Etiology of epidemic outbreaks COVID-19 in Wuhan, Hubei province, Chinese People Republic associated with 2019-nCoV (Nidovirales, Coronaviridae, Coronavirinae, Betacoronavirus, Subgenus Sarbecovirus): lessons of SARS-CoV outbreak

[Genetic diversity of Siberian bovine coronavirus isolates (Coronaviridae: Coronavirinae: Betacoronavirus-1: Bovine-Like coronaviruses)]

INTRODUCTION

Bovine coronaviruses (BCoVs) are causative agents of diarrhea, respiratory diseases in calves and winter cow dysentery. The study of genetic diversity of these viruses is topical issue. The purpose of the research is studying the genetic diversity of BCoV isolates circulating among dairy cattle in Siberia.

MATERIALS AND METHODS

Specimens used in this study were collected from animals that died or was forcedly slaughtered before the start of the study. The target for amplification were nucleotide sequences of S and N gene regions.

RESULTS

Based on the results of RT-PCR testing, virus genome was present in 16.3% of samples from calves with diarrheal syndrome and in 9.9% with respiratory syndrome. The nucleotide sequences of S gene region were determined for 18 isolates, and N gene sequences - for 12 isolates. Based on S gene, isolates were divided into two clades each containing two subclades. First subclade of first clade (European line) included 11 isolates. Second one included classic strains Quebec and Mebus, strains from Europe, USA and Korea, but none of sequences from this study belonged to this subclade. 6 isolates belonged to first subclade of second clade (American-Asian line). Second subclade (mixed line) included one isolate. N gene sequences formed two clades, one of them included two subclades. First subclade included 3 isolates (American-Asian line), and second subclade (mixed) included one isolate. Second clade (mixed) included 8 sequences. No differences in phylogenetic grouping between intestinal and respiratory isolates, as well as according to their geographic origin were identified.

CONCLUSION

The studied population of BCoV isolates is heterogeneous. Nucleotide sequence analysis is a useful tool for studying molecular epidemiology of BCoV. It can be beneficial for choice of vaccines to be used in a particular geographic region.

Verification of a case of mixed infection with Lyme disease, tick-borne encephalitis and COVID-19

Background. The relationship between pathogens of new diseases and tick-borne infections is an underinvestigated direction in the problem of infectious diseases.The aim. To show the features of identifying the markers of Borrelia burgdorferi, tickborne encephalitis and SARS-CoV-2 pathogens on the example of a case of a triple mixed infection (Lyme disease, tick-borne encephalitis and COVID-19) and using comprehensive studies.Methods. In 2019–2021, a comprehensive study of 7 blood samples from a patient with mixed infection was carried out. We used real-time polymerase chain reaction (PCR), enzyme immunoassay (ELISA) and determined antigen, IgM, IgG antibodies, and avidity index (AI) of IgG antibodies.Results. Ixodid tick-borne borreliosis was diagnosed in a patient 5 months after contagion. Only high-avid Lyme-IgG antibodies were detected. Low-avid Lyme- IgG antibodies appeared against the background of a reduced general condition. At the same time, high-avid IgG (cut-off index (COI) – 7.8) and IgM (COI = 1.2) antibodies to the TBE virus were detected. In July 2020, the patient was infected with SARSCoV-2. TBE virus which passed into the body simultaneously with Borrelia in the fall of 2019 was activated. Although the patient did not have specific symptoms of TBE, in subsequent blood samples (No. 4, 5, 6) we found TBEV antigen (optical density (OD) – 4.3; 1.9 and 2.0 respectively) and IgM (COI = 1.3; 0,9 and 0 respectively). These results were recognized as TBEV activation, which contributed to an increase in the avidity of IgG antibodies (AI = 65 %; 100 % and 63 % respectively). IgM antibodies to SARSCoV-2 virus were not detected, as opposed to the high levels of IgG (COI = 8.2; 8.1; 8.4 and 14.7 respectively).Conclusions. Therefore, using not only the common methods of diagnosing (PCR and ELISA), but also the determination of the antibody avidity degree, we have shown that when analyzing a case of a triple mixed infection, B. burgdorferi dominates in the human body and causes a long-term chronic course of the disease.

[130th anniversary of virology]

130 years ago, in 1892, our great compatriot Dmitry Iosifovich Ivanovsky (18641920) discovered a new type of pathogen viruses. Viruses have existed since the birth of life on Earth and for more than three billion years, as the biosphere evolved, they are included in interpopulation interactions with representatives of all kingdoms of life: archaea, bacteria, protozoa, algae, fungi, plants, invertebrates, and vertebrates, including the Homo sapiens (Hominidae, Homininae). Discovery of D.I. Ivanovsky laid the foundation for a new science virology. The rapid development of virology in the 20th century was associated with the fight against emerging and reemerging infections, epidemics (epizootics) and pandemics (panzootics) of which posed a threat to national and global biosecurity (tick-borne and other encephalitis, hemorrhagic fevers, influenza, smallpox, poliomyelitis, HIV, parenteral hepatitis, coronaviral and other infections). Fundamental research on viruses created the basis for the development of effective methods of diagnostics, vaccine prophylaxis, and antiviral drugs. Russian virologists continue to occupy leading positions in some priority areas of modern virology in vaccinology, environmental studies oz zoonotic viruses, studies of viral evolution in various ecosystems, and several other areas. A meaningful combination of theoretical approaches to studying the evolution of viruses with innovative methods for studying their molecular genetic properties and the creation of new generations of vaccines and antiviral drugs on this basis will significantly reduce the consequences of future pandemics or panzootics. The review presents the main stages in the formation and development of virology as a science in Russia with an emphasis on the most significant achievements of soviet and Russian virologists in the fight against viral infectious diseases.

Post-COVID-19 Syndrome in Outpatients and Its Association with Viral Load

INTRODUCTION

The COVID-19 pandemic is the result of the SARS-CoV-2 virus, which has caused more than 100 million infections and more than 2.5 million deaths worldwide, representing a serious public health problem. The gold method for detecting this virus is qRT-PCR, which is a semiquantitative technique where the viral load can be established through its cycle threshold (Ct). It has also been reported that COVID-19 generates long-term symptoms (post-COVID-19).

METHODS

After three months, a survey was performed on 70 COVID-19 confirmed patients; subsequently, we divided them into four groups (persistent symptoms, chemo-sensitive, cognitive issues, and changes in habit) in order to determine the correlation between viral load and post-COVID-19 symptoms.

RESULTS

Data show that fatigue, nervousness, anosmia, and diet changes are common long-term symptoms; in addition, a negative correlation was found between viral load and the number of post-COVID-19 symptoms.

CONCLUSION

COVID-19 generates long-term symptoms which can cause problems with psychological and social repercussions.

Review of Method and a New Tool for Decline and Inactive SARS-CoV-2 in Wastewater Treatment

Following the recent outbreak of the COVID-19 pandemic caused by the SARS-CoV-2 virus, monitoring sewage has become crucial, according to reports that the virus was detected in sewage. Currently, various methods are discussed for understanding the SARS-CoV-2 using wastewater surveillance. This paper first introduces the fundamental knowledge of primary, secondary, and tertiary water treatment on SARS-CoV-2. Next, a thorough overview is presented to summarize the recent developments and breakthroughs in removing SARS-CoV-2 using solar water disinfection (SODIS) and UV (UVA (315–400 nm), UVB (280-315 nm), and UVC (100–280 nm)) process. In addition, Due to the fact that the distilled water can be exposed to sunlight if there is no heating source, it can be disinfected using solar water disinfection (SODIS). SODIS, on the other hand, is a well-known method of reducing pathogens in contaminated water; moreover, UVC can inactivate SARS-CoV-2 when the wavelength is between 100 to 280 nanometers. High temperatures (more than 56°C) and UVC are essential for eliminating SARS-CoV-2; however, the SODIS systems use UVA and work at lower temperatures (less than45°C). Therefore, using SODIS methods for wastewater treatment (or providing drinking water) is not appropriate during a situation like the ongoing pandemic. Finally, a wastewater-based epidemiology (WBE) tracking tool for SARS-CoV-2 can be used to detect its presence in wastewater.

Sanitary Aspects of Countering the Spread of COVID-19 in Russia

Due to the conditions that cause the spread of COVID-19, national health systems worldwide are under severe strain. Most countries face similar difficulties such as a lack of medical personnel and equipment and tools for diagnosis and treatment, overrun hospitals, and forced restriction of planned medical care. Public authorities in healthcare take the following measures due to increased pressure: limiting the transmission and spread of the virus (social distancing and quarantine), mobilizing medical personnel, ensuring the availability of diagnostic and treatment tools, and providing a sufficient number of premises, which are not always suitable for the provision of medical care (buildings and structures). To date, the stages of management decision-making to counter coronavirus infection and the risk of COVID-19 transmission at various facilities have not been analyzed. The authors propose a methodology for assessing the COVID-19 transmission risk at various social and transport facilities. A survey of 1325 respondents from Moscow demonstrated the most significant risk factors, such as visitation avoidance, infection risk, and facemask wearing. Risk categories were determined and objects classified according to high, medium, and low-risk levels.

Síndrome inflamatorio multisistémico en niños con COVID-19: una visión desde la reumatología

La enfermedad por coronavirus 2019 (COVID-19), producida por el SARS-CoV-2, ha tomado una gran importancia en los últimos meses y se encuentra bajo constante investigación por distintas áreas de la medicina, incluida la reumatología, en la búsqueda de la mejor evidencia científica. En el caso de la población pediátrica cobra especial importancia puesto que en un principio se pensaba que el impacto de la pandemia en esta población sería menor, debido a la baja presencia de casos severos, pero la evidencia actual reporta la existencia de cuadros clínicos en niños con diagnóstico de COVID-19 que se caracterizan por un estado inflamatorio alterado consistente en una tormenta de citocinas proinflamatorias que produce manifestaciones similares a las presentadas en enfermedades autoinmunes como la enfermedad de Kawasaki. Se le ha denominado síndrome inflamatorio multisistémico en niños asociado temporalmente con SARS-CoV-2, el cual en muchos casos precisa internación en unidades de cuidados intensivos pediátricos y el manejo multidisciplinario por diversas especialidades.

The next-generation coronavirus diagnostic techniques with particular emphasis on the SARS-CoV-2

The potential zoonotic coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2) are of global health concerns. Early diagnosis is the milestone in their mitigation, control, and eradication. Many diagnostic techniques are showing great success and have many advantages, such as the rapid turnover of the results, high accuracy, and high specificity and sensitivity. However, some of these techniques have several pitfalls if samples were not collected, processed, and transported in the standard ways and if these techniques were not practiced with extreme caution and precision. This may lead to false-negative/positive results. This may affect the downstream management of the affected cases. These techniques require regular fine-tuning, upgrading, and optimization. The continuous evolution of new strains and viruses belong to the coronaviruses is hampering the success of many classical techniques. There are urgent needs for next generations of coronaviruses diagnostic assays that overcome these pitfalls. This new generation of diagnostic tests should be able to do simultaneous, multiplex, and high-throughput detection of various coronavirus in one reaction. Furthermore, the development of novel assays and techniques that enable the in situ detection of the virus on the environmental samples, especially air, water, and surfaces, should be given considerable attention in the future. These approaches will have a substantial positive impact on the mitigation and eradication of coronaviruses, including the current SARS-CoV-2 pandemic.

Can the European Hedgehog (Erinaceus europaeus) Be a Sentinel for One Health Concerns?

Erinaceus europaeus is a cosmopolitan mammalian species broadly distributed in Europe, from natural to suburban areas. Due to its ecological role and susceptibility to distinct zoonotic agents, E. europaeus could be a suitable sentinel candidate for many global problems that negatively affect human and animal health. Hedgehogs can work as bioindicators to environmental contamination and can be hosts for multiple tickborne zoonotic agents. Thus, people who directly or indirectly make physical contact with this species are exposed to a variety of threats. Moreover, it has also been studied as an indicator for antibiotic resistance, which was already confirmed for tetracyclines. Additionally, it was also reported as a reservoir for methicillin-resistant Staphylococcus aureus (MRSA). More recently, hedgehogs have been recently recognised as potential reservoirs of MERS-CoV-like strains. Among other animals, this species can possibly represent an intermediate reservoir for SARS-CoV-2. The aim of this review is to briefly expose the scientific attainments about hedgehog health, namely agents, diseases, and threats that significantly affect general health concerns and that contribute to achieve One Health principles.

Using Deep Learning Model for Adapting and Managing COVID-19 Pandemic Crisis

The purpose of current paper is to create a smart and effective tool for telemedicine to early detect and diagnose COVID-19 disease and therefore help to manage Pandemic Crisis (MCPC) in Sultanate of Oman, as a tool for future pandemic containment. In this paper, we used tools to create robust models in real-time to support Telemedicine, it is Machine Learning (ML), Deep Learning (DL), Convolutional Neural Networks using Tensorflow (CNN-TF), and CNN Deployment. These models will assist telemedicine, 1) developing Automated Medical Immediate Diagnosis service (AMID). 2) Analysis of Chest X-rays image (CXRs). 3) Simplifying Classification of confirmed cases according to its severity. 4) Overcoming the lack of experience, by improving the performance of medical diagnostics and providing recommendations to the medical staff. The results show that the best Regression among the five Regression models is Random Forest Regression. while the best classification among the eight classification models and Recurrent Neural Network using Tensorflow (RNNTF) is Random Forest classification, and the best Clustering model among two Clustering models is K-Means++. Furthermore, CNN-TF model was able to discriminate between those with positive cases Covid-19 and those with negative cases.

Using Deep Learning Model for Adapting and Managing COVID-19 Pandemic Crisis

The purpose of current paper is to create a smart and effective tool for telemedicine to early detect and diagnose COVID-19 disease and therefore help to manage Pandemic Crisis (MCPC) in Sultanate of Oman, as a tool for future pandemic containment. In this paper, we used tools to create robust models in real-time to support Telemedicine, it is Machine Learning (ML), Deep Learning (DL), Convolutional Neural Networks using Tensorflow (CNN-TF), and CNN Deployment. These models will assist telemedicine, 1) developing Automated Medical Immediate Diagnosis service (AMID). 2) Analysis of Chest X-rays image (CXRs). 3) Simplifying Classification of confirmed cases according to its severity. 4) Overcoming the lack of experience, by improving the performance of medical diagnostics and providing recommendations to the medical staff. The results show that the best Regression among the five Regression models is Random Forest Regression. while the best classification among the eight classification models and Recurrent Neural Network using Tensorflow (RNNTF) is Random Forest classification, and the best Clustering model among two Clustering models is K-Means++. Furthermore, CNN-TF model was able to discriminate between those with positive cases Covid-19 and those with negative cases.

[Bats of the subtropical climate zone of the Krasnodar Territory of Russia as a possible reservoir of zoonotic viral infections]

Emerging and reemerging infections pose a grave global health threat. The emergence of the SARS-CoV-2 virus and the resulting COVID-19 pandemic have demonstrated the importance of studying of zoonotic viruses directly in natural foci. For SARS-like coronaviruses, as well as for many other zoonotic pathogens (including hemorrhagic fevers and rabies agents), the main reservoir are horseshoe bats (Rhinolophus spp.), which are widely distributed in Eurasia and Africa. Their range also covers the southern regions of Russia, including the North Caucasus and Crimea. Large colonies of these animals are located on the territory of Sochi National Park (SNP; subtropical zone of Krasnodar Territory, Greater Sochi region, North Caucasus). In total, according to long-term observations, up to 23 species of bats were registered here, including the great (Rh. ferrumequinum), the lesser (Rh. hipposideros), and the Mediterranean (Rh. euryale) horseshoe bats.This review provides information on zoonotic viruses associated with species of bats distributed in the subtropical zone of Krasnodar Territory of Russia, and analyzes their possible role as a natural reservoir of emerging and reemerging infections. Studying the circulation of zoonotic viruses in bats is an important element of monitoring viral populations in natural foci.

Features of Hematological and Hemostasiological Parameters in Coronavirus Infection COVID-19 and Community-Acquired Pneumonia

Against the background of priority attention paid to the COVID-19 pandemic, there are also cases of community-acquired pneumonia of a different genesis. Identification of the features of lung lesions in such diseases is relevant during the spread of seasonal respiratory infections. The comparative study of the dynamics of hematological and hemostasiological parameters of blood in patients with pneumonia of various origins is of interest in terms of searching for predictors of the prognosis of the diseases development.

Aim. To compare the features of clinical symptoms, hematological and hemostasiological parameters in patients with pneumonia caused by COVID-19 and in patients with community-acquired pneumonia.

Materials and methods. During cross-sectional study two groups were formed: group 1 consisted of 92 patients diagnosed with moderate community-acquired pneumonia caused by COVID-19 infection; group 2 included 40 patients diagnosed with moderate community-acquired bilateral polysegmental pneumonia.

Results. It was found that patients with COVID-19 had an older age (69 vs 39.3 years), a lower body temperature at admission (37.5 vs 38.85 °C), a lower percentage of reduced oxygen saturation (less than 89 % in 5.4 % of cases vs 10 % of cases). In most cases, the average values of some hematological parameters in patients with COVID-19 did not go beyond the reference range. Leukopenia (below 4 × 109 cells/l) and lymphopenia (below 1.1 × 109 cells/l) were observed in 26 % and 38 % of cases respectively; thrombocytopenia (less than 100 × 109 cells/l) – in 12.2 % of cases; hyperfibrinogenemia (more than 4 g/l) – in 65.3 % of cases. A direct correlation was found between platelet levels and leukocytes (R = 0.53; p < 0.001) and lymphocytes (R = 0.29; p = 0.06). Compared with the patients of the group 2,on average, patients with COVID-19 had significantly lower levels of leukocytes and lymphocytes (2.5 times each; p < 0.001) and an increased level of fibrinogen (by 45 %; p < 0.001).

Conclusion. In patients with pneumonia caused by COVID-19, we revealed the particular features of clinical symptoms, hematological and hemostasiological blood parameters compared to community-acquired nonspecific pneumonia.

A Study on the Psychological Wound of COVID-19 in University Students

An increasing number of studies have addressed the psychological impact of the COVID-19 crisis on the general population. Nevertheless, far less is known about the impact on specific populations such as university students, whose psychological vulnerability has been shown in previous research. This study sought to examine different indicators of mental health in university students during the Spanish lockdown; we also analyzed the main sources of stress perceived by students in relation to the COVID-19 crisis, and the coping strategies adopted when faced with the situation. Data was collected from 932 students (704 women) through a web-based platform. Measures of anxiety (i.e., GAD-7), depression (PHQ-9), irritability, and self-perceived change in mental health were administered, as well as ad hoc measures of stressors and coping strategies. Results indicated that students experienced considerable psychological problems during the confinement, with higher rates of emotional difficulties in women and undergraduate students than in men and postgraduates, respectively. Psychological distress was mainly related to several specific domains of stressors, as perceived by the participants: academic future, task overload, worsening of interpersonal conflicts, and restrictions in pleasant social contact; and far less related to the spread of the disease and its consequences for physical health. As regards coping strategies, both reframing skills and daily routines were shown to be the most effective. A path-analysis model integrating stressors, coping, and mental health revealed that coping strategies partially mediated the effect of stressors on psychological health. In general, results suggest that students' psychological health was substantially affected by the COVID-19 situation and that the academic and relational changes were the most notable sources of stress. This study reinforces the need to monitor and promote mental health in university students to boost resilience in times of crisis. Our results on effective coping strategies may inform preventive programs aimed at helping students to deal with challenges like the COVID-19 pandemic.

[Peculiarities of the influenza and ARVI viruses circulation during epidemic season 2019-2020 in some regions of Russia]

INTRODUCTION

The surveillance of influenza viruses in ARVI structure and study of their properties in epidemic season 2019-2020 in Russian Federation are actual for investigations due to tasks of Global Influenza Strategy initiated by WHO in 2019.

MATERIAL AND METHODS

The data of epidemiological surveillance on influenza- and ARVI-associated morbidity and hospitalization in different age groups of population were analyzed; virological, genetic and statistical methods were used.

RESULTS

Preschool children were involved in epidemic the most. Meanwhile, the highest rate of hospitalization was observed in patients of 18-40 years old. Influenza A(H1N1)pdm09 virus dominated in etiology of ARVI in hospitalized patients and pneumonia. The role of respiratory viruses in severe cases of pneumonia and bronchoalveolar syndrome in children was shown. The differences in spectrum of circulating viruses caused ARVI in different regions of Russia were found. Influenza A(H1N1)pdm09 and B/Victoria-like viruses were the main etiological agents that caused of epidemic; its activity among all ARVI was 7.3 and 8.0%, respectively. The differences in antigenic properties of influenza A(H3N2) and B epidemic strains compared to vaccine viruses were found. The populations of epidemic strains were presented by following dominant genetic groups: 6B1.A5/183P for A(H1N1)pdm09, 3С.2а1b+137F for A(H3N2) and V1A.3 line B/Victoria-like for B viruses. The good profile of epidemic strains susceptibility to anti-neuraminidase inhibitors has been saved. The most of the studied influenza strains had the receptor specificity characteristic of human influenza viruses.

CONCLUSIONS

Obtained results identified the peculiarities of viruses caused the influenza and ARVI in epidemic season 2019-2020 in different regions of Russia. These results suggested the important role of influenza A(H1N1) pdm09 in severe cases and pneumonia in adults 18-40 years old. The continuing drift in influenza viruses was found, which, apparently, could not but affect the efficacy of vaccine prophylaxis and was also considered in the recommendations of WHO experts on the composition of influenza vaccines for the countries of the Northern Hemisphere in the 2020-2021 season.

Analysis of Promising Approaches to COVID-19 Vaccine Development

The number of confirmed COVID-19 cases worldwide amounted to 50 million at the beginning of November 2020. This is clearly not enough for the formation of herd immunity, which will prevent repeated outbreaks of the disease. Quarantine measures can only curb the spread of the disease to some extent, therefore specific preventive measures are needed to create collective immunity to COVID-19.The underlying principle of collective immunity is indirect protection of the whole of the population by immunising a certain part of it. Vaccination is the most effective approach to prevention of epidemic outbreaks.

The aim of the study was to analyse promising approaches to the development of vaccines against novel coronavirus COVID-19 infection. The paper summarises data on development studies and clinical trials of COVID-19 vaccines conducted in different countries. It analyses the pros and cons of different platforms for vaccine development (attenuated vaccines, inactivated vaccines, subunit vaccines, DNA and RNA vaccines, recombinant vector vaccines). The paper presents a potential design of novel vaccines. It was concluded that COVID-19 vaccines might be developed both for immunising high-risk groups and for mass immunisation. An optimal solution for the second task would be to develop human or monkey adenovirus vector-based vaccines whose mass production has already been unveiled.

COVID-19: Underpinning Research for Detection, Therapeutics, and Vaccines Development

BACKGROUND

The newly emerged coronavirus SARS-CoV-2, first reported in December 2019, has infected about five and a half million people globally and resulted in nearly 9063264 deaths until the 24th of June 2020. Nevertheless, the highly contagious virus has instigated an unimaginably rapid response from scientific and medical communities.

OBJECTIVES

Pioneering research on molecular mechanisms underlying the viral transmission, molecular pathogenicity, and potential treatments will be highlighted in this review. The development of antiviral drugs specific to SARS-CoV-2 is a complicated and tedious process. To accelerate scientific discoveries and advancement, researchers are consolidating available data from associated coronaviruses into a single pipeline, which can be readily made available to vaccine developers.

METHODS

In order to find studies evaluating the COVID-19 virus epidemiology, repurposed drugs and potential vaccines, web searches and bibliographical bases have been used with keywords that matches the content of this review.

RESULTS

The published results of SARS-CoV-2 structures and interactomics have been used to identify potential therapeutic candidates. We illustrate recent publications on SARS-CoV-2, concerning its molecular, epidemiological, and clinical characteristics, and focus on innovative diagnostics technologies in the production pipeline. This objective of this review is to enhance the comprehension of the unique characteristics of SARS-CoV-2 and strengthen future control measures.

Lay Summary

An innovative analysis is evaluating the nature of the COVID-19 pandemic. The aim is to increase knowledge of possible viral detection methods, which highlights several new technology limitations and advantages. We have assessed some drugs currently for patients (Lopinavir, Ritonavir, Anakinra and Interferon beta 1a), as the feasibility of COVID-19 specific antivirals is not presently known. The study explores the race toward vaccine development and highlights some significant trials and candidates in various clinical phases. This research addresses critical knowledge gaps by identifying repurposed drugs currently under clinical trials. Findings will be fed back rapidly to the researchers interested in COVID 19 and support the evidence and potential of possible therapeutics and small molecules with their mode of action.

COVID-19: etiology, clinical picture, treatment

Whereas the XX century marked the history of acute respiratory disease investigation as a period for generating in-depth system of combating influenza viruses (Articulavirales: Orthomyxoviridae, Alpha-/Betainfluenzavirus) (based on environmental and virological monitoring of influenza A virus in its natural reservoir — aquatic and semi-aquatic birds — to supervising epidemic influenza), a similar system is necessary to build up in the XXI century with regard to especially dangerous betacoronaviruses (Nidovirales: Coronaviridae, Betacoronavirus): Severe acute respiratory syndrome-related coronavirus (SARS-CoV) (subgenus Sarbecovirus), Severe acute respiratory syndrome-related coronavirus 2 (SARSCoV-2) (Sarbecovirus), Middle East respiratory syndrome-related coronavirus (MERS-CoV) (Merbecovirus). This became particularly evident after pandemic potential has been revealed in 2020 by the SARS-CoV-2. This review provides an insight into the historic timeline of discovering this virus, its current taxonomy, ecology, virion morphology, life cycle, molecular biology, pathogenesis and clinical picture of the etiologically related COVID-19 (Coronavirus disease 2019) as well as data available in the scientific literature on the anti-SARS-CoV-2-effectiveness of passive immunotherapy and most debated drugs used to treat COVID-19: Chloroquine, Hydroxychloroquine, Nitazoxanide, Ivermectin, Lopinavir and Ritonavir, Camostat mesilate, Remdesivir, Ribavirin, Tocilizumab, Anakinra, corticosteroids, and type I interferons. The pathogenesis of SARS-CoV-2 infection implicates decreased efficacy of artificial respiration, which, in this case might be replaced by more efficient extracorporeal membrane blood oxygenation supplemented with nitrogen oxide and/or Heliox inhalations.

[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).