Detection of potentially novel paramyxovirus and coronavirus viral RNA in bats and rats in the Mekong Delta region of southern Viet Nam

Survey of white-footed mice in Connecticut, USA reveals low SARS-CoV-2 seroprevalence and infection with divergent betacoronaviruses

Diverse mammalian species display susceptibility to and infection with SARS-CoV-2. Potential SARS-CoV-2 spillback into rodents is understudied despite their host role for numerous zoonoses and human proximity. We assessed exposure and infection among white-footed mice (Peromyscus leucopus) in Connecticut, USA. We observed 1% (6/540) wild-type neutralizing antibody seroprevalence among 2020-2022 residential mice with no cross-neutralization of variants. We detected no SARS-CoV-2 infections via RT-qPCR, but identified non-SARS-CoV-2 betacoronavirus infections via pan-coronavirus PCR among 1% (5/468) of residential mice. Sequencing revealed two divergent betacoronaviruses, preliminarily named Peromyscus coronavirus-1 and -2. Both belong to the Betacoronavirus 1 species and are ~90% identical to the closest known relative, Porcine hemagglutinating encephalomyelitis virus. Low SARS-CoV-2 seroprevalence suggests white-footed mice may not be sufficiently susceptible or exposed to SARS-CoV-2 to present a long-term human health risk. However, the discovery of divergent, non-SARS-CoV-2 betacoronaviruses expands the diversity of known rodent coronaviruses and further investigation is required to understand their transmission extent.

Detection of Alpha- and Betacoronaviruses in Small Mammals in Western Yunnan Province, China

The genetic diversity of coronaviruses (CoVs) is high, and their infection in animals has not yet been fully revealed. By RT-PCR detection of the partial RNA-dependent RNA polymerase (RdRp) gene of CoVs, we screened a total of 502 small mammals in the Dali and Nujiang prefectures of Western Yunnan Province, China. The number of overall CoV positives was 20, including β-CoV (n = 13) and α-CoV (n = 7), with a 3.98% prevalence in rectal tissue samples. The identity of the partial RdRp genes obtained for 13 strains of β-CoV was 83.42-99.23% at the nucleotide level, and it is worth noting that the two strains from Kachin red-backed voles showed high identity to BOV-36/IND/2015 from Indian bovines and DcCoV-HKU23 from dromedary camels (Camelus dromedarius) in Morocco; the nucleotide identity was between 97.86 and 98.33%. Similarly, the identity of the seven strains of α-CoV among the partial RdRp sequences was 94.00-99.18% at nucleotide levels. The viral load in different tissues was measured by quantitative RT-PCR (qRT-PCR). The average CoV viral load in small mammalian rectal tissue was 1.35 × 106 copies/g; differently, the mean CoV viral load in liver, heart, lung, spleen, and kidney tissue was from 0.97 × 103 to 3.95 × 103 copies/g, which revealed that CoV has extensive tropism in rectal tissue in small mammals (p < 0.0001). These results revealed the genetic diversity, epidemiology, and infective tropism of α-CoV and β-CoV in small mammals from Dali and Nujiang, which deepens the comprehension of the retention and infection of coronavirus in natural hosts.

Genotype and Phenotype Characterization of Rhinolophus sp. Sarbecoviruses from Vietnam: Implications for Coronavirus Emergence

Bats are a major reservoir of zoonotic viruses, including coronaviruses. Since the emergence of SARS-CoV in 2002/2003 in Asia, important efforts have been made to describe the diversity of Coronaviridae circulating in bats worldwide, leading to the discovery of the precursors of epidemic and pandemic sarbecoviruses in horseshoe bats. We investigated the viral communities infecting horseshoe bats living in Northern Vietnam, and report here the first identification of sarbecoviruses in Rhinolophus thomasi and Rhinolophus siamensis bats. Phylogenetic characterization of seven strains of Vietnamese sarbecoviruses identified at least three clusters of viruses. Recombination and cross-species transmission between bats seemed to constitute major drivers of virus evolution. Vietnamese sarbecoviruses were mainly enteric, therefore constituting a risk of spillover for guano collectors or people visiting caves. To evaluate the zoonotic potential of these viruses, we analyzed in silico and in vitro the ability of their RBDs to bind to mammalian ACE2s and concluded that these viruses are likely restricted to their bat hosts. The workflow applied here to characterize the spillover potential of novel sarbecoviruses is of major interest for each time a new virus is discovered, in order to concentrate surveillance efforts on high-risk interfaces.

Coronavirus sampling and surveillance in bats from 1996-2019: a systematic review and meta-analysis

The emergence of SARS-CoV-2 highlights a need for evidence-based strategies to monitor bat viruses. We performed a systematic review of coronavirus sampling (testing for RNA positivity) in bats globally. We identified 110 studies published between 2005 and 2020 that collectively reported positivity from 89,752 bat samples. We compiled 2,274 records of infection prevalence at the finest methodological, spatiotemporal and phylogenetic level of detail possible from public records into an open, static database named datacov, together with metadata on sampling and diagnostic methods. We found substantial heterogeneity in viral prevalence across studies, reflecting spatiotemporal variation in viral dynamics and methodological differences. Meta-analysis identified sample type and sampling design as the best predictors of prevalence, with virus detection maximized in rectal and faecal samples and by repeat sampling of the same site. Fewer than one in five studies collected and reported longitudinal data, and euthanasia did not improve virus detection. We show that bat sampling before the SARS-CoV-2 pandemic was concentrated in China, with research gaps in South Asia, the Americas and sub-Saharan Africa, and in subfamilies of phyllostomid bats. We propose that surveillance strategies should address these gaps to improve global health security and enable the origins of zoonotic coronaviruses to be identified.

One Health Surveillance Highlights Circulation of Viruses with Zoonotic Potential in Bats, Pigs, and Humans in Viet Nam

A One Health cross-sectoral surveillance approach was implemented to screen biological samples from bats, pigs, and humans at high-risk interfaces for zoonotic viral spillover for five viral families with zoonotic potential in Viet Nam. Over 1600 animal and human samples from bat guano harvesting sites, natural bat roosts, and pig farming operations were tested for coronaviruses (CoVs), paramyxoviruses, influenza viruses, filoviruses and flaviviruses using consensus PCR assays. Human samples were also tested using immunoassays to detect antibodies against eight virus groups. Significant viral diversity, including CoVs closely related to ancestors of pig pathogens, was detected in bats roosting at the human-animal interfaces, illustrating the high risk for CoV spillover from bats to pigs in Viet Nam, where pig density is very high. Season and reproductive period were significantly associated with the detection of bat CoVs, with site-specific effects. Phylogeographic analysis indicated localized viral transmission among pig farms. Our limited human sampling did not detect any known zoonotic bat viruses in human communities living close to the bat cave and harvesting bat guano, but our serological assays showed possible previous exposure to Marburg virus-like (Filoviridae), Crimean-Congo hemorrhagic fever virus-like (Bunyaviridae) viruses and flaviviruses. Targeted and coordinated One Health surveillance helped uncover this viral pathogen emergence hotspot.

Paramyxoviruses in rodents: A review

Paramyxoviruses have been shown to infect a wide range of hosts, including rodents, and humans. Several novel murine paramyxoviruses have been discovered in the last several decades. Although these viruses are unclassified, they are recognized as Beilong virus, Mojiang virus (MojV), and Tailam virus in rats, Jeilongvirus, Nariva, Paju Apodemus paramyxovirus-1 and -2 in mice, and Pentlands paramyxovirus-1, -2, and -3 in squirrels. These paramyxoviruses were reported mainly in China and a few other countries like Australia, the Republic of Korea, Trinidad, and France. In June 2012, it becomes a great concern in China whereby, three miners were reported dead potentially caused by a novel zoonotic MojV, a henipa-like virus isolated from tissue samples of rats from the same cave. Rats are considered to be natural hosts for the MojV from the literature research. The classified paramyxovirus, Sendai virus in rodents is also reviewed. Paramyxoviruses infection in rodents leads to respiratory distress such as necrotizing rhinitis, tracheitis, bronchiolitis, and interstitial pneumonia. Infections caused by paramyxoviruses often spread between species, manifesting disease in spillover hosts, including humans. This review focuses on the paramyxoviruses in rodents, including the epidemiological distributions, transmission and pathogenesis, clinical manifestations, diagnostic methods, and control and prevention of paramyxoviruses infection to provide a better understanding of these highly mutating viruses.

Testing bats in rehabilitation for SARS-CoV-2 before release into the wild

Several studies have suggested SARS-CoV-2 originated from a viral ancestor in bats, but whether transmission occurred directly or via an intermediary host to humans remains unknown. Concerns of spillover of SARS-CoV-2 into wild bat populations are hindering bat rehabilitation and conservation efforts in the United Kingdom and elsewhere. Current protocols state that animals cared for by individuals who have tested positive for SARS-CoV-2 cannot be released into the wild and must be isolated to reduce the risk of transmission to wild populations. Here, we propose a reverse transcription-quantitative polymerase chain reaction (RT-qPCR)-based protocol for detection of SARS-CoV-2 in bats, using fecal sampling. Bats from the United Kingdom were tested following suspected exposure to SARS-CoV-2 and tested negative for the virus. With current UK and international legislation, the identification of SARS-CoV-2 infection in wild animals is becoming increasingly important, and protocols such as the one developed here will help improve understanding and mitigation of SARS-CoV-2 in the future.

The Characterization of Multiple Novel Paramyxoviruses Highlights the Diverse Nature of the Subfamily Orthoparamyxovirinae

The subfamily Orthoparamyxovirinae is a group of single-stranded, negative-sense RNA viruses that contains many human, animal, and zoonotic pathogens. While there are currently only forty-two recognized species in this subfamily, recent research has revealed that much of its diversity remains to be characterized. Using a newly developed nested PCR-based screening assay, we report here the discovery of fifteen orthoparamyxoviruses in rodents and shrews from Belgium and Guinea, thirteen of which are believed to represent new species. Using a combination of nanopore and sanger sequencing, complete genomes could be determined for almost all these viruses, enabling a detailed evaluation of their genome characteristics. While most viruses are thought to belong to the rapidly expanding genus Jeilongvirus, we also identify novel members of the genera Narmovirus, Henipavirus, and Morbillivirus. Together with other recently discovered orthoparamyxoviruses, both henipaviruses and the morbillivirus discovered here appear to form distinct rodent-/shrew-borne clades within their respective genera, clustering separately from all currently classified viruses. In the case of the henipaviruses, a comparison of the different members of this clade revealed the presence of a secondary conserved open reading frame, encoding for a transmembrane protein, within the F gene, the biological relevance of which remains to be established. While the characteristics of the viruses described here shed further light on the complex evolutionary origin of paramyxoviruses, they also illustrate that the diversity of this group of viruses in terms of genome organization appears to be much larger than previously assumed.

Detection of Lassa virus in wild rodent feces: Implications for Lassa fever burden within households in the endemic region of Faranah, Guinea

Lassa arenavirus (LASV) is the cause of Lassa Fever in humans in West Africa. The multimammate mouse (Mastomys natalensis) is a reservoir host of LASV and the primary source of human infections. Humans are assumed to become infected due to contact with this animal or its excretions. Thus far, the available literature does not describe the sampling of feces as a means to detect LASV in M. natalensis populations. More evidence is needed to know if feces of naturally infected M. natalensis can be LASV-positive and an exposure risk to humans. This study sampled feces deposits in households from three villages in the LASV-endemic region of Faranah, Guinea. PCR analysis found 10 out of 88 samples to be positive for LASV, and sequencing showed clustering to previously identified Yarawelia and Dalafilani strains. We conclude that feces sampling is a viable, non-invasive method for the determination and sequencing of LASV strains.

Transmission of SARS-CoV-2 virus and ambient temperature: a critical review

The coronavirus disease 2019 (COVID-19) pandemic has brought unprecedented public health, and social and economic challenges. It remains unclear whether seasonal changes in ambient temperature will alter spreading trajectory of the COVID-19 epidemic. The probable mechanism on this is still lacking. This review summarizes the most recent research data on the effect of ambient temperature on the COVID-19 epidemic characteristic. The available data suggest that (i) mesophilic traits of viruses are different due to their molecular composition; (ii) increasing ambient temperature decreases the persistence of some viruses in aquatic media; (iii) a 1°C increase in the average monthly minimum ambient temperatures (AMMAT) was related to a 0.72% fewer mammalian individuals that would be infected by coronavirus; (iv) proportion of zoonotic viruses of mammals including humans is probably related to their body temperature difference; (v) seasonal divergence between the northern and southern hemispheres may be a significant driver in determining a waved trajectory in the next 2 years. Further research is needed to understand its effects and mechanisms of global temperature change so that effective strategies can be adopted to curb its natural effects. This paper mainly explores possible scientific hypothesis and evidences that local communities and authorities should consider to find optimal solutions that can limit the transmission of SARS-CoV-2 virus.

Evolution, Ecology, and Zoonotic Transmission of Betacoronaviruses: A Review

Coronavirus infections have been a part of the animal kingdom for millennia. The difference emerging in the twenty-first century is that a greater number of novel coronaviruses are being discovered primarily due to more advanced technology and that a greater number can be transmitted to humans, either directly or via an intermediate host. This has a range of effects from annual infections that are mild to full-blown pandemics. This review compares the zoonotic potential and relationship between MERS, SARS-CoV, and SARS-CoV-2. The role of bats as possible host species and possible intermediate hosts including pangolins, civets, mink, birds, and other mammals are discussed with reference to mutations of the viral genome affecting zoonosis. Ecological, social, cultural, and environmental factors that may play a role in zoonotic transmission are considered with reference to SARS-CoV, MERS, and SARS-CoV-2 and possible future zoonotic events.

Coronavirus 2019 Infectious Disease Epidemic: Where We Are, What Can Be Done and Hope For

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads mainly by means of aerosols (microdroplets) in enclosed environments, especially those in which temperature and humidity are regulated by means of air-conditioning. About 30% of individuals infected with SARS-CoV-2 develop coronavirus disease 2019 (COVID-19) disease. Among them, approximately 25% require hospitalization. In medicine, cases are identified as those who become ill. During this pandemic, cases have been identified as those with a positive SARS-CoV-2 polymerase chain reaction test, including approximately 70% who were asymptomatic-this has caused unnecessary anxiety. Individuals more than 65 years old, those affected by obesity, diabetes, asthma, or are immune-depressed owing to cancer and other conditions, are at a higher risk of hospitalization and of dying of COVID-19. Healthy individuals younger than 40 years very rarely die of COVID-19. Estimates of the COVID-19 mortality rate vary because the definition of COVID-19-related deaths varies. Belgium has the highest death rate at 154.9 per 100,000 persons, because it includes anyone who died with symptoms compatible with COVID-19, even those never tested for SARS-CoV-2. The United States includes all patients who died with a positive test, whether they died because of, or with, SARS-CoV-2. Countries that include only patients in which COVID-19 was the main cause of death, rather than a cofactor, have lower death rates. Numerous therapies are being developed, and rapid improvements are anticipated. Because of disinformation, only approximately 50% of the U.S. population plans to receive a COVID-19 vaccine. By sharing accurate information, physicians, health professionals, and scientists play a key role in addressing myths and anxiety, help public health officials enact measures to decrease infections, and provide the best care for those who become sick. In this article, we discuss these issues.

Emergence of Bat-Related Betacoronaviruses: Hazard and Risks

The current Coronavirus Disease 2019 (COVID-19) pandemic, with more than 111 million reported cases and 2,500,000 deaths worldwide (mortality rate currently estimated at 2.2%), is a stark reminder that coronaviruses (CoV)-induced diseases remain a major threat to humanity. COVID-19 is only the latest case of betacoronavirus (β-CoV) epidemics/pandemics. In the last 20 years, two deadly CoV epidemics, Severe Acute Respiratory Syndrome (SARS; fatality rate 9.6%) and Middle East Respiratory Syndrome (MERS; fatality rate 34.7%), plus the emergence of HCoV-HKU1 which causes the winter common cold (fatality rate 0.5%), were already a source of public health concern. Betacoronaviruses can also be a threat for livestock, as evidenced by the Swine Acute Diarrhea Syndrome (SADS) epizootic in pigs. These repeated outbreaks of β-CoV-induced diseases raise the question of the dynamic of propagation of this group of viruses in wildlife and human ecosystems. SARS-CoV, SARS-CoV-2, and HCoV-HKU1 emerged in Asia, strongly suggesting the existence of a regional hot spot for emergence. However, there might be other regional hot spots, as seen with MERS-CoV, which emerged in the Arabian Peninsula. β-CoVs responsible for human respiratory infections are closely related to bat-borne viruses. Bats are present worldwide and their level of infection with CoVs is very high on all continents. However, there is as yet no evidence of direct bat-to-human coronavirus infection. Transmission of β-CoV to humans is considered to occur accidentally through contact with susceptible intermediate animal species. This zoonotic emergence is a complex process involving not only bats, wildlife and natural ecosystems, but also many anthropogenic and societal aspects. Here, we try to understand why only few hot spots of β-CoV emergence have been identified despite worldwide bats and bat-borne β-CoV distribution. In this work, we analyze and compare the natural and anthropogenic environments associated with the emergence of β-CoV and outline conserved features likely to create favorable conditions for a new epidemic. We suggest monitoring South and East Africa as well as South America as these regions bring together many of the conditions that could make them future hot spots.

Metagenomic Snapshots of Viral Components in Guinean Bats

To prevent the emergence of zoonotic infectious diseases and reduce their epidemic potential, we need to understand their origins in nature. Bats in the order Chiroptera are widely distributed worldwide and are natural reservoirs of prominent zoonotic viruses, including Nipah virus, Marburg virus, and possibly SARS-CoV-2. In this study, we applied unbiased metagenomic and metatranscriptomic approaches to decipher the virosphere of frugivorous and insectivorous bat species captured in Guéckédou, Guinea, the epicenter of the West African Ebola virus disease epidemic in 2013–2016. Our study provides a snapshot of the viral diversity present in these bat species, with several novel viruses reported for the first time in bats, as well as some bat viruses closely related to known human or animal pathogens. In addition, analysis of Mops condylurus genomic DNA samples revealed the presence of an Ebola virus nucleoprotein (NP)-derived pseudogene inserted in its genome. These findings provide insight into the evolutionary traits of several virus families in bats and add evidence that nonretroviral integrated RNA viruses (NIRVs) derived from filoviruses may be common in bat genomes.

New Insights Into the Physiopathology of COVID-19: SARS-CoV-2-Associated Gastrointestinal Illness

Although SARS-CoV-2 is considered a lung-tropic virus that infects the respiratory tract through binding to the ACE2 cell-surface molecules present on alveolar lungs epithelial cells, gastrointestinal symptoms have been frequently reported in COVID-19 patients. What can be considered an apparent paradox is that these symptoms (e.g., diarrhea), sometimes precede the development of respiratory tract illness as if the breathing apparatus was not its first target during viral dissemination. Recently, evidence was reported that the gut is an active site of replication for SARS-CoV-2. This replication mainly occurs in mature enterocytes expressing the ACE2 viral receptor and TMPRSS4 protease. In this review we question how SARS-CoV-2 can cause intestinal disturbances, whether there are pneumocyte-tropic, enterocyte-tropic and/or dual tropic strains of SARS-CoV-2. We examine two major models: first, that of a virus directly causing damage locally (e.g., by inducing apoptosis of infected enterocytes); secondly, that of indirect effect of the virus (e.g., by inducing changes in the composition of the gut microbiota followed by the induction of an inflammatory process), and suggest that both situations probably occur simultaneously in COVID-19 patients. We eventually discuss the consequences of the virus replication in brush border of intestine on long-distance damages affecting other tissues/organs, particularly lungs.

Paramyxovirus circulation in bat species from French Guiana

Bats are recognized as reservoirs of numerous viruses. Among them, paramyxoviruses, for example, Hendra and Nipah viruses, are highly pathogenic to humans. Nothing is known regarding the circulation of this viral family in bats from French Guiana. To search for the presence of paramyxoviruses in this territory, 103 bats of seven different species were sampled and screened using a molecular approach. Four distinct paramyxovirus sequences were detected from three bat species (Desmodus rotundus, Carollia perspicillata, and Pteronotus alitonus) at high prevalence rates. In D. rotundus, two types of paramyxovirus co-circulate, with most of the bats co-infected. The phylogenetic analysis of these sequences revealed that three of them were closely related to previously characterized sequences from D. rotundus, C. perspicillata, and P. parnellii from Brazil and Costa Rica. The fourth sequence, identified in D. rotundus, was closely related to the one detected in P. alitonus in French Guiana and to previously described sequences detected in P. parnellii in Costa Rica. All paramyxovirus sequences detected in this study are close to the Jeilongvirus genus. Altogether, our results and those of previous studies indicate a wide geographical distribution of these paramyxoviruses (from Central to South America) and suggest potential cross-species transmissions of paramyxoviruses between two different bat families: Mormoopidae (P. alitonus) and Phyllostomidae (D. rotundus). In addition, their closeness to paramyxoviruses identified in rodents emphasizes the need to investigate the role of these animals as potential reservoirs or incidental hosts. Finally, the high prevalence rates of some paramyxoviruses in certain bat species, associated with the presence of large bat colonies and, in some cases, their potential proximity with humans are all parameters that can contribute to the risk of cross-species transmission between bat species and to the emergence of new paramyxoviruses in humans, a risk that deserves further investigation.

COVID-19: Time to exonerate the pangolin from the transmission of SARS-CoV-2 to humans

The emergence of COVID-19 has triggered many works aiming at identifying the animal intermediate potentially involved in the transmission of SARS-CoV-2 to humans. The presence of SARS-CoV-2-related viruses in Malayan pangolins, in silico analysis of the ACE2 receptor polymorphism and sequence similarities between the Receptor Binding Domain (RBD) of the spike proteins of pangolin and human Sarbecoviruses led to the proposal of pangolin as intermediary. However, the binding affinity of the pangolin ACE2 receptor for SARS-CoV-2 RBD was later on reported to be low. Here, we provide evidence that the pangolin is not the intermediate animal at the origin of the human pandemic. Moreover, data available do not fit with the spillover model currently proposed for zoonotic emergence which is thus unlikely to account for this outbreak. We propose a different model to explain how SARS-CoV-2 related coronaviruses could have circulated in different species, including humans, before the emergence of COVID-19.

Metagenomic Insights into the Sewage RNA Virosphere of a Large City

Sewage-associated viruses can cause several human and animal diseases, such as gastroenteritis, hepatitis, and respiratory infections. Therefore, their detection in wastewater can reflect current infections within the source population. To date, no viral study has been performed using the sewage of any large South American city. In this study, we used viral metagenomics to obtain a single sample snapshot of the RNA virosphere in the wastewater from Santiago de Chile, the seventh largest city in the Americas. Despite the overrepresentation of dsRNA viruses, our results show that Santiago’s sewage RNA virosphere was composed mostly of unknown sequences (88%), while known viral sequences were dominated by viruses that infect bacteria (60%), invertebrates (37%) and humans (2.4%). Interestingly, we discovered three novel genogroups within the Picobirnaviridae family that can fill major gaps in this taxa’s evolutionary history. We also demonstrated the dominance of emerging Rotavirus genotypes, such as G8 and G6, that have displaced other classical genotypes, which is consistent with recent clinical reports. This study supports the usefulness of sewage viral metagenomics for public health surveillance. Moreover, it demonstrates the need to monitor the viral component during the wastewater treatment and recycling process, where this virome can constitute a reservoir of human pathogens.

Coronavirus testing indicates transmission risk increases along wildlife supply chains for human consumption in Viet Nam, 2013-2014

Outbreaks of emerging coronaviruses in the past two decades and the current pandemic of a novel coronavirus (SARS-CoV-2) that emerged in China highlight the importance of this viral family as a zoonotic public health threat. To gain a better understanding of coronavirus presence and diversity in wildlife at wildlife-human interfaces in three southern provinces in Viet Nam 2013-2014, we used consensus Polymerase Chain Reactions to detect coronavirus sequences. In comparison to previous studies, we observed high proportions of positive samples among field rats (34.0%, 239/702) destined for human consumption and insectivorous bats in guano farms (74.8%, 234/313) adjacent to human dwellings. Most notably among field rats, the odds of coronavirus RNA detection significantly increased along the supply chain from field rats sold by traders (reference group; 20.7% positivity, 39/188) by a factor of 2.2 for field rats sold in large markets (32.0%, 116/363) and 10.0 for field rats sold and served in restaurants (55.6%, 84/151). Coronaviruses were also detected in rodents on the majority of wildlife farms sampled (60.7%, 17/28). These coronaviruses were found in the Malayan porcupines (6.0%, 20/331) and bamboo rats (6.3%, 6/96) that are raised on wildlife farms for human consumption as food. We identified six known coronaviruses in bats and rodents, clustered in three Coronaviridae genera, including the Alpha-, Beta-, and Gammacoronaviruses. Our analysis also suggested either mixing of animal excreta in the environment or interspecies transmission of coronaviruses, as both bat and avian coronaviruses were detected in rodent feces on wildlife farms. The mixing of multiple coronaviruses, and their apparent amplification along the wildlife supply chain into restaurants, suggests maximal risk for end consumers and likely underpins the mechanisms of zoonotic spillover to people.

Identification and characterization of Jingmen tick virus in rodents from Xinjiang, China

Jingmen tick virus (JMTV) is a recently identified virus which provides an unexpected connection between segmented and unsegmented RNA viruses. Recent investigations reveal that JMTV including JMTV-like virus (Alongshan virus) could be associated with human disease, suggesting the significance of JMTV in public health. To better understand the genetic diversity and host range of JMTV, a total of 164 rodents representing 8 species were collected in Qapqal Xibe county of Xinjiang Uygur Autonomous Region, China, and were screened for JMTVs using RT- PCR. Consequently, JMTV was identified in 42 rodents including 23 Microtus arvalis voles (24.5%), 9 Apodemus uralensis mice (29.0%), 5 Mus musculus mice, 1 Rhombomys opimus gerbil, 1 Meriones tamariscinus gerbil, 1 Meriones libycus gerbil, 1 Cricetulus migratorius hamster and 1 Microtus gregalis vole. Interestingly, nearly complete genome sequences were successfully recovered from 7 JMTV positive samples. Although the newly identified rodent JMTVs were closely related to those previously identified in ticks from China, based on the phylogenetic analysis of the S1, S2 and S3 segments, the newly identified rodent viruses clustered into two genetic groups. One group comprised of viruses only found in M. arvalis, while another group included viruses from A. uralensis, C. migratorius and M. gregalis. However, all rodent viruses clustered together in the S4 tree. Considering rodents live in close proximity to humans, more efforts are needed to investigate the role of rodents in the evolution and transmission of JMTV in nature.

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Jingmen tick virus (JMTV) was found in 8 species of rodents from Xinjiang of China.

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Two sub-lineages of JMTVs were co-circulating in these rodents in Xinjiang.

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One sub-lineage of viruses was only identified in Microtus arvalis voles.

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Our data indicate that rodents are one of the natural hosts of JMTV.

Coronavirus surveillance of wildlife in the Lao People's Democratic Republic detects viral RNA in rodents

Coronaviruses can become zoonotic, as in the case of COVID-19, and hunting, sale, and consumption of wild animals in Southeast Asia increases the risk for such incidents. We sampled and tested rodents (851) and other mammals and found betacoronavirus RNA in 12 rodents. The sequences belong to two separate genetic clusters and are closely related to those of known rodent coronaviruses detected in the region and distantly related to those of human coronaviruses OC43 and HKU1. Considering the close human-wildlife contact with many species in and beyond the region, a better understanding of virus diversity is urgently needed for the mitigation of future risks.

Meat consumption: Which are the current global risks? A review of recent (2010-2020) evidences

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Consumption of fatty meats may increase risks of cardiovascular diseases and cancer.

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Production of red meats increases greenhouse gases (GHG) emissions contributing to the global warming.

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Consumption of wild meats can pose some serious risks of transmission of viruses from animals to humans.

Meat consumption has been increasing since the 1960s, but especially from the 1980s decade to today. Although meat means an important source of nutrients, it is also evident that a great consumption of this source of proteins has also a negative environmental impact. Livestock production does not only have a negative influence on GHG emissions, but also on the water footprint, water pollution, and water scarcity. With respect to human health, in 2015 the International Agency for Research on Cancer (IARC) stated that red meat was a probable carcinogen to humans (Group 2A), while consumption of processed meat was carcinogenic to humans (Group 1). Most environmental contaminants (PCDD/Fs, PCBs, PBDEs, PCNs, etc.) that are frequently found in meats are highly soluble in fats. Therefore, avoiding ingesting fats from red meats and meat products, doubtless would help in the prevention, not only of the well-known cardiovascular diseases derived of fats consumption, but also of certain kinds of cancers, mainly colorectal cancer. On the other hand, consumption of meat – especially wild meat – is related to virus infections, as many viruses have been found in wild meat trade markets. Based on the scientific literature here reviewed, we have noted that the results of the investigations conducted after the statement of the IARC, have corroborated the recommendation of reducing significantly the consumption of red meats and meat products. In turn, the reduction of meat consumption should contribute to the reduction of GHG emissions and their considerable impact on global warming and climate change. It seems evident that human dietary habits regarding meat consumption in general, and red meats and wild meats in particular, should be significantly modified downward, as much and as soon as possible.

Expansion of the metazoan virosphere: progress, pitfalls, and prospects

Metagenomic sequencing has led to a recent and rapid expansion of the animal virome. It has uncovered a multitude of new virus lineages from under-sampled host groups, including many that break up long branches in the virus tree, and many that display unexpected genome sizes and structures. Although there are challenges to inferring the existence of a virus from a `virus-like sequence', in the absence of an isolate the analysis of nucleic acid (including small RNAs) and sequence data can provide considerable confidence. As a consequence, this period of molecular natural history is helping to reshape our views of deep virus evolution.

Detection and Characterization of Homologues of Human Hepatitis Viruses and Pegiviruses in Rodents and Bats in Vietnam

Rodents and bats are now widely recognised as important sources of zoonotic virus infections in other mammals, including humans. Numerous surveys have expanded our knowledge of diverse viruses in a range of rodent and bat species, including their origins, evolution, and range of hosts. In this study of pegivirus and human hepatitis-related viruses, liver and serum samples from Vietnamese rodents and bats were examined by PCR and sequencing. Nucleic acids homologous to human hepatitis B, C, E viruses were detected in liver samples of 2 (1.3%) of 157 bats, 38 (8.1%), and 14 (3%) of 470 rodents, respectively. Hepacivirus-like viruses were frequently detected (42.7%) in the bamboo rat, Rhizomys pruinosus, while pegivirus RNA was only evident in 2 (0.3%) of 638 rodent serum samples. Complete or near-complete genome sequences of HBV, HEV and pegivirus homologues closely resembled those previously reported from rodents and bats. However, complete coding region sequences of the rodent hepacivirus-like viruses substantially diverged from all of the currently classified variants and potentially represent a new species in the Hepacivirus genus. Of the viruses identified, their routes of transmission and potential to establish zoonoses remain to be determined.

Detection of potentially novel paramyxovirus and coronavirus viral RNA in bats and rats in the Mekong Delta region of southern Viet Nam

Bats and rodents are being increasingly recognized as reservoirs of emerging zoonotic viruses. Various studies have investigated bat viruses in tropical regions, but to date there are no data regarding viruses with zoonotic potential that circulate in bat and rat populations in Viet Nam. To address this paucity of data, we sampled three bat farms and three wet markets trading in rat meat in the Mekong Delta region of southern Viet Nam. Faecal and urine samples were screened for the presence of RNA from paramyxoviruses, coronaviruses and filoviruses. Paramyxovirus RNA was detected in 4 of 248 (1%) and 11 of 222 (4.9%) bat faecal and urine samples, respectively. Coronavirus RNA was detected in 55 of 248 (22%) of bat faecal samples; filovirus RNA was not detected in any of the bat samples. Further, coronavirus RNA was detected in 12 of 270 (4.4%) of rat faecal samples; all samples tested negative for paramyxovirus. Phylogenetic analysis revealed that the bat paramyxoviruses and bat and rat coronaviruses were related to viruses circulating in bat and rodent populations globally, but showed no cross-species mixing of viruses between bat and rat populations within Viet Nam. Our study shows that potentially novel variants of paramyxoviruses and coronaviruses commonly circulate in bat and rat populations in Viet Nam. Further characterization of the viruses and additional human and animal surveillance is required to evaluate the likelihood of viral spillover and to assess whether these viruses pose a risk to human health.

Assessing the Diversity of Rodent-Borne Viruses: Exploring of High-Throughput Sequencing and Classical Amplification/Sequencing Approaches

Rodents are distributed throughout the world and interact with humans in many ways. They provide vital ecosystem services, some species are useful models in biomedical research and some are held as pet animals. However, many rodent species can have adverse effects such as damage to crops and stored produce, and they are of health concern because of the transmission of pathogens to humans and livestock. The first rodent viruses were discovered by isolation approaches and resulted in break-through knowledge in immunology, molecular and cell biology, and cancer research. In addition to rodent-specific viruses, rodent-borne viruses are causing a large number of zoonotic diseases. Most prominent examples are reemerging outbreaks of human hemorrhagic fever disease cases caused by arena- and hantaviruses. In addition, rodents are reservoirs for vector-borne pathogens, such as tick-borne encephalitis virus and Borrelia spp., and may carry human pathogenic agents, but likely are not involved in their transmission to human. In our days, next-generation sequencing or high-throughput sequencing (HTS) is revolutionizing the speed of the discovery of novel viruses, but other molecular approaches, such as generic RT-PCR/PCR and rolling circle amplification techniques, contribute significantly to the rapidly ongoing process. However, the current knowledge still represents only the tip of the iceberg, when comparing the known human viruses to those known for rodents, the mammalian taxon with the largest species number. The diagnostic potential of HTS-based metagenomic approaches is illustrated by their use in the discovery and complete genome determination of novel borna- and adenoviruses as causative disease agents in squirrels. In conclusion, HTS, in combination with conventional RT-PCR/PCR-based approaches, resulted in a drastically increased knowledge of the diversity of rodent viruses. Future improvements of the used workflows, including bioinformatics analysis, will further enhance our knowledge and preparedness in case of the emergence of novel viruses. Classical virological and additional molecular approaches are needed for genome annotation and functional characterization of novel viruses, discovered by these technologies, and evaluation of their zoonotic potential.