Ebola virus RNA detection on fomites in close proximity to confirmed Ebola patients; N'Zerekore, Guinea, 2015

Natural History of Nonhuman Primates After Oral Exposure to Ebola Virus Variant Makona

BACKGROUND

The primary route of infection by Ebola virus (EBOV) is through contact of mucosal surfaces. Few studies have explored infection of nonhuman primates (NHPs) via the oral mucosa, which is a probable portal of natural infection in humans.

METHODS

To further characterize the pathogenesis of EBOV infection via the oral exposure route, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona.

RESULTS

Infection with 100 or 50 PFU of EBOV Makona via the oral route resulted in 50% and 83% lethality, respectively. Animals that progressed to fatal disease exhibited lymphopenia, marked coagulopathy, high viral loads, and increased levels of serum markers of inflammation and hepatic/renal injury. Survival in these cohorts was associated with milder fluctuations in leukocyte populations, lack of coagulopathy, and reduced or absent serum markers of inflammation and/or hepatic/renal function. Surprisingly, 2 surviving animals from the 100- and 50-PFU cohorts developed transient low-level viremia in the absence of other clinical signs of disease. Conversely, all animals in the 10 PFU cohort remained disease free and survived to the study end point.

CONCLUSIONS

Our observations highlight the susceptibility of NHPs, and by extension, likely humans, to relatively low doses of EBOV via the oral route.

Pathogenesis of Aerosolized Ebola Virus Variant Makona in Nonhuman Primates

BACKGROUND

Highly pathogenic filoviruses such as Ebola virus (EBOV) hold capacity for delivery by artificial aerosols, and thus potential for intentional misuse. Previous studies have shown that high doses of EBOV delivered by small-particle aerosol cause uniform lethality in nonhuman primates (NHPs), whereas only a few small studies have assessed lower doses in NHPs.

METHODS

To further characterize the pathogenesis of EBOV infection via small-particle aerosol, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona, which may help define risks associated with small particle aerosol exposures.

RESULTS

Despite using challenge doses orders of magnitude lower than previous studies, infection via this route was uniformly lethal across all cohorts. Time to death was delayed in a dose-dependent manner between aerosol-challenged cohorts, as well as in comparison to animals challenged via the intramuscular route. Here, we describe the observed clinical and pathological details including serum biomarkers, viral burden, and histopathological changes leading to death.

CONCLUSIONS

Our observations in this model highlight the striking susceptibility of NHPs, and likely humans, via small-particle aerosol exposure to EBOV and emphasize the need for further development of diagnostics and postexposure prophylactics in the event of intentional release via deployment of an aerosol-producing device.

Occurrence of Human Viruses on Fomites in the Environment: A Systematic Review and Meta-analysis

Documenting the occurrence of viruses on fomites is crucial in determining the significance of fomite-mediated transmission and the potential use of fomites for environmental disease surveillance. We conducted a systematic review and meta-analysis to compile information on the occurrence of human viruses on fomites in the environment; we identified 134 peer-reviewed papers. We compiled sampling and measurement methods, results, quality control information, and whether virus data were compared with community health data from the papers. We conducted univariate and multivariate analyses to investigate if presence of virus on fomites was associated with virus type (enveloped, nonenveloped), sampling location (healthcare setting, nonhealthcare temporary setting, nonhealthcare nontemporary setting), and area of fomite swabbed (<50, 50-100, >100 cm2). Across 275 data sets from the 134 papers, there was the most data available for Coronaviridae and from fomites at hospitals. Positivity rates, defined as the percent positive fomite samples, were low (median = 6%). Data were available on viruses from 16 different viral families, but data on viruses from 9 families had few (n < 5) data sets. Many human virus families were not identified in this review (11 families). Less than 15% of the data sets reported virus concentrations in externally valid units (viruses per area of surface), and 16% provided a quantitative comparison between virus and health data. Virus type and area swabbed were significant predictors of virus presence on fomites, and the positivity rate of data sets collected from healthcare settings and nonhealthcare nontemporary settings (e.g., individual housing) were significantly higher than those collected in nonhealthcare temporary settings (e.g., restaurants). Data from this review indicates that viruses may be present on fomites, that fomite-mediated virus transmission may occur, and that fomites may provide information on circulation of infectious diseases in the community. However, more quantitative data on diverse viruses are needed, and method reporting needs significant improvements.

Providing On-Site Laboratory and Biosafety Just-In-Time Training Inside a Box-Based Laboratory during the West Africa Ebola Outbreak: Supporting Better Preparedness for Future Health Emergencies

The Biological Light Fieldable Laboratory for Emergencies (B-LiFE) is a box-based modular laboratory with the capacity to quickly deploy on-site in cases of uncontrolled spread of infectious disease. During the 2014-2015 West Africa Ebola outbreak, this tent laboratory provided diagnostic support to the N'Zerekore Ebola Treatment Center (ETC), Guinea, for three months. One of the objectives of B-LiFE deployment was to contribute, as much as possible, to national capacity building by training local scientists. Two Guinean biologists were selected according to their basic biological knowledge and laboratory skills among 50 candidate trainees, and were integrated into the team through "just-in-time training" (JiTT), which helped the biologists acquire knowledge and laboratory skills beyond their expertise. The JiTT program was conducted according to standard laboratory procedures, in line with international biosafety guidelines adapted to field conditions. Supervised acquisition of field-laboratory practices mainly focused on biochemical testing and Ebola viral load quantification using routine PCR-based detection, including the Biofire FilmArray^® system (BFA), a novel, as yet non-validated, automated assay for diagnostic testing of Ebola virus disease at the time of B-LiFE deployment. During the JiTT, the two biologists were closely involved in all laboratory activities, including BFA validation and biosafety procedures. Meanwhile, this successful JiTT enhanced the B-LiFE in-field operational capacity and contributed to national capacity building. A post-training evaluation and contacts were organised to assess the evolution and technical skills gained by the two researchers during the B-LiFE mission. At the end of the B-LiFE mission, both biologists were enrolled in follow-on programmes to curb the epidemic spreading in Africa. These results demonstrate that during infectious disease outbreaks or major crises, the JiTT approach can rapidly expand access to critical diagnostic testing and train local staff to do so.

Antimicrobial coatings for environmental surfaces in hospitals: a potential new pillar for prevention strategies in hygiene

Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements.

Telecommunication Facilities, Key Support for Data Management and Data Sharing by a Biological Mobile Laboratory Deployed to Counter Emerging Biological Threats and Improve Public Health Crisis Preparedness

In the case of rapid outbreaks of infectious diseases in remote locations, the lack of real-time information from the field and rapid spread of misinformation can be a major issue. To improve situational awareness and decision-making at all levels of operational deployment, there is an urgent need for accurate, reliable, and timely results from patients from the affected area. This requires a robust and fast channel of communication connecting first responders on-site, crisis managers, decision-makers, and the institutions involved in the survey of the crisis at national, regional, and international levels. This has been the rationale sustaining the development of advanced communication tools in the Biological Light Fieldable Laboratory for Emergencies (B-LiFE). The benefit of terrestrial (TETRA, LTE, 5G, and Wi-Fi-Fi) and SatCom communications is illustrated through a series of missions and exercises conducted in the previous five years. These tools were used by B-LiFE operators to provide accurate, comprehensive, timely, and relevant information and services in real time. The focus of this article is to discuss the development and benefits of the integration of multi-mission, multi-user nomadic, rapidly deployable telecommunication nodes for emergency uses (TEN) in the capacity of B-LiFE. Providing reliable communication channels through TEN enables the development and use of an ICT toolbox called MIML_LIMS (multi-institution, multi-mission, multi-laboratory LIMS), a tool which is mandatory for efficient and secure data management and data sharing by a mobile laboratory.

Efficacy of microbicides for inactivation of Ebola-Makona virus on a non-porous surface: a targeted hygiene intervention for reducing virus spread

Microbicides play critical roles in infection prevention and control of Ebola virus by decontaminating high-touch environmental surfaces (HITES), interrupting the virus-HITES-hands nexus. We evaluated the efficacy of formulations containing different microbicidal actives for inactivating Ebola virus-Makona strain (EBOV/Mak) on stainless-steel carriers per ASTM E2197-11. Formulations of sodium hypochlorite (NaOCl) (0.05-1%), ethanol (70%), chloroxylenol (PCMX) (0.12-0.48% by weight) in hard water, and a ready-to-use disinfectant spray with 58% ethanol (EDS), were tested at contact times of 0, or 0.5 to 10 min at ambient temperature. EBOV/Mak was inactivated (> 6 log₁₀) by 70% ethanol after contact times ≥ 2.5 min, by 0.5% and 1% NaOCl or EDS (> 4 log₁₀) at contact times ≥ 5 min, and by 0.12-0.48% PCMX (> 4.2 log₁₀) at contact times ≥ 5 min. Residual infectious virus in neutralized samples was assessed by passage on cells and evaluation for viral cytopathic effect. No infectious virus was detected in cells inoculated with EBOV/Mak exposed to NaOCl (0.5% or 1%), PCMX (0.12% to 0.48%), or EDS for ≥ 5 min. These results demonstrate ≥ 6 log₁₀ inactivation of EBOV/Mak dried on prototypic surfaces by EDS or formulations of NaOCl (≥ 0.5%), PCMX (≥ 0.12%), or 70% ethanol at contact times ≥ 5 min.

Persistence of Bacteriophage Phi 6 on Porous and Nonporous Surfaces and the Potential for Its Use as an Ebola Virus or Coronavirus Surrogate

The infection of health care workers during the 2013 to 2016 Ebola outbreak raised concerns about fomite transmission. In the wake of the coronavirus disease 2019 (COVID-19) pandemic, investigations are ongoing to determine the role of fomites in coronavirus transmission as well. The bacteriophage phi 6 has a phospholipid envelope and is commonly used in environmental studies as a surrogate for human enveloped viruses. The persistence of phi 6 was evaluated as a surrogate for Ebola virus (EBOV) and coronaviruses on porous and nonporous hospital surfaces. Phi 6 was suspended in a body fluid simulant and inoculated onto 1-cm2 coupons of steel, plastic, and two fabric curtain types. The coupons were placed at two controlled absolute humidity (AH) levels: a low AH of 3.0 g/m3 and a high AH of 14.4 g/m3 Phi 6 declined at a lower rate on all materials under low-AH conditions, with a decay rate of 0.06-log10 PFU/day to 0.11-log10 PFU/day, than under the higher AH conditions, with a decay rate of 0.65-log10 PFU/h to 1.42-log10 PFU/day. There was a significant difference in decay rates between porous and nonporous surfaces at both low AH (P < 0.0001) and high AH (P < 0.0001). Under these laboratory-simulated conditions, phi 6 was found to be a conservative surrogate for EBOV under low-AH conditions in that it persisted longer than Ebola virus in similar AH conditions. Additionally, some coronaviruses persist longer than phi 6 under similar conditions; therefore, phi 6 may not be a suitable surrogate for coronaviruses.IMPORTANCE Understanding the persistence of enveloped viruses helps inform infection control practices and procedures in health care facilities and community settings. These data convey to public health investigators that enveloped viruses can persist and remain infective on surfaces, thus demonstrating a potential risk for transmission. Under these laboratory-simulated Western indoor hospital conditions, we assessed the suitability of phi 6 as a surrogate for environmental persistence research related to enveloped viruses, including EBOV and coronaviruses.

The Emerging Threat of Ebola

Ebola is one of the deadliest infectious disease of the modern era. Over 50% of those infected die. Prior to 1976, the disease was unknown. No one knows exactly where it came from, but it is postulated that a mutation in an animal virus allowed it to jump species and infect humans. In 1976 simultaneous outbreaks of Ebola occurred in what is now South Sudan and the Democratic Republic of the Congo (DRC). For 20 years, only sporadic cases were seen, but in 1995 a new outbreak occurred killing hundreds in the DRC. Since that time the frequency of these outbreaks has been increasing. It is uncertain why this is occurring, but many associate it with increasing human encroachment into forested areas bringing people and animals into more intimate contact and increased mobility of previously remote population. This chapter will navigate Ebola in the context of global health and security.

There are multiple objectives of this chapter. First is to provide a basic understanding of Ebola disease processes and outbreak patterns. Second, is to explore the interplay between social determinants of health and Ebola. The role of technology in spreading Ebola outbreaks will be explained as will Ebola’s potential as a bioweapon. Readers will gain understanding of the link between environmental degradation and Ebola outbreaks.

This chapter will be divided into five main sections. These are (1) a case study; (2) Ebola Disease process; (3) Social determinants of health and Ebola; (4) Ebola in the modern era, and (5) the link between Ebola and environmental degradation.

Contribution of Environment Sample-Based Detection to Ebola Outbreak Management

Detection of chains of transmission is critical to interrupt Ebola virus (EBOV) outbreaks. For >25 years, quantitative reverse transcription polymerase chain reaction performed on biological fluids has been the reference standard for EBOV detection and identification. In the current study, we investigated the use of environmental sampling to detect EBOV shed from probable case patients buried without the collection of bodily fluids. During the 2012 Bundibugyo virus (BDBV) outbreak in the Democratic Republic of the Congo, environmental samples were screened for BDBV RNA by means of real-time polymerase chain reaction. Low levels of BDBV genomic RNA were detected in a hospital and in a house. Detection of BDBV RNA in the house led to the identification of the last chain of transmission still active, which resulted in the safe burial of the person with the last laboratory-confirmed case of this outbreak. Overall, environmental sampling can fill specific gaps to help confirm EBOV positivity and therefore be of value in outbreak management.

Effectiveness of Dettol Antiseptic Liquid for Inactivation of Ebola Virus in Suspension

The efficacy of Dettol Antiseptic Liquid (DAL) for inactivating Ebola virus (Makona C07 variant) (EBOV/Mak) within an organic load in suspension was evaluated per ASTM E1052-11. Three DAL lots were evaluated at dilutions of 1:10, 1:20, and 1:40, with contact times of 0.5, 1, 5, and 10 min. Approximately 7 log₁₀ tissue culture infectious dose₅₀ (TCID₅₀) of EBOV/Mak was exposed to DAL at ambient temperature. Each dilution tested reduced the infectious EBOV/Mak titer by ~5 log₁₀ within one min. Detectable virus was still present after an 0.5-min exposure, but each DAL dilution caused >4 log₁₀ reduction within this time. Detection of virus below the limit of detection of the TCID₅₀ assay was assessed by inoculating flasks of Vero E6 cells with undiluted neutralized sample and evaluating the cultures for cytopathic effect after 14 days incubation. No infectious virus was detected with this non-quantitative method in samples subjected to DAL for 5 or 10 min, regardless of the dilution evaluated. The rapid and substantial inactivation of EBOV/Mak by DAL suggests that use of this hygiene product could help prevent the spread of Ebola virus disease during outbreaks.

Ebola virus disease

Ebolaviruses are pathogenic agents associated with a severe, potentially fatal, systemic disease in man and great apes. Four species of ebolaviruses have been identified in west or equatorial Africa. Once the more virulent forms enter the human population, transmission occurs primarily through contact with infected body fluids and can result in major epidemics in under-resourced settings. These viruses cause a disease characterised by systemic viral replication, immune suppression, abnormal inflammatory responses, major fluid and electrolyte losses, and high mortality. Despite recent progress on vaccines, and with no licensed prophylaxis or treatment available, case management is essentially supportive with management of severe multiple organ failure resulting from immune-mediated cell damage. The 2013-16 outbreak was classified by WHO as a Public Health Emergency of International Concern, which drew attention to the challenges of diseases caused by infections with ebolaviruses and questioned scientific, clinical, and societal preparation to handle future epidemics.

Exploring the role of genome and structural ions in preventing viral capsid collapse during dehydration

Even though viruses evolve mainly in liquid milieu, their horizontal transmission routes often include episodes of dry environment. Along their life cycle, some insect viruses, such as viruses from the Dicistroviridae family, withstand dehydrated conditions with presently unknown consequences to their structural stability. Here, we use atomic force microscopy to monitor the structural changes of viral particles of Triatoma virus (TrV) after desiccation. Our results demonstrate that TrV capsids preserve their genome inside, conserving their height after exposure to dehydrating conditions, which is in stark contrast with other viruses that expel their genome when desiccated. Moreover, empty capsids (without genome) resulted in collapsed particles after desiccation. We also explored the role of structural ions in the dehydration process of the virions (capsid containing genome) by chelating the accessible cations from the external solvent milieu. We observed that ion suppression helps to keep the virus height upon desiccation. Our results show that under drying conditions, the genome of TrV prevents the capsid from collapsing during dehydration, while the structural ions are responsible for promoting solvent exchange through the virion wall.

Ebola virus disease: Biological and diagnostic evolution from 2014 to 2017

The Ebola virus disease outbreak observed in West Africa from March 2014 to June 2016 has led to many fundamental and applied research works. Knowledge of this virus has substantially increased. Treatment of many patients in epidemic countries and a few imported cases in developed countries led to developing new diagnostic methods and to adapt laboratory organization and biosafety precautions to perform conventional biological analyses. Clinical and biological monitoring of patients infected with Ebola virus disease helped to determine severity criteria and bad prognosis markers. It also contributed to showing the possibility of viral sanctuaries in patients and the risk of transmission after recovery. After a summary of recent knowledge of environmental and clinical viral persistence, we aimed to present new diagnostic methods and other biological tests that led to highlighting the pathophysiological consequences of Ebola virus disease and its prognostic markers. We also aimed to describe our lab experience in the care of Ebola virus-infected patients, especially technical and logistical changes between 2014 and 2017.