionadas à COVID-19. Nesse contexto, ressalta-se que foi possível perceber que a "infodemia", ou seja, o excesso de informações, precisas ou não, sobre a COVID-19 traz inúmeros impactos maléficos para a saúde mental da população e dos profissionais de saúde, bem como para os serviços de saúde e para a sociedade. Esse fato demonstra a necessidade de realização de pesquisas e de ações educativas que proporcionem a diminuição dos efeitos nocivos ocasionados por esse fenômeno.

RESUMEN Este estudio tiene como objetivo reflexionar sobre los impactos negativos que la difusión desenfrenada de noticias sobre el COVID-19 puede traer a la salud y a la sociedad. Por tanto, se necesitan acciones e intervenciones que prevengan o minimicen estos impactos y que sensibilicen a la población sobre el correcto manejo de la información, a fin de reducir las repercusiones nocivas de la infodemia sobre esta nueva afección. Se trata de un análisis reflexivo de las consecuencias que la "infodemia" puede ocasionar en la salud y la sociedad, debido a la difusión desenfrenada de noticias relacionadas con el COVID-19. En este contexto, se destaca que se pudo percibir que la "infodemia", es decir, el exceso de información, veraz o no, sobre el COVID-19 trae numerosos impactos nocivos en la salud mental de la población y los profesionales de la salud, así como para los servicios de salud y para la sociedad. Este hecho demuestra la necesidad de llevar a cabo acciones de investigación y educación que permitan reducir los efectos nocivos que genera este fenómeno.

ABSTRACT This study aims to reflect on the negative impacts that the unbridled dissemination of news about COVID-19 can bring to health and to society. Thus, there is a need for actions and interventions that prevent or minimize these impacts and that sensitize the population about the correct handling of information, in order to reduce the harmful repercussions of the infodemic regarding this new disease. It is a reflective analysis of the consequences that "infodemic" can cause to health and society, due to the unbridled dissemination of news related to COVID-19. In this context, it is emphasized that it was possible to perceive that the "infodemic", that is, the excess of information, whether accurate or not, about COVID-19 brings innumerable harmful impacts on the mental health of the population and health professionals, as well as for health services and society. This fact demonstrates the need to conduct research and educational actions that provide a reduction in the harmful effects caused by this phenomenon.

Zoonotic evolution and implications of microbiome in viral transmission and infection.

The outbreak and spread of new strains of coronavirus (SARS-CoV-2) remain a global threat with increasing cases in affected countries. The evolutionary tree of SARS-CoV-2 revealed that Porcine Reproductive and Respiratory Syndrome virus 2, which belongs to the Beta arterivirus genus from the Arteriviridae family is possibly the most ancient ancestral origin of SARS-CoV-2 and other Coronaviridae. This review focuses on phylogenomic distribution and evolutionary lineage of zoonotic viral cross-species transmission of the Coronaviridae family and the implications of bat microbiome in zoonotic viral transmission and infection. The review also casts light on the role of the human microbiome in predicting and controlling viral infections. The significance of microbiome-mediated interventions in the treatment of viral infections is also discussed. Finally, the importance of synthetic viruses in the study of viral evolution and transmission is highlighted.

[Tracing the origins of SARS-COV-2 in coronavirus phylogenies]. / Retrouver les origines du SARS-CoV-2 dans les phylogénies de coronavirus.

SARS-CoV-2 is a new human coronavirus (CoV), which emerged in People's Republic of China at the end of 2019 and is responsible for the global Covid-19 pandemic that caused more than 540 000 deaths in six months. Understanding the origin of this virus is an important issue and it is necessary to determine the mechanisms of its dissemination in order to be able to contain new epidemics. Based on phylogenetic inferences, sequence analysis and structure-function relationships of coronavirus proteins, informed by the knowledge currently available, we discuss the different scenarios evoked to account for the origin - natural or synthetic - of the virus. On the basis of currently available data, it is impossible to determine whether SARS-CoV-2 is the result of a natural zoonotic emergence or an accidental escape from experimental strains. Regardless of its origin, the study of the evolution of the molecular mechanisms involved in the emergence of this pandemic virus is essential to develop therapeutic and vaccine strategies.

TITLE: Retrouver les origines du SARS-CoV-2 dans les phylogénies de coronavirus. ABSTRACT: Le SARS-CoV-2 est un nouveau coronavirus (CoV) humain. Il a émergé en Chine fin 2019 et est responsable de la pandémie mondiale de Covid-19 qui a causé plus de 540 000 décès en six mois. La compréhension de l'origine de ce virus est une question importante et il est nécessaire de déterminer les mécanismes de sa dissémination afin de pouvoir se prémunir de nouvelles épidémies. En nous fondant sur des inférences phylogénétiques, l'analyse des séquences et les relations structure-fonction des protéines de coronavirus, éclairées par les connaissances actuellement disponibles, nous discutons les différents scénarios évoqués pour rendre compte de l'origine - naturelle ou synthétique - du virus.

Discovery and Sequence Analysis of Four Deltacoronaviruses from Birds in the Middle East Reveal Interspecies Jumping with Recombination as a Potential Mechanism for Avian-to-Avian and Avian-to-Mammalian Transmission.

The emergence of Middle East respiratory syndrome showed once again that coronaviruses (CoVs) in animals are potential source for epidemics in humans. To explore the diversity of deltacoronaviruses in animals in the Middle East, we tested fecal samples from 1,356 mammals and birds in Dubai, The United Arab Emirates. Four novel deltacoronaviruses were detected from eight birds of four species by reverse transcription-PCR (RT-PCR): FalCoV UAE-HKU27 from a falcon, HouCoV UAE-HKU28 from a houbara bustard, PiCoV UAE-HKU29 from a pigeon, and QuaCoV UAE-HKU30 from five quails. Complete genome sequencing showed that FalCoV UAE-HKU27, HouCoV UAE-HKU28, and PiCoV UAE-HKU29 belong to the same CoV species, suggesting recent interspecies transmission between falcons and their prey, houbara bustards and pigeons, possibly along the food chain. Western blotting detected specific anti-FalCoV UAE-HKU27 antibodies in 33 (75%) of 44 falcon serum samples, supporting genuine infection in falcons after virus acquisition. QuaCoV UAE-HKU30 belongs to the same CoV species as porcine coronavirus HKU15 (PorCoV HKU15) and sparrow coronavirus HKU17 (SpCoV HKU17), discovered previously from swine and tree sparrows, respectively, supporting avian-to-swine transmission. Recombination involving the spike protein is common among deltacoronaviruses, which may facilitate cross-species transmission. FalCoV UAE-HKU27, HouCoV UAE-HKU28, and PiCoV UAE-HKU29 originated from recombination between white-eye coronavirus HKU16 (WECoV HKU16) and magpie robin coronavirus HKU18 (MRCoV HKU18), QuaCoV UAE-HKU30 from recombination between PorCoV HKU15/SpCoV HKU17 and munia coronavirus HKU13 (MunCoV HKU13), and PorCoV HKU15 from recombination between SpCoV HKU17 and bulbul coronavirus HKU11 (BuCoV HKU11). Birds in the Middle East are hosts for diverse deltacoronaviruses with potential for interspecies transmission.IMPORTANCE During an attempt to explore the diversity of deltacoronaviruses among mammals and birds in Dubai, four novel deltacoronaviruses were detected in fecal samples from eight birds of four different species: FalCoV UAE-HKU27 from a falcon, HouCoV UAE-HKU28 from a houbara bustard, PiCoV UAE-HKU29 from a pigeon, and QuaCoV UAE-HKU30 from five quails. Genome analysis revealed evidence of recent interspecies transmission between falcons and their prey, houbara bustards and pigeons, possibly along the food chain, as well as avian-to-swine transmission. Recombination, which is known to occur frequently in some coronaviruses, was also common among these deltacoronaviruses and occurred predominantly at the spike region. Such recombination, involving the receptor binding protein, may contribute to the emergence of new viruses capable of infecting new hosts. Birds in the Middle East are hosts for diverse deltacoronaviruses with potential for interspecies transmission.

SARS-like WIV1-CoV poised for human emergence.

Outbreaks from zoonotic sources represent a threat to both human disease as well as the global economy. Despite a wealth of metagenomics studies, methods to leverage these datasets to identify future threats are underdeveloped. In this study, we describe an approach that combines existing metagenomics data with reverse genetics to engineer reagents to evaluate emergence and pathogenic potential of circulating zoonotic viruses. Focusing on the severe acute respiratory syndrome (SARS)-like viruses, the results indicate that the WIV1-coronavirus (CoV) cluster has the ability to directly infect and may undergo limited transmission in human populations. However, in vivo attenuation suggests additional adaptation is required for epidemic disease. Importantly, available SARS monoclonal antibodies offered success in limiting viral infection absent from available vaccine approaches. Together, the data highlight the utility of a platform to identify and prioritize prepandemic strains harbored in animal reservoirs and document the threat posed by WIV1-CoV for emergence in human populations.

Bat origin of human coronaviruses.

Bats have been recognized as the natural reservoirs of a large variety of viruses. Special attention has been paid to bat coronaviruses as the two emerging coronaviruses which have caused unexpected human disease outbreaks in the 21st century, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV), are suggested to be originated from bats. Various species of horseshoe bats in China have been found to harbor genetically diverse SARS-like coronaviruses. Some strains are highly similar to SARS-CoV even in the spike protein and are able to use the same receptor as SARS-CoV for cell entry. On the other hand, diverse coronaviruses phylogenetically related to MERS-CoV have been discovered worldwide in a wide range of bat species, some of which can be classified to the same coronavirus species as MERS-CoV. Coronaviruses genetically related to human coronavirus 229E and NL63 have been detected in bats as well. Moreover, intermediate hosts are believed to play an important role in the transmission and emergence of these coronaviruses from bats to humans. Understanding the bat origin of human coronaviruses is helpful for the prediction and prevention of another pandemic emergence in the future.

The emerging novel Middle East respiratory syndrome coronavirus: the "knowns" and "unknowns".

A novel lineage C betacoronavirus, originally named human coronavirus EMC/2012 (HCoV-EMC) and recently renamed Middle East respiratory syndrome coronavirus (MERS-CoV), that is phylogenetically closely related to Tylonycteris bat coronavirus HKU4 and Pipistrellus bat coronavirus HKU5, which we discovered in 2007 from bats in Hong Kong, has recently emerged in the Middle East to cause a severe acute respiratory syndrome (SARS)-like infection in humans. The first laboratory-confirmed case, which involved a 60-year-old man from Bisha, the Kingdom of Saudi Arabia (KSA), who died of rapidly progressive community-acquired pneumonia and acute renal failure, was announced by the World Health Organization (WHO) on September 23, 2012. Since then, a total of 70 cases, including 39 fatalities, have been reported in the Middle East and Europe. Recent clusters involving epidemiologically-linked household contacts and hospital contacts in the Middle East, Europe, and Africa strongly suggested possible human-to-human transmission. Clinical and laboratory research data generated in the past few months have provided new insights into the possible animal reservoirs, transmissibility, and virulence of MERS-CoV, and the optimal laboratory diagnostic options and potential antiviral targets for MERS-CoV-associated infection.

Update: severe respiratory illness associated with a novel coronavirus--worldwide, 2012-2013.

CDC continues to work closely with the World Health Organization (WHO) and other partners to better understand the public health risk posed by a novel coronavirus that was first reported to cause human infection in September 2012. Genetic sequence analyses have shown that this new virus is different from any other known human coronaviruses, including the one that caused severe acute respiratory syndrome (SARS). As of March 7, 2013, a total of 14 confirmed cases of novel coronavirus infection have been reported to WHO, with eight deaths. Illness onsets have occurred from April 2012 through February 2013. To date, no cases have been reported in the United States.

[Bats, viruses and humans: coronaviruses on the rise?]. / Von Fledermläusen, Viren und Menschen: Coronaviren auf dem Vormarsch?

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.

Detection of corona-like virus in a case of flaccid paraparesis in Belém, Pará State, Brazil / Detecção de virus corona-like em um caso de paraparesia flácida em Belém, Estado do Pará, Brasil

In this study, we analyzed a fecal sample of a female infant with paralysis and other clinical symptoms that resembled poliomyelitis. Negative staining electron microscopy showed viral particles with a diameter of approximately 120 nm and displaying a crown-like appearance with surface projections. Ultrathin sections showed particles budding from the membranes of the Golgi apparatus. Based on these results, we propose the association of this virus with the neurological disorder and tentatively assign it to the Coronaviridae family. Further studies are required on this proposed relationship.

Neste estudo, analisamos uma amostra fecal de criança do sexo feminino com paralisia e outros sintomas clínicos que se assemelharam à poliomielite. A microscopia eletrônica (contrastação negativa) mostrou partículas com 120 nm de diâmetro, exibindo projeções na superfície semelhantes a uma coroa. Cortes ultrafinos mostraram partículas brotando do complexo de Golgi. Com base nesses resultados, propomos a associação deste vírus com o distúrbio neurológico e o associamos provisoriamente à família Coronaviridae. Estudos adicionais são necessários para esclarecer a relação proposta.

Evolutionary insights into the ecology of coronaviruses.

Although many novel members of the Coronaviridae have recently been recognized in different species, the ecology of coronaviruses has not been established. Our study indicates that bats harbor a much wider diversity of coronaviruses than any other animal species. Dating of different coronavirus lineages suggests that bat coronaviruses are older than those recognized in other animals and that the human severe acute respiratory syndrome (SARS) coronavirus was directly derived from viruses from wild animals in wet markets of southern China. Furthermore, the most closely related bat and SARS coronaviruses diverged in 1986, an estimated divergence time of 17 years prior to the outbreak, suggesting that there may have been transmission via an unknown intermediate host. Analysis of lineage-specific selection pressure also indicated that only SARS coronaviruses in civets and humans were under significant positive selection, also demonstrating a recent interspecies transmission. Analysis of population dynamics revealed that coronavirus populations in bats have constant population growth, while viruses from all other hosts show epidemic-like increases in population. These results indicate that diverse coronaviruses are endemic in different bat species, with repeated introductions to other animals and occasional establishment in other species. Our findings suggest that bats are likely the natural hosts for all presently known coronavirus lineages and that all coronaviruses recognized in other species were derived from viruses residing in bats. Further surveillance of bat and other animal populations is needed to fully describe the ecology and evolution of this virus family.

Emerging viruses set to soar.

The emergence rate of novel viruses, such as the coronavirus that sparked SARS, could well be on the rise. Researchers now think that the SARS virus split from group 2 coronaviruses, and that this happened relatively recently on the scale of coronavirus evolution.

[Mating activity of male SHR rats infected with sialodacryoadenitis virus].

The male SHR rats infected with sialodacryoadenitis (SDA) virus did not show any abnormal mating activity. However, high mortality was seen in embryos of diseased dams after cage-mating with infected males on Day 4 to Day 11 postinoculation.

Transmission of sialodacryoadenitis virus (SDAV) from infected rats to rats and mice through handling, close contact, and soiled bedding.

Thirty mice and six rats were exposed through handling, soiled bedding, or close contact to rats previously inoculated with sialodacryoadenitis virus (SDAV). All exposed rats developed coronaviral antibody without clinical signs or lesions of SDAV infection. Exposed mice had no lesions or clinical signs of coronavirus infection. Mice exposed by handling or by soiled bedding did not develop coronavirus antibody. Two of 10 mice exposed to SDAV-inoculated rats by close contact were coronavirus seropositive when tested 3 weeks postexposure. SDAV-inoculated rats and mice developed coronavirus lesions and antibody. These results suggest that rat-to-rat transmission of SDAV is likely via fomites or handling; however, rat-to-mouse transmission is unlikely when animals are housed and husbanded using modern techniques. Results also suggest that coronavirus antibody in mice is due to exposure to mouse coronavirus and not to rat coronaviruses.

Seroconversion of pigs in contact with dogs exposed to canine coronavirus.

In order to determine if canine coronavirus (CCV) could be transmitted to pigs, two dogs were inoculated orally with virulent CCV. After 24 h, the dogs were moved to an isolation room that contained three three-day-old pigs. A wire mesh fence, allowing close contact between the animals, separated the dogs from the pigs. The dogs and pigs were observed for 14 days for clinical signs of disease. Samples of blood were obtained from dogs and pigs immediately before the dogs were inoculated with virus and 14 and 28 days later. The dogs developed mild clinical signs of an infection, but the pigs remained normal throughout the observation period. The dogs shed CCV for eight days after exposure. All three pigs developed neutralizing antibodies against CCV and transmissible gastroenteritis virus by 14 days after they were exposed to the dogs.