MERS-CoV Viruses Research Articles

Systematic assessment of SARS-CoV-2 virus in wastewater, rivers and drinking water – A catchment-wide appraisal

Human coronaviruses (HCoVs) attracted attention in 2002 with the severe acute respiratory syndrome (SARS) outbreak, caused by the SARS-CoV virus (mortality rate 9.6%), and gained further notoriety in 2012 with the Middle East respiratory syndrome (MERS) (mortality rate 34.3%). Currently, the world is experiencing an unprecedented crisis due to the COVID-19 global pandemic, caused by the SARS-CoV-2 virus in 2019. The virus can pass to the faeces of some patients, as was the case of SARS-CoV and MERS-CoV viruses. This suggests that apart from the airborne (droplets and aerosols) and person-to-person (including fomites) transmission, the faecal–oral route of transmission could also be possible for HCoVs. In this eventuality, natural water bodies could act as a virus reservoir of infection. Here, the temporospatial migration and attenuation of the SARS-CoV-2 virus in municipal wastewater, the receiving environment, and drinking water is evaluated, using the polymerase chain reaction (PCR), in the South African setting. SARS-CoV-2 viral RNA was identified in raw wastewater influent but was below the detection limit in the latter treatment stages. This suggests that the virus decays from as early as primary treatment and this could be attributed to wastewater's hydraulic retention time (2–4 h), composition, and more importantly temperature (>25 °C). Therefore, the probability of SARS-CoV-2 virus transportation in water catchments, in the eventuality that the virus remains infective in wastewater, appears to be low in the South African setting. Finally, catchment-wide monitoring offers a snapshot of the status of the catchment in relation to contagious viruses and can play a pivotal role in informing the custodians and downstream water users of potential risks embedded in water bodies.

Traces of SARS-CoV-2 RNA in Peripheral Blood Cells of Patients with COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third virus that caused coronavirus-related outbreaks over the past 20 years. The outbreak was first reported in December 2019 in Wuhan, China, but rapidly progressed into a pandemic of an unprecedented scale since the 1918 flu pandemic. Besides respiratory complications in patients with COVID-19, clinical characterization of severe infection cases showed several other comorbidities, including multiple organ failure, and septic shock. To better understand the systemic pathogenesis of COVID-19, we interrogated the virus's presence in the peripheral blood cells, which might provide a form of trafficking or hiding to the virus. By analyzing >2 billion sequence reads of high-throughput transcriptome sequence data from 180 samples of patients with active SARS-CoV-2 infection or healthy controls collected from 6 studies, we found evidence of traces of SARS-CoV-2 RNA in peripheral blood mononuclear cells in two samples from two independent studies. In contrast, the viral RNA was abundant in bronchoalveolar lavage specimens from the same patients. We also devised a “viral spike-to-actin” RNA normalization as a metric to compare across various samples and minimize errors caused by intersample variability in total human RNA abundance. Our observation suggests immune presentation and discounts the possibility of extensive viral infection of lymphocytes or monocytes.

SARS-CoV-2 routes of transmission and recommendations for preventing acquisition: joint British Infection Association (BIA), Healthcare Infection Society (HIS), Infection Prevention Society (IPS) and Royal College of Pathologists (RCPath) guidance

SARS-CoV-2 routes of transmission and recommendations for preventing acquisition: joint British Infection Association (BIA), Healthcare Infection Society (HIS), Infection Prevention Society (IPS) and Royal College of Pathologists (RCPath) guidance

Analisis Clustering Virus MERS-CoV Menggunakan Metode Spectral Clustering Dan Algoritma K-Means

<p><em>The MERS-Cov virus has spread to other countries outside Saudi Arabia. This is because the MERS-CoV virus can mutate rapidly so it is feared that it could threaten public health and even world health. This virus develops and becomes an acute respiratory disease and the mortality rate reaches 30% among 536 cases. One way to classify the MERS-CoV virus is by grouping the DNA sequences of the MERS-CoV virus which have similar characteristics and functions. Spectral clustering is a grouping method that can identify DNA gene expression. This method is also able to partition DNA data with a more complex structure than the partition clustering method. The purpose of this study was to analyze the MERS-CoV virus clustering using the spectral clustering method and the k-means algorithm. This study used a quantitative descriptive literature approach. The results showed that the results of clustering using the spectral clustering method and the k-means algorithm produced three clusters and were more homogeneous than clustering using k-means only.</em></p>

Orlando’nun Hemşirelikte Etkileşim Modeline Göre Covid-19 Pozitif Lohusanın Hemşirelik Bakımı: Olgu Sunumu

Recently, the use of theories in nursing, which is a professional profession, is increasing. Nursing theories and models serve as guidance for nurses in the fields of education, research, and practice. It distinguishes the professional nursing profession from other occupational groups and improves the quality of the care offered to the patient. One of the models used is Orlando's Nursing Process Theory.The period of puerperium is a process in which healthy connection between mother baby and family members is ensured, health is protected and improved, physiological and psychological processes are observed. Covid 19 is called Severe Acute Respiratory Syndrome. Covid 19; Similar to mers-cov and SARS-CoV viruses, it is described as a zoonotic virus that infects people from animals to humans. Covid 19 is a disease that requires isolation, affecting lohusas to get adequate support from family members. As one of the features of the postpartum period, the deeper psychological effects and social distance requirements of the puerperant woman that are already psycho-socially difficult to follow have revealed the need to privatize nursing care to be carried out in lohusas caught up in this disease.In this study, puerperant woman diagnosed with COVID 19 in the clinic was applied to provide nursing care using the Nursing Process Theory of Orlando. Verbal and written permission was obtained from the puerperant woman before the study. Between 3-9 May 2020, when puerperant woman was in the clinic, the data was collected by face-to-face interview method. Orlando's nursing process theory was determined by the patient's needs, planned, implemented in accordance with the nursing process for nursing actions, and as a result, a positive improvement process was observed in the patient's behavior. Orlando's Nursing Process Theory is also recommended in other clinics, such as psychiatry and obstetrics.

The Evaluation оf Potential Threat оf Animal’s Coronaviruses аs Human’s Patogens

The introduction of SARS-CoV-2 coronavirus from a natural reservoir into the human population subsequently caused the COVID-19 pandemic, that had a huge impact on all spheres of human activity dramatically increased interest in this group of viruses. Given that such an introduction of the coronavirus was already the third in a row in 21 century (after outbreaks caused by SARS-CoV and MERS-CoV viruses), there are quite good reasons to fear the appearance of new diseases, the etiological agents of which will be representatives of the Coronaviridae family in the future. The purpose of this review is to assess the potential risk of coronaviruses of animals as possible human pathogens. When preparing the review, the following data were used: data published in leading foreign journals as well as in Internet sources that address some aspects of the COVID-19 pandemic. The following main aspects of this problem are considered: a spontaneous formation during the evolution of animal coronaviruses, highly pathogenic to humans; a possibility of transmission of human coronavirus to animals, its genetic interaction with the coronavirus, the owner of which is this animal, the acquisition of viral progeny, a set of new properties and reverse transmission from animal to man a pathogen that may have increased pathogenicity. Animal coronaviruses are considered by belonging to a certain taxonomic group of their natural hosts. The main focus is on bat coronaviruses (as a reservoir of SARS-CoV, MERS-CoV and SARS-CoV-2 viruses), as well as avian coronaviruses, due to the potential ability of these animals to become vectors of spread of new emergent diseases and the coronaviruses of carnivores, due to the established during the COVID-19 pandemic fact of transmission of the SARS-CoV-2 virus from man to mink and from mink to man. Studying the features of molecular evolution it will help you better understand the mechanisms of occurrence and adaptation to humans pathogens of emergent viral diseases.

A novel One-pot rapid diagnostic technology for COVID-19

Novel coronavirus disease (COVID-19) caused by SARS-CoV-2 is an ongoing global pandemic associated with high rates of morbidity and mortality. RT-qPCR has become the diagnostic standard for the testing of SARS-CoV-2 in most countries. COVID-19 diagnosis generally relies upon RT-qPCR-mediated identification of SARS-CoV-2 viral RNA, which is costly, labor-extensive, and requires specialized training and equipment. Herein, we established a novel one-tube rapid diagnostic approach based upon formamide and colorimetric RT-LAMP (One-Pot RT-LAMP) that can be used to diagnose COVID-19 without the extraction of specific viral RNA. The technique could visually detect SARS-CoV-2 within 45 min with a limit of detection of 5 copies per reaction in extracted RNA, and about 7.66 virus copies per μL in viral transport medium. The One-Pot RT-LAMP test showed a high specificity without cross-reactivity with 12 viruses including SARS-CoV, MERS-CoV, and human infectious influenza virus (H1N1/H3N2 of influenza A and B virus, ect. We validated this One-Pot RT-LAMP approach by its successful use for the analysis of 45 clinical nasopharyngeal swab samples, yielding results identical to those of traditional RT-qPCR analyses, while achieving good selectivity and sensitivity relative to a commercial RT-qPCR approach. As such, this One-Pot RT-LAMP technology may be a valid means of conducting high-sensitivity, low-cost and rapid SARS-CoV-2 identification without the extraction of viral RNA.

Novel coronavirus disease 2019 (COVID-19) and challenges in dental practices

The Covid-19 virus appearing in Wuhan in December, 2019 and acting by binding to ACE-2 receptors in the respiratory system has caused many people to die by spreading to the whole world. The virus, which has been detected to spread faster than SARS-CoV and MERS-CoV viruses, spreads from person to person rapidly. People should not be together because it is transmitted from person to person through the respiratory tract. For this reason, it is recommended not to go to health institutions, provided that it is not urgent. However, many emergency patients go to dental clinics and hospitals for treatment. In this review; with possible contamination routes of Covid-19 such as airborne spread, contact spread and contaminated surface spread during patient diagnosis and treatment to prevent Covid-19 contamination, methods preventing spread such as hand hygiene, personal protective measures for dentists, intraoral rubber dam before dental procedures were indicated. It was also mentioned that the fast rotating tool with valves having negative pressure should be used and most importantly, the materials used in the dental clinic should be disposed in accordance with medical waste protocol.
 How to cite this article:
 Novel coronavirus disease 2019 (COVID-19) and challenges in dental practices. Int Dent Res 2020;10(3):100-15. https://doi.org/10.5577/intdentres.2020.vol10.n3.5
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Is there scientific evidence of the mouthwashes effectiveness in reducing viral load in Covid-19? A systematic review.

BackgroundThe aim of this research is to verify whether there is evidence in the literature regarding the decrease in viral load present in saliva after using three types of mouthwashes. Material and MethodsClinical and/or in vitro experimental studies that have used mouthwashes as a form of intervention to reduce the viral load in saliva were included. Combinations of words and appropriate truncations were adapted for each of the seven selected electronic bases including grey literature. ResultsThe selection of articles was carried out in two phases by two independent reviewers. After removing duplicate articles, 1245 references were maintained, and 2 articles were included in the Systematic Review. Both studies were performed in vitro and tested the virucidal action of the PVP-I solution for mouthwash at two different concentrations, 1% without dilution and 7% with 1:30 dilution, on the SARS-CoV and MERS-CoV viruses. Both showed a viral reduction of ≥ 99.99% with 15 s exposure. ConclusionsBased on the evidence currently available in the literature, PVP-I, at concentrations of 1 and 7%, appears to be the most effective mouthwash for reducing the viral load of COVID-19 present in human saliva. However, the guidelines for dental care refer to the use of hydrogen peroxide but there is insufficient scientific evidence to support this recommendation. Key words:COVID-19, Coronavirus, Mouthwash, Chlorhexidine, Hydrogen Peroxide, PVP-I.

COVID-19: A Review of Current Evidence on Phylogenetics and Etiopathogenesis

COVID-19 represents the latest pandemic caused by the SARS-CoV-2 coronavirus. Coronaviruses are RNA viruses that cause a largely viral mediated immune-related syndrome similar to the SARS epidemic. Following metagenomic sequencing, SARS-CoV-2 closely resembles SARS-CoV (79% similarity) and MERS-CoV virus (50% similarity). Despite this, clinical observations have found varying degrees of infectivity and pathogenesis amongst these viruses. Phylogenetic origins of SARS-CoV-2 have found connections to bats and pangolins as possible zoonotic reservoirs. It enters the host cells via the receptor binding site of the ACE-2 receptor. Upon entering the host cells, cytopathic effects and interruption of respiratory cilia occur with a resultant cascade of pro-inflammatory cytokines and chemokines. Common clinical features of COVID-19 include fever, cough and fatigue. COVID-19 infected patients also present with various gastrointestinal, gustatory, dermatologic, ocular, cardiovascular, neurologic and coagulopathic manifestations. Dyspnea, sore throat, nasal congestion, musculoskeletal pain, headaches and chills were also observed. Emerging data supports that COVID 19 has disproportionately affected specific ethnic groups, particularly racial minorities for various health and institutional reasons. It is estimated around 5% of all cases are severe, presenting with respiratory failure, shock, acute respiratory syndrome and arrhythmias. Co-infection with other pathogens was also seen with various other viruses such as rhinoviruses, respiratory syncytial virus and other coronaviruses. COVID-19 is able to spread asymptomatically and causes slightly different manifestations in pregnant ladies and the pediatric populations. ARDS in COVID-19 patients is suspected to be a unique clinical entity as lung function testing found high driving pressures with abnormally low lung compliance and low lung recruitability. This requires a unique approach to ventilating COVID-19 ARDS patients. In conclusion, new emerging data will require healthcare professionals to adapt and more studies are required to overcome this critical pandemic.

A Recent Achievement in the Discovery and Development of Vaccines and Therapeutic Agents in the Race for COVID-19 Protection and Treatment.

Currently, the coronavirus disease 2019 (COVID-19) is a big challenge to the healthcare systems in the world. Several researchers in the world have immediately carried out clinical investigations for the discovery of vaccines and drugs. Different studies have shown that antiviral measures including small bioactive compounds targeting multifaceted molecular communications take in COVID-19 infection. The drug development archived in this review emphasizes mainly on drugs that are effective for the Management of MERS-CoV, SARS-CoV, and other RNA viruses. The investigation of therapeutic agents for COVID-19 includes anti-inflammatory agents, antibodies, and nucleic acid-based treatments targeting virus gene expression as well as different sorts of vaccines. Numerous patents revealed techniques of these biologics with the potential for treating and preventing coronavirus infections, which may apply to COVID-19. Phase 3 clinical trials such as Sputnik V, AZD1222, mRNA-1273, BNT162b2, Ad5-nCoV, Anti-COVID antibodies, Kevzara; Actemra, Jakafi; Baricitinib, and some others were undergoing in the race for Covid-19 treatment. However, there’s still a lack of a review on vaccines and drugs for COVID-19 management. Therefore, this review summarizes different studies that are ongoing in the race for Covid-19 protection and treatment.

Role of Kaletra (combination of lopinavir and ritonavir) in the treatment of COVID-19 virus infection; an issue related to kidney transplant patients – A review study on current knowledge

A number of therapies are prescribed for the treatment of COVID-19, but none of them have proven efficacy. In this review article, we summarized the pharmacodynamic and pharmacokinetic properties, effect and potential toxicity of Kaletra (combination of lopinavir and ritonavir) among kidney transplant (KTP) patients who have COVID-19. We used a variety of sources by searching through PubMed, Scopus, Embase and Current Content to collect current data about our issue. Articles published in the English language, as full-text manuscripts, and or as abstract form were included in the study. Lopinavir and ritonavir are two structurally related novel protease inhibitors which have antiretroviral properties. They have primarily been used as part of combination therapy for the treatment of HIV, SARS-CoV and MERS-CoV viruses. However, it seems that use of Kaletra is not associated with clinical improvement, or reduces mortality among patients including KTP recipients who have laboratory-confirmed COVID-19. On the other hand, co-administration of Kaletra with medications that are commonly used among KTP recipients including calcineurin inhibitors and mTOR inhibitors has profound drug-drug interactions. Co-administration of Kaletra with these medications could lead to significant and unexpected increase of blood concentrations of both calcineurin and mTOR inhibitors and therefore frequent monitoring of the immunosuppressive drugs concentrations are necessary to optimize immunosuppressive therapy and prevention of toxicity. It is important to note that frequent monitoring of the immunosuppressive drugs concentration is expensive and also not easily available in many countries including our country. According to the above important points, we recommend that use of Kaletra among KTP patients who have laboratory-confirmed COVID-19 should be avoided especially among patients who are still on calcineurin and mTOR inhibitors.

Evaluation of potential anti-COVID-19 therapies

Evaluation of potential anti-COVID-19 therapies

Remdesivir Strongly Binds to Both RNA-Dependent RNA Polymerase and Main Protease of SARS-CoV-2: Evidence from Molecular Simulations.

The outbreak of a new coronavirus SARS-CoV-2 (severe acute respiratory syndrome–coronavirus 2) has caused a global COVID-19 (coronavirus disease 2019) pandemic, resulting in millions of infections and thousands of deaths around the world. There is currently no drug or vaccine for COVID-19, but it has been revealed that some commercially available drugs are promising, at least for treating symptoms. Among them, remdesivir, which can block the activity of RNA-dependent RNA polymerase (RdRp) in old SARS-CoV and MERS-CoV viruses, has been prescribed to COVID-19 patients in many countries. A recent experiment showed that remdesivir binds to SARS-CoV-2 with an inhibition constant of μM, but the exact target has not been reported. In this work, combining molecular docking, steered molecular dynamics, and umbrella sampling, we examined its binding affinity to two targets including the main protease (Mpro), also known as 3C-like protease, and RdRp. We showed that remdesivir binds to Mpro slightly weaker than to RdRp, and the corresponding inhibition constants, consistent with the experiment, fall to the μM range. The binding mechanisms of remdesivir to two targets differ in that the electrostatic interaction is the main force in stabilizing the RdRp–remdesivir complex, while the van der Waals interaction dominates in the Mpro–remdesivir case. Our result indicates that remdesivir can target not only RdRp but also Mpro, which can be invoked to explain why this drug is effective in treating COVID-19. We have identified residues of the target protein that make the most important contribution to binding affinity, and this information is useful for drug development for this disease.

Overview of SARS-CoV-2 Outbreak and Potential Therapeutic Strategies

The increasing severity of the ongoing COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an urgent global issue to be addressed. Despite several heroic and concerted efforts, morbidity and mortality continue to increase. Providing a therapeutic respite in the form of an effective antiviral agent and, potentially, a vaccine remains an uphill task. The SARS-CoV-2 is an enveloped positive-sense single-stranded RNA virus, with an unusual potential for rapid reproduction and mutation, transmitted majorly through aerosols. The virus replicates in the mucosa of the upper respiratory tract, which accounts for its early symptoms. Multiple organs can be affected and can also be asymptomatic. SARS-CoV-2 has genomic similitude to the SARS-CoV and MERS-CoV viruses, being members of the same family, Betacoronaviridae. These similarities have been explored as potential therapeutic targets. Developing a drug at a pandemic speed usually involves initial drug repurposing strategies, and the ongoing pandemic has not been an exception. With notable recruitments ranging from the old antimalarial agent, Chloroquine/Hydroxychloroquine, to the macrolide Azithromycin, to ACE inhibitors, to antiviral agents like Lopinavir/Ritonavir and more recently, the RNA polymerase inhibitor, Remdesivir, the search is still ongoing. Sourcing from highly reputable reports and studies conducted so far, this review elaborates on the biology of the SARS-CoV-2 virus, highlighting its structure, shared genetic similarities and variants, with respect to being potential therapeutic targets, as well as a commentary on the therapeutic approaches that have been explored in the quest to develop an effective antiviral agent.

Repositioning of Drugs to Counter COVID-19 Pandemic - An Insight.

COVID-19 is a pandemic, caused by the novel coronavirus 2 (SARS-CoV-2) which is a severe acute respiratory syndrome. The devastating impact of this novel coronavirus outbreak has necessitated the need for rapid and effective antiviral therapies against SARS-CoV-2 to control the spread of the disease and importantly, alleviate the severe life-threatening symptoms and disorders. Drug repurposing strategy offers an attractive, immediate and realistic approach to tackle this growing pandemic of COVID-19. Due to the similarities with the SARS-CoV-1 virus and phylogenetic relation to the MERS-CoV virus, accelerated screening of approved drugs and the development of repositioning strategies have proved to be critical for the survival of many COVID-19 patients. Numerous scientific investigations from the initial years of the coronavirus outbreak along with upcoming advances of immunotherapy and vaccines, may prove to be beneficial. Currently, several repurposing strategies are under different phases of clinical trials and provide a definitive framework for the development of future therapies for the effective treatment of COVID-19. This review article summarizes the latest developments and trends in drug repurposing strategy for COVID-19 treatment.

Building the National SARS-CoV-2 Laboratory Diagnostic Capacity in Taiwan.

Through early and proactive laboratory testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes novel coronavirus 2019, Taiwan has demonstrated an efficient and rapid control response to contain the outbreak. Two days after the World Health Organization announced the complete viral genome sequence, the national laboratory of the Taiwan Centers for Disease Control developed a specific real-time reverse transcription polymerase chain reaction (real-time RT-PCR) test for SARS-CoV-2. The national laboratory network was further strengthened through the recruitment of medical centers and regional hospitals distributed throughout most geographical regions of the country. Ultimately, a network of 60 laboratories with a capacity of 7,342 real-time RT-PCR tests per day was established. Between January 14 and August 5, 2020, a total of 158,772 tests were conducted, corresponding to 120,487 cases. Test results were obtained within 24 hours, enabling an efficient and rapid control response.

Sampling and detection of corona viruses in air: A mini review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a strain of coronaviruses that causes coronavirus disease 2019 (COVID-19). In these days, the spread of the SARS-CoV-2 virus through the air has become a controversial topic among scientists. Various organizations provide standard methods for monitoring biological agents in the air. Nevertheless, there has been no standard recommended method for sampling and determination of viruses in air. This manuscript aimed at reviewing published papers for sampling and detection of corona viruses, especially SARS-Cov-2 as a global health concern. It was found that SARS-Cov 2 was present in some air samples that were collected from patient's rooms in hospitals. This result warrants its airborne transmission potential. However, due to the fact that in the most reviewed studies, sampling was performed in the patient's room, it seems difficult to discriminate whether it is airborne or is transmitted through respiratory droplets. Moreover, some other disrupting factors such as patient distance from the sampler, using protective or oxygen masks by patients, patient activities, coughing and sneezing during sampling time, air movement, air conditioning, sampler type, sampling conditions, storage and transferring conditions, can affect the results. About the sampling methods, most of the used samplers such as PTFE filters, gelatin filers and cyclones showed suitable performance for trapping SARS-Co and MERS-Cov viruses followed by PCR analysis.

Pneumonia Corona Virus Infection Disease-19 (COVID-19)

Sejak awal tahun 2020 terjadi peningkatan jumlah kasus infeksi virus COVID-19, yang sebelumnya dikenal dengan nama 2019-nCov. Diketahui hingga bulan Februari 2020 sudah terkonfirmasi lebih dari 70.000 kasus positif infeksi COVID-19. COVID-19 diketahui merupakan virus dari keluarga coronaviridae, yang juga merupakan keluarga dari virus SARS-CoV dan MERS-CoV yang pernah menyebabkan wabah pada tahun 2002 dan 2012 silam. Patogenesis COVID-19 belum diketahui secara pasti, namun diduga mirip dengan patogenesis SARS-CoV dan MERS-CoV. Rerata mortalitas COVID-19 adalah 2.3%, lebih rendah dibandingkan dengan mortalitas SARS-CoV dan MERS-CoV. Outbreak COVID-19 juga diduga dimulai dari sebuah pasar penjualan makanan laut lokal pada musim dingin, lingkungan yang hampir sama pada saat outbreak virus SARS. Pada artikel ilmiah ini akan dibahas secara mendalam mengenai definisi operasional yang dapat dipakai dalam manajemen pasien dengan dugaan infeksi COVID-19. Akan dibahas pula manifestasi klinis dan tata laksana pada pasien dengan dugaan dan konfirmasi infeksi COVID-19.

Source of the COVID-19 pandemic: ecology and genetics of coronaviruses (Betacoronavirus: Coronaviridae) SARS-CoV, SARS-CoV-2 (subgenus Sarbecovirus), and MERS-CoV (subgenus Merbecovirus).

Since the early 2000s, three novel zooanthroponous coronaviruses (Betacoronavirus) have emerged. The first outbreak of infection (SARS) caused by SARS-CoV virus occurred in the fall of 2002 in China (Guangdong Province). A second outbreak (MERS) associated with the new MERS-CoV virus appeared in Saudi Arabia in autumn 2012. The third epidemic, which turned into a COVID-19 pandemic caused by SARS-CoV-2 virus, emerged in China (Hubei Province) in the autumn 2019. This review focuses on ecological and genetic aspects that lead to the emergence of new human zoanthroponous coronaviruses. The main mechanism of adaptation of zoonotic betacoronaviruses to humans is to changes in the receptor-binding domain of surface protein (S), as a result of which it gains the ability to bind human cellular receptors of epithelial cells in respiratory and gastrointestinal tract. This process is caused by the high genetic diversity and variability combined with frequent recombination, during virus circulation in their natural reservoir - bats (Microchiroptera, Chiroptera). Appearance of SARS-CoV, SARS-CoV-2 (subgenus Sarbecovirus), and MERS (subgenus Merbecovirus) viruses is a result of evolutionary events occurring in bat populations with further transfer of viruses to the human directly or through the intermediate vertebrate hosts, ecologically connected with bats. This review is based on the report at the meeting «Coronavirus - a global challenge to science» of the Scientific Council «Life Science» of the Russian Academy of Science: Lvov D.K., Alkhovsky S.V., Burtseva E.I. COVID-19 pandemic sources: origin, biology and genetics of coronaviruses of SARS-CoV, SARS-CoV-2, MERS-CoV (Conference hall of Presidium of RAS, 14 Leninsky Prospect, Moscow, Russia. April 16, 2020).