Asymptomatic Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection: Extent and implications for infection control: A systematic review

Antibody-dependent enhancement (ADE) of SARS-CoV-2 in patients exposed to MERS-CoV and SARS-CoV-2 antigens

This study evaluated the potential for antibody-dependent enhancement (ADE) in serum samples from patients exposed to Middle East respiratory syndrome coronavirus (MERS-CoV). Furthermore, we evaluated the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on ADE in individuals with a MERS infection history. We performed ADE assay in sera from MERS recovered and SARS-CoV-2-vaccinated individuals using BHK cells expressing FcgRIIa, SARS-CoV-2, and MERS-CoV pseudoviruses (PVs). Further, we analyzed the association of ADE to serum IgG levels and neutralization. Out of 16 MERS patients, nine demonstrated ADE against SARS-CoV-2 PV, however, none of the samples demonstrated ADE against MERS-CoV PV. Furthermore, out of the seven patients exposed to SARS-CoV-2 vaccination after MERS-CoV infection, only one patient (acutely infected with MERS-CoV) showed ADE for SARS-CoV-2 PV. Further analysis indicated that IgG1, IgG2, and IgG3 against SARS-CoV-2 S1 and RBD subunits, IgG1 and IgG2 against the MERS-CoV S1 subunit, and serum neutralizing activity were low in ADE-positive samples. In summary, samples from MERS-CoV-infected patients exhibited ADE against SARS-CoV-2 and was significantly associated with low levels of neutralizing antibodies. Subsequent exposure to SARS-CoV-2 vaccination resulted in diminished ADE activity while the PV neutralization assay demonstrated a broadly reactive antibody response in some patient samples.

Unveiling the Inhibitory Potentials of Peptidomimetic Azanitriles and Pyridyl Esters towards SARS-CoV-2 Main Protease: A Molecular Modelling Investigation

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for COVID-19, which was declared a global pandemic in March 2020 by the World Health Organization (WHO). Since SARS-CoV-2 main protease plays an essential role in the virus’s life cycle, the design of small drug molecules with lower molecular weight has been a promising development targeting its inhibition. Herein, we evaluated the novel peptidomimetic azatripeptide and azatetrapeptide nitriles against SARS-CoV-2 main protease. We employed molecular dynamics (MD) simulations to elucidate the selected compounds’ binding free energy profiles against SARS-CoV-2 and further unveil the residues responsible for the drug-binding properties. Compound 8 exhibited the highest binding free energy of −49.37 ± 0.15 kcal/mol, followed by compound 7 (−39.83 ± 0.19 kcal/mol), while compound 17 showed the lowest binding free energy (−23.54 ± 0.19 kcal/mol). In addition, the absorption, distribution, metabolism, and excretion (ADME) assessment was performed and revealed that only compound 17 met the drug-likeness parameters and exhibited high pharmacokinetics to inhibit CYP1A2, CYP2C19, and CYP2C9 with better absorption potential and blood-brain barrier permeability (BBB) index. The additional intermolecular evaluations suggested compound 8 as a promising drug candidate for inhibiting SARS-CoV-2 Mpro. The substitution of isopropane in compound 7 with an aromatic benzene ring in compound 8 significantly enhanced the drug’s ability to bind better at the active site of the SARS-CoV-2 Mpro.

Super-spreaders of novel coronaviruses that cause SARS, MERS and COVID-19: A systematic review

PURPOSE

Most index cases with novel coronavirus infections transmit disease to just one or two other individuals, but some individuals "super-spread"-they infect many secondary cases. Understanding common factors that super-spreaders may share could inform outbreak models, and be used to guide contact tracing during outbreaks.

METHODS

We searched in MEDLINE, Scopus, and preprints to identify studies about people documented as transmitting pathogens that cause SARS, MERS, or COVID-19 to at least nine other people. We extracted data to describe them by age, sex, location, occupation, activities, symptom severity, any underlying conditions, disease outcome and undertook quality assessment for outbreaks published by June 2021.

RESULTS

The most typical super-spreader was a male age 40+. Most SARS or MERS super-spreaders were very symptomatic, the super-spreading occurred in hospital settings and frequently the individual died. In contrast, COVID-19 super-spreaders often had very mild disease and most COVID-19 super-spreading happened in community settings.

CONCLUSIONS

SARS and MERS super-spreaders were often symptomatic, middle- or older-age adults who had a high mortality rate. In contrast, COVID-19 super-spreaders tended to have mild disease and were any adult age. More outbreak reports should be published with anonymized but useful demographic information to improve understanding of super-spreading, super-spreaders, and the settings in which super-spreading happens.

SARS-CoV-2 infections among asymptomatic individuals contributed to COVID-19 cases: A cross-sectional study among prospective air travelers from Ghana

Background

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by asymptomatic individuals has been reported since the early stages of the coronavirus disease 2019 (COVID-19) outbreak in various parts of the world. However, there are limited data regarding SARS-CoV-2 among asymptomatic individuals in Ghana. The aim of the study was to use test data of prospective travelers from Ghana as a proxy to estimate the contribution of asymptomatic cases to the spread of COVID-19.

Methods

The study analyzed the SARS-CoV-2 PCR test data of clients whose purpose for testing was classified as "Travel" at the COVID-19 walk-in test center of the Noguchi Memorial Institute for Medical Research (NMIMR) from July 2020 to July 2021. These individuals requesting tests for travel generally had no clinical symptoms of COVID-19 at the time of testing. Data were processed and analyzed using Microsoft Excel office 16 and STATA version 16. Descriptive statistics were used to summarize data on test and demographic characteristics.

Results

Out of 42,997 samples tested at the center within that period, 28,384 (66.0%) were classified as "Travel" tests. Of these, 1,900 (6.7%) tested positive for SARS-CoV-2. The majority (64.8%) of the "Travel" tests were requested by men. The men recorded a SARS-CoV-2 positivity of 6.9% compared to the 6.4% observed among women. Test requests for SARS-CoV-2 were received from all regions of Ghana, with a majority (83.3%) received from the Greater Accra Region. Although the Eastern region recorded the highest SARS-CoV-2 positivity rate of 8.35%, the Greater Accra region contributed 81% to the total number of SARS-CoV-2 positive cases detected within the period of study.

Conclusion

Our study found substantial SARS-CoV-2 positivity among asymptomatic individuals who, without the requirement for a negative SARS-CoV-2 result for travel, would have no reason to test. These asymptomatic SARS-CoV-2-infected individuals could have traveled to other countries and unintentionally spread the virus. Our findings call for enhanced tracing and testing of asymptomatic contacts of individuals who tested positive for SARS-CoV-2.

COVID-19 isolation/quarantine rules in home care patients

The spread of Severe Acute Respiratory Syndrome Coronavirus 2 new variants increased the number of subjects in home isolation and quarantine. The aim of this study was to assess the compliance with coronavirus disease 2019 home isolation rules for 32 subjects in home care in Marche Region, Italy. The results showed that subjects in home isolation were better informed about isolation rules (P = 0.007) than those who were in quarantine. They had lower educational level (P < 0.001) and none/single income (P < 0.001) and higher rate of clinical manifestation. The education for a safe quarantine should be strengthened widely, especially among disadvantaged subjects.

A cross-sectional study of epidemiological determinants for Covid-19 infection among nurses of a tertiary care hospital

BACKGROUND

All health care workers including nurses are working in the frontline against coronavirus disease 2019 (Covid-19), which keeps them at high risk of getting infected. This study was conducted to identify risk factors for Covid-19 infection and compliance to Covid appropriate behavior among nurses.

MATERIAL AND METHODS

A cross-sectional study was conducted on 150 nurses in a tertiary care hospital attached to a medical college in Mumbai, from April 2020 to December 2020. Data were collected telephonically using an interviewer-administered pre-validated, semi-structured questionnaire. Data entry and analysis were performed using SPSS version 21.0.

RESULTS

The mean age of the nurses was 38.19 ± 12.14 years. The majority (80.7%) were exposed to Covid-19 while taking active care of Covid patients; a total of 108 (72%) were symptomatic at the time of testing; dietary modifications because of fear of Covid were performed by 121 (80.2%); 92.77% used the appropriate personal protective equipment (PPE) category according to the workplace; 121 (80.77%) followed all steps of donning and doffing at all times, and 19 (12.77%) reported a breach in PPE. A greater proportion of nurses working in Covid duties opted for hospital isolation than home isolation (p = 0.003). Risk factors such as sleep, shift duty, shift pattern, food timing, mode of travel, and type of PPE during travel were also found to be significantly associated with work type - Covid versus non-Covid (p < 0.05).

CONCLUSIONS

Use of workplace appropriate PPE, proper donning and doffing facilities, duty shifts with a fixed duration, adequate hand hygiene practices, and regular food intake with adequate sleep can prevent Covid-19 infection at the workplace among nurses.

A generalized epidemiological model with dynamic and asymptomatic population

In this paper, we develop an extension of compartmental epidemiological models which is suitable for COVID-19. The model presented in this paper comprises seven compartments in the progression of the disease. This model, named as the SINTRUE (Susceptible, Infected and pre-symptomatic, Infected and Symptomatic but Not Tested, Tested Positive, Recorded Recovered, Unrecorded Recovered, and Expired) model. The proposed model incorporates transmission due to asymptomatic carriers and captures the spread of the disease due to the movement of people to/from different administrative boundaries within a country. In addition, the model allows estimating the number of undocumented infections in the population and the number of unrecorded recoveries. The associated parameters in the model can help architect the public health policy and operational management of the pandemic. The results show that the testing rate of the asymptomatic patients is a crucial parameter to fight against the pandemic. The model is also shown to have a better predictive capability than the other epidemiological models.

Lessons from SARS-CoV, MERS-CoV, and SARS-CoV-2 Infections: What We Know So Far

Within past decades, human infections with emerging and reemerging zoonotic viral pathogens have raised the eminent public health concern. Since November 2002, three highly pathogenic and major deadly human coronaviruses of the βετα-genera (β-hCoVs), namely, severe acute respiratory distress syndrome-coronavirus (SARS-CoV), middle east respiratory syndrome-coronavirus (MERS-CoV), and SARS-CoV-2, have been globally emerged and culminated in the occurrence of SARS epidemic, MERS outbreak, and coronavirus disease 19 (COVID-19) pandemic, respectively. The global emergence and spread of these three major deadly β-hCoVs have extremely dreadful impacts on human health and become an economic burden. Unfortunately, clear specific and highly efficient medical countermeasures for these three β-hCoVs and their underlying fatal illnesses remain under development. Although they belong to the same family and share many features and convergent evolution, these three deadly β-hCoVs have some important and obvious differences. By utilizing their lessons and gaining a deeper understanding of these β-hCoVs, we can identify areas of improvement and provide preparedness plans for fighting and controlling the future reemerging human infections that might arise from them or from other potential pathogenic hCoVs. Therefore, this review summarizes the state-of-the-art information and compares the similarities and dissimilarities between SARS-CoV, MERS-CoV, and SARS-CoV-2, in terms of their evolution trait, genome organization, host cell entry mechanisms, tissue infectivity tropisms, transmission routes and contagiousness, and the clinical characteristics, laboratory features, and immunological abnormalities of their related illnesses. It also provides an overview of the emerging SARS-CoV-2 variants. Additionally, it discusses the challenges of the most proposed treatment options for SARS-CoV-2 infections.

Comparative overview of emerging RNA viruses: Epidemiology, pathogenesis, diagnosis and current treatment

From many decades, emerging infections have threatened humanity. The pandemics caused by different CoVs have already claimed and will continue to claim millions of lives. The SARS, Ebola, MERS epidemics and the most recent emergence of COVID-19 pandemic have threatened populations across borders. Since a highly pathogenic CoV has been evolved into the human population in the twenty-first century known as SARS, scientific advancements and innovative methods to tackle these viruses have increased in order to improve response preparedness towards the unpredictable threat posed by these rapidly emerging pathogens. Recently published review articles on SARS-CoV-2 have mainly focused on its pathogenesis, epidemiology and available treatments. However, in this review, we have done a systematic comparison of all three CoVs i.e., SARS, MERS and SARS-CoV-2 along with Ebola and Zika in terms of their epidemiology, virology, clinical features and current treatment strategies. This review focuses on important emerging RNA viruses starting from Zika, Ebola and the CoVs which include SARS, MERS and SARS-CoV-2. Each of these viruses has been elaborated on the basis of their epidemiology, virulence, transmission and treatment. However, special attention has been given to SARS-CoV-2 and the disease caused by it i.e., COVID-19 due to current havoc caused worldwide. At the end, insights into the current understanding of the lessons learned from previous epidemics to combat emerging CoVs have been described. The travel-related viral spread, the unprecedented nosocomial outbreaks and the high case-fatality rates associated with these highly transmissible and pathogenic viruses highlight the need for new prophylactic and therapeutic actions which include but are not limited to clinical indicators, contact tracing, and laboratory investigations as important factors that need to be taken into account in order to arrive at the final conclusion.

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Recently published review articles on SARS-CoV-2 have mainly focused on its pathogenesis, epidemiology and available treatments.

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The pandemics caused by different CoVs have already claimed and will continue to claim millions of lives.

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This review focuses on important emerging RNA viruses starting from Zika, Ebola and the CoVs which include SARS, MERS and SARS-CoV-2.

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Globally, numerous studies and researchers have recently started fighting this virus.

Visualization and analysis of mapping knowledge domains for coronavirus research

BACKGROUND

In recent years, many countries around the world have been threatened by COVs. The aim of this study was to better grasp developments and trends in research on coronavirus around the world and to promote theoretical research into their prevention and control.

METHODS

Research on coronavirus was reviewed and analyzed using bibliometrics based on a total of 4860 publications collected from the Web of Science Core Collection database. Yearly quantitative distribution of literature, country/region distribution, organization distribution, main source journal distribution, subject category distribution, research knowledge bases, and research hotspots and frontiers were all analyzed, and CiteSpace and VOSviewer were used to plot knowledge domain maps, Excel was used to plot keyword strategy diagram.

RESULTS

Coronavirus research could be roughly divided into 4 stages: preliminary development stage (before 2000), rapid growth stage (2000-2005), slow decline stage (2006-2011) and sustained growth stage (since 2012). America had taken the leading position in this field. The study of COVs involves many subject categories, mainly includes virology, veterinary sciences, biology, and immunology. At present, the key words in the field of coronavirus research were mainly divided into 6 major hot clusters, namely, the introduction and structure analysis of coronavirus, the research on the outbreak source and transmission of coronavirus, the research on the infection pathway of coronavirus in human body, the research on the pathogenesis of coronavirus, the research on the diagnosis and symptoms of coronavirus infection, and the research on the treatment of coronavirus.

CONCLUSION

Coronavirus, which occurs all over the world, often causes huge casualties and economic losses, and poses a serious threat to the safe and stable operation of the social and economic system. Objective literature review and analysis can help scholars in related fields to deepen their overall understanding. And, there are several key issues that should be further explored in future research.

Inferring the reproduction number using the renewal equation in heterogeneous epidemics

Real-time estimation of the reproduction number has become the focus of modelling groups around the world as the SARS-CoV-2 pandemic unfolds. One of the most widely adopted means of inference of the reproduction number is via the renewal equation, which uses the incidence of infection and the generation time distribution. In this paper, we derive a multi-type equivalent to the renewal equation to estimate a reproduction number which accounts for heterogeneity in transmissibility including through asymptomatic transmission, symptomatic isolation and vaccination. We demonstrate how use of the renewal equation that misses these heterogeneities can result in biased estimates of the reproduction number. While the bias is small with symptomatic isolation, it can be much larger with asymptomatic transmission or transmission from vaccinated individuals if these groups exhibit substantially different generation time distributions to unvaccinated symptomatic transmitters, whose generation time distribution is often well defined. The bias in estimate becomes larger with greater population size or transmissibility of the poorly characterized group. We apply our methodology to Ebola in West Africa in 2014 and the SARS-CoV-2 in the UK in 2020-2021.

Systematic Screening for SARS-CoV-2 to Detect Asymptomatic Infections: An Epitome of Taiwan’s Outbreak

Background

Increased studies have revealed that asymptomatic carriers substantially impact the epidemic and that asymptomatic transmission is very common. Therefore, the asymptomatic transmission threat to the spread of the pandemic should not be neglected.

Methods

The local outbreak in Taiwan, especially in Taipei City, is unprecedented and paramount and has claimed hundreds of lives, tens of thousands of cases, and enormous economic costs. As care providers and gatekeepers of infectious diseases, Taipei City Hospital has to perform regular polymerase chain reaction (PCR) results of admitted patients and healthcare workers (HCWs) to achieve these goals.

Results

In this study, the results revealed a low positive rate of less than 1%, but the asymptomatic proportions could range from 42% to 46%, which bolsters that systematic screening was effective in controlling coronavirus disease-19 (COVID-19) of Novel Coronavirus or Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) and might be an exemplar to other similar scenarios. Universal screening of admitted patients may be important and necessary, especially in asymptomatic patients.

Conclusions

Regular screening for healthcare providers is also important during this pandemic, and it is recommended that admitted patients and healthcare providers undergo systemic PCR testing.

Middle East Respiratory Syndrome Coronavirus

The past two decades have witnessed the emergence of three zoonotic coronaviruses which have jumped species to cause lethal disease in humans: severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2. MERS-CoV emerged in Saudi Arabia in 2012 and the origins of MERS-CoV are not fully understood. Genomic analysis indicates it originated in bats and transmitted to camels. Human-to-human transmission occurs in varying frequency, being highest in healthcare environment and to a lesser degree in the community and among family members. Several nosocomial outbreaks of human-to-human transmission have occurred, the largest in Riyadh and Jeddah in 2014 and South Korea in 2015. MERS-CoV remains a high-threat pathogen identified by World Health Organization as a priority pathogen because it causes severe disease that has a high mortality rate, epidemic potential, and no medical countermeasures. MERS-CoV has been identified in dromedaries in several countries in the Middle East, Africa, and South Asia. MERS-CoV-2 causes a wide range of clinical presentations, although the respiratory system is predominantly affected. There are no specific antiviral treatments, although recent trials indicate that combination antivirals may be useful in severely ill patients. Diagnosing MERS-CoV early and implementation infection control measures are critical to preventing hospital-associated outbreaks. Preventing MERS relies on avoiding unpasteurized or uncooked animal products, practicing safe hygiene habits in health care settings and around dromedaries, community education and awareness training for health workers, as well as implementing effective control measures. Effective vaccines for MERS-COV are urgently needed but still under development.

Optical Biosensors for Diagnostics of Infectious Viral Disease: A Recent Update

The design and development of biosensors, analytical devices used to detect various analytes in different matrices, has emerged. Biosensors indicate a biorecognition element with a physicochemical analyzer or detector, i.e., a transducer. In the present scenario, various types of biosensors have been deployed in healthcare and clinical research, for instance, biosensors for blood glucose monitoring. Pathogenic microbes are contributing mediators of numerous infectious diseases that are becoming extremely serious worldwide. The recent outbreak of COVID-19 is one of the most recent examples of such communal and deadly diseases. In efforts to work towards the efficacious treatment of pathogenic viral contagions, a fast and precise detection method is of the utmost importance in biomedical and healthcare sectors for early diagnostics and timely countermeasures. Among various available sensor systems, optical biosensors offer easy-to-use, fast, portable, handy, multiplexed, direct, real-time, and inexpensive diagnosis with the added advantages of specificity and sensitivity. Many progressive concepts and extremely multidisciplinary approaches, including microelectronics, microelectromechanical systems (MEMSs), nanotechnologies, molecular biology, and biotechnology with chemistry, are used to operate optical biosensors. A portable and handheld optical biosensing device would provide fast and reliable results for the identification and quantitation of pathogenic virus particles in each sample. In the modern day, the integration of intelligent nanomaterials in the developed devices provides much more sensitive and highly advanced sensors that may produce the results in no time and eventually help clinicians and doctors enormously. This review accentuates the existing challenges engaged in converting laboratory research to real-world device applications and optical diagnostics methods for virus infections. The review's background and progress are expected to be insightful to the researchers in the sensor field and facilitate the design and fabrication of optical sensors for life-threatening viruses with broader applicability to any desired pathogens.

Neutrophils and Lymphocytes Can Help Distinguish Asymptomatic COVID-19 From Moderate COVID-19

Introduction

Asymptomatic coronavirus disease 2019 (COVID-19) and moderate COVID-19 may be the most common COVID-19 cases. This study was designed to develop a diagnostic model for patients with asymptomatic and moderate COVID-19 based on demographic, clinical, and laboratory variables.

Methods

This retrospective study divided the subjects into 2 groups: asymptomatic COVID-19 (without symptoms, n = 15) and moderate COVID-19 (with symptoms, n = 57). Demographic characteristics, clinical data, routine blood tests, other laboratory tests, and inpatient data were collected and analyzed to compare patients with asymptomatic COVID-19 and moderate COVID-19.

Results

Comparison of the asymptomatic COVID-19 group with the moderate COVID-19 group yielded the following results: the patients were younger (P = 0.045); the cluster of differentiation (CD)8+ (cytotoxic) T cell level was higher (P = 0.017); the C-reactive protein (CRP) level was lower (P = 0.001); the white blood cell (WBC, P < 0.001), neutrophil (NEU, P = 0.036), lymphocyte (LYM, P = 0.009), and eosinophil (EOS, P = 0.036) counts were higher; and the serum iron level (P = 0.049) was higher in the asymptomatic COVID-19 group. The multivariate analysis showed that the NEU count (odds ratio [OR] = 2.007, 95% confidence interval (CI): 1.162 - 3.715, P = 0.014) and LYM count (OR = 9.380, 95% CI: 2.382 - 36.934, P = 0.001) were independent factors for the presence of clinical symptoms after COVID-19 infection. The NEU count and LYM count were diagnostic predictors of asymptomatic COVID-19. This diagnostic prediction model showed high discriminatory power, consistency, and net clinical benefits.

Conclusions

The proposed model can distinguish asymptomatic COVID-19 from moderate COVID-19, thereby helping clinicians identify and distinguish patients with potential asymptomatic COVID-19 from those with moderate COVID-19.

Adverse events related to COVID-19 vaccines: the need to strengthen pharmacovigilance monitoring systems

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a new species of β-coronavirus genus named severe acute respiratory syndrome coronavirus 2. The COVID-19 pandemic, which started in late 2019 and continues as at mid-2021, has caused enormous damage to health and lives globally. The urgent public health need has led to the development of vaccines against COVID-19 in record-breaking time. The COVID-19 vaccines have been widely rolled out for the masses by many countries following approval for emergency use by the World Health Organization and regulatory agencies in many countries. In addition, several COVID-19 vaccine candidates are undergoing clinical trials. However, myths, fears, rumors, and misconceptions persist, particularly in regard to adverse events. In this commentary, we describe the adverse events associated with COVID-19 vaccines and discuss why it is essential to have a functional adverse event monitoring system in this context.

Detection of SARS-CoV-2 infection in asymptomatic populations using the DiaSorin molecular Simplexa and Roche Cobas EUA assays

Identification of asymptomatic patients is necessary to control the COVID-19 pandemic and testing is one of the measures to detect this population. We evaluated the clinical correlation of the DiaSorin Molecular Simplexa COVID-19 Direct (DiaSorin Molecular) and Roche Cobas 6800 SARS-CoV-2 (Roche) assays using 253 oropharyngeal (OP) swab specimens collected from asymptomatic patients. Agreement between DiaSorin Molecular and Roche was 97% (95% CI, 0.94 to 0.99), with a κ statistic of 0.90 (95% CI, 0.83 to 0.97) and a PPA of 89% (95% CI, 0.76 to 0.96) and NPA of 99% (95% CI, 0.97 to 0.99). Simple regression analysis of Ct values revealed a regression line of y = 1.065*X - 5.537 with a Pearson's r of 0.8542, indicating a good correlation between both platforms. The DiaSorin Molecular assay demonstrates clinical performance comparable to that of Roche in this population.

Human Coronaviruses: Counteracting the Damage by Storm

Over the past 18 years, three highly pathogenic human (h) coronaviruses (CoVs) have caused severe outbreaks, the most recent causative agent, SARS-CoV-2, being the first to cause a pandemic. Although much progress has been made since the COVID-19 pandemic started, much about SARS-CoV-2 and its disease, COVID-19, is still poorly understood. The highly pathogenic hCoVs differ in some respects, but also share some similarities in clinical presentation, the risk factors associated with severe disease, and the characteristic immunopathology associated with the progression to severe disease. This review aims to highlight these overlapping aspects of the highly pathogenic hCoVs-SARS-CoV, MERS-CoV, and SARS-CoV-2-briefly discussing the importance of an appropriately regulated immune response; how the immune response to these highly pathogenic hCoVs might be dysregulated through interferon (IFN) inhibition, antibody-dependent enhancement (ADE), and long non-coding RNA (lncRNA); and how these could link to the ensuing cytokine storm. The treatment approaches to highly pathogenic hCoV infections are discussed and it is suggested that a greater focus be placed on T-cell vaccines that elicit a cell-mediated immune response, using rapamycin as a potential agent to improve vaccine responses in the elderly and obese, and the potential of stapled peptides as antiviral agents.

Implications of the Emergence of a New Variant of SARS-CoV-2, VUI-202012/01

Twelve months after the realization that SARS-CoV-2 caused a respiratory syndrome in Wuhan, China, with the constantly worsening COVID-19 pandemic and economic crisis globally, and with international news of vaccine development, a new viral variant, referred to as "SARS-CoV-2 VUI-202012/01" or "B.1.1.7" has been reported in London and southeast England. The variant may have emerged in late September 2020 and carries some 17 mutations. Whether a single or a combination of different mutations would change the viral transmissibility, virulence, clinical and epidemiological presentations, or vaccine efficiency is unknown. Transmission by asymptomatic carriers of the new variant is also unknown. Mutation pressure by antiviral agents or vaccines have not yet been induced; however, additional mutations are expected following global vaccination and, later, after administration of validated treatments. Thus, preparedness for fast emergence of new variants is prudent. One can also expect less virulent but highly transmissible variants, which could facilitate herd immunity. Development of clinical and rapid laboratory tests is required to follow up the vaccinated individuals for a secondary infection potentially by the new variant. Importantly, restrictive countermeasures, personal hygiene, face-masking, spatial distancing, and travel bans remain pertinent in fighting the virus.

Seroprevalence of human coronaviruses among patients visiting hospital-based sentinel sites in Uganda

Background

Human coronaviruses are causative agents of respiratory infections with several subtypes being prevalent worldwide. They cause respiratory illnesses of varying severity and have been described to be continuously emerging but their prevalence is not well documented in Uganda. This study assessed the seroprevalence of antibodies against the previously known human coronaviruses prior 2019 in Uganda.

Methods

A total 377 serum samples collected from volunteers that showed influenza like illness in five hospital-based sentinel sites and archived were analyzed using a commercial Qualitative Human Coronavirus Antibody IgG ELISA kit. Although there is no single kit available that can detect the presence of all the circulating coronaviruses, this kit uses a nucleoprotein, aa 340–390 to coat the wells and since there is significant homology among the various human coronavirus strains with regards to the coded for proteins, there is significant cross reactivity beyond HCoV HKU-39849 2003. This gives the kit a qualitative ability to detect the presence of human coronavirus antibodies in a sample.

Results

The overall seroprevalence for all the sites was 87.53% with no significant difference in the seroprevalence between the Hospital based sentinel sites (p = 0.8). Of the seropositive, the age group 1–5 years had the highest percentage (46.97), followed by 6–10 years (16.67) and then above 20 (16.36). An odds ratio of 1.6 (CI 0.863–2.97, p = 0.136) showed that those volunteers below 5 years of age were more likely to be seropositive compared to those above 5 years. The seropositivity was generally high throughout the year with highest being recorded in March and the lowest in February and December.

Conclusions

The seroprevalence of Human coronaviruses is alarmingly high which calls for need to identify and characterize the circulating coronavirus strains so as to guide policy on the control strategies.

COVID Obesity: A One-Year Narrative Review

On 11 March 2020, coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization (WHO). This study focuses on a narrative review about the illness during the first year of the pandemic in relation to obesity. Databases were used to search studies published up to 8 December 2020. In total, 4430 articles and other scientific literature were found, and 24 articles were included in this one-year narrative review. The mean BMI value of severe COVID-19 patients ranged from 24.5 to 33.4 kg/m2, versus <18.5 to 24.3 kg/m2 for non-severe patients. Articles using the terms obesity or overweight without indicating the BMI value in these patients were common, but this is not useful, as the anthropometric parameters, when not defined by this index, are confusing due to the classification being different in the West compared to among Asian and Korean criteria-based adults. We proposed a new term, called COVID obesity, to define the importance of this anthropometric parameter, among others, in relation with this pandemic.

Asymptomatic Transmission During the Coronavirus Disease 2019 Pandemic and Implications for Public Health Strategies

SARS-CoV-2 spread rapidly within months despite global public health strategies to curb transmission by testing symptomatic patients and encouraging social distancing. Here, we summarize rapidly emerging evidence highlighting transmission by asymptomatic and pre-symptomatic individuals. Viral load of asymptomatic carriers is comparable to symptomatic patients, viral shedding is highest before symptom onset suggesting high transmissibility before symptoms. Within universally tested subgroups, surprisingly high percentages of COVID-19 positive asymptomatic individuals were found. Asymptomatic transmission was reported in several clusters. A Wuhan study showed an alarming rate of intrahospital transmission, and several countries reported higher prevalence among healthcare workers than the general population. This raises concern that health workers could act as silent disease vectors. Therefore, current public health strategies relying solely on ‘symptom onset’ for infection identification need urgent reassessment. Extensive universal testing irrespective of symptoms may be considered with priority placed on groups with high frequency exposure to positive patients.

Magnitude of asymptomatic COVID-19 cases throughout the course of infection: A systematic review and meta-analysis

BACKGROUND

Asymptomatic SARS-CoV-2 infections are responsible for potentially significant transmission of COVID-19. Worldwide, a number of studies were conducted to estimate the magnitude of asymptomatic COVID-19 cases. However, there is a need for more robust and well-designed studies to have a relevant public health intervention. Synthesis of the available studies significantly strengthens the quality of evidences for public health practice. Thus, this systematic review and meta-analysis aimed to determine the overall magnitude of asymptomatic COVID-19 cases throughout the course of infection using available evidences.

METHODS

We followed the PRISMA checklist to present this study. Two experienced review authors (MA and DBK) were systematically searched international electronic databases for studies. We performed meta-analysis using R statistical software. The overall weighted proportion of asymptomatic COVID-19 cases throughout the course infection was computed. The pooled estimates with 95% confidence intervals were presented using forest plot. Egger's tests were used to assess publication bias, and primary estimates were pooled using a random effects model. Furthermore, a sensitivity analysis was conducted to assure the robustness of the result.

RESULTS

A total of 28 studies that satisfied the eligibility criteria were included in this systematic review and meta-analysis. Consequently, in the meta-analysis, a total of 6,071 COVID-19 cases were included. The proportion of asymptomatic infections among the included studies ranged from 1.4% to 78.3%. The findings of this meta-analysis showed that the weighted pooled proportion of asymptomatic COVID-19 cases throughout the course of infection was 25% (95%CI: 16-38). The leave-one out result also revealed that the weighted pooled average of asymptomatic SARS-CoV-2 infection was between 28% and 31.4%.

CONCLUSIONS

In conclusion, one-fourth of SARS-CoV-2 infections are remained asymptomatic throughout the course infection. Scale-up of testing, which targeting high risk populations is recommended to tackle the pandemic.

Asymptomatic SARS-CoV-2 Carriers: A Systematic Review and Meta-Analysis

Asymptomatic cases of SARS-CoV-2 can be unknown carriers magnifying the transmission of COVID-19. This study appraised the frequency of asymptomatic individuals and estimated occurrence by age group and gender by reviewing the existing published data on asymptomatic people with COVID-19. Three electronic databases, PubMed, Embase, and Web of Science (WoS), were used to search the literature following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The study population for this review included asymptomatic individuals infected with SARS-CoV-2 reported in original articles published up to 30 April 2020. A random effects model was applied to analyze pooled data on the prevalence of asymptomatic cases among all COVID-19 patients and also by age and gender. From the meta-analysis of 16 studies, comprising 2,788 SARS-CoV-2 infected patients, the pooled prevalence according to the random effect size of asymptomatic cases was 48.2% (95% CI, 30-67%). Of the asymptomatic cases, 55.5% (95% CI, 43.6-66.8%) were female and 49.6% (95% CI, 20.5-79.1%) were children. Children and females were more likely to present as asymptomatic COVID-19 cases and could act as unknown carriers of SARS-CoV-2. Symptom-based screening might fail to identify all SARS-CoV-2 infections escalating the threat of global spread and impeding containment. Therefore, a mass surveillance system to track asymptomatic cases is critical, with special attention to females and children.

High MERS-CoV seropositivity associated with camel herd profile, husbandry practices and household socio-demographic characteristics in Northern Kenya

Despite high exposure to Middle East respiratory syndrome coronavirus (MERS-CoV), the predictors for seropositivity in the context of husbandry practices for camels in Eastern Africa are not well understood. We conducted a cross-sectional survey to describe the camel herd profile and determine the factors associated with MERS-CoV seropositivity in Northern Kenya. We enrolled 29 camel-owning households and administered questionnaires to collect herd and household data. Serum samples collected from 493 randomly selected camels were tested for anti-MERS-CoV antibodies using a microneutralisation assay, and regression analysis used to correlate herd and household characteristics with camel seropositivity. Households reared camels (median = 23 camels and IQR 16–56), and at least one other livestock species in two distinct herds; a home herd kept near homesteads, and a range/fora herd that resided far from the homestead. The overall MERS-CoV IgG seropositivity was 76.3%, with no statistically significant difference between home and fora herds. Significant predictors for seropositivity (P ⩽ 0.05) included camels 6–10 years old (aOR 2.3, 95% CI 1.0–5.2), herds with ⩾25 camels (aOR 2.0, 95% CI 1.2–3.4) and camels from Gabra community (aOR 2.3, 95% CI 1.2–4.2). These results suggest high levels of virus transmission among camels, with potential for human infection.

Association of cardiac biomarkers and comorbidities with increased mortality, severity, and cardiac injury in COVID-19 patients: A meta-regression and decision tree analysis

BACKGROUND

Coronavirus disease-2019 (COVID-19) has a deleterious effect on several systems, including the cardiovascular system. We aim to systematically explore the association of COVID-19 severity and mortality rate with the history of cardiovascular diseases and/or other comorbidities and cardiac injury laboratory markers.

METHODS

The standardized mean difference (SMD) or odds ratio (OR) and 95% confidence intervals (CIs) were applied to estimate pooled results from the 56 studies. The prognostic performance of cardiac markers for predicting adverse outcomes and to select the best cutoff threshold was estimated by receiver operating characteristic curve analysis. Decision tree analysis by combining cardiac markers with demographic and clinical features was applied to predict mortality and severity in patients with COVID-19.

RESULTS

A meta-analysis of 17 794 patients showed patients with high cardiac troponin I (OR = 5.22, 95% CI = 3.73-7.31, P < .001) and aspartate aminotransferase (AST) levels (OR = 3.64, 95% CI = 2.84-4.66, P < .001) were more likely to develop adverse outcomes. High troponin I more than 13.75 ng/L combined with either advanced age more than 60 years or elevated AST level more than 27.72 U/L was the best model to predict poor outcomes.

CONCLUSIONS

COVID-19 severity and mortality are complicated by myocardial injury. Assessment of cardiac injury biomarkers may improve the identification of those patients at the highest risk and potentially lead to improved therapeutic approaches.

Incidence of COVID-19 among returning travelers in quarantine facilities: A longitudinal study and lessons learned

INTRODUCTION

The emergence of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) had resulted in an unpresented global pandemic. In the initial events, the Kingdom of Saudi Arabia implemented mandatory quarantine of returning travelers in order to contain COVID-19 cases.

MATERIALS AND METHODS

This is a longitudinal study of the arriving travelers to Quarantine facilities and the prevalence of positive SARS-CoV-2 as detected by RT-PCR.

RESULTS

During the study period, there was a total of 1928 returning travelers with 1273 (66%) males. The age range was 28 days-69 years. Of all the travelers, 23 (1.2%) tested positive for SARS-CoV-2. Of the first swab, 14/1928 (0.7%) tested positive. The positivity rate was 0.63% and 0.92% among males and females, respectively (P = 0.57). The second swab was positive in 9 (0.5%) of the other 1914 who were initially negative with a positivity rate of 0.39% and 0.62% among males and females, respectively (P = 0.49). There was no statistical difference in the positivity rates between first and second swab (P = 0.4). Of all travelers, 40 (n = 26, 1.3%) were admitted from the quarantine facility to the hospital due to COVID-19 related positive results or development of symptoms such as fever, cough, and respiratory symptoms; and 14 (0.7%) were admitted due to non-COVID-19 related illness.

CONCLUSION

This study showed the efforts put for facility quarantine and that such activity yielded a lower incidence of positive cases. There was a need to have a backup healthcare facility to accommodate those developing a medical need for evaluation and admission for non-COVID-19 related illnesses.

Asymptomatic infection by SARS-CoV-2 in healthcare workers: A study in a large teaching hospital in Wuhan, China

OBJECTIVES

To investigate the proportion and characteristics of asymptomatic infection among healthcare workers (HCWs).

METHODS

This study retrospectively investigated 1407 HCWs who were screened for COVID-19 by chest computed tomography (CT) scans and nasopharyngeal swabs for SARS-CoV-2 nucleic acid. Demographics, CT features, nasopharyngeal swabs, baseline symptoms, and laboratory data were collected.

RESULTS

Of 1407 HCWs, 235 had symptoms and 1172 were asymptomatic close contacts, of which, 107 were symptomatic cases and 84 were close contacts who had abnormal CT findings. Of 152 symptomatic individuals and 908 close contacts tested for SARS-CoV-2 nucleic acid, 122 symptomatic cases and 38 close contacts had positive reverse-transcriptase real-time polymerase chain (RT-PCR) test results. The rate of confirmed asymptomatic infections was 4.2% (38/908). Both symptomatic and asymptomatic infected cases had high titrations of specific IgG or had ≥four-fold increase in IgG during convalescence compared with the acute phase. Combining the RT-PCR tests and serological findings, the rate of asymptomatic infections was 9.7% (88/908). In terms of the duration of viral shedding, there was no significant difference between symptomatic mild/moderate participants and asymptomatic infections.

CONCLUSIONS

The findings demonstrated that a high rate of asymptomatic SARS-CoV-2 carriers existed among healthcare worker close contacts during the outbreak of COVID-19.

The unique features of SARS-CoV-2 transmission: Comparison with SARS-CoV, MERS-CoV and 2009 H1N1 pandemic influenza virus

From 2002 to 2019, three deadly human coronaviruses (hCoVs), severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle Eastern respiratory syndrome coronavirus (MERS‐CoV) and severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) emerged to produce outbreaks of SARS, MERS and coronavirus disease 2019 (Covid‐19), respectively. All three hCoVs are members of the Betacoronavirus genus in the subfamily Orthocoronavirinae and share many similarities in virology and epidemiology. However, the pattern and scale of Covid‐19 global spread is similar to 2009 pandemic H1N1 influenza (H1N1pdm09), rather than SARS or MERS. Covid‐19 exhibits high viral shedding in the upper respiratory tract at an early stage of infection, and has a high proportion of transmission competent individuals that are pre‐symptomatic, asymptomatic and mildly symptomatic, characteristics seen in H1N1pdm09 but not in SARS or MERS. These two traits of Covid‐19 and H1N1pdm09 result in reduced efficiency in identification of transmission sources by symptomatic screening and play important roles in their ability to spread unchecked to cause pandemics. To overcome these attributes of Covid‐19 in community transmission, identifying the transmission source by testing for virus shedding and interrupting chains of transmission by social distancing and public masking are required.

SARS-CoV-2/COVID-19 and advances in developing potential therapeutics and vaccines to counter this emerging pandemic

A novel coronavirus (SARS-CoV-2), causing an emerging coronavirus disease (COVID-19), first detected in Wuhan City, Hubei Province, China, which has taken a catastrophic turn with high toll rates in China and subsequently spreading across the globe. The rapid spread of this virus to more than 210 countries while affecting more than 25 million people and causing more than 843,000 human deaths, it has resulted in a pandemic situation in the world. The SARS-CoV-2 virus belongs to the genus Betacoronavirus, like MERS-CoV and SARS-CoV, all of which originated in bats. It is highly contagious, causing symptoms like fever, dyspnea, asthenia and pneumonia, thrombocytopenia, and the severely infected patients succumb to the disease. Coronaviruses (CoVs) among all known RNA viruses have the largest genomes ranging from 26 to 32 kb in length. Extensive research has been conducted to understand the molecular basis of the SARS-CoV-2 infection and evolution, develop effective therapeutics, antiviral drugs, and vaccines, and to design rapid and confirmatory viral diagnostics as well as adopt appropriate prevention and control strategies. To date, August 30, 2020, no effective, proven therapeutic antibodies or specific drugs, and vaccines have turned up. In this review article, we describe the underlying molecular organization and phylogenetic analysis of the coronaviruses, including the SARS-CoV-2, and recent advances in diagnosis and vaccine development in brief and focusing mainly on developing potential therapeutic options that can be explored to manage this pandemic virus infection, which would help in valid countering of COVID-19.

The incidence of the novel coronavirus SARS-CoV-2 among asymptomatic patients: A systematic review

BACKGROUND

The recent outbreak of the coronavirus disease 2019 (COVID-19) has quickly spread globally since its discovery in Wuhan, China, in December 2019. A comprehensive strategy - including surveillance, diagnostics, research, and clinical treatment - is urgently needed to win the battle against COVID-19. Recently, numerous studies have reported the incidence of SARS-CoV-2 in asymptomatic patients. Yet, the incidence and viral transmission from the asymptomatic cases are not yet apparent.

AIM

To estimate the incidence of COVID-19 among asymptomatic cases and describe its epidemiological and clinical significance this review systematically examined the published literature on SARS-CoV-2 in asymptomatic patients.

METHODS

The literature was searched through four scientific databases: PubMed, Web of Science, Scopus, and Science Direct.

RESULTS

Sixty-three studies satisfied the inclusion criteria. The majority of the reported studies were from China. However, there was a lack of SARS-CoV-2 epidemiological studies, from several countries worldwide, tracing the actual incidence of COVID-19, especially in asymptomatic patients. Studies with a large sample size (>1000) estimated that the percentage of people contracting SARS-CoV-2 and likely to be asymptomatic ranged from 1.2-12.9%. However, other studies with a smaller sample size reported a much higher incidence and indicated that up to 87.9% of COVID-19 infected individuals could be asymptomatic. Most of these studies indicated that asymptopatics are a potential source of infection to the community.

CONCLUSION

This review highlighted the need for more robust and well-designed studies to better estimate COVID-19 incidence among asymptomatic patients worldwide. Early identification of asymptomatic cases, as well as monitoring and tracing close contacts, could help in mitigating the spread of COVID-19.

The SARS-CoV-2 main protease as drug target

The unprecedented pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is threatening global health. The virus emerged in late 2019 and can cause a severe disease associated with significant mortality. Several vaccine development and drug discovery campaigns are underway. The SARS-CoV-2 main protease is considered a promising drug target, as it is dissimilar to human proteases. Sequence and structure of the main protease are closely related to those from other betacoronaviruses, facilitating drug discovery attempts based on previous lead compounds. Covalently binding peptidomimetics and small molecules are investigated. Various compounds show antiviral activity in infected human cells.

Design of an air isolation and purification (AIP) desk for medical use and characterization of its efficacy in ambient air isolation and purification

The incidences of nosocomial infections (NIs) are increasing throughout the world, especially for those airborne diseases caused by pathogens or air particulates that float in air. In this study, we designed and manufactured a desk for clinic consultation room air purification and air isolation between doctor and patient. The air isolation and purification (AIP) desk has a high efficiency particulate air (HEPA) filter on the tope and several primary efficiency filters on the sides for air purification. The air circulating between inlet and outlet forms a wind-curtain between doctor and patient. The Computational Fluid Dynamics (CFD) model was used to calculate the speed of the air flow and the angle of sampler. We tested the air purification function of the AIP desk in rooms sized about 3.6 × 2.8 × 2.8 m (L × W × H) and found that the AIP desk could significantly remove the tested air pollutants like smoke particulates and microorganisms like Staphylococcus albus (S. albus)and human adenovirus type 5 (HAdV-5). The wind-curtain can significantly block the exhale air of patient being transmitted to the respiratory area of doctor setting in the opposite of AIP desk. Thus, the AIP desk can be used in hospital setting to reduce the risk of NIs and protect both doctors and patients.

From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses

Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.

From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses

Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.

Diagnostic and prognostic value of hematological and immunological markers in COVID-19 infection: A meta-analysis of 6320 patients

OBJECTIVE

Evidence-based characterization of the diagnostic and prognostic value of the hematological and immunological markers related to the epidemic of Coronavirus Disease 2019 (COVID-19) is critical to understand the clinical course of the infection and to assess in development and validation of biomarkers.

METHODS

Based on systematic search in Web of Science, PubMed, Scopus, and Science Direct up to April 22, 2020, a total of 52 eligible articles with 6,320 laboratory-confirmed COVID-19 cohorts were included. Pairwise comparison between severe versus mild disease, Intensive Care Unit (ICU) versus general ward admission and expired versus survivors were performed for 36 laboratory parameters. The pooled standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated using the DerSimonian Laird method/random effects model and converted to the Odds ratio (OR). The decision tree algorithm was employed to identify the key risk factor(s) attributed to severe COVID-19 disease.

RESULTS

Cohorts with elevated levels of white blood cells (WBCs) (OR = 1.75), neutrophil count (OR = 2.62), D-dimer (OR = 3.97), prolonged prothrombin time (PT) (OR = 1.82), fibrinogen (OR = 3.14), erythrocyte sedimentation rate (OR = 1.60), procalcitonin (OR = 4.76), IL-6 (OR = 2.10), and IL-10 (OR = 4.93) had higher odds of progression to severe phenotype. Decision tree model (sensitivity = 100%, specificity = 81%) showed the high performance of neutrophil count at a cut-off value of more than 3.74x109/L for identifying patients at high risk of severe COVID-19. Likewise, ICU admission was associated with higher levels of WBCs (OR = 5.21), neutrophils (OR = 6.25), D-dimer (OR = 4.19), and prolonged PT (OR = 2.18). Patients with high IL-6 (OR = 13.87), CRP (OR = 7.09), D-dimer (OR = 6.36), and neutrophils (OR = 6.25) had the highest likelihood of mortality.

CONCLUSIONS

Several hematological and immunological markers, in particular neutrophilic count, could be helpful to be included within the routine panel for COVID-19 infection evaluation to ensure risk stratification and effective management.

Children with SARS-CoV-2 infection during an epidemic in China (outside of Hubei province)

Background

Limited studies have reported the clinical and epidemiological characteristics of children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to provide the epidemiological characteristics of children with COVID-19 throughout China (outside of Hubei Province) based on public data.

Methods

This was an observational, cross-sectional study. We included a total of 279 diagnosed children based on the data of children infected with SARS-CoV-2 reported by the Health Commission in each province, autonomous region, municipality, or special administrative region in China (outside of Hubei Province) from January 24, 2020 to February 16, 2020.

Results

The number of newborns (0 days ≤ age ≤28 days), infants (28 days < age ≤1 year), children (1 year < age ≤5 years), and children (5 years < age ≤18 years) accounted for 0.7%, 6.5%, 23.7%, and 69.2% of the total number of infected children, respectively. We found that from January 23, 2020, to January 31, 2020, infected children mainly came from Wuhan, China. After February 3, 2020, family clustering transmission became the main mode of transmission.

Conclusions

Family clustering transmission is currently the main model of transmission in children. Considering the mild symptoms in infected children, the possibility that children may be a source of the transmission should not be ignored.

SARS-CoV-2 Screening Test for Japanese Returnees From Wuhan, China, January 2020

Background

Severe acute respiratory syndrome–related coronavirus 2 (SARS-CoV-2) was found to be the causative microorganism of coronavirus disease 2019 (COVID-19), which started to spread in Wuhan, China. This study was to evaluate the effectiveness of questionnaire, symptoms-based screening, and polymerase chain reaction (PCR) screening of returnees from COVID-19-endemic areas on a chartered flight, to examine the proportion of infected persons and the proportion of asymptomatic persons among infected persons who returned from Wuhan.

Methods

A retrospective cohort study was done in 7 tertiary medical institutions in Japan. A total of 566 Japanese who returned from Wuhan participated in the study.

Results

Overall, 11 of the 566 passengers had a positive SARS-CoV-2 PCR result for pharyngeal swabs and 6 were asymptomatic. Only fever differed between SARS-CoV-2-positive and -negative individuals (P < .043). Six of the 11 PCR-positive individuals were asymptomatic; 4 remained positive on day 10, and 1 asymptomatic person tested positive up to day 27. Two of the 11 were negative on the first PCR test and positive on the second.

Conclusions

Our results will be important insights on screening returnees from locked-down cities, as well as providing important data on the proportion of asymptomatic individuals infected with SARS-CoV-2. A 13-day observation period and a second round of PCR may be effective to screen patients, including asymptomatic infections.

Features of enteric disease from human coronaviruses: Implications for COVID-19

Coronaviruses have long been studied in both human and veterinary fields. Whereas the initial detection of endemic human respiratory coronaviruses was problematic, detection of these and newly discovered human coronaviruses has been greatly facilitated with major advances in the laboratory. Nevertheless, technological factors can affect the accuracy and timeliness of virus detection. Many human coronaviruses can be variably found in stool samples. All human coronaviruses have been variably associated with symptoms of gastroenteritis. Coronaviruses can occasionally be cultured from enteric specimens, but most detection is accomplished with genetic amplification technologies. Excretion of viral RNA in stool can extend for a prolonged period. Culture‐positive stool samples have been found to exceed a fourteen day period after onset of infection for some coronaviruses. Virus can also sometimes be cultured from patients' respiratory samples during the late incubation period. Relatively asymptomatic patients may excrete virus. Both viable and nonviable virus can be found in the immediate environment of the patient, the health care worker, and less often the public. These lessons from the past study of animal and human coronaviruses can be extended to presumptions for severe acute respiratory syndrome coronavirus 2. Already, the early reports from the coronavirus disease‐2019 pandemic are confirming some concerns. These data have the cumulative potential to cause us to rethink some current and common public health and infection control strategies.

coronaviruses are variably found in human enteric samples during the course of infection.

abdominal and intestinal illnesses are associated with coronavirus infections.

enteric excretion of live virus and viral RNA have been confirmed.

occasionally, live virus can be found in stool samples to exceed a fourteen day period after disease onset, and virus can also be cultured from these samples during the late incubation period or from asymptomatic individuals.

Novel 2019 coronavirus: Genome structure, clinical trials, and outstanding questions

IMPACT STATEMENT

Early availability of the sequence, the genetic material of SARS-CoV-2 (the virus that causes COVID-19), has prompted efforts towards identifying a safe and effective vaccine in the current public health emergency. To that end, understanding the pathophysiology of disease is crucial for scientists around the world. Since conventional vaccine development and manufacturing may take several years, it is important to think about alternative strategies that we could use to mitigate imminent catastrophe. We hope that this article will open up new avenues and provide insights that could potentially save hundreds of lives affected by COVID-19.

Emergence of deadly severe acute respiratory syndrome coronavirus-2 during 2019-2020

Wuhan, the city in Hubei province in China is in the focus of global community due to the outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), formerly known as 2019-nCoV. The virus emerged in humans from Wuhan seafood market probably via zoonotic transmission. Within a few days the virus spread its tentacles rapidly to neighboring cities in China and to different geographical regions through travelers and to some extent by human to human transmission leading to significant disease burden globally. More than 2,00,000 people (including more than 8000 deaths) have been infected with this respiratory illness across 167 countries and territories worldwide leading to a pandemic. The present review provides an outline about emergence and spread of SARS-CoV-2 from Wuhan, China in 2019-2020. We have also provided information about the classification, genome, proteins, clinical presentation of COVID-19, type of clinical specimens to be collected and diagnostic methods adopted to identify the respiratory illness. In addition we have also provided information about transmission dynamics, prevention measures and treatment options that are available at the present. Subsequently, we have given a comprehensive overview of the spread of this infection from China to the other parts of the globe. Management of the ongoing outbreak of SARS-CoV-2 encompassing surveillance, clinical, immunological, genetic and evolutionary investigations are likely to provide the desired results. Joint efforts of global scientific community are needed at this hour in terms of enhancement of research on development of accurate diagnostics, antiviral therapeutics and finally into formation of an effective vaccine against the emerging novel coronavirus.

Clinical features of the first cases and a cluster of Coronavirus Disease 2019 (COVID-19) in Bolivia imported from Italy and Spain

INTRODUCTION

In March 2020, Coronavirus Disease 2019 (COVID-19) arrived in Bolivia. Here, we report the main clinical findings, and epidemiological features of the first series of cases, and a cluster, confirmed in Bolivia.

METHODS

For this observational, retrospective and cross-sectional study, information was obtained from the Hospitals and the Ministry of Health for the cases that were laboratory-diagnosed and related, during March 2020. rRT-PCR was used for the detection of the RNA of SARS-CoV-2 following the protocol Charité, Berlin, Germany, from nasopharyngeal swabs.

RESULTS

Among 152 suspected cases investigated, 12 (7.9%) were confirmed with SARS-CoV-2 infected by rRT-PCR. The median age was 39 years (IQR 25-43), six of them male. Two cases proceed from Italy and three from Spain. Nine patients presented fever, and cough, five sore throat, and myalgia, among other symptoms. Only a 60 y-old woman with hypertension was hospitalized. None of the patients required ICU nor fatalities occurred in this group.

CONCLUSIONS

This is the first report of surveillance of COVID-19 in Bolivia, with patients managed mainly with home isolation. Preparedness for a significant epidemic, as is going on in other countries, and the deployment of response plans for it, in the country is now taking place to mitigate the impact of the COVID-19 pandemic in the population.

Assessment of the quality of systematic reviews on COVID-19: A comparative study of previous coronavirus outbreaks

Several systematic reviews (SRs) have been conducted on the COVID-19 outbreak, which together with the SRs on previous coronavirus outbreaks, form important sources of evidence for clinical decision and policy making. Here, we investigated the methodological quality of SRs on COVID-19, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). Online searches were performed to obtain SRs on COVID-19, SARS, and MERS. The methodological quality of the included SRs was assessed using the AMSTAR-2 tool. Descriptive statistics were used to present the data. In total, of 49 SRs that were finally included in our study, 17, 16, and 16 SRs were specifically on COVID-19, MERS, and SARS, respectively. The growth rate of SRs on COVID-19 was the highest (4.54/month) presently. Of the included SRs, 6, 12, and 31 SRs were of moderate, low, and critically low quality, respectively. SRs on SARS showed the optimum quality among the SRs on the three diseases. Subgroup analyses showed that the SR topic (P < .001), the involvement of a methodologist (P < .001), and funding support (P = .046) were significantly associated with the methodological quality of the SR. According to the adherence scores, adherence to AMSTAR-2 items sequentially decreased in SRs on SARS, MERS, and COVID-19. The methodological quality of most SRs on coronavirus outbreaks is unsatisfactory, and those on COVID-19 have higher risks of poor quality, despite the rapid actions taken to conduct SRs. The quality of SRs should be improved in the future. Readers must exercise caution in accepting and using the results of these SRs.

Imitation dynamics in the mitigation of the novel coronavirus disease (COVID-19) outbreak in Wuhan, China from 2019 to 2020

Background

The coronavirus disease 2019 (COVID-19) was first identified in Wuhan, China on December 2019 in patients presenting with atypical pneumonia. Although ‘city-lockdown’ policy reduced the spatial spreading of the COVID-19, the city-level outbreaks within each city remain a major concern to be addressed. The local or regional level disease control mainly depends on individuals self-administered infection prevention actions. The contradiction between choice of taking infection prevention actions or not makes the elimination difficult under a voluntary acting scheme, and represents a clash between the optimal choice of action for the individual interest and group interests.

Methods

We develop a compartmental epidemic model based on the classic susceptible-exposed-infectious-recovered model and use this to fit the data. Behavioral imitation through a game theoretical decision-making process is incorporated to study and project the dynamics of the COVID-19 outbreak in Wuhan, China. By varying the key model parameters, we explore the probable course of the outbreak in terms of size and timing under several public interventions in improving public awareness and sensitivity to the infection risk as well as their potential impact.

Results

We estimate the basic reproduction number, R₀, to be 2.5 (95% CI: 2.4−2.7). Under the current most realistic setting, we estimate the peak size at 0.28 (95% CI: 0.24−0.32) infections per 1,000 population. In Wuhan, the final size of the outbreak is likely to infect 1.35% (95% CI: 1.00−2.12%) of the population. The outbreak will be most likely to peak in the first half of February and drop to daily incidences lower than 10 in June 2020. Increasing sensitivity to take infection prevention actions and the effectiveness of infection prevention measures are likely to mitigate the COVID-19 outbreak in Wuhan.

Conclusions

Through an imitating social learning process, individual-level behavioral change on taking infection prevention actions have the potentials to significantly reduce the COVID-19 outbreak in terms of size and timing at city-level. Timely and substantially resources and supports for improving the willingness-to-act and conducts of self-administered infection prevention actions are recommended to reduce to the COVID-19 associated risks.