Ebola Research Articles

Mathematical Modeling and Analysis of Ebola Virus Disease Dynamics: Implications for Intervention Strategies and Healthcare Resource Optimization

Mathematical Modeling and Analysis of Ebola Virus Disease Dynamics: Implications for Intervention Strategies and Healthcare Resource Optimization

Modeling Ebola Dynamics with a Φ-Piecewise Hybrid Fractional Derivative Approach

Ebola virus disease (EVD) is a severe and often fatal illness posing significant public health challenges. This study investigates EVD transmission dynamics using a novel fractional mathematical model with five distinct compartments: individuals with low susceptibility (S1), individuals with high susceptibility (S2), infected individuals (I), exposed individuals (E), and recovered individuals (R). To capture the complex dynamics of EVD, we employ a Φ-piecewise hybrid fractional derivative approach. We investigate the crossover effect and its impact on disease dynamics by dividing the study interval into two subintervals and utilize the Φ-Caputo derivative in the first interval and the Φ-ABC derivative in the second interval. The study determines the basic reproduction number R0, analyzes the stability of the disease-free equilibrium and investigates the sensitivity of the parameters to understand how variations affect the system’s behavior and outcomes. Numerical simulations support the model and demonstrate consistent results with the theoretical analysis, highlighting the importance of fractional calculus in modeling infectious diseases. This research provides valuable information for developing effective control strategies to combat EVD.

Community perspectives of Ebola Viral Disease in high-risk transmission border regions of Tanzania: a qualitative inquiry

BackgroundTanzania faces ever-rising concerns due to the recurrence of the Ebola Virus Disease (EVD) in neighbouring Democratic Republic of Congo (DRC) and Uganda. This necessitates a better understanding of the community perspectives in high-risk regions for effective risk communication and preparedness.MethodsThis rapid ethnographic assessment study used explorative qualitative methods to collect data. People from diverse backgrounds participated in 59 in-depth interviews, 57 Key Informant interviews, and 35 focus group discussions. Data was analysed using a thematic analysis approach.FindingThe study revealed existence of awareness of EVD and its symptoms, with radio and television being the main sources of information. However, there were varied perceptions of EVD’s cause and transmission, some attributed it to bats, monkeys, and wild animal meat, while others associated it with high fever, a dirty environment, changing dietary patterns, and the COVID-19 virus. Physical contact with an infected person’s body fluids and eating meat from infected animals were perceived as EVD transmission routes. Women, school children, boda-boda (motorcycle) riders, and fishermen were considered the most susceptible to EVD infections due to their daily activities. Preventive measures included avoiding physical contact, touching fluids, and refraining from eating wild animal meat. Prompt reporting of suspected cases to health facilities was deemed crucial for earlier outbreak identification and containment.ConclusionThe high-risk regions of Tanzania had a high level of awareness and perceived susceptibility to EVD, coupled with varying degrees of misperception about the etiology and its transmission. To improve community perspectives and preparedness in the case of an outbreak, there is a need for ongoing risk communication and participation in EVD prevention and responses.

Impact of Ebola Virus Disease and ECOWAS Membership on Intra-Regional Trade in West Africa

The West African sub-region bore the brunt of the world's largest Ebola outbreak, significantly impacting the economic activities and trade shares of the affected countries. This study seeks to examine the repercussions of the Ebola Virus Disease (EVD) on the trade shares of affected countries and to explore the potential influence of ECOWAS membership on intra-regional trade in West Africa. Using the Poison Pseudo Maximum Likelihood (PPML) estimation technique, an analysis of the augmented gravity model of international trade was conducted. The findings indicate a two-fold reduction in the trade shares of affected countries with their intra-regional partners due to the Ebola Virus Disease. Additionally, with Mauritania expressing its desire to join the ECOWAS sub-region, there is a need to explore the impact of the Regional Economic Community on intra-regional trade. Furthermore, the study reveals that ECOWAS membership has the potential to double trade levels in West Africa. The findings also suggest that Mauritania stands to gain significant benefits from becoming a member of the ECOWAS. In conclusion, this study highlights the necessity for ECOWAS to proactively respond to disease outbreaks and underscores the importance of increased research investment. Moreover, it emphasizes the need for the ECOWAS to further improve infrastructure to facilitate intra-regional trade, especially in transportation.

The Role of Community Beliefs and Practices on the Spread of Ebola in Uganda, September 2022.

On September 20, 2022, Uganda declared an Sudan Virus Disease (SVD) outbreak in Mubende District. Another eight districts were infected September-November 2022. We examined how Ugandan community beliefs and practices spread Sudan Ebola Virus (SUDV) in 2022. A qualitative study was conducted in Mubende, Kassanda, and Kyegegwa districts in February 2023. Nine focus group discussions and six key informant interviews were held. We investigated whether community beliefs and practices contributed to spreading Sudan Ebola Virus (SUDV). Interviews were recorded, translated, transcribed, and thematically analyzed. The community deaths, later found to be due to Sudan Virus Disease(SVD), were often attributed to witchcraft or poisoning. Key informants reported that SVD patients often sought traditional healers or spiritual leaders before or after formal healthcare failed. They also found that traditional healers treated SVD patients without precautions. Religious leaders praying for SVD patients and their symptomatic contacts, SVD patients hiding in friends' homes, and exhuming SVD patients from safe and dignified burials to allow traditional burials were other themes. Diversity in community beliefs and culture likely contributed to spreading the 2022 Ugandan SVD outbreak. Public health systems, traditional healers, and religious leaders can help Uganda control ebolavirus outbreaks by identifying socially acceptable and scientifically supported infection control methods.

Global burden of viral infectious diseases of poverty based on Global Burden of Diseases Study 2021.

Viral infectious diseases of poverty (vIDPs) remain a significant global health challenge. Despite their profound impact, the burden of these diseases is not comprehensively quantified. This study aims to analyze the global burden of six major vIDPs, including coronavirus disease 2019 (COVID-19), HIV/AIDS, acute hepatitis, dengue, rabies, and Ebola virus disease (EVD), using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 (GBD 2021). Following the GBD 2021 framework, we analyzed the incidence, mortality, and disability-adjusted life years (DALYs) of the six vIDPs across 204 countries and territories from 1990 to 2021. We examined the association between the Socio-Demographic Index (SDI) and the burden of vIDPs. All estimates were reported as numbers and rates per 100,000 population, calculated using the Bayesian statistical model employed by GBD 2021, with 95% uncertainty intervals (UI). In 2021, vIDPs caused approximately 8.7 million deaths and 259.2 million DALYs, accounting for 12.8% and 9.0% of the global all-cause totals, respectively. Globally, the burden of vIDPs varied significantly: COVID-19 caused around 7.9 million (95% UI: 7.5, 8.4) deaths and 212.0 million (95% UI 197.9, 234.7) DALYs in 2021. Acute hepatitis had the second-highest age-standardized incidence rate, with 3411.5 (95% UI: 3201.8, 3631.3) per 100,000 population, while HIV/AIDS had a high age-standardized prevalence rate, with 483.1 (95% UI: 459.0, 511.4) per 100,000 population. Dengue incidence cases rose from 26.5 million (95% UI: 3.9, 51.9) in 1990 to 59.0 million (95% UI: 15.5, 106.9) in 2021. Rabies, although reduced in prevalence, continued to pose a significant mortality risk. EVD had the lowest overall burden but significant outbreak impacts. Age-standardized DALY rates for vIDPs were significantly negatively correlated with SDI: acute hepatitis (r = -0.8, P < 0.0001), rabies (r = -0.7, P < 0.0001), HIV/AIDS (r = -0.6, P < 0.0001), COVID-19 (r = -0.5, P < 0.0001), dengue (r = -0.4, P < 0.0001), and EVD (r = -0.2, P < 0.005). VIDPs pose major public health challenges worldwide, with significant regional, age, and gender disparities. The results underscore the need for targeted interventions and international cooperation to mitigate the burden of these diseases. Policymakers can use these findings to implement cost-effective interventions and improve health outcomes, particularly in regions with high or increasing burdens.

A Narrative Review on the Pandemic Zoonotic RNA Virus Infections Occurred During the Last 25 Years.

Pandemic zoonotic RNA virus infections have continued to threaten humans and animals worldwide. The objective of this review was to highlight the epidemiology and socioeconomic impacts of pandemic zoonotic RNA virus infections that occurred between 1997 and 2021. Literature search was done from Web of Science, PubMed, Google Scholar and Scopus databases, cumulative case fatalities of individual viral infection calculated, and geographic coverage of the pandemics were shown by maps. Seven major pandemic zoonotic RNA virus infections occurred from 1997 to 2021 and were presented in three groups: The first group consists of highly pathogenic avian influenza (HPAI-H5N1) and swine-origin influenza (H1N1) viruses with cumulative fatality rates of 53.5% and 0.5% in humans, respectively. Moreover, HPAI-H5N1 infection caused 90-100% death in poultry and economic losses of >$10billion worldwide. Similarly, H1N1 caused a serious infection in swine and economic losses of 0.5-1.5% of the Gross Domestic Product (GDP) of the affected countries. The second group consists of severe acute respiratory syndrome-associated coronavirus infection (SARS-CoV), Middle East Respiratory Syndrome (MERS-CoV) and Coronavirus disease 2019 (COVID-19) with case fatalities of 9.6%, 34.3% and 2.0%, respectively in humans; but this group only caused mild infections in animals. The third group consists of Ebola and Zika virus infections with case fatalities of 39.5% and 0.02%, respectively in humans but causing only mild infections in animals. Similar infections are expected in the near future, and hence strict implementation of conventional biosecurity-based measures and development of efficacious vaccines would help minimize the impacts of the next pandemic infection.

Understanding Ethical Concerns Involving Vulnerable Human Participant Populations in Medical Research: Mixed-Method Analysis of Liberian Ebola Survivors' Experiences in PREVAIL I-VII.

Background: As the number of large-scale outbreaks continues to rise worldwide, clinical trials are increasingly engaging disease-affected peoples within the Minority World (nations with over 80% poverty rates). Yet global health research inadequately addresses potential ethical issues of including impoverished, disease-affected populations and their contextual vulnerabilities in medical research. Objective: This paper presents a mixed-method analysis from our 2022 semi-structured survey capturing the experiences of Liberian Ebola Virus Disease (EVD) survivors serving as study participants in the Partnership for Research on Ebola Virus in Liberia (PREVAIL) clinical trials. Methods: Firstly, we conducted an extensive literature review of the scholarship related to biomedical research and ethical standards protecting study participants to inform our survey method and design. Applying a theoretical framework on vulnerability, we then qualitatively explored the survey responses of 19 EVD survivors' perceptions and experiences taking part in PREVAIL, including their expectations, treatment, delivered benefits, and quality of care. We further quantitatively codified their statements for underlying themes of reported negative experiences against standard ethical regulations in biomedical research, conducting a statistical analysis to inform generalizability. Most of the 19 survivors reported facing extreme ongoing vulnerabilities related to their disease status, including physical impairments, psychosocial stress, and socio-economic inequity. Results: Initially, the survivors tended to experience a sense of hope and pride in volunteering for PREVAIL. One in five participants reported benefiting from PREVAIL's regular medical diagnoses. However, most of their survey responses indicated prevalent negative shared experiences, including continually being confused or misinformed of their study participant rights, roles, and benefits; being burdened by heavy participation transaction costs; and repeated incidents of poor treatment and discrimination by PREVAIL staff after initial recruitment. PREVAIL participant satisfaction ranking is negatively correlated with receiving insufficient financial compensation (r = -0.51), extensive time requirements for each medical visit (-0.40), and being poorly treated by clinical staff (-0.67).

Immunogenicity of various variants of Ebola and Marburg virus glycoprotein genes in recombinant adenoviral vectors

INTRODUCTION. Marburg and Ebola viruses cause severe haemorrhagic fever in humans and primates. Currently, there are no licensed prophylactic vaccines that can simultaneously prevent the spread or reduce the severity of both diseases caused by these filoviruses. The development of effective prophylactic vaccines requires studies aimed at selecting the most immunogenic forms of protective antigens.AIM. This study aimed to evaluate humoral immune induction in animals after administration of recombinant adenoviral vectors expressing various forms of Ebola and Marburg virus glycoproteins (GPs).MATERIALS AND METHODS. Samples of recombinant human adenovirus type 5 (rAd5) were obtained using homologous recombination in Escherichia coli, growth in HEK293 cells, and purification by CsCl gradient ultracentrifugation. The resulting rAd5 samples were characterised in terms of their identity (PCR and whole-genome sequencing), the concentration of viral particles (fluorescence spectroscopy), and the concentration of infectious viral particles (TCID50 assay). Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the GP-specific IgG titres in the sera of immunised mice.RESULTS. The authors constructed rAd5 samples, and each construct contained an expression cassette with a GP gene form encoding a full-length GP, a GP without the mucin-like domain, or a GP without both the glycan cap and the mucin-like domain. Each of these forms was studied using the GPs of four filoviruses, including Zaire Ebola virus, Sudan Ebola virus, Bundibugyo Ebola virus, and Marburg virus. Neither of the forms had a critical effect on the rAd5 replicative capacity. Three weeks after immunisation, the highest GP-specific IgG production was induced by the rAd5 samples encoding either the full-length GP or the GP without the mucin-like domain. The GP without both the glycan cap and the mucin-like domain was the least immunogenic antigen regardless of the filovirus species.CONCLUSIONS. The most promising constructs for the development of filovirus vaccines based on recombinant adenoviral vectors are the constructs that include the genes encoding the fulllength GP or the GP without the mucin-like domain.

Screening for Eye Disease in Ebola Virus Disease Survivors: Program Implementation During an Active Outbreak in the North Kivu and Ituri Provinces, Democratic Republic of the Congo.

First identified in the Democratic Republic of the Congo (DRC, formerly Zaire) in 1976, Ebola virus disease (EVD) outbreaks have afflicted thousands of Congolese over the past several decades. The nation's largest outbreak of EVD in 2018-2020 was complicated by security challenges as well as large case numbers across an expansive geographic region. These factors provided challenges for logistical considerations as well as clinical coverage. In conjunction with the EVD survivor care program spearheaded by the Ministry of Health in DRC, the DRC Intitut National de Recherche Biomédicale, (DRC Institut National de Recherche Biomedicale, DRC National Institute of Biomedical Research) and others, we launched a multidimensional effort to provide ophthalmic care to EVD survivors. During the engagement period, 237 EVD survivors were screened, 56% of which were women. The 237 EVD survivors constituted ∼75% of the total EVD survivors who were discharged at the time of the intervention. The mean time from EVD symptom onset to evaluation was 4.6 months ± 1.8 SD (range: 24d to 8.5mo). Ninety-seven (41%) of EVD survivors screened reported ocular symptoms during or after acute illness, such as itchy eyes (49%), eye pain (25%), and tears (24%). Ophthalmic findings, including retinal scarring, active uveitis, dry eye disease, cataracts, and glaucoma, were also identified. The need for continued monitoring and longitudinal care for EVD survivors is evident from the expanding body of literature pertaining to post-acute sequelae, including ophthalmic manifestations. Initiatives for such care should be conducted across and in conjunction with multidisciplinary stakeholders for contextualization and effectiveness.

A public, cross-reactive glycoprotein epitope confounds Ebola virus serology.

Ebola disease (EBOD) in humans is a severe disease caused by at least four related viruses in the genus Orthoebolavirus, most often by the eponymous Ebola virus. Due to human-to-human transmission and incomplete success in treating cases despite promising therapeutic development, EBOD is a high priority in public health research. Yet despite almost 50 years since EBOD was first described, the sources of these viruses remain undefined and much remains to be understood about the disease epidemiology and virus emergence and spread. One important approach to improve our understanding is detection of antibodies that can reveal past human infections. However, serosurveys routinely describe seroprevalences that imply infection rates much higher than those clinically observed. Proposed hypotheses to explain this difference include existence of common but less pathogenic strains or relatives of these viruses, misidentification of EBOD as something else, and a higher proportion of subclinical infections than currently appreciated. The work presented here maps B-cell epitopes in the spike protein of Ebola virus and describes a single epitope that is cross-reactive with an antigen seemingly unrelated to orthoebolaviruses. Antibodies against this epitope appear to explain most of the unexpected reactivity towards the spike, arguing against common but unidentified infections in the population. Importantly, antibodies of cross-reactive donors from within and outside the known EBOD geographic range bound the same epitope. In light of this finding, it is plausible that epitope mapping enables broadly applicable specificity improvements in the field of serology.

Corneal and Conjunctival Abnormalities in a Cohort of Survivors from the Western African Ebola Virus Disease Outbreak

PurposeTo characterize corneal and conjunctival abnormalities (CCAs) and their impact on visual acuity in a cohort of survivors from the Western African Ebola virus disease (EVD) outbreak. DesignA post hoc analysis of 121 patients, who had previously undergone screening for the Ebola Virus Persistence in Ocular Tissues and Fluids study, was performed. MethodsPatients underwent a comprehensive ophthalmic exam at the Lowell and Ruth Gess Eye Hospital in Freetown, Sierra Leone. Demographic (including age, sex, and the number of days spent in the Ebola treatment unit and examination (such as visual acuity, and ocular complications) data were collected and used for the analysis. Visual acuity was either uncorrected or corrected with spectacles. Descriptive and inferential statistical analyses were performed, and a p-value < 0.05 was considered statistically significant. ResultsA total of 242 eyes (121 patients) were included in this study. The mean age was 31.5 ± 16.1 years, and 70% were female. Of 242 eyes, 28 (11.5%) eyes of 15 patients (12.4%) presented with at least one or more corneal or conjunctival abnormalities. Within eyes that demonstrated CCAs, the findings included dry eye (28.6% of eyes), band keratopathy (25% of eyes), and corneal scar (21.4% of eyes). Corneal edema was found in 14.3% of eyes, while pterygium and epithelial bullae were each found in 7.1% of affected eyes. Patients without CCAs had better visual acuity compared to patients with CCAs although the difference was not statistically significant (0.82 ± 1.17 vs 1.01 ± 1.29, p=0.4). A subset of patients with CCAs also reported ocular symptoms including eye pain, light sensitivity, excessive tearing, and blurry vision. ConclusionIn this post hoc analysis, we observed CCAs in 12% of EVD survivors. These findings highlight the potential for corneal and conjunctival sequelae during EVD survivorship and the need for ongoing ophthalmic care for this vulnerable population.

Safety and immunogenicity of a delayed booster dose of the rVSVΔG-ZEBOV-GP vaccine for prevention of Ebola virus disease: a multicentre, open-label, phase 2 randomised controlled trial

rVSVΔG-ZEBOV-GP is the first approved vaccine with clinical efficacy against Ebola virus disease. Although a seroprotective threshold has not been defined for those at occupational risk of exposure, the current vaccine strategy is to attain a sustained high level of antibody titres. The aim of this trial was to explore the effects of delayed boosting upon both the height and duration of antibody titres following primary immunisation. In this open-label phase 2 randomised controlled trial, we compared antibody titres at month 36in participants who had received a homologous booster dose at month 18following primary immunisation with those who had received no booster. From Oct 25, 2016, to Jan 29, 2020, healthy adults aged 18years or older deemed at occupational risk of exposure to Ebola virus due to laboratory work, clinical duties, or travel to an active endemic region were recruited from four hospital clinics in the USA and one hospital clinic in Canada and received primary vaccination with 2×107 plaque-forming unit per mL of VSVΔG-ZEBOV-GP. 18months later, individuals who consented and were still eligible were randomly assigned 1:1 to receive either a homologous booster dose or no booster. Study visits for safety and serial blood collections for antibody titres were done on enrolled participants at months 0, 1, 3, 6, 12, 18, 19, 24, 30, and 36. Through July, 2021, a web-based application was used for randomisation, including assignments with schedules for each of the five sites using mixed permuted blocks. The trial was not masked to participants or site staff. The primary endpoint was a comparison of geometric mean titres (GMTs) of anti-Ebola virus glycoprotein IgG antibody at month 36 (ie, 18months after randomisation) for all randomly assigned participants who completed the 36months of follow-up (primary analysis cohort). Investigators were aware of antibody titres from baseline (enrolment) through month 18but were masked to summary data by randomisation group after month 18. This study is registered with ClinicalTrials.gov (NCT02788227). Of the 248participants who enrolled and received their primary immunisation, 114proceeded to the randomisation step at month 18. The two randomisation groups were balanced: 57participants (24 [42%] of whom were female; median age was 42years [IQR 35-50]) were randomly assigned to the booster group and 57 (24 [42%] of whom were female; median age was 42years [IQR 36-51]) to the no-booster group. Of those randomly assigned, 92participants (45 in the booster group and 47in the no-booster group) completed 36months of follow-up. At 18months after primary immunisation, GMTs in the no-booster group increased from a baseline of 10ELISA units (EU)/mL (95% CI 7-14) to 1451EU/mL (1118-1882); GMTs in the booster group increased from 9EU/mL (6-16) to 1769EU/mL (1348-2321). At month 19, GMTs were 31 408EU/mL (23 181-42 554) for the booster group and 1406EU/mL (1078-1833) for the no-booster group; at month 36, GMTs were 10 146EU/mL (7960-12 933) for the booster group and 1240EU/mL (984-1563) for the no-booster group. Accordingly, the geometric mean ratio (GMR) of antibody titres had increased almost 21-fold more in the booster versus no-booster group at 1month after booster administration (GMR 20·6; 95% CI 18·2-23·0; p<0·0001) and was still over 7-fold higher at month 36 (GMR 7·8; 95% CI 5·5-10·2; p<0·0001). Consistent with previous reports of this vaccine's side-effects, transient mono-articular or oligo-articular arthritis was diagnosed in 18 (9%) of 207primary vaccination recipients; after randomisation, arthritis was diagnosed in one (2%)of 57participants in the no-booster group. No new cases of arthritis developed after booster administration. Four serious adverse events occurred following randomisation: one (epistaxis) in the booster group and three (gastrointestinal haemorrhage, prostate cancer, and tachyarrhythmia) in the no-booster group. None of the serious adverse events was judged attributable to the booster vaccination assignment. In addition to no new safety concerns and in marked contrast to earlier trials evaluating short-term boosting, delaying a rVSVΔG-ZEBOV-GP booster until month 18resulted in an increase in GMT that remained several-fold above the no-booster group GMT for at least 18months. These findings could have implications for defining the optimal timing of booster doses as pre-exposure prophylaxis in populations at ongoing risk for Ebola virus exposure. The Division of Intramural Research and the Division of Clinical Research of the National Institute of Allergyand Infectious Diseases at the US National Institutes of Health, Canadian Immunization Research Network through the Public Health Agency of Canada, Canadian Institutes of Health Research, and the US Defense Threat Reduction Agency.

Preventive strategies for Zoonoses diseases: Rising concerned among the population

Zoonoses are any disease or infection that is naturally transmissible from vertebrate animals to humans. More than 200 types of zoonoses are recognized till date. Zoonoses comprise a large percentage of new and existing diseases in humans. Certain zoonoses, like rabies, can be completely avoided with vaccination and other preventative measures. A few diseases, like HIV, start off as zoonoses before evolving into strains that are exclusive to humans. Disease outbreaks that repeat frequently include salmonellosis and the Ebola virus. Others have the potential to start worldwide pandemics, as the new corona virus that causes COVID-19. It is estimated that over 60% of the western families own a pet as a result reverse zoonoses and zoonoses has become a major problem. Each pathogen has different preventive measures for zoonotic diseases. In this present review work, we have highlighted some of the preventive strategies of these infectious diseases. In the agricultural sector, safe and adequate rules for animal care contribute to a lower risk of food borne zoonotic disease outbreaks through the consumption of meat, eggs, dairy products, and even some plants. Surface water protections in the natural environment, trash removal guidelines, and standards for clean drinking water are very crucial. Campaigns to educate people about the importance of washing your hands after coming into touch with animals and other behavioral changes can help stop the spread of zoonotic diseases in the community. Limiting Transmission Risks, Boosting the Body’s Defences, Understanding Vaccination, promoting veterinary public health at collective scale, Anticipating risks through monitoring and assessment are some of the preventive measures for Zoonoses.

A fatty acid-ordered plasma membrane environment is critical for Ebola virus matrix protein assembly and budding

Plasma membrane (PM) domains and order phases have been shown to play a key role in the assembly, release, and entry of several lipid-enveloped viruses. In the present study, we provide a mechanistic understanding of the Ebola virus (EBOV) matrix protein VP40 interaction with PM lipids and their effect on VP40 oligomerization, a crucial step for viral assembly and budding. VP40 matrix formation is sufficient to induce changes in the PM fluidity. We demonstrate that the distance between the lipid headgroups, the fatty acid tail saturation, and the PM order are important factors for the stability of VP40 binding and oligomerization at the PM. The use of FDA-approved drugs to fluidize the PM destabilizes the viral matrix assembly leading to a reduction in budding efficiency. Overall, these findings support an EBOV assembly mechanism that reaches beyond lipid headgroup specificity by using ordered PM lipid regions independent of cholesterol.

Global Health Security in Vision Care: Health Systems Strengthening During Ebola Virus Disease Outbreak Responses.

During the last decade, global health security has been threatened by major Ebola virus disease outbreaks in Western Africa (2014 to 2016) and in eastern Democratic Republic of the Congo (2018 to 2020). Particularly in Western Africa, the outbreak initially overwhelmed health care capacity in already fragile health systems. Thousands of survivors were at risk of newly recognized postacute ocular complications, and their need for urgent ophthalmic care challenged national vision health systems with scarce eye care services. In these unprecedently large outbreaks with implications for global health security, agile eye care responses were challenging, including in regard to decision coordination and requisite logistical needs. In this report, we detail vision care initiatives implemented in response to these outbreaks and highlight the need to include vision care as a critical component of the response to infectious disease outbreaks with eye health implications.

Establishing Vitreoretinal Surgery Capacity in Sierra Leone: Challenges and Opportunities to Address Retinal Health Disparities in Resource-limited Settings.

A range of challenges exists regarding vitreoretinal (VR) surgical services in resource-limited settings, including Sierra Leone. As a result, retinal pathologies may contribute to vision loss and blindness. In the wake of the 2013 to 2016 outbreak of Ebola virus disease in West Africa, gaps in ophthalmic care were underscored as survivors were experiencing a constellation of sequelae, including uveitis and VR disease. Given the unmet needs in addressing VR disease, systems for retinal surgical care were required. To further understand long-term ocular complications in Ebola survivors and molecular and immunologic factors associated with this, research infrastructure was developed for retinal evaluation and surgery. The 5 "S'" framework was implemented and considered staff, space, stuff, systems, and social support. The ongoing development of retinal health infrastructure has helped to address challenges related to program implementation, development of surgical capacity, and alignment with local stakeholders and collaborator objectives. VR surgical services have been established in Sierra Leone through multidisciplinary partnerships and collaboration and serve patients in-country, as well as others in West Africa who have traveled for care. Continued engagement across stakeholders can aim to address challenges and promote effective care delivery.

Functional Simulation Exercise on Functionality of National Public Health Emergency Operations Centers in the African Region: Review of Strengths and Gaps.

National public health emergency operations centers (PHEOCs) serve as hubs for coordinating information and resources for effective emergency management. In the International Health Regulations (IHR 2005) Monitoring and Evaluation Framework, a simulation exercise is 1 of 4 components that can be used to test the functionality of a country's emergency response capabilities in a simulated situation. To test the functionality of PHEOCs in World Health Organization African Region member states, a regional functional exercise simulating an Ebola virus disease outbreak was conducted. The public health actions taken in response to the simulated outbreak were evaluated against the exercise objectives. Thematic analysis was conducted to summarize key strengths and areas for improvement. From December 6 to 7, 2022, more than 1,000 representatives from 36 of the 47 African Region member states participated in the exercise from their respective PHEOCs. Approximately 95% of the 461 participants polled agreed with the positive responses to the postexercise survey. More than half of the PHEOC participants were able to test their existing emergency preparedness and response plans and became familiar with the expected roles to be fulfilled during an event. Of the participants who responded to the survey, over 90% reported that the exercise helped them understand their roles during emergency management. The exercise met its objectives and provided an opportunity to test the functionality of PHEOCs using realistic scenarios, and it helped participants understand existing response systems and procedures. However, the exercise also revealed areas for improvement in terms of the timing and preparation of participants. We recommend conducting functional exercises at the regional and national levels at least once a year, early or midyear, to allow many stakeholders to take part in the exercise. Moreover, there is a need to train country-level evaluators and controllers in designing and conducting functional exercises.

Emerging Infectious Diseases and the Eye: Ophthalmic Manifestations, Pathogenesis, and One Health Perspectives.

Infectious diseases may lead to ocular complications including uveitis, an ocular inflammatory condition with potentially sight-threatening sequelae, and conjunctivitis, inflammation of the conjunctiva. Emerging infectious pathogens with known ocular findings include Ebola virus, Zika virus, Avian influenza virus, Nipah virus, severe acute respiratory syndrome coronaviruses, and Dengue virus. Re-emerging pathogens with ocular findings include Toxoplasma gondii and Plasmodium species that lead to malaria. The concept of One Health involves a collaborative and interdisciplinary approach to achieve optimal health outcomes by combining human, animal, and environmental health factors. This approach examines the interconnected and often complex human-pathogen-intermediate host interactions in infectious diseases that may also result in ocular disease, including uveitis and conjunctivitis. Through a comprehensive review of the literature, we review the ophthalmic findings of emerging infectious diseases, pathogenesis, and One Health perspectives that provide further insight into the disease state. While eye care providers and vision researchers may often focus on key local aspects of disease process and management, additional perspective on host-pathogen-reservoir life cycles and transmission considerations, including environmental factors, may offer greater insight to improve outcomes for affected individuals and stakeholders.

Mathematical analysis of Ebola considering transmission at treatment centres and survivor relapse using fractal-fractional Caputo derivatives in Uganda

In this article, we seek to formulate a robust mathematical model to study the Ebola disease through fractal-fractional operators. The study thus incorporates the transmission rate in the treatment centers and the relapse rate, since the Ebola virus persists or mostly hides in the immunologically protected sites of survivors. The Ebola virus disease (EVD) is one of the infectious diseases that has recorded a high death rate in countries where it is endemic, and Uganda is not an exception. The world at large has suffered from this deadly disease since 1976 when it was declared epidemic by the World Health Organization. The study employed fractal-fractional operators to identify the epidemiological patterns of EVD, especially in treatment centers and relapse. Memory loss and relapse are mostly observed in EVD survivors and this justifies the use of fractional operators to capture the true dynamics of the disease. Through dynamical analysis, the model is proven to be positive and bounded in the region. The model is further explicitly shown to have a solution that is unique and stable. The reproduction number was duly computed by using the next-generation matrix approach. By taking EVD epidemic cases in Uganda, the study fitted all parameters to real data. It has been shown through sensitivity index analysis that the transmission rate outside treatment centers and relapse have a significant effect on the endemic state of the disease, as they lead to an increase in the basic reproduction ratio.