Ebola virus: a clear and present danger

Revolutionizing viral disease vaccination: the promising clinical advancements of non-replicating mRNA vaccines

The mRNA vaccine technology was developed rapidly during the global pandemic of COVID-19. The crucial role of the COVID-19 mRNA vaccine in preventing viral infection also have been beneficial to the exploration and application of other viral mRNA vaccines, especially for non-replication structure mRNA vaccines of viral disease with outstanding research results. Therefore, this review pays attention to the existing mRNA vaccines, which are of great value for candidates for clinical applications in viral diseases. We provide an overview of the optimization of the mRNA vaccine development process as well as the good immune efficacy and safety shown in clinical studies. In addition, we also provide a brief description of the important role of mRNA immunomodulators in the treatment of viral diseases. After that, it will provide a good reference or strategy for research on mRNA vaccines used in clinical medicine with more stable structures, higher translation efficiency, better immune efficacy and safety, shorter production time, and lower production costs than conditional vaccines to be used as preventive or therapeutic strategy for the control of viral diseases in the future.

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.

The Need for Dedicated Microbiology Leadership in the Clinical Microbiology Laboratory

Clinical microbiology laboratories play a crucial role in patient care using traditional and innovative diagnostics. Challenges faced by laboratories include emerging pathogens, rapidly evolving technologies, health care-acquired infections, antibiotic-resistant organisms, and diverse patient populations. Despite these challenges, many clinical microbiology laboratories in the United States are not directed by doctoral level microbiology-trained individuals with sufficient time dedicated to laboratory leadership. The manuscript highlights the need for medical microbiology laboratory directors with appropriate training and qualifications.

Structural risk analysis of a potential Ebola outbreak with respect to infrastructural aspects amid the current COVID-19 pandemic

Due to the ease and increased volume of global interaction, it remains unclear whether the current coronavirus disease (COVID-19) pandemic will be a one-off event or whether the world is at risk of recurrent pandemics as a result of globalization. To address this important issue, the present study assessed the risk of a possible future Ebola pandemic. The risk profile of Hubei province in China was compared with that of the Democratic Republic of Congo (DRC) in terms of travel and infrastructure, since DRC is considered a major epicenter for Ebola outbreaks. Recurrence patterns of previous Ebola outbreaks were analyzed in a cumulative outbreak model. Internationally available data on air traffic, flight destinations, passenger numbers, population density, distribution and domestic traffic routes were all analyzed and compared between the DRC and Hubei province. DRC is a major epicenter for Ebola outbreaks, with 13 recorded outbreaks from 1976 until 2020. International airports at both Kinshasa, the capital city of the DRC and Wuhan, the capital city of Hubei province, are heavily frequented destinations and represent major transfer hubs on their respective continents. Volumes of flights to and from extracontinental destinations account for <25% of total flights at both airports with similar total international passenger volumes. However, the volume of domestic commuting by aviation is >30-fold higher at Hubei province compared with that of the DRC. This finding is also reflected by the higher population density and homogeneity in terms of population per square kilometer in Hubei. Following the analysis of decades of Ebola reports, it became evident that the DRC remains a hotspot for potential Ebola outbreaks in the future due to constantly recurrent local outbreaks. In terms of the international aviation network, numerous important similarities between Kinshasa and Hubei Province were observed as regards connectivity. The present comparative analysis extends beyond biological factors underlying Ebola and COVID-19 transmissions and confirms that the DRC, Kinshasa in particular, is not a remote location. Although internal commuting and population density may be lower in the DRC compared with those in Hubei province, integration into the international aviation network is similarly extensive. The international community must increase its focus and efforts in preventing another possible global pandemic commencing in Africa, and in particular the DRC.

Contact Transmission of Vaccinia to an Infant Diagnosed by Viral Culture and Metagenomic Sequencing

Targeted molecular diagnostic tests and accurate immunoassays have transformed the landscape of clinical virology, calling into question the usefulness of traditional viral culture. Here we present a case where viral culture, followed by metagenomic sequencing, was central to the diagnosis of an unexpected viral infection, with significant clinical and public health implications.

Staufen1 Interacts with Multiple Components of the Ebola Virus Ribonucleoprotein and Enhances Viral RNA Synthesis

Ebola virus (EBOV) is a negative-strand RNA virus with significant public health importance. Currently, no therapeutics are available for Ebola, which imposes an urgent need for a better understanding of EBOV biology. Here we dissected the virus-host interplay between EBOV and host RNA-binding proteins. We identified novel EBOV host factors, including Staufen1, which interacts with multiple viral factors and is required for efficient viral RNA synthesis.

Ebola virus (EBOV) genome and mRNAs contain long, structured regions that could hijack host RNA-binding proteins to facilitate infection. We performed RNA affinity chromatography coupled with mass spectrometry to identify host proteins that bind to EBOV RNAs and identified four high-confidence proviral host factors, including Staufen1 (STAU1), which specifically binds both 3′ and 5′ extracistronic regions of the EBOV genome. We confirmed that EBOV infection rate and production of infectious particles were significantly reduced in STAU1-depleted cells. STAU1 was recruited to sites of EBOV RNA synthesis upon infection and enhanced viral RNA synthesis. Furthermore, STAU1 interacts with EBOV nucleoprotein (NP), virion protein 30 (VP30), and VP35; the latter two bridge the viral polymerase to the NP-coated genome, forming the viral ribonucleoprotein (RNP) complex. Our data indicate that STAU1 plays a critical role in EBOV replication by coordinating interactions between the viral genome and RNA synthesis machinery.

Computer-Aided Discovery and Characterization of Novel Ebola Virus Inhibitors

The Ebola virus (EBOV) causes severe human infection that lacks effective treatment. A recent screen identified a series of compounds that block EBOV-like particle entry into human cells. Using data from this screen, quantitative structure-activity relationship models were built and employed for virtual screening of a ∼17 million compound library. Experimental testing of 102 hits yielded 14 compounds with IC₅₀ values under 10 μM, including several sub-micromolar inhibitors, and more than 10-fold selectivity against host cytotoxicity. These confirmed hits include FDA-approved drugs and clinical candidates with non-antiviral indications, as well as compounds with novel scaffolds and no previously known bioactivity. Five selected hits inhibited BSL-4 live-EBOV infection in a dose-dependent manner, including vindesine (0.34 μM). Additional studies of these novel anti-EBOV compounds revealed their mechanisms of action, including the inhibition of NPC1 protein, cathepsin B/L, and lysosomal function. Compounds identified in this study are among the most potent and well-characterized anti-EBOV inhibitors reported to date.

Chiroptera

With over 1200 species identified, bats represent almost one quarter of the world’s mammals. Bats provide crucial environmental services, such as insect control and pollination, and inhabit a wide variety of ecological niches on all continents except Antarctica. Despite their ubiquity and ecological importance, relatively little has been published on diseases of bats, while much has been written on bats’ role as reservoirs in disease transmission. This chapter will focus on diseases and pathologic processes most commonly reported in captive and free-ranging bats. Unique anatomical and histological features and common infectious and non-infectious diseases will be discussed. As recognition of both the importance and vulnerability of bats grows, particularly following population declines in North America due to the introduction of the fungal disease white-nose syndrome, efforts should be made to better understand threats to the health of this unique group of mammals.

Contrasting academic and lay press print coverage of the 2013-2016 Ebola Virus Disease outbreak

Under a traditional paradigm, only those with the expected background knowledge consume academic literature. The lay press, as well as government and non-government agencies, play a complementary role of extracting findings of high interest or importance and translating them for general viewing. The need for accurate reporting and public advising is paramount when attempting to tackle epidemic outbreaks through behavior change. Yet, public trust in media outlets is at a historic low. The Crisis and Emergency Risk Communication (CERC) model for media reporting on public health emergencies was established in 2005 and has subsequently been used to analyze media reporting on outbreaks of influenza and measles as well as smoking habits and medication compliance. However, no media analysis had yet been performed on the 2013–2016 Ebola Virus Disease (EVD) outbreak. This study compared the EVD information relayed by lay press sources with general review articles in the academic literature through a mixed-methods analysis. These findings suggest that comprehensive review articles could not serve as a source to clarify and contextualize the uncertainties around the EVD outbreak, perhaps due to adherence to technical accuracy at the expense of clarity within the context of outbreak conditions. This finding does not imply inferiority of the academic literature, nor does it draw direct causation between confusion in review articles and public misunderstanding. Given the erosion of the barriers siloing academia, combined with the demands of today’s fast-paced media environment, contemporary researchers should realize that no study is outside the public forum and to therefore consider shifting the paradigm to take personal responsibility in the process of accurately translating their scientific words into public policy actions to best serve as a source of clarity.

Understanding Ebola: the 2014 epidemic

Near the end of 2013, an outbreak of Zaire ebolavirus (EBOV) began in Guinea, subsequently spreading to neighboring Liberia and Sierra Leone. As this epidemic grew, important public health questions emerged about how and why this outbreak was so different from previous episodes. This review provides a synthetic synopsis of the 2014-15 outbreak, with the aim of understanding its unprecedented spread. We present a summary of the history of previous epidemics, describe the structure and genetics of the ebolavirus, and review our current understanding of viral vectors and the latest treatment practices. We conclude with an analysis of the public health challenges epidemic responders faced and some of the lessons that could be applied to future outbreaks of Ebola or other viruses.

Towards detection and diagnosis of Ebola virus disease at point-of-care

Ebola outbreak-2014 (mainly Zaire strain related Ebola virus) has been declared most widely spread deadly persistent epidemic due to unavailability of rapid diagnostic, detection, and therapeutics. Ebola virus disease (EVD), a severe viral hemorrhagic fever syndrome caused by Ebola virus (EBOV) is transmitted by direct contact with the body fluids of infected person and objects contaminated with virus or infected animals. World Health Organization (WHO) has declared EVD epidemic as public health emergency of international concern with severe global economic burden. At fatal EBOV infection stage, patients usually die before the antibody response. Currently, rapid blood tests to diagnose EBOV infection include the antigen or antibodies capture using ELISA and RNA detection using RT/Q-PCR within 3-10 days after the onset of symptoms. Moreover, few nanotechnology-based colorimetric and paper-based immunoassay methods have been recently reported to detect Ebola virus. Unfortunately, these methods are limited to laboratory only. As state-of-the art (SoA) diagnostics time to confirm Ebola infection, varies from 6h to about 3 days, it causes delay in therapeutic approaches. Thus developing a cost-effective, rapid, sensitive, and selective sensor to detect EVD at point-of-care (POC) is certainly worth exploring to establish rapid diagnostics to decide therapeutics. This review highlights SoA of Ebola diagnostics and also a call to develop rapid, selective and sensitive POC detection of EBOV for global health care. We propose that adopting miniaturized electrochemical EBOV immunosensing can detect virus level at pM concentration within ∼40min compared to 3 days of ELISA test at nM levels.

Early Viral Entry Assays for the Identification and Evaluation of Antiviral Compounds

Cell-based systems are useful for discovering antiviral agents. Dissecting the viral life cycle, particularly the early entry stages, allows a mechanistic approach to identify and evaluate antiviral agents that target specific steps of the viral entry. In this report, the methods of examining viral inactivation, viral attachment, and viral entry/fusion as antiviral assays for such purposes are described, using hepatitis C virus as a model. These assays should be useful for discovering novel antagonists/inhibitors to early viral entry and help expand the scope of candidate antiviral agents for further drug development.

Ebola Virus Disease: Rapid Diagnosis and Timely Case Reporting are Critical to the Early Response for Outbreak Control

Ebola virus disease (EVD) is a life-threatening zoonosis caused by infection with the Ebola virus. Since the first reported EVD outbreak in the Democratic Republic of the Congo, several small outbreaks have been reported in central Africa with about 2,400 cases occurring between 1976 and 2013. The 2013-2015 EVD outbreak in west Africa is the first documented outbreak in this region and the largest ever with over 27,000 cases and more than 11,000 deaths. Although EVD transmission rates have recently decreased in west Africa, this crisis continues to threaten global health and security, particularly since infected travelers could spread EVD to other resource-limited areas of the world. Because vaccines and drugs are not yet licensed for EVD, outbreak control is dependent on the use of non-pharmaceutical interventions (e.g., infection control practices, isolation of EVD cases, contact tracing with follow-up and quarantine, sanitary burial, health education). However, delays in diagnosing and reporting EVD cases in less accessible rural areas continue to hamper control efforts. New advances in rapid diagnostics for identifying presumptive EVD cases and in mobile-based technologies for communicating critical health-related information should facilitate deployment of an early response to prevent the amplification of sporadic EVD cases into large-scale outbreaks.

Ebola: a review for emergency providers

Filoviruses, including Ebola virus, are associated with outbreaks of severe febrile illness with high fatality rates in humans. The 2014 outbreak of Ebola virus in West Africa is by far the largest outbreak in history and the first to spread to highly populated urban areas. The potential for such an epidemic to spread beyond Africa through international travel has raised concern in the world community as well as in American and international health agencies. This article presents background information, personal and public protective strategies, and treatment recommendations for emergency physicians.

One-Step Reverse-Transcription FRET-PCR for Differential Detection of Five Ebolavirus Species

Ebola is an emerging infectious disease caused by a deadly virus belonging to the family Filoviridae, genus Ebolavirus. Based on their geographical distribution, Ebolavirus has been classified into total five species so far, mainly Zaire, Sudan, Taï Forest, Bundibugyo and Reston. It is important to be able to differentiate the Ebolavirus species as they significantly differ in pathogenicity and more than one species can be present in an area. We have developed a one-step step-down RT-PCR detecting all five Ebolavirus species with high sensitivity (1 copy of Ebolavirus DNA, 10 copies of RNA and 320 copies of RNA spiked in 1 ml whole blood). The primers and FRET-probes we designed enabled us to differentiate five Ebolavirus species by distinct T_m (Zaire: flat peaks between 53.0°C and 56.9°C; Sudan: 51.6°C; Reston: flat peaks between 47.5°C and 54.9°C; Tai Forest: 52.8°C; Bundibugyo: dual peaks at 48.9°C and 53.5°C), and by different amplicon sizes (Zaire 255bp, Sudan 211bp, Reston 192bp, Taï Forest 166bp, Bundibugyo 146bp). This one-size-fit-all assay enables the rapid detection and discrimination of the five Ebolavirus species in a single reaction.