Ebola virus disease

Holistic One Health Surveillance Framework: Synergizing Environmental, Animal, and Human Determinants for Enhanced Infectious Disease Management

Recent pandemics, including the COVID-19 outbreak, have brought up growing concerns about transmission of zoonotic diseases from animals to humans. This highlights the requirement for a novel approach to discern and address the escalating health threats. The One Health paradigm has been developed as a responsive strategy to confront forthcoming outbreaks through early warning, highlighting the interconnectedness of humans, animals, and their environment. The system employs several innovative methods such as the use of advanced technology, global collaboration, and data-driven decision-making to come up with an extraordinary solution for improving worldwide disease responses. This Review deliberates environmental, animal, and human factors that influence disease risk, analyzes the challenges and advantages inherent in using the One Health surveillance system, and demonstrates how these can be empowered by Big Data and Artificial Intelligence. The Holistic One Health Surveillance Framework presented herein holds the potential to revolutionize our capacity to monitor, understand, and mitigate the impact of infectious diseases on global populations.

Ebola virus disease: A narrative review

Ebola virus disease (EVD), which is also referred to as Ebola hemorrhagic fever, is a highly contagious and frequently lethal sickness caused by the Ebola virus. In 1976, the disease emerged in two simultaneous outbreaks in Sudan and the Democratic Republic of Congo. Subsequently, it has caused intermittent outbreaks in several African nations. The virus is primarily spread via direct contact with the bodily fluids of an infected individual or animal. EVD is distinguished by symptoms such as fever, fatigue, muscle pain, headache, and hemorrhage. The outbreak of EVD in West Africa in 2014-2016 emphasized the need for effective control and prevention measures. Despite advancements and the identification of new treatments for EVD, the primary approach to treatment continues to be centered around providing supportive care. Early detection and supportive care can enhance the likelihood of survival. This includes intravenous fluids, electrolyte replacement, and treatment of secondary infections. Experimental therapies, for instance, monoclonal antibodies and antiviral drugs, have shown promising results in animal studies and some clinical trials. Some African countries have implemented the use of vaccines developed for EVD, but their effectiveness and long-term safety are still being studied. This article provides an overview of the history, transmission, symptoms, diagnosis, treatment, epidemiology, and Ebola coinfection, as well as highlights the ongoing research efforts to develop effective treatments and vaccines to combat this deadly virus.

Government Preparedness Towards Ebola and Covid-19 Health Crises in Ghana

The African continent has witnessed most health crises including yellow fever, meningitis, cholera, and Ebola. Two recent health crises faced by Ghana have been the Ebola virus and the Covid-19 virus diseases. This paper attempts to compare these two crises to understand what preparedness approaches were used by the government of Ghana during these two crises. Also, the paper attempts to identify what the similarities and differences have been and why these similarities and differences existed in the preparedness towards these crises that happened over different periods and whether Ghana’s Covid-19 preparedness was based on lessons from Ebola. Through the policy legacies analytical framework and a review of the literature, the paper argues that Ghana’s preparedness shows a lot of similarities from the training of healthcare workers, the health infrastructure introduced, approaches to public engagement, and political decisions made to fight both crises.

Community engagement in Ebola outbreaks in sub-Saharan Africa and implications for COVID-19 control: A scoping review

OBJECTIVES

There is a paucity of scoping data on the specific roles community engagement played in preventing and managing the Ebola virus disease (EVD) outbreak in sub-Saharan Africa. We assessed the role, benefits, and mechanisms of community engagement to understand its effect on EVD case detection, survival, and mortality in sub-Saharan Africa. The implications for COVID-19 prevention and control were also highlighted.

METHODS

We searched for articles between 2010 and 2020 in the MEDLINE and Embase databases. The study types included were randomized trials, quasiexperimental studies, observational studies, case series, and reports.

RESULTS

A total of 903 records were identified for screening. A total of 216 articles met the review criteria, 103 were initially selected, and 44 were included in the final review. Our findings show that effective community involvement during the EVD outbreak depended on the survival rates, testimonials of survivors, risk perception, and the inclusion of community leaders. Community-based interventions improved knowledge and attitudes, case findings, isolation efforts, and treatment uptake.

CONCLUSION

Although the studies included in this review were of highly variable quality, findings from this review may provide lessons for the role of community engagement in the COVID-19 pandemic's prevention and control in sub-Saharan Africa.

The concept of one health applied to the problem of zoonotic diseases

Zoonotic diseases are a burden on healthcare systems globally, particularly underdeveloped nations. Numerous vertebrate animals (e.g., birds, mammals and reptiles) serve as amplifier hosts or reservoirs for viral zoonoses. The spread of zoonotic disease is associated with environmental factors, climate change, animal health as well as other human activities including globalization, urbanization and travel. Diseases at the human-animal environment interface (e.g., zoonotic diseases, vector-borne diseases, food/water borne diseases) continue to pose risk to animals and humans with a great significant mortality and morbidity. It is estimated that of 1400 infectious diseases known to affect humans, 60% of them are of animal origin. In addition, 75% of the emerging infectious diseases have a zoonotic nature, worldwide. The one health concept plays an important role in the control and prevention of zoonoses by integrating animal, human, and environmental health through collaboration and communication among osteopaths, wildlife, physicians, veterinarians professionals, public health and environmental experts, nurses, dentists, physicists, biomedical engineers, plant pathologists, biochemists, and others. No one sector, organization, or person can address issues at the animal-human-ecosystem interface alone.

Genome structure and genetic diversity in the Ebola virus

Ebola is a deadly pathogen responsible for Ebola virus disease, first came to prominence in the year 1976. This rapidly evolving virus imposed a serious threat to the human population in the last few decades and also continues to be a probable threat to our race. A better understanding of the virus in terms of its genomic structure is very much needed to develop an effective antiviral therapy against this deadly pathogen. Complete knowledge of its genomic structure and variations will help us and the entire scientific community to design effective therapy in terms of either vaccine development or the development of proper antiviral medicine.

A lateral flow biosensor based on gold nanoparticles detects four hemorrhagic fever viruses

The pathogen of viral hemorrhagic fever (VHF), which is harmful to human health, is a hemorrhagic fever virus. Clinicians have long needed convenient and sensitive point-of-care rapid diagnostic tests (RDTs) for hemorrhagic fever viruses. Commonly used methods for pathogen detection rely on conventional culture-based tests, antibody-based assays and polymerase chain reaction (PCR)-based techniques. However, these methods are costly, laborious and time-consuming. Herein, we present a simple and sensitive biosensor for the rapid detection of hemorrhagic fever viruses. For this assay, we develop lateral flow biosensors (LFBs) based on magnetic beads and nicking enzyme-assisted isothermal strand-displacement amplification (SDA) for the detection of hemorrhagic fever viruses. The detection limit of this assay is 10 fM.

Molecular characterization, pathogen-host interaction pathway and in silico approaches for vaccine design against COVID-19

COVID-19 has forsaken the world because of extremely high infection rates and high mortality rates. At present we have neither medicine nor vaccine to prevent this pandemic. Lockdowns, curfews, isolations, quarantines, and social distancing are the only ways to mitigate their infection. This is badly affecting the mental health of people. Hence, there is an urgent need to address this issue. Coronavirus disease 2019 (COVID-19) is caused by a novel Betacorona virus named SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) which has emerged in the city of Wuhan in China and declared a pandemic by WHO since it affected almost all the countries the world, infected 24,182,030 people and caused 825,798 death as per data are compiled from John Hopkins University (JHU). The genome of SARS-CoV-2 has a single-stranded positive (+) sense RNA of ∼30 kb nucleotides. Phylogenetic analysis reveals that SARS-CoV-2 shares the highest nucleotide sequence similarity (∼79 %) with SARS-CoV. Envelope and nucleocapsids are two evolutionary conserved regions of SARS-CoV-2 having a sequence identity of about 96 % and 89.6 %, respectively as compared to SARS-CoV. The characterization of SARS-CoV-2 is based on polymerase chain reaction (PCR) and metagenomic next-generation sequencing. Transmission of this virus in the human occurs through the respiratory tract and decreases the respiration efficiency of lungs. Humans are generally susceptible to SARS-CoV-2 with an incubation period of 2-14 days. The virus first infects the lower airway and bind with angiotensin-converting enzyme 2 (ACE2) of alveolar epithelial cells. Due to the unavailability of drugs or vaccines, it is very urgent to design potential vaccines or drugs for COVID-19. Reverse vaccinology and immunoinformatic play an important role in designing potential vaccines against SARS-CoV-2. The suitable vaccine selects for SARS-CoV-2 based on binding energy between the target protein and the designed vaccine. The stability and activity of the designed vaccine can be estimated by using molecular docking and dynamic simulation approaches. This review mainly focused on the brief up to date information about COVID-19, molecular characterization, pathogen-host interaction pathways involved during COVID-19 infection. It also covers potential vaccine design against COVID-19 by using various computational approaches. SARS-CoV-2 enters brain tissue through the different pathway and harm human's brain and causes severe neurological disruption.

Ebola Virus Dose Response Model for Aerosolized Exposures: Insights from Primate Data

This study develops dose-response models for Ebolavirus using previously published data sets from the open literature. Two such articles were identified in which three different species of nonhuman primates were challenged by aerosolized Ebolavirus in order to study pathology and clinical disease progression. Dose groups were combined and pooled across each study in order to facilitate modeling. The endpoint of each experiment was death. The exponential and exact beta-Poisson models were fit to the data using maximum likelihood estimation. The exact beta-Poisson was deemed the recommended model because it more closely approximated the probability of response at low doses though both models provided a good fit. Although transmission is generally considered to be dominated by person-to-person contact, aerosolization is a possible route of exposure. If possible, this route of exposure could be particularly concerning for persons in occupational roles managing contaminated liquid wastes from patients being treated for Ebola infection and the wastewater community responsible for disinfection. Therefore, this study produces a necessary mathematical relationship between exposure dose and risk of death for the inhalation route of exposure that can support quantitative microbial risk assessment aimed at informing risk mitigation strategies including personal protection policies against occupational exposures.

Cutaneous manifestations of viral outbreaks

As the world tries to grapple with the COVID-19 pandemic, dermatologists are left in a lurch as there is a lacuna in dermatologic literature as well as training regarding the cutaneous manifestations of varied viral agents capable of causing epidemics/pandemics or the potential to be bio-weaponised. Such outbreaks have the potential to become a pandemic given this age of globalisation. The quote by George Santayana stands true 'Those who cannot remember the past are condemned to repeat it'. Thus, this article lends a perspective to the recent viral outbreaks and is aimed at summarising these agents and their clinical features to serve as a quick reference for dermatologists.

Ebola in the Eastern Democratic Republic of Congo: One Health approach to infectious disease control

The Democratic Republic of Congo (DRC) is facing its tenth outbreak of Ebola virus disease (EVD), in North-Kivu and Ituri provinces. This is the second most deadly EVD outbreak in history, after the one that occurred in West Africa in 2014. The DRC Ministry of Health (MoH), supported by the World Health Organization (WHO) and a range of regional and international partners, are implementing EVD response plans in these affected areas such as screening of suspect cases at points of entry, case detection, contact tracing, laboratory testing, case management and infection prevention and control, safe and dignified burials, ring vaccination (this involves vaccination of infected individuals, direct contacts of infected individuals and contacts of their contacts), and therapeutics, community mobilization and free access to healthcare services. Despite these efforts, there has been a sharp rise in the number of confirmed cases within the identified affected areas, and due to a number of challenges unique to DRC, there has been an expansion in the geographical extent of transmission. The significance of the proximity of these regions to wildlife and the Virunga National Park is questionable in the EVD transmission dynamics. The close interaction between human, animal, and environmental factors, in combination with high population movement due to regular rebel attacks in these regions, suggest the need for the integration of the One Health approach in the holistic response plans for control and prevention of EVD. This paper seeks to highlight the implications and importance of a One Health–based approach into the infectious diseases control program implementation in DRC.

Kidney Diseases Associated With Parvovirus B19, Hanta, Ebola, and Dengue Virus Infection: A Brief Review

Viral infection-associated kidney diseases are an emerging public health issue in both developing and developed countries. Many new viruses have emerged with new paradigms of kidney injury, either directly through their cytopathic effect or indirectly through immune-mediated glomerulopathy, tubulointerstitial disease, and acute kidney injury as part of multiorgan failure. Herein, we will discuss Parvovirus, which causes glomerulopathy, and Hanta, Ebola, and Dengue viruses, which cause viral hemorrhagic fever and acute kidney injury. Clinical manifestations also depend on extrarenal organ systems involved. Diagnosis of these viral infections is mainly based on a high index of suspicion, serologic testing, and isolation of viral DNA/RNA. Management is largely conservative, as specific antiviral agents are unavailable.

A conserved transcriptional response to intranasal Ebola virus exposure in nonhuman primates prior to onset of fever

Ebola virus disease (EVD), caused by Ebola virus (EBOV), is a severe illness characterized by case fatality rates of up to 90%. The sporadic nature of outbreaks in resource-limited areas has hindered the ability to characterize the pathogenesis of EVD at all stages of infection but particularly early host responses. Pathogenesis is often studied in nonhuman primate (NHP) models of disease that replicate major aspects of human EVD. Typically, NHP models use a large infectious dose, are carried out through intramuscular or aerosol exposure, and have a fairly uniform disease course. By contrast, we report our analysis of the host response to EBOV after intranasal exposure. Twelve cynomolgus macaques were infected with 100 plaque-forming units of EBOV/Makona through intranasal exposure and presented with varying times to onset of EVD. We used RNA sequencing and a newly developed NanoString CodeSet to monitor the host response via changes in RNA transcripts over time. When individual animal gene expression data were phased based on the onset of sustained fever, the first clinical sign of severe disease, mathematical models indicated that interferon-stimulated genes appeared as early as 4 days before fever onset. This demonstrates that lethal EVD has a uniform and predictable response to infection regardless of time to onset. Furthermore, expression of a subset of genes could predict disease development before other host-based indications of infection such as fever.

Recent loss of closed forests is associated with Ebola virus disease outbreaks

Ebola virus disease (EVD) is a contagious, severe and often lethal form of hemorrhagic fever in humans. The association of EVD outbreaks with forest clearance has been suggested previously but many aspects remained uncharacterized. We used remote sensing techniques to investigate the association between deforestation in time and space, with EVD outbreaks in Central and West Africa. Favorability modeling, centered on 27 EVD outbreak sites and 280 comparable control sites, revealed that outbreaks located along the limits of the rainforest biome were significantly associated with forest losses within the previous 2 years. This association was strongest for closed forests (>83%), both intact and disturbed, of a range of tree heights (5–>19 m). Our results suggest that the increased probability of an EVD outbreak occurring in a site is linked to recent deforestation events, and that preventing the loss of forests could reduce the likelihood of future outbreaks.

Host Transcriptional Response to Ebola Virus Infection

Ebola virus disease (EVD) is a serious illness that causes severe disease in humans and non-human primates (NHPs) and has mortality rates up to 90%. EVD is caused by the Ebolavirus and currently there are no licensed therapeutics or vaccines to treat EVD. Due to its high mortality rates and potential as a bioterrorist weapon, a better understanding of the disease is of high priority. Multiparametric analysis techniques allow for a more complete understanding of a disease and the host response. Analysis of RNA species present in a sample can lead to a greater understanding of activation or suppression of different states of the immune response. Transcriptomic analyses such as microarrays and RNA-Sequencing (RNA-Seq) have been important tools to better understand the global gene expression response to EVD. In this review, we outline the current knowledge gained by transcriptomic analysis of EVD.

Spatial Determinants of Ebola Virus Disease Risk for the West African Epidemic

INTRODUCTION

Although many studies have investigated the probability of Ebola virus disease (EVD) outbreaks while other studies have simulated the size and speed of EVD outbreaks, few have investigated the environmental and population-level predictors of Ebola transmission once an outbreak is underway. Identifying strong predictors of transmission could help guide and target limited public health resources during an EVD outbreak. We examined several environmental and population-level demographic predictors of EVD risk from the West African epidemic.

METHODS

We obtained district-level estimates from the World Health Organization EVD case data, demographic indicators obtained from the Demographic and Health surveys, and satellite-derived temperature, rainfall, and land cover estimates. A Bayesian hierarchical Poisson model was used to estimate EVD risk and to evaluate the spatial variability explained by the selected predictors.

RESULTS

 We found that districts had greater risk of EVD with increasing proportion of households not possessing a radio (RR 2.79, 0.90-8.78; RR 4.23, 1.16-15.93), increasing rainfall (RR 2.18; 0.66-7.20; 5.34, 1.20-23.90), and urban land cover (RR 4.87, 1.56-15.40; RR 5.74, 1.68-19.67).

DISCUSSION

 The finding of radio ownership and reduced EVD transmission risk suggests that the use of radio messaging for control and prevention purposes may have been crucial in reducing the EVD transmission risk in certain districts, although this association requires further study. Future research should examine the etiologic relationships between the identified risk factors and human-to-human transmission of EVD with a focus on factors related to population mobility and healthcare accessibility, which are critical features of epidemic propagation and control.

The predictor of mortality outcome in adult patients with Ebola virus disease during the 2014-2015 outbreak in Guinea

The purpose of this study was to examine the association of any demographic and clinical factors with mortality outcome among adult patients with Ebola virus disease (EVD) in Guinea. This retrospective observational study analyzed medical records of laboratory confirmed EVD adult patients during the 2014-2015 EVD outbreak in Guinea. The associations between any demographic or clinical variables and mortality outcome of EVD were assessed using univariate and multivariate logistic regression analyses. Of 2,310 EVD adult patients included for analysis, the overall case fatality rate was 68.1%. Univariate analyses identified factors possibly associated with mortality outcome, including patient age (p < 0.001), history of visiting or close contact with a suspected or confirmed EVD patient (p = 0.035), and seven clinical symptoms on admission, i.e., fever (p = 0.003), hiccups (p < 0.001), vomiting (p = 0.003), diarrhea (p < 0.001), cough (p = 0.001), sore throat (p = 0.016), and unexplained bleeding (p = 0.021). The multivariate analysis showed that patient age was independently associated with mortality outcome of EVD (OR = 1.06; 95%CI = 1.03-1.09; p < 0.001), while none the of clinical symptoms on admission were significantly associated with the mortality outcome. Our analysis indicates that older age was the only independent factor associated with death among EVD adult patients in Guinea. This suggests that older EVD patients should receive intensive medical care and be carefully monitored.

Knowledge and attitude regarding Ebola virus disease among medical students of Rawalpindi: A preventable threat not yet confronted

OBJECTIVE

To assess the knowledge and attitude regarding Ebola virus disease (EVD) among medical students of Rawalpindi.

METHODS

A descriptive cross sectional study was carried out in a medical college of Rawalpindi from September 2014-November 2014. About 400 students were inducted with 77% (n=308) response rate. After taking informed verbal consent from students and administration, a pre-designed and pre-tested questionnaire was circulated among students of third, fourth and final year MBBS as well as third and fourth year BDS. The data collected was entered and analyzed using SPSS 20.

RESULTS

The response rate was 77% (308/400). About 244 (79.2%) of students had heard about EVD before. One hundred and sixty four (53.2%) of the students correctly identified that no treatment is available for EVD as yet. Also 163 (52.9%) said that no vaccine was available against the virus either. Washing hands every time after touching a patient in clinics/wards was important for 151 (49.0%) while 223 (72.4%) claimed to use proper techniques to dispose off used injections.

CONCLUSION

Students have basic knowledge regarding EVD. However, there is deficient information regarding the diagnosis and precautionary measures required to control it.

Ebola virus disease epidemic in West Africa: lessons learned and issues arising from West African countries

The current Ebola virus disease (EVD) outbreak ravaging three nations in West Africa has affected more than 14,000 persons and killed over 5,000. It is the longest and most widely spread Ebola epidemic ever seen. At the time of this overview (written November 2014), having affected eight different nations, Nigeria and Senegal were able to control and eliminate the virus within a record time. Ghana has successfully, to date, kept the virus away from the country, despite economic and social relationships with affected nations. What lessons can we learn from Nigeria, Senegal and Ghana in the current epidemic? How can the world improve the health systems in low- and middle-income countries to effectively manage future outbreaks? Recently, the Royal College of Physicians launched a new partnership with the West African College of Physicians to curtail the effects of HIV/AIDS, malaria and tuberculosis in the region. We believe that strengthened health systems, skilled human resources for health and national ownership of problems are key to effective management of outbreaks such as EVD.

Ebola Hemorrhagic Fever as a Public Health Emergency of International Concern; a Review Article

Ebola hemorrhagic fever (EHF) was first reported in 1976 with two concurrent outbreaks of acute viral hemorrhagic fever centered in Yambuku (near the Ebola river), Democratic Republic of Congo, and in Nzara, Sudan. The current outbreak of the Ebola virus was started by reporting the first case in March 2014 in the forest regions of southeastern Guinea. Due to infection rates raising over 13,000% within a 6-month period, Ebola is now considered as a global public health emergency and on August 8(th), 2014 the World Health Organization (WHO) declared the epidemic to be a Public Health Emergency of International Concern. With more than 5000 involved cases and nearly 3000 deaths, this event has turned into the largest and most dangerous Ebola virus outbreak in the world. Based on the above-mentioned, the present article aimed to review the virologic characteristics, transmission, clinical manifestation, diagnosis, treatment, and prevention of Ebola virus disease.