Ebola Virus Infection Associated with Transmission from Survivors

Jamaican fruit bats' competence for Ebola but not Marburg virus is driven by intrinsic differences

Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic filoviruses that cause hemorrhagic fever in humans. Correlative data implicate bats as natural EBOV hosts, but neither a full-length genome nor an EBOV isolate has been found in any bats sampled. Here, we model filovirus infection in the Jamaican fruit bat (JFB), Artibeus jamaicensis, by inoculation with either EBOV or MARV through a combination of oral, intranasal, and subcutaneous routes. Infection with EBOV results in systemic virus replication and oral shedding of infectious virus. MARV replication is transient and does not shed. In vitro, JFB cells replicate EBOV more efficiently than MARV, and MARV infection induces innate antiviral responses that EBOV efficiently suppresses. Experiments using VSV pseudoparticles or replicating VSV expressing the EBOV or MARV glycoprotein demonstrate an advantage for EBOV entry and replication early, respectively, in JFB cells. Overall, this study describes filovirus species-specific phenotypes for both JFB and their cells.

Associations of inflammatory markers with post-acute clinical findings among survivors of Ebola virus disease with and without viral RNA shedding in the semen in Liberia: a nested case-control study

BACKGROUND

A high proportion of survivors of Ebola virus disease (EVD) have post-acute sequelae of EVD (PASE), but the relationship between inflammation and PASE pathogenesis is poorly understood. This study tests the hypothesis that inflammation is associated with PASE among survivors with and without viral RNA shedding in the semen.

METHODS

This was a case-control study nested in a longitudinal cohort that recruited confirmed survivors of EVD and their uninfected contacts from the 2013-16 EVD epidemic in Liberia, starting on June 1, 2015. We included participants aged at least 18 years with clinical data and plasma available at cohort baseline for analysis. A semen donation substudy tested male survivors for Ebola virus RNA shedding in the semen. A sex-stratified and survivor-stratified random sample of cases (survivors) and controls (contacts) was obtained to select stored baseline plasma samples for cytokine testing of markers of inflammation, immune regulation, and antiviral responses. Serostatus of cases and controls was confirmed by Filovirus Animal Nonclinical Group assay. We identified inflammatory markers (adjusted p≤0·05) elevated in cases compared with controls and then used these biomarkers in analyses comparing survivors with and without pre-specified PASE-associated clinical findings (self-reported symptoms and abnormal examination findings). Survivors with viral RNA shedding in the semen formed subgroup analyses.

FINDINGS

Our analysis cohort consisted of 1044 participants (594 survivors of EVD and 450 uninfected contacts); 515 (49·3%) were female and 529 (50·7%) were male. The subcohort of 243 male survivors with data on viral shedding included 81 (33%) participants with viral shedding in semen. Median time from acute EVD to baseline was 317 days (IQR 271-366). Survivors of EVD showed a pattern of elevated inflammatory markers indicative of macrophage (MCP-1, IL-1β, and M-CSF) and angiogenic factor activation (VEGF-A) compared with controls (adjusted p<0·05). In survivors with viral shedding in the semen compared with controls, VEGF-A was the only inflammatory marker that was significantly higher (adjusted p<0·001). After restricting the analysis to survivors, each inflammatory marker had a specific pattern of clinical findings. Higher levels of IL-1β were associated with higher odds of urinary frequency (p=0·002), musculoskeletal abnormalities (p=0·003), and abdominal abnormalities (p=0·03). By contrast, higher levels of MCP-1 were associated with lower odds of the same clinical findings. M-CSF was the only inflammatory marker associated with lower odds of joint pain (p=0·04). Higher levels of VEGF-A were associated with higher odds of abnormal chest findings in the overall survivor group (p=0·02) and in the subgroup with viral shedding in the semen (p=0·02).

INTERPRETATION

We found evidence of distinct biological pathways for PASE. Although viral RNA shedding in the semen could be associated with angiogenic activation, it did not explain many of the PASE symptoms and exam findings associated with the elevated macrophage markers, suggesting the pathobiology of some clinical manifestations might be autoimmunity, immune dysregulation, or another biological mechanism. These findings could inform shared biological pathways with other infection-associated chronic conditions, including post-acute sequelae of SARS-CoV-2 infection.

FUNDING

National Cancer Institute and National Institute of Allergy and Infectious Diseases at the US National Institutes of Health.

rVSVΔG-ZEBOV-GP Vaccine Is Highly Immunogenic and Efficacious Across a Wide Dose Range in a Nonhuman Primate EBOV Challenge Model

The recombinant vesicular stomatitis virus-Zaire Ebolavirus envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP) was highly effective against Ebola virus disease in a ring vaccination trial conducted during the 2014-2016 outbreak in Guinea and is licensed by regulatory agencies including US FDA, EMA, and prequalified by WHO. Vaccination studies in a nonhuman primate (NHP) model guided initial dose selection for clinical trial evaluation. We summarize two dose-ranging studies with the clinical-grade rVSVΔG-ZEBOV-GP vaccine candidate to assess the impact of dose level on immune responses and efficacy in an NHP Ebola virus (EBOV) challenge model. Forty-six cynomolgus macaques were vaccinated with a wide range of rVSVΔG-ZEBOV-GP doses and challenged 42 days later intramuscularly with 1000 pfu EBOV. Vaccination with rVSVΔG-ZEBOV-GP induced relatively high levels of EBOV-specific IgG and neutralizing antibodies, measured using the same validated assays as used in rVSVΔG-ZEBOV-GP clinical trials. Similar responses were observed across dose groups from 1 × 108 to 1 × 102 pfu. A single vaccination conferred 98% protection from lethal intramuscular EBOV challenge across all dose groups. These results demonstrate that robust antibody titers are induced in NHPs across a wide range of rVSVΔG-ZEBOV-GP vaccine doses, correlating with high levels of protection against death from EBOV challenge.

ZMapp reduces diffusion of Ebola viral particles in fresh human cervicovaginal mucus

Vaginal transmission from semen of male Ebola virus (EBOV) survivors has been implicated as a potential origin of Ebola virus disease (EVD) outbreaks. While EBOV in semen must traverse cervicovaginal mucus (CVM) to reach target cells, the behaviour of EBOV in CVM is poorly understood. CVM contains substantial quantities of IgG, and arrays of IgG bound to a virion can develop multiple Fc-mucin bonds, immobilizing the IgG/virion complex in mucus. Here, we measured the real-time mobility of fluorescent Ebola virus-like-particles (VLP) in 50 CVM specimens from 17 women, with and without ZMapp, a cocktail of 3 monoclonal IgGs against EBOV. ZMapp-mediated effective trapping of Ebola VLPs in CVM from a subset of women across the menstrual cycle, primarily those with Lactobacillus crispatus dominant microbiota. Our work underscores the influence of the vaginal microbiome on IgG-mucin crosslinking against EBOV and identifies bottlenecks in the sexual transmission of EBOV.

Stress from environmental change drives clearance of a persistent enteric virus

Persistent viral infections are associated with long-term health issues and prolonged transmission. How external perturbations after initial exposure affect the duration of infection is unclear. We discovered that murine astrovirus, an enteric RNA virus, persists indefinitely when mice remain unperturbed but is cleared rapidly after cage change. Besides eliminating the external viral reservoir, cage change also induced a transcriptional defense response in the intestinal epithelium. We further identified that displacing infected animals initially caused a temporary period of immune suppression through the stress hormone corticosterone, which was followed by an immune rebound characterized by an increase in CD8 T cells responsible for the epithelial antiviral responses. Our findings show how viral persistence can be disrupted by preventing re-exposure and activating immunity upon stress recovery, indicating that external factors can be manipulated to shorten the duration of a viral infection.

Efficacy of Polyphenylene Carboxymethylene (PPCM) Gel at Protecting Type I Interferon Receptors Knockout Mice from Intravaginal Ebola Virus Challenge

Ebola virus (EBOV) is one of three filovirus members of the Orthoebolavirus genus that can cause severe Ebola disease (EBOD) in humans. Transmission predominantly occurs from spillover events from wildlife but has also happened between humans with infected bodily fluids. Specifically, the sexual route through infectious male survivors could be the origin of flare up events leading to the deaths of multiple women. More studies are needed to comprehend this route of infection which has recently received more focus. The use of microbicides prior to intercourse is of interest if neither of the Ebola vaccines are an option. These experimental products have been used against sexually transmitted diseases, and recently polyphenylene carboxymethylene (PPCM) showed efficacy against EBOV in vitro. Shortly after, the first animal model of EBOV sexual transmission was established using type I interferon receptors (IFNAR-/-) knockout female mice in which mortality endpoint could be achieved. Here, we investigated PPCM efficacy against a mouse-adapted (ma)EBOV isolate in IFNAR-/- mice and demonstrated that 4% PPCM gel caused a 20% reduction in mortality in two distinct groups compared to control groups when inoculated prior to virus challenge. Among animals that succumbed to disease despite PPCM treatment, we report an increase in median survival time as well as a less infectious virus, and fewer virus positive vaginal swabs compared to those from vehicle-treated animals, altogether indicating the beneficial effect of using PPCM prior to exposure. A post-study analysis of the different gel formulations tested indicated that buffering the gels would have prevented an increase in acidity seen only in vehicles, suggesting that PPCM antiviral efficacy against EBOV was suboptimal in our experimental set-up. These results are encouraging and warrant further studies using optimized stable formulations with the goal of providing additional safe protective countermeasures from sexual transmission of EBOV in humans.

Molecular determinants of cross-species transmission in emerging viral infections

SUMMARYSeveral examples of high-impact cross-species transmission of newly emerging or re-emerging bat-borne viruses, such as Sudan virus, Nipah virus, and severe acute respiratory syndrome coronavirus 2, have occurred in the past decades. Recent advancements in next-generation sequencing have strengthened ongoing efforts to catalog the global virome, in particular from the multitude of different bat species. However, functional characterization of these novel viruses and virus sequences is typically limited with regard to assessment of their cross-species potential. Our understanding of the intricate interplay between virus and host underlying successful cross-species transmission has focused on the basic mechanisms of entry and replication, as well as the importance of host innate immune responses. In this review, we discuss the various roles of the respective molecular mechanisms underlying cross-species transmission using different recent bat-borne viruses as examples. To delineate the crucial cellular and molecular steps underlying cross-species transmission, we propose a framework of overall characterization to improve our capacity to characterize viruses as benign, of interest, or of concern.

Healthcare Providers' and Frontline Workers' Experiences of an Ebola Vaccine Trial in the Boende Health District of the Democratic Republic of the Congo

This study explored the experiences of healthcare providers (HCPs) and frontline workers who were involved in an Ebola vaccine trial in the Democratic Republic of the Congo. The researchers interviewed a total of 99 participants (HCPs and frontline workers) living and working in the Boende health district during the period of the study, from February to March 2022. These individuals included a mix of trial participants and non-trial participants (staff of the trial, local health authorities, and head nurses of health centers). In-depth individual interviews, as well as focus group discussions (FGDs), were used to understand interviewees' experiences and perceptions. The data were analyzed to identify the main themes. The findings unveiled a multitude of positive experiences among interviewees/FGD participants. The commitment of the trial investigators to improve the study site and to equip the volunteers with necessary skills and knowledge greatly contributed to a positive trial experience. However, some interviewees felt that the reimbursement for time and travel expenses during their trial visits was insufficient in comparison with their expectations. Additionally, there were expressions of worry about the frequency of blood draws during scheduled trial visits. Our findings emphasize the critical importance of addressing and continuously considering the perspectives and concerns of trial participants before designing and implementing vaccine trials. By actively incorporating their inputs, researchers can mitigate concerns and tailor communication strategies, potentially enhancing the overall success and impact of the vaccine trial.

Australian emergency nurses' experiences of working with personal protective equipment during the COVID-19 pandemic. A qualitative study

INTRODUCTION

The COVID-19 pandemic has exposed a need to understand the challenges associated with wearing Personal protective Equipment (PPE). The aim in this study was to explore emergency nurses' experiences early in the COVID-19 pandemic in Australia and the impact of PPE use on their practice.

METHODS

An explorative descriptive qualitative study was conducted between January 2022 and April 2022. Eighteen emergency nurses and six leaders participated. Semi-structured interviews (n = 21) and one focus group were conducted. Interview transcripts were analysed using Braun and Clarke's framework.

RESULTS

Two major themes were identified. The first theme was: (1) The shifting ground of the COVID-19 pandemic response. Associated sub-themes were: i) What's the go with PPE today? ii) In the beginning we were scrambling for masks; iii) Emergency is the true frontline. The second theme was: (2) Physical and emotional impacts of emergency nursing work. Sub-themes were: (i) Facing the fear of exposure; (ii) By the end of the shift I am just absolutely spent; iii) Discomfort of wearing PPE impacts on compliance.

CONCLUSIONS

Healthcare leaders need to secure PPE supply chains and evaluate the effectiveness and side-effects of different PPE designs to minimise occupational harms associated with prolonged PPE use.

Antibody responses to recombinant vesicular stomatitis virus-Zaire Ebolavirus vaccination for Ebola virus disease across doses and continents: 5-year durability

OBJECTIVES

To report 5-year persistence and avidity of antibodies produced by the live-attenuated recombinant vesicular stomatitis virus (rVSV) expressing the Zaire Ebolavirus (ZEBOV) glycoprotein (GP), known as rVSV-ZEBOV (Ervebo®).

METHODS

Healthy adults vaccinated with 300,000 or 10-50 million plaque-forming units of rVSV-ZEBOV in the WHO-coordinated trials of 2014-2015 were followed for up to 4 (Lambaréné, Gabon) and 5 (Geneva, Switzerland) years. We report seropositivity rates, geometric mean titres (GMTs), and population distribution of ZEBOV-GP ELISA IgG antibodies, neutralizing antibodies (pseudovirus and live-virus neutralization) and antibody avidity; the primary outcome was ZEBOV-GP ELISA IgG GMTs at 4 or 5 years compared with 1 year (Y1) after immunization.

RESULTS

Among the 168 eligible vaccinees (Geneva: 97 and Lambaréné: 71) enrolled 1 year post-immunization, 146 (87%) remained enrolled at 4 years (Geneva: n = 88, Lambaréné: n = 58), and 84 (87%, Geneva) at 5 years post-vaccination. ZEBOV-GP ELISA IgG GMTs plateaued, with no declining trend from 1 year through the last time point assessed (1147.8 [95% CI 874.3-1507.0] at Y1 versus 1548.1 [95% CI 1136.6-2108.5] at Y5 in Geneva volunteers receiving ≥10 million plaque-forming units of rVSV-ZEBOV), their avidity matching that of ZEBOV convalescents. Live-virus neutralizing antibodies were detected for shorter periods and in fewer vaccinees (53/95 [56%] at Y1 versus 35/84 [42%] at Y5 in Geneva volunteers, all dose levels).

DISCUSSION

Titres at Y1 emerged as a correlate of antibody persistence at Y5. The findings of persistent ZEBOV-GP ELISA IgG titres yet shorter-lasting, lower titres of live-virus neutralizing antibodies suggest the contribution of antibody-mediated protective mechanisms other than neutralization. Long-term clinical efficacy of rVSV-ZEBOV, however, requires further study.

The Susceptibility of BALB/c Mice to a Mouse-Adapted Ebola Virus Intravaginal Infection

Ebola virus (EBOV) causes Ebola virus disease (EVD), which is characterized by hemorrhagic fever with high mortality rates in humans. EBOV sexual transmission has been a concern since the 2014-2016 outbreak in Africa, as persistent infection in the testis and transmission to women was demonstrated. The only study related to establishing an intravaginal small animal infection model was recently documented in IFNAR^-/- mice using wild-type and mouse-adapted EBOV (maEBOV), and resulted in 80% mortality, supporting epidemiological data. However, this route of transmission is still poorly understood in women, and the resulting EVD from it is understudied. Here, we contribute to this field of research by providing data from immunocompetent BALB/c mice. We demonstrate that progesterone priming increased the likelihood of maEBOV vaginal infection and of exhibiting the symptoms of disease and seroconversion. However, our data suggest subclinical infection, regardless of the infective dose. We conclude that maEBOV can infect BALB/c mice through vaginal inoculation, but that this route of infection causes significantly less disease compared to intraperitoneal injection at a similar dose, which is consistent with previous studies using other peripheral routes of inoculation in that animal model. Our data are inconsistent with the disease severity described in female patients, therefore suggesting that BALB/c mice are unsuitable for modeling typical EVD following vaginal challenge with maEBOV. Further studies are required to determine the mechanisms by which EVD is attenuated in BALB/c mice, using maEBOV via the vaginal route, as in our experimental set-up.

Characterization of an air-liquid interface primary human vaginal epithelium to study Ebola virus infection and testing of antivirals

Ebola virus (EBOV) is the causative agent of the often-fatal Ebola virus disease (EVD) characterized by hemorrhagic fever in humans and non-human primates. Sexual transmission from male survivors has been at the origin of multiple outbreak flare-ups between 2015 and 2021. However, this route is still poorly understood and the resulting EVD from it is also understudied. To support epidemiological studies documenting sexual transmission to women, and as a transition from previously using monolayer vaginal epithelial cells (VK2/E6E7), we first determined the biological relevance of two similar air-liquid interface models of the human vaginal epithelium (VEC and VLC Epivaginal™) and then characterized their susceptibility to EBOV and virus-induced inflammation. Finally, we evaluated toxicity of Polyphenylene Carboxymethylene (PPCM) microbicide in VLC and reassessed its antiviral effect. As expected, the VEC, but also VLC model showed stratified layers including a lamina propria under an epithelial structure similar to the full thickness of the human vaginal epithelium. However, we could not detect the immune cells featured in the most relevant model (VLC) of the vaginal epithelium using the dendritic cell CD1a and CD11c markers. Consistent with our previous work using the VK2/E6E7 cell line, infectious virus was detected from the apical side of both primary human cell systems, but only when using a high infective dose, with titers remaining at a constant level of 103-4 pfu/ml over 7 days suggesting lasting infectious virus shedding. In addition, infection caused disruption of the epithelium of both models and virus antigen was found from the apical superficial layers down to the lamina propria suggesting full virus penetration and overall confirming the susceptibility of the human vaginal tissue for EBOV. Just like previously seen in VK2/E6E7 cells, VLC infection also caused significant increase in inflammatory markers including IL-6, IL-8, and IP-10 suggesting vaginitis which is again consistent with tissue lesions seen in non-human primates. Finally, both virus infection and virus-induced inflammatory response in VLC could be prevented by a single 5-min PPCM microbicide treatment prior infection.

The prophylactic and therapeutic efficacy of the broadly active antiviral ribonucleoside N4-Hydroxycytidine (EIDD-1931) in a mouse model of lethal Ebola virus infection

The unprecedented magnitude of the 2013-2016 Ebola virus (EBOV) epidemic in West Africa resulted in over 11 000 deaths and spurred an international public health emergency. A second outbreak in 2018-2020 in DRC resulted in an additional >3400 cases and nearly 2300 deaths (WHO, 2020). These large outbreaks across geographically diverse regions highlight the need for the development of effective oral therapeutic agents that can be easily distributed for self-administration to populations with active disease or at risk of infection. Herein, we report the in vivo efficacy of N⁴-hydroxycytidine (EIDD-1931), a broadly active ribonucleoside analog and the active metabolite of the prodrug EIDD-2801 (molnupiravir), in murine models of lethal EBOV infection. Twice daily oral dosing with EIDD-1931 at 200 mg/kg for 7 days, initiated either with a prophylactic dose 2 h before infection, or as therapeutic treatment starting 6 h post-infection, resulted in 92-100% survival of mice challenged with lethal doses of EBOV, reduced clinical signs of Ebola virus disease (EVD), reduced serum virus titers, and facilitated weight loss recovery. These results support further investigation of molnupiravir as a potential therapeutic or prophylactic treatment for EVD.

Protection against Marburg Virus and Sudan Virus in NHP by an Adenovector-Based Trivalent Vaccine Regimen Is Correlated to Humoral Immune Response Levels

The Marburg virus (MARV) and Sudan virus (SUDV) belong to the filovirus family. The sporadic human outbreaks occur mostly in Africa and are characterized by an aggressive disease course with high mortality. The first case of Marburg virus disease in Guinea in 2021, together with the increased frequency of outbreaks of Ebola virus (EBOV), which is also a filovirus, accelerated the interest in potential prophylactic vaccine solutions against multiple filoviruses. We previously tested a two-dose heterologous vaccine regimen (Ad26.Filo, MVA-BN-Filo) in non-human primates (NHP) and showed a fully protective immune response against both SUDV and MARV in addition to the already-reported protective effect against EBOV. The vaccine-induced glycoprotein (GP)-binding antibody levels appear to be good predictors of the NHP challenge outcome as indicated by the correlation between antibody levels and survival outcome as well as the high discriminatory capacity of the logistic model. Moreover, the elicited GP-specific binding antibody response against EBOV, SUDV, and MARV remains stable for more than 1 year. Overall, the NHP data indicate that the Ad26.Filo, MVA-BN-Filo regimen may be a good candidate for a prophylactic vaccination strategy in regions at high risk of filovirus outbreaks.

Ebola virus persistence and disease recrudescence in the brains of antibody-treated nonhuman primate survivors

Effective therapeutics have been developed against acute Ebola virus disease (EVD) in both humans and experimentally infected nonhuman primates. However, the risk of viral persistence and associated disease recrudescence in survivors receiving these therapeutics remains unclear. In contrast to rhesus macaques that survived Ebola virus (EBOV) exposure in the absence of treatment, we discovered that EBOV, despite being cleared from all other organs, persisted in the brain ventricular system of rhesus macaque survivors that had received monoclonal antibody (mAb) treatment. In mAb-treated macaque survivors, EBOV persisted in macrophages infiltrating the brain ventricular system, including the choroid plexuses. This macrophage infiltration was accompanied by severe tissue damage, including ventriculitis, choroid plexitis, and meningoencephalitis. Specifically, choroid plexus endothelium-derived EBOV infection led to viral persistence in the macaque brain ventricular system. This resulted in apoptosis of ependymal cells, which constitute the blood-cerebrospinal fluid barrier of the choroid plexuses. Fatal brain-confined recrudescence of EBOV infection manifested as severe inflammation, local pathology, and widespread infection of the ventricular system and adjacent neuropil in some of the mAb-treated macaque survivors. This study highlights organ-specific EBOV persistence and fatal recrudescent disease in rhesus macaque survivors after therapeutic treatment and has implications for the long-term follow-up of human survivors of EVD.

Postmortem Surveillance for Ebola Virus Using OraQuick Ebola Rapid Diagnostic Tests, Eastern Democratic Republic of the Congo, 2019–2020

After a pilot study, we tested 443 cadavers using OraQuick Ebola rapid diagnostic tests during surveillance after the 10th Ebola outbreak in the Democratic Republic of the Congo. No false negative and 2% false-positive results were reported. Quickly returning results and engaging the community enabled timely public health actions.

Host Sex Steroids Interact With Virus Infection: New Insights Into Sex Disparity in Infectious Diseases

Sex hormones are steroid hormones synthesized from the gonads of animals and tissues such as the placenta and adrenocortical reticular zone. The physiological functions of sex hormones are complex. Sex hormones are not only pathologically correlated with many diseases of the reproductive system, but are etiological factors in some viral infectious diseases, including disease caused by infections of coronaviruses, herpesviruses, hepatitis viruses, and other kinds of human viruses, which either exhibit a male propensity in clinical practice, or crosstalk with androgen receptor (AR)-related pathways in viral pathogenesis. Due to the global pandemic of coronavirus disease 2019 (COVID-19), the role of androgen/AR in viral infectious disease is highlighted again, majorly representing by the recent advances of AR-responsive gene of transmembrane protease/serine subfamily member 2 (TMPRSS2), which proteolytically activates the receptor-mediated virus entry by many coronaviruses and influenza virus, along with the role of androgen-mediated signaling for the transcription of hepatitis B virus (HBV), and the role of sex hormone responsive genes during Zika virus (ZIKV) pathogenesis, et al. Collectively, we propose to provide a comprehensive overview of the role of male sex hormones during multiple phases in the life cycle of different human viruses, which may be partly responsible for the sex-specific prevalence, severity and mortality of some diseases, therefore, may provide clues to develop more efficient prevention and treatment strategies for high-risk populations.

Tolerance and Persistence of Ebola Virus in Primary Cells from Mops condylurus, a Potential Ebola Virus Reservoir

Although there have been documented Ebola virus disease outbreaks for more than 40 years, the natural reservoir host has not been identified. Recent studies provide evidence that the Angolan free-tailed bat (Mops condylurus), an insectivorous microbat, is a possible ebolavirus reservoir. To investigate the potential role of this bat species in the ecology of ebolaviruses, replication, tolerance, and persistence of Ebola virus (EBOV) were investigated in 10 different primary bat cell isolates from M. condylurus. Varying EBOV replication kinetics corresponded to the expression levels of the integral membrane protein NPC1. All primary cells were highly tolerant to EBOV infection without cytopathic effects. The observed persistent EBOV infection for 150 days in lung primary cells, without resultant selective pressure leading to virus mutation, indicate the intrinsic ability of EBOV to persist in this bat species. These results provide further evidence for this bat species to be a likely reservoir of ebolaviruses.

Scoping Review of Healthcare Literature on Mobile, Wearable, and Textile Sensing Technology for Continuous Monitoring

Remote monitoring of health can reduce frequent hospitalisations, diminishing the burden on the healthcare system and cost to the community. Patient monitoring helps identify symptoms associated with diseases or disease-driven disorders, which makes it an essential element of medical diagnoses, clinical interventions, and rehabilitation treatments for severe medical conditions. This monitoring can be expensive and time-consuming and provide an incomplete picture of the state of the patient. In the last decade, there has been a significant increase in the adoption of mobile and wearable devices, along with the introduction of smart textile solutions that offer the possibility of continuous monitoring. These alternatives fuel a technology shift in healthcare, one that involves the continuous tracking and monitoring of individuals. This scoping review examines how mobile, wearable, and textile sensing technology have been permeating healthcare by offering alternate solutions to challenging issues, such as personalised prescriptions or home-based secondary prevention. To do so, we have selected 222 healthcare literature articles published from 2007 to 2019 and reviewed them following the PRISMA process under the schema of a scoping review framework. Overall, our findings show a recent increase in research on mobile sensing technology to address patient monitoring, reflected by 128 articles published in journals and 19 articles in conference proceedings between 2014 and 2019, which represents 57.65% and 8.55% respectively of all included articles.

Persistence of Ebola virus in semen among Ebola virus disease survivors in Sierra Leone: A cohort study of frequency, duration, and risk factors

BACKGROUND

Sexual transmission chains of Ebola virus (EBOV) have been verified and linked to EBOV RNA persistence in semen, post-recovery. The rate of semen persistence over time, including the average duration of persistence among Ebola virus disease (EVD) survivors, is not well known. This cohort study aimed to analyze population estimates of EBOV RNA persistence rates in semen over time, and associated risk factors in a population of survivors from Sierra Leone.

METHODS AND FINDINGS

In this cohort study from May 2015 to April 2017 in Sierra Leone, recruitment was conducted in 2 phases; the first enrolled 100 male participants from the Western Area District in the capital of Freetown, and the second enrolled 120 men from the Western Area District and from Lungi, Port Loko District. Mean age of participants was 31 years. The men provided semen for testing, analyzed by quantitative reverse transcription PCR (qRT-PCR) for the presence of EBOV RNA. Follow-up occurred every 2 weeks until the endpoint, defined as 2 consecutive negative qRT-PCR results of semen specimen testing for EBOV RNA. Participants were matched with the Sierra Leone EVD case database to retrieve cycle threshold (Ct) values from the qRT-PCR analysis done in blood during acute disease. A purposive sampling strategy was used, and the included sample composition was compared to the national EVD survivor database to understand deviations from the general male survivor population. At 180 days (6 months) after Ebola treatment unit (ETU) discharge, the EBOV RNA semen positive rate was 75.4% (95% CI 66.9%-82.0%). The median persistence duration was 204 days, with 50% of men having cleared their semen of EBOV RNA after this time. At 270 days, persistence was 26.8% (95% CI 20.0%-34.2%), and at 360 days, 6.0% (95% CI 3.1%-10.2%). Longer persistence was significantly associated with severe acute disease, with probability of persistence in this population at 1 year at 10.1% (95% CI 4.6%-19.8%) compared to the probability approaching 0% for those with mild acute disease. Age showed a dose-response pattern, where the youngest men (≤25 years) were 3.17 (95% CI 1.60, 6.29) times more likely to be EBOV RNA negative in semen, and men aged 26-35 years were 1.85 (95% CI 1.04, 3.28) times more likely to be negative, than men aged >35 years. Among participants with both severe acute EVD and a higher age (>35 years), persistence remained above 20% (95% CI 6.0%-50.6%) at 1 year. Uptake of safe sex recommendations 3 months after ETU discharge was low among a third of survivors. The sample was largely representative of male survivors in Sierra Leone. A limitation of this study is the lack of knowledge about infectiousness.

CONCLUSIONS

In this study we observed that EBOV RNA persistence in semen was a frequent phenomenon, with high population rates over time. This finding will inform forthcoming updated recommendations on risk reduction strategies relating to sexual transmission of EBOV. Our findings support implementation of a semen testing program as part of epidemic preparedness and response. Further, the results will enable planning of the magnitude of testing and targeted counseling needs over time.

Ebola virus antibody decay-stimulation in a high proportion of survivors

Neutralizing antibody function provides a foundation for the efficacy of vaccines and therapies^1–3. Here, using a robust in vitro Ebola virus (EBOV) pseudo-particle infection assay and a well-defined set of solid-phase assays, we describe a wide spectrum of antibody responses in a cohort of healthy survivors of the Sierra Leone EBOV outbreak of 2013–2016. Pseudo-particle virus-neutralizing antibodies correlated with total anti-EBOV reactivity and neutralizing antibodies against live EBOV. Variant EBOV glycoproteins (1995 and 2014 strains) were similarly neutralized. During longitudinal follow-up, antibody responses fluctuated in a ‘decay–stimulation–decay’ pattern that suggests de novo restimulation by EBOV antigens after recovery. A pharmacodynamic model of antibody reactivity identified a decay half-life of 77–100 days and a doubling time of 46–86 days in a high proportion of survivors. The highest antibody reactivity was observed around 200 days after an individual had recovered. The model suggests that EBOV antibody reactivity declines over 0.5–2 years after recovery. In a high proportion of healthy survivors, antibody responses undergo rapid restimulation. Vigilant follow-up of survivors and possible elective de novo antigenic stimulation by vaccine immunization should be considered in order to prevent EBOV viral recrudescence in recovering individuals and thereby to mitigate the potential risk of reseeding an outbreak.

In many survivors of Ebola virus infection, antibody responses show long-term patterns of decline followed by restimulation, possibly owing to recrudescence of persisting virus.

Quarantines: Between Precaution and Necessity. A Look at COVID-19

The events surrounding COVID-19, combined with the mandatory quarantines widely imposed in Asia and Europe since the virus outbreak, have reignited discussion of the balance between individual rights and liberties and public health during epidemics and pandemics. This article analyses this issue from the perspectives of precaution and necessity. There is a difficult relationship between these two seemingly opposite principles, both of which are frequently invoked in this domain. Although the precautionary principle (PP) encourages the use of quarantines, including mandatory quarantines, and associated restrictive measures, the principle of necessity (PN) puts a break on such measures. The COVID-19 pandemic reveals once again the different interrelations between these two principles. However, the alleged conflict between the PN and the PP is based on a superficial analysis. The relation between these two principles is far more complex, as this article will demonstrate.

Atypical Ebola Virus Disease in a Nonhuman Primate following Monoclonal Antibody Treatment Is Associated with Glycoprotein Mutations within the Fusion Loop

Ebola virus remains a global threat to public health and biosecurity, yet we still know relatively little about its pathogenesis and the complications that arise following recovery. With nearly 20,000 survivors from the 2013–2016 West African outbreak, as well as over 1,000 survivors of the recent outbreak in the DRC, we must consider the consequences of virus persistence and recrudescent disease, even if they are rare.

Ebola virus (EBOV) is responsible for numerous devastating outbreaks throughout Africa, including the 2013–2016 West African outbreak as well as the two recent outbreaks in the Democratic Republic of the Congo (DRC), one of which is ongoing. Although EBOV disease (EVD) has typically been considered a highly lethal acute infection, increasing evidence suggests that the virus can persist in certain immune-privileged sites and occasionally lead to EVD recrudescence. Little is understood about the processes that contribute to EBOV persistence and recrudescence, in part because of the rarity of these phenomena but also because of the absence of an animal model that recapitulates them. Here, we describe a case of EBOV persistence associated with atypical EVD in a nonhuman primate (NHP) following inoculation with EBOV and treatment with an experimental monoclonal antibody cocktail. Although this animal exhibited only mild signs of acute EVD, it developed severe disease 2 weeks later and succumbed shortly thereafter. Viremia was undetectable at the time of death, despite abundant levels of viral RNA in most tissues, each of which appeared to harbor a distinct viral quasispecies. Remarkably, sequence analysis identified a single mutation in glycoprotein (GP) that not only resisted antibody-mediated neutralization but also increased viral growth kinetics and virulence. Overall, this report represents the most thoroughly characterized case of atypical EVD in an NHP described thus far, and it provides valuable insight into factors that may contribute to EBOV persistence and recrudescent disease.

Recent successes in therapeutics for Ebola virus disease: no time for complacency

The PALM trial in the Democratic Republic of the Congo identified a statistically significant survival benefit for two monoclonal antibody-based therapeutics in the treatment of acute Ebola virus disease; however, substantial gaps remain in improving the outcomes of acute Ebola virus disease and for the survivors. Ongoing efforts are needed to develop more effective strategies, particularly for individuals with severe disease, for prevention and treatment of viral persistence in immune-privileged sites, for optimisation of post-exposure prophylaxis, and to increase therapeutic breadth. As antibody-based approaches are identified and advanced, promising small-molecule antivirals currently in clinical stage development should continue to be evaluated for filovirus diseases, with consideration of their added value in combination approaches with bundled supportive care, their penetration in tissues of interest, the absence of interaction with glycoprotein-based vaccines, and filoviral breadth.

Personal protective equipment for viral hemorrhagic fevers

PURPOSE OF REVIEW

Viral hemorrhagic fevers (VHF) encompass many organisms that have caused sporadic outbreaks with high case fatality rates. This article reviews VHF with reported human-to-human transmission and describes updates about personal protective equipment (PPE) for healthcare personnel (HCP) and others. We summarize existing information about appropriate PPE use, training, and compliance for care of VHF patients in endemic and nonendemic countries, as well as addresses the challenges HCP experience when using PPE.

RECENT FINDINGS

PPE is essential in protecting HCP from exposure to disease-causing pathogens. Recent evidence shows that anyone involved in care, management, and transport of certain VHF patients must use elements of PPE as part of appropriate infection prevention and control (IPC) practices. Strict adherence to standard precautions has effectively interrupted human-to-human transmission of a number of VHF. However, unclear protocols, inconsistent training, climate challenges, and cultural sensitivities impede proper PPE use. Appropriate PPE use can drastically reduce the risk of HCP exposure to VHF.

SUMMARY

Infections caused by certain VHFs can be highly pathogenic and associated with significant morbidity and mortality. Though it is well documented that use of PPE and good IPC practices are critical to reducing transmission, little conclusive evidence exists about the ideal PPE ensemble or components. Concerns with comfort, compliance, training, and usability may impede proper PPE use. Basic PPE elements, used appropriately as part of stringent IPC, must always form the foundation of care for HCP-treating patients with VHF. More research is required to identify the ideal PPE ensemble for caring for VHF patients in various settings.

Ebola outbreak in West Africa, 2014 - 2016: Epidemic timeline, differential diagnoses, determining factors, and lessons for future response

The outbreak of Ebola virus disease (EVD) that raged between 2014 and 2016 in the West African sub-region was one of the global epidemics that spiked international public health concern in the last decade. Since the discovery of ebolavirus in 1976, the 2014-2016 epidemics have been the worst with significant case fatality rates and socioeconomic impact in the affected countries. This review looks at important health determinants that directly accounted for the spatial events of rapid spread and severity of EVD in West Africa, with consequent high fatality rates. It also brings up a time-point health determinant model to conceptualize understanding of this important outbreak with a view to enlightening the public andproviding valuable recommendations that may be crucial to preventing or curtailing any future outbreak of the disease.

Perceptions on the collection of body fluids for research on persistence of Ebola virus: A qualitative study

Background

Against the background of the international public health emergency related to the Ebola outbreak in the Democratic Republic of Congo, in addition to other recent large Ebola epidemics, the issue of transmission due to viral persistence from survivors’ body fluids is becoming increasingly urgent. Clinical research in which body fluids play a role is critical and semen testing programs are part of the suggested response to the outbreak. Broad acceptance and understanding of testing programs and research, often in resource poor settings, is essential for the success and sustainability of clinical studies and an accurate epidemic response. Study participants’ perceptions on the collection of body fluids are therefore relevant for the programmatic planning and implementation of clinical studies.

Study aim and methods

In this qualitative study we aimed to explore the perceptions on bio-sampling in the Sierra Leone Ebola Virus Persistence Study (SLEVP study). We were interested to understand how norms on gender and sexuality related to perceptions and experiences of study participants and staff, specifically, in what way perceptions of the body, on intimacy and on body fluids related to the study process. We purposively sampled former study participants for in-depth interviews and focus-group discussions. We conducted 56 in-depth interviews and eight focus group discussions with 93 participants. In a participatory approach we included study participants in the analysis of data.

Results

Overall the SLEVP study was well perceived by study participants and study staff. Study participants conceived the testing of their body fluids positively and saw it as a useful means to know their status. However, some study participants were ambivalent and sometimes reluctant towards sampling of certain body fluids (especially semen, blood and vaginal fluid) due to religious or cultural reasons. Self-sampling was described by study participants as a highly unusual phenomenon. Several narratives were related to the loss of body fluids (especially semen) that would make men weak and powerless, or women dizzy and sick (especially blood). Some rumors indicated mistrust related to study aims that may have been expressions of broader societal challenges and historical circumstances. These reservations could eventually be overcome by guaranteeing confidentiality and privacy and by comprehensive professional counseling.

Conclusion

In the course of the sampling exercise, study participants were often obliged to transgress cultural and intimate boundaries. It is therefore important to understand the potential importance some of these perceptions have on the recruitment of study participants and the acceptability of studies, on a symbolic as well as a structural level. In order to capture any reservations it is necessary to provide plenty of possibilities of information sharing and follow-up of continuous consent.

Recent studies have shown that the Ebola Virus might persist in body fluids of survivors of the disease. Clinical research in which body fluids (semen, vaginal fluids, blood, sweat, tears, breast milk and rectal fluids) are sampled play an increasingly important role, specifically in light of growing EVD epidemics. The success of these studies, e.g. how many participants are recruited in a study and how many are staying until the end of a study, is highly dependent on the participants’ cooperation and understanding of testing programs. However, until now there has been only little research on how studies and testing programs in which body fluids are sampled are perceived and understood by study participants. In this study we were therefore interested to understand how study participants perceived the sampling and collection of body fluids and how their cultural or religious background may influence the willingness to participate and stay in a clinical study. We conducted one-to-one interviews and focus-group discussions with 93 former study participants of a viral persistence study. We found that overall study participants conceived the testing of their body fluids positively and saw it as a useful means to know their status. However, some study participants were ambivalent and sometimes reluctant towards sampling of certain body fluids (especially semen, blood and vaginal fluid) due to religious or cultural reasons. Self-sampling was described by study participants as a highly unusual phenomenon. Participants explained that the collection of certain body fluids would make men weak and powerless (especially the sampling of semen), or women dizzy and sick (especially blood). Rumors indicated that some participants mistrusted the study aims. In the course of the sampling exercise, study participants often felt that they had to transgress cultural and intimate boundaries. We conclude that it is important to understand the potential importance some of these perceptions have on the recruitment of study participants and the acceptability of studies. The understanding of the socio-cultural context of clinical research is relevant for the programmatic planning of such research.

Providing healthcare to Ebola survivors: A qualitative exploratory investigation of healthcare providers' views and experiences in Sierra Leone

Although the experiences of healthcare workers regarding caring for Ebola patients during the West African Ebola outbreak have been explored, little is known about healthcare workers' experiences in providing care to Ebola survivors. We employed a qualitative design to address this gap in the literature. Healthcare providers described the health complaints of Ebola survivors as similar to those of ordinary patients, but disproportionately frequent and severe. During the Ebola outbreak, fear of infection with the Ebola virus affected healthcare providers' confidence to provide care to survivors leading to the provision of symptomatic or no treatment. At the close of the Ebola outbreak, healthcare providers cited previous experience in providing care to Ebola patients, being more knowledgeable, peer support, commitment to professional duty and the implementation of the CPES programme as motivators that helped boost their confidence to providing care. However, healthcare providers described the unavailability of medicines, the inability to undertake laboratory investigations, the lack of access to specialised care and uncoordinated referrals from peripheral health units as their current challenges to providing care. Such enablers and barriers need to be prioritised within the Sierra Leone health system to further strengthen initiatives aimed at improving healthcare delivery to Ebola survivors.

Ebola Virus Disease: Epidemiology, Clinical Features, Management, and Prevention

Ebola virus disease (EVD) is a deadly zoonotic disease caused by the Ebola virus. There is no specific treatment approved for EVD. Supportive care and management of complications are mainstays of treatment. Effective outbreak control requires a multidisciplinary team effort applying case management, infection prevention and control practices, surveillance and contact tracing, a good laboratory service, safe and dignified burials, and social and community mobilization. This article highlights the epidemiology, clinical features, diagnosis, management, and prevention of EVD. The emerging diagnostic technologies, rapid viral characterization, geospatial mapping of EVD transmission, and new treatments and vaccines are discussed.

Ebola virus disease

Ebola virus disease (EVD) is a severe and frequently lethal disease caused by Ebola virus (EBOV). EVD outbreaks typically start from a single case of probable zoonotic transmission, followed by human-to-human transmission via direct contact or contact with infected bodily fluids or contaminated fomites. EVD has a high case-fatality rate; it is characterized by fever, gastrointestinal signs and multiple organ dysfunction syndrome. Diagnosis requires a combination of case definition and laboratory tests, typically real-time reverse transcription PCR to detect viral RNA or rapid diagnostic tests based on immunoassays to detect EBOV antigens. Recent advances in medical countermeasure research resulted in the recent approval of an EBOV-targeted vaccine by European and US regulatory agencies. The results of a randomized clinical trial of investigational therapeutics for EVD demonstrated survival benefits from two monoclonal antibody products targeting the EBOV membrane glycoprotein. New observations emerging from the unprecedented 2013-2016 Western African EVD outbreak (the largest in history) and the ongoing EVD outbreak in the Democratic Republic of the Congo have substantially improved the understanding of EVD and viral persistence in survivors of EVD, resulting in new strategies toward prevention of infection and optimization of clinical management, acute illness outcomes and attendance to the clinical care needs of patients.

From Ancient to Emerging Infections: The Odyssey of Viruses in the Male Genital Tract

The male genital tract (MGT) is the target of a number of viral infections that can have deleterious consequences at the individual, offspring, and population levels. These consequences include infertility, cancers of male organs, transmission to the embryo/fetal development abnormalities, and sexual dissemination of major viral pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus. Lately, two emerging viruses, Zika and Ebola, have additionally revealed that the human MGT can constitute a reservoir for viruses cleared from peripheral circulation by the immune system, leading to their sexual transmission by cured men. This represents a concern for future epidemics and further underlines the need for a better understanding of the interplay between viruses and the MGT. We review here how viruses, from ancient viruses that integrated the germline during evolution through old viruses (e.g., papillomaviruses originating from Neanderthals) and more modern sexually transmitted infections (e.g., simian zoonotic HIV) to emerging viruses (e.g., Ebola and Zika) take advantage of genital tract colonization for horizontal dissemination, viral persistence, vertical transmission, and endogenization. The MGT immune responses to viruses and the impact of these infections are discussed. We summarize the latest data regarding the sources of viruses in semen and the complex role of this body fluid in sexual transmission. Finally, we introduce key animal findings that are relevant for our understanding of viral infection and persistence in the human MGT and suggest future research directions.

[Epidemic and emerging prone-infectious diseases: Lessons learned and ways forward]

Africa along side with south-east Asia are the epicentres of emerging and epidemic prone-infectious diseases and megacity biosecurity threat scenarios. Massive mobility and reluctance in the populations exposed to epidemic and emerging prone-infectious diseases coupled by a weak health system made disease alert and control measures difficult to implement. The investigation of virus detection and persistence in semen across a range of emerging viruses is useful for clinical and public health reasons, in particular for viruses that lead to high mortality or morbidity rates or to epidemics. Innovating built facility to safely treat patients with highly pathogenic infectious diseases is urgently need, not only to prevent the spread of infection from patients to healthcare workers but also to offer provision of relatively invasive organ support, whenever considered appropriate, without posing additional risk to staff. Despite multiple challenges, the need to conduct research during epidemics is inevitable, and candidate products must continue undergoing rigorous trials. Preparedness including management of complex humanitarian crises with community distrust is a cornerstone in response to high consequence emerging infectious disease outbreaks and imposes strengthening of the public health response infrastructure and emergency outbreak systems in high-risk regions.

Ebola virus: A global public health menace: A narrative review

Ebola virus disease (EVD), a fatal viral hemorrhagic illness, is due to infection with the Ebola virus of the Filoviridae family. The disease has evolved as a global public health menace due to a large immigrant population. Initially, the patients present with nonspecific influenza-like symptoms and eventually terminate into shock and multiorgan failure. There exists no specific treatment protocol for EVD and only supportive and symptomatic therapy is the line of treatment. This review article provides a detailed overview of the Ebola virus; it's clinical and oral manifestations, diagnostic aids, differential diagnosis, preventive aspects, and management protocol.

Post-Ebola psychosocial experiences and coping mechanisms among Ebola survivors: a systematic review

OBJECTIVE

A myriad of physical and psychosocial sequelae have been reported among Ebola survivors from previous Ebola virus disease (EVD) outbreaks, including the most recent in West Africa. This review examines the various forms of psychological distress experienced by EVD survivors, family and community reactions to EVD survivors and EVD survivors' coping mechanisms.

METHODS

We conducted a literature search of original articles employing Medline (Ovid), PubMed, Web of Science, Scopus, CINAHL, EBSCO host academic search complete, PsycINFO (EBSCO) and Embase databases.

RESULTS

Our search identified 1890 articles of which 24 met our inclusion criteria. Various forms of psychological distress were prevalent among EVD survivors including depression, anxiety, anger, grief, guilt, flashbacks, sadness, worthlessness, substance addiction, suicidal tendencies and self-stigmatisation. Family and community responses to EVD survivors ranged from acceptance to rejection, isolation, stigmatisation and discrimination. EVD survivors' coping strategies included engagement with religious faith, EVD survivors associations and involvement in EVD prevention and control interventions.

CONCLUSION

Psychological distress, including that resulting from family and community stigma and discrimination, appears common among EVD survivors. Community-based mental health and psychosocial interventions integrated within a broader package of care for EVD survivors that also recognises the physical health challenges are required. Well-designed longitudinal studies can provide clear insights on the nature and trajectory of the psychosocial issues currently experienced by EVD survivors.