Postmortem stability of Ebola virus

Low-Input, High-Resolution 5' Terminal Filovirus RNA Sequencing with ViBE-Seq

Although next-generation sequencing (NGS) has been instrumental in determining the genomic sequences of emerging RNA viruses, de novo sequence determination often lacks sufficient coverage of the 5' and 3' ends of the viral genomes. Since the genome ends of RNA viruses contain the transcription and genome replication promoters that are essential for viral propagation, a lack of terminal sequence information hinders the efforts to study the replication and transcription mechanisms of emerging and re-emerging viruses. To circumvent this, we have developed a novel method termed ViBE-Seq (Viral Bona Fide End Sequencing) for the high-resolution sequencing of filoviral genome ends using a simple yet robust protocol with high fidelity. This technique allows for sequence determination of the 5' end of viral RNA genomes and mRNAs with as little as 50 ng of total RNA. Using the Ebola virus and Marburg virus as prototypes for highly pathogenic, re-emerging viruses, we show that ViBE-Seq is a reliable technique for rapid and accurate 5' end sequencing of filovirus RNA sourced from virions, infected cells, and tissue obtained from infected animals. We also show that ViBE-Seq can be used to determine whether distinct reverse transcriptases have terminal deoxynucleotidyl transferase activity. Overall, ViBE-Seq will facilitate the access to complete sequences of emerging viruses.

RT-PCR Result of SARS-CoV-2 Viral RNA in Cadavers and Viral Transmission Risk to Handlers

During the onset of the pandemic, a common research question was asked by the hospital staff, and family members who were handling COVID-19-infected cadavers, "does COVID-19-positive dead body harbor SARS-CoV-2 viral RNA?" Several research findings were reported but due to the lack of proper research findings, the question remained unanswered. The present study was planned to observe the virus transmission risk from cadavers to the handlers. A pilot study was conducted on 54 cadavers who died in COVID-ICU (SARS-CoV-2-positive diagnosed by RT-PCR) during 2021-2022. Skin swab sample from 54 dead bodies and 54 glove samples of handlers were taken within 1 hour of death for the RT-PCR test. Viability results from RT-PCR show that the infection risk was 50% in cadavers, whereas the transmission risk to handlers while handling was 7%, which is minimal. The SARS-CoV-2 viability was high in cases of those died after a long time of infection. Based on the RT-PCR result and data analysis the interpretation of the study was that the SARS-CoV-2 transmission risk from dead bodies to the handlers is minimal but the SARS-CoV-2 viability persists in the cadavers. This fact is helpful for the people who will conduct funeral activities, autopsy staff, and hospital staff handling dead bodies.

How to cite this article

Panda B, Singh N, Singh G, Patro ARK, Mohanty AP, Patnaik PK, et al. RT-PCR Result of SARS-CoV-2 Viral RNA in Cadavers and Viral Transmission Risk to Handlers. Indian J Crit Care Med 2024;28(6):614-616.

Infection prevention and control studies for care of patients with suspected or confirmed filovirus disease in healthcare settings, with focus on Ebola and Marburg: an integrative review

Objective

To review evidence pertaining to methods for preventing healthcare-associated filovirus infections (including the survivability of filoviruses in clinical environments and the chlorine concentration required for effective disinfection), and to assess protocols for determining the risk of health worker (HW) exposures to filoviruses.

Design

Integrative review.

Data sources

PubMed, Embase, Google Scholar, internet-based sources of international health organisations (eg, WHO, CDC), references of the included literature and grey literature.

Study selection

Laboratory science, clinical research and real-world observational studies identified through comprehensive search strings that pertained to Ebola disease and Marburg disease and the three research objectives.

Methods

Using the framework of population, intervention or exposure, outcomes, study types and report characteristics, reviewers extracted data and critically appraised the evidence using predefined data extraction forms and summary tables. The extraction forms, summary tables and critical appraisals varied based on the included literature; we used both the QUIPS Risk-of-Bias tool when possible and an internally developed instrument to systematically extract and review the evidence from observational and experimental studies. Evidence was then synthesised and summarised to create summary recommendations.

Results

Thirty-six studies (including duplicates across research questions) were included in our reviews. All studies that related to the review questions were either (1) descriptive, real-world studies (ie, environmental audits of various surfaces in operational Ebola Treatment Units) or (2) controlled, laboratory studies (ie, experimental studies on the survivability of ebolaviruses in controlled conditions), presenting a range of concerns pertaining to bias and external validity. Our reviews of viral survivability evidence revealed significant disconnections between laboratory-based and real-world findings. However, there is greater viral persistence in liquid than dried body fluids, with the possible exception of blood, and ebolaviruses can survive for significant periods of time in dried substrate. Evidence suggests that 0.5% hypochlorite solution should be used for disinfection activity. Spills should be cleaned with covering and soaking for 15 min. Existing literature suggests that within a well-resourced clinical environment with trained, foreign HWs and established protocols, transmission of ebolaviruses as an occupational risk is a rare event. Despite the high rates of HW infections within public African healthcare settings, no evidence with low risk of bias exists to assess the risk of various occupational exposures given that all high-quality studies were conducted on foreign Ebola clinicians who had low overall rates of infection. This review underscores the critical need for better-quality evidence to inform best practices to ensure HW safety during filovirus disease epidemics.

Performance of a safe and dignified burial intervention during an Ebola epidemic in the eastern Democratic Republic of the Congo, 2018-2019

BACKGROUND

A protracted Ebola Virus Disease (EVD) epidemic in the eastern Ituri, North and South Kivu provinces of the Democratic Republic of Congo (DRC) caused 3470 confirmed and probable cases between July 2018 and April 2020. During the epidemic, the International Federation of Red Cross and Red Crescent Societies (IFRC) supported the DRC Red Cross and other local actors to offer safe and dignified burials (SDB) for suspected and confirmed EVD cases, so as to reduce transmission associated with infectious dead bodies. We conducted a retrospective cohort study of the SDB service's performance in order to inform future applications of this intervention.

METHODS

We analysed data on individual SDB responses to quantify performance based on key indicators and against pre-specified service standards. Specifically, we defined SDB timeliness as response within 24 h and success as all components of the service being implemented. Combining the database with other information sources, we also fit generalised linear mixed binomial models to explore factors associated with unsuccessful SDB.

RESULTS

Out of 14,624 requests for SDB, 99% were responded to, 89% within 24 h. Overall, 61% of SDBs were successful, somewhat below target (80%), with failures clustered during a high-insecurity period. Factors associated with increased odds of unsuccessful SDB included reported community and/or family nonacceptance, insecurity and suspensions of the EVD response, low health facility coverage and high coverage of radio and telephony. Burials supported by mobile Civil Protection (local authorities) and/or static, community-based 'harm reduction' teams were associated with lower odds of failure.

CONCLUSIONS

A large-scale, timely and moderately performant SDB service proved feasible during the challenging eastern DRC EVD response. Burial teams that are managed by community actors and operate locally, and supported rather than owned by the Red Cross or other humanitarian organisations, are a promising modality of delivering this pillar of EVD control.

Global dynamics of a compartmental model to assess the effect of transmission from deceased

During several epidemics, transmission from deceased people significantly contributed to disease spread, but mathematical analysis of this transmission has not been seen in the literature numerously. Transmission of Ebola during traditional burials was the most well-known example; however, there are several other diseases, such as hepatitis, plague or Nipah virus, that can potentially be transmitted from disease victims. This is especially true in the case of serious epidemics when healthcare is overwhelmed and the operative capacity of the health sector is diminished, such as seen during the COVID-19 pandemic. We present a compartmental model for the spread of a disease with an imperfect vaccine available, also considering transmission from deceased infected in general. The global dynamics of the system are completely described by constructing appropriate Lyapunov functions. To support our analytical results, we perform numerical simulations to assess the importance of transmission from the deceased, considering the data collected from three infectious diseases, Ebola virus disease, COVID-19, and Nipah fever.

Molecular Diagnosis of COVID-19 Sudden and Unexplained Deaths: The Insidious Face of the Pandemic

The COVID-19 epidemic has led to a significant increase in the number of deaths. This has resulted in forensic autopsies focusing on additional diagnostic possibilities. The following article is a summary of 23 autopsies of sudden and unexplained deaths. Particularly noteworthy are the described cases of children whose deaths were originally classified as SIDS (sudden infant death syndrome). All tests were performed at the Department of Forensic Medicine and Forensic Genetics, Pomeranian Medical University in Szczecin. Autopsy analyses were extended to include diagnostics of the SARS-CoV-2 virus using molecular methods and a detailed histopathological analysis of lung tissue. The material for molecular tests consisted of a nasopharyngeal swab taken postmortem and a lung tissue homogenate. In both cases, the RT-PCR method with CT cut-off point analysis was used for diagnosis. In all analyzed cases, the lungs showed massive congestion and increased fragility and cohesion. The tested material showed the presence of the SARS-CoV-2 virus, which indicated various stages of infection. It was observed that the higher the virus expression in the lungs, the lower or undetectable it was in the nasopharyngeal swab. This may explain false negative results during life in swabs. An interesting finding is that child deaths classified as SIDS also showed the presence of the virus. This may constitute a new direction of research.

A narrative review of high-level isolation unit operational and infrastructure features

High-level isolation units (HLIUs) are specially designed facilities for care and management of patients with suspected or confirmed high-consequence infectious diseases (HCIDs), equipped with unique infrastructure and operational features. While individual HLIUs have published on their experiences caring for patients with HCIDs and two previous HLIU consensus efforts have outlined key components of HLIUs, we aimed to summarise the existing literature that describes best practices, challenges and core features of these specialised facilities. A narrative review of the literature was conducted using keywords associated with HLIUs and HCIDs. A total of 100 articles were used throughout the manuscript from the literature search or from alternate methods like reference checks or snowballing. Articles were sorted into categories (eg, physical infrastructure, laboratory, internal transport); for each category, a synthesis of the relevant literature was conducted to describe best practices, experiences and operational features. The review and summary of HLIU experiences, best practices, challenges and components can serve as a resource for units continuing to improve readiness, or for hospitals in early stages of developing their HLIU teams and planning or constructing their units. The COVID-19 pandemic, a global outbreak of mpox, sporadic cases of viral haemorrhagic fevers in Europe and the USA, and recent outbreaks of Lassa fever, Sudan Ebolavirus, and Marburg emphasise the need for an extensive summary of HLIU practices to inform readiness and response.

Ebola virus disease: A review for the emergency medicine clinician

INTRODUCTION

Ebolavirus, the causative agent of Ebola virus disease (EVD) has been responsible for sporadic outbreaks mainly in sub-Saharan Africa since 1976. EVD is associated with high risk of transmission, especially to healthcare workers during patient care.

OBJECTIVE

The purpose of this review is to provide a concise review of EVD presentation, diagnosis, and management for emergency clinicians.

DISCUSSION

EVD is spread through direct contact, including blood, bodily fluids or contact with a contaminated object. Patients may present with non-specific symptoms such as fevers, myalgias, vomiting, or diarrhea that overlap with other viral illnesses, but rash, bruising, and bleeding may also occur. Laboratory analysis may reveal transaminitis, coagulopathy, and disseminated intravascular coagulation. The average clinical course is approximately 8-10 days with an average case fatality rate of 50%. The mainstay of treatment is supportive care, with two U.S. Food and Drug Administration-approved monoclonal antibody treatments (Ebanga and Inmazeb). Survivors of the disease may have a complicated recovery, marked by long-term symptoms.

CONCLUSION

EVD is a potentially deadly condition that can present with a wide range of signs and symptoms. Emergency clinicians must be aware of the presentation, evaluation, and management to optimize the care of these patients.

Do pathogens always evolve to be less virulent? The virulence–transmission trade-off in light of the COVID-19 pandemic

The direction the evolution of virulence takes in connection with any pathogen is a long-standing question. Formerly, it was theorized that pathogens should always evolve to be less virulent. As observations were not in line with this theoretical outcome, new theories emerged, chief among them the transmission–virulence trade-off hypotheses, which predicts an intermediate level of virulence as the endpoint of evolution. At the moment, we are very much interested in the future evolution of COVID-19’s virulence. Here, we show that the disease does not fulfill all the assumptions of the hypothesis. In the case of COVID-19, a higher viral load does not mean a higher risk of death; immunity is not long-lasting; other hosts can act as reservoirs for the virus; and death as a consequence of viral infection does not shorten the infectious period. Consequently, we cannot predict the short- or long-term evolution of the virulence of COVID-19.

A Timeframe for SARS-CoV-2 Genomes: A Proof of Concept for Postmortem Interval Estimations

Establishing the timeframe when a particular virus was circulating in a population could be useful in several areas of biomedical research, including microbiology and legal medicine. Using simulations, we demonstrate that the circulation timeframe of an unknown SARS-CoV-2 genome in a population (hereafter, estimated time of a queried genome [QG]; tE-QG) can be easily predicted using a phylogenetic model based on a robust reference genome database of the virus, and information on their sampling dates. We evaluate several phylogeny-based approaches, including modeling evolutionary (substitution) rates of the SARS-CoV-2 genome (~10-3 substitutions/nucleotide/year) and the mutational (substitutions) differences separating the QGs from the reference genomes (RGs) in the database. Owing to the mutational characteristics of the virus, the present Viral Molecular Clock Dating (VMCD) method covers timeframes going backwards from about a month in the past. The method has very low errors associated to the tE-QG estimates and narrow intervals of tE-QG, both ranging from a few days to a few weeks regardless of the mathematical model used. The SARS-CoV-2 model represents a proof of concept that can be extrapolated to any other microorganism, provided that a robust genome sequence database is available. Besides obvious applications in epidemiology and microbiology investigations, there are several contexts in forensic casework where estimating tE-QG could be useful, including estimation of the postmortem intervals (PMI) and the dating of samples stored in hospital settings.

Detection of SARS-CoV-2 Genome in Stool and Plasma Samples of Laboratory Confirmed Iranian COVID-19 Patients

Coronavirus disease 2019 (COVID19), caused by the severe acute respiratory syndrome coronavirus 2 (SARSCoV2), was first discovered in China in late 2019 and quickly spread worldwide. Although nasopharyngeal swab sampling is still the most popular approach identify SARS-CoV-2 carriers, other body samples may reveal the virus genome, indicating the potential for virus transmission via non-respiratory samples. In this study, researchers looked at the presence and degree of SARS-CoV-2 genome in stool and plasma samples from 191 Iranian COVID-19 patients, and looked for a link between these results and the severity of their disease. SARS-CoV-2 RNA shedding in feces and plasma of COVID-19 patients was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Medical data were collected and evaluated, including Clinical features, demographics, radiological, and laboratory findings of the patients. Plasma samples from 117 confirmed laboratory patients were evaluated and 24 out of 117 patients (20.51%) tested positive for SARS-COV-2 RNA. Besides, 20 out of 74 patients (27.03%) tested positive for SARS-COV-2 RNA in stool samples. There seems to be no relationship between the presence of SARS-CoV-2 genome in fecal and plasma samples of Covid-19 patients and the severity of illness. We provide evidence of the SARS-CoV-2 genome presence in stool and plasma samples of Iranian COVID-19 patients.

Efficacy of disinfectants for inactivation of Ebola virus in suspension by integrated cell culture coupled with real-time RT-PCR

BACKGROUND

Ebola virus can be transmitted by contact with environmental surfaces (fomites) contaminated with secretions and excretions from infected individuals. Due to their potential to cause a public health emergency and the absence of efficacious drugs and vaccines, a crucial intervention may involve the use of an effective virucidal agent for disinfecting contaminated surfaces.

METHODS

In this study, the virucidal efficacy of three disinfectants against Ebola virus, Micro-Chem Plus detergent disinfectant cleaner (MCP), FWD and ethanol, was evaluated in suspension tests according to the Technical Standard for Disinfection of China. All products at different concentrations were tested with application times ranging from 15 s to 8 min by using a quantitative suspension test, and a comparative inactivation analysis was performed. A reduction in the virus titre of ≥4 log10 was regarded as evidence of virucidal activity.

RESULTS

MCP and FWD, which contain dual quaternary ammonium compounds, are highly effective at inactivating the Ebola virus within 15 s of contact time, despite a slight difference between them at lower concentrations. Similar to the results in the literature, our results confirmed the excellent virucidal activity of medical ethanol for Ebola virus, which can reduce viral titres to background levels within 15 s at a concentration of 38% (v/v).

CONCLUSION

These three disinfectants display sufficient inactivation efficacy for the Ebola virus at reasonably short contact times, which may be practically achieved in the field. The use of these disinfectants for decontamination in health care settings and laboratories could mitigate the risk of Ebola virus transmission.

Another casualty of the SARS-CoV-2 pandemic-the environmental impact

Cemetery leachate generated by the process of cadaveric decomposition is a significant contaminant of several matrices in the cemetery environment (soil, groundwater, and surface water). The biogenic amines cadaverine and putrescine stand out among the cemetery leachate contaminants, since they are potentially carcinogenic compounds. This review article presents a discussion of possible environmental impacts caused by the increase in deaths resulting from COVID-19 as its central theme. The study also aims to demonstrate the importance of considering, in this context, some climatic factors that can alter both the time of bodily decomposition and the longevity of the virus in the environment. Additionally, some evidence for the transmission of the virus to health professionals and family members after the patient's death and environmental contamination after the burial of the bodies will also be presented. Several sources were consulted, such as scientific electronic databases (NCBI), publications by government agencies (e.g., ARPEN, Brazil) and internationally recognized health and environmental agencies (e.g., WHO, OurWorldInData.org), as well as information published on reliable websites available for free (e.g., CNN) and scientific journals related to the topic. The data from this study sounds the alarm on the fact that an increase in the number of deaths from the complications of COVID-19 has generated serious environmental problems, resulting from Cemetery leachate.

Do We Really Need Hazard Prevention at the Expense of Safeguarding Death Dignity in COVID-19?

To date, little is known regarding the transmission risks of SARS-CoV-2 infection for subjects involved in handling, transporting, and examining deceased persons with known or suspected COVID-19 positivity at the time of death. This experimental study aims to define if and/or how long SARS-CoV-2 persists with replication capacity in the tissues of individuals who died with/from COVID-19, thereby generating infectious hazards. Sixteen patients who died with/from COVID-19 who underwent autopsy between April 2020 and April 2021 were included in this study. Based on PMI, all samples were subdivided into two groups: 'short PMI' group (eight subjects who were autopsied between 12 to 72 h after death); 'long PMI' (eight subjects who were autopsied between 24 to 78 days after death). All patients tested positive for RT-PCR at nasopharyngeal swab both before death and on samples collected during post-mortem investigation. Moreover, a lung specimen was collected and frozen at -80 °C in order to perform viral culture. The result was defined based on the cytopathic effect (subjective reading) combined with the positivity of the RT-PCR test (objective reading) in the supernatant. Only in one sample (PMI 12 h), virus vitality was demonstrated. This study, supported by a literature review, suggests that the risk of cadaveric infection in cases of a person who died from/with COVID-19 is extremely low in the first hours after death, becoming null after 12 h after death, confirming the World Health Organization (WHO) assumed in March 2020 and suggesting that the corpse of a subject who died from/with COVID-19 should be generally considered not infectious.

Development and validation of portable, field-deployable Ebola virus point-of-encounter diagnostic assay for wildlife surveillance

Early detection of Ebola virus spillover into wildlife is crucial for rapid response. We developed and validated a portable, cold-chain independent Ebola virus RT-qPCR assay.

METHODS

The field syringe-based RNA extraction method was compared with a conventional laboratory-based spin-column RNA extraction method. Next, the qPCR efficiency and limit of detection of the assay was compared to standard laboratory-based reagents and equipment. The specificity of the assay was confirmed by testing against multiple Zaire Ebolavirus (EBOV) variants and other ebolavirus species. Lastly, swabs from an EBOV-infected non-human primate carcass, stored at environmental conditions mimicking central and west Africa, were analyzed to mimic in field conditions.

RESULTS

The syringe-based RNA extraction method performed comparably to a standard laboratory spin-column-based method. The developed assay was comparable in sensitivity and specificity to standard laboratory-based diagnostic assays. The assay specifically detected EBOV and not any of the other tested ebolavirus species, including Reston ebolavirus, Sudan ebolavirus, Bundibugyo ebolavirus, and Tai Forrest ebolavirus. Notably, the assays limit of detection for EBOV isolates were all below 4 genome copies/μL. The assay was able to detect EBOV in oral, nasal, thoracic cavity, and conjunctiva swabs obtained from an infected non-human primate.

CONCLUSION

We developed a field-based Ebolavirus assay which is comparable in sensitivity and specificity to laboratory-based assays. Currently, the assay is being incorporated into wildlife carcass surveillance in the Republic of the Congo and is being adapted for other infectious disease agents.

How long can SARS-CoV-2 persist in human corpses?

We report the finding of the SARS-CoV-2 genome in the corpse of an exhumed infected person, one month after her death. The viral gene targets were still present in her lungs and heart, however, the virus was no longer alive. Infectious risks from human corpses should be considered.

The paradoxical problem with COVID-19 ocular infection: Moderate clinical manifestation and potential infection risk

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which induced mainly the respiratory damage also caused ocular surface symptoms. However, the detailed description of ocular manifestations, severity fluctuations in confirmed COVID-19 adult patients still lacked. We analyzed onset clinical symptoms and duration, ocular symptoms, needs for medication, outcomes in 28 conjunctivitis patients who were extracted from 3198 COVID-19 patients hospitalized in Huoshenshan Hospital and Taikangtongji Hospital, Wuhan, China. The expression levels of ACE2, TMPRSS2, ANPEP, DPP4, NRP1 on fetal and adult ocular surface and mouse lacrimal glands were assessed by single cell seq analysis. Our results indicated that conjunctivitis was a rare and self-limited complication in adults with COVID-19 while the existence of coronavirus receptors on human ocular surface and mouse lacrimal glands indicated the risk of SARS-CoV-2 infection. Our research firstly examined SARS-CoV-2 receptors, including the new discovered one, NRP1, on the fetal ocular surface and in the mouse lacrimal glands.

Historical Discoveries on Viruses in the Environment and Their Impact on Public Health

BACKGROUND

Transmission of many viruses occurs by direct transmission during a close contact between two hosts, or by an indirect transmission through the environment. Several and often interconnected factors, both abiotic and biotic, determine the persistence of these viruses released in the environment, which can last from a few seconds to several years. Moreover, viruses in the environment are able to travel short to very long distances, especially in the air or in water.

SUMMARY

Although well described now, the role of these environments as intermediaries or as reservoirs in virus transmission has been extensively studied and debated in the last century. The majority of these discoveries, such as the pioneer work on bacteria transmission, the progressive discoveries of viruses, as well as the persistence of the influenza virus in the air varying along with droplet sizes, or the role of water in the transmission of poliovirus, have contributed to the improvement of public health. Recent outbreaks of human coronavirus, influenza virus, and Ebola virus have also demonstrated the contemporaneity of these research studies and the need to study virus persistence in the environment. Key Messages: In this review, we discuss historical discoveries that contributed to describe biotic and abiotic factors determining viral persistence in the environment.

Modelling the daily risk of Ebola in the presence and absence of a potential vaccine

Ebola virus - one of the deadliest viral diseases, with a mortality rate around 90% - damages the immune system and organs, with symptoms including episodic fever, chills, malaise and myalgia. The Recombinant Vesicular Stomatitis Virus-based candidate vaccine (rVSV-ZEBOV) has demonstrated clinical efficacy against Ebola in ring-vaccination clinical trials. In order to evaluate the potential effect of this candidate vaccine, we developed risk equations for the daily risk of Ebola infection both currently and after vaccination. The risk equations account for the basic transmission probability of Ebola and the lowered risk due to various protection protocols: vaccination, hazmat suits, reduced contact with the infected living and dead bodies. Parameter space was sampled using Latin Hypercube Sampling, a statistical method for generating a near-random sample of parameter values. We found that at a high transmission rate of Ebola (i.e., if the transmission rate is greater than 90%), a large fraction of the population must be vaccinated (>80%) to achieve a 50% decrease in the daily risk of infection. If a vaccine is introduced, it must have at least 50% efficacy, and almost everyone in the affected areas must receive it to effectively control outbreaks of Ebola. These results indicate that a low-efficacy Ebola vaccine runs the risk of having vaccinated people be overconfident in a weak vaccine and hence the possibility that the vaccine could make the situation worse, unless the population can be sufficiently educated about the necessity for high vaccine uptake.

Possible importance of carcasses for ebolavirus persistence in the ecosystem

Some outbreaks caused by ebolaviruses have been associated with wildlife mortalities in the past. Here, we discuss the possible roles played by animal carcasses during an ebolavirus outbreak. Corpses of wild animals that died due to ebolavirus infection or other reasons might be eaten by vertebrates and invertebrates, spreading live ebolaviruses to other animals, including humans. To prevent and contain an ebolavirus outbreak, not only potential reservoirs but also all organisms with a high likelihood of virus exposure need to be investigated.

Long-term wildlife mortality surveillance in northern Congo: a model for the detection of Ebola virus disease epizootics

Ebolavirus (EBOV) has caused disease outbreaks taking thousands of lives, costing billions of dollars in control efforts and threatening great ape populations. EBOV ecology is not fully understood but infected wildlife and consumption of animal carcasses have been linked to human outbreaks, especially in the Congo Basin. Partnering with the Congolese Ministry of Health, we conducted wildlife mortality surveillance and educational outreach in the northern Republic of Congo (RoC). Designed for EBOV detection and to alert public health authorities, we established a low-cost wildlife mortality reporting network covering 50 000 km². Simultaneously, we delivered educational outreach promoting behavioural change to over 6600 people in rural northern RoC. We achieved specimen collection by training project staff on a safe sampling protocol and equipping geographically distributed bases with sampling kits. We established in-country diagnostics for EBOV testing, reducing diagnostic turnaround time to 3 days and demonstrated the absence of EBOV in 58 carcasses. Central Africa remains a high-risk EBOV region, but RoC, home to the largest remaining populations of great apes, has not had an epidemic since 2005. This effort continues to function as an untested early warning system in RoC, where people and great apes have died from past Ebola virus disease outbreaks. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.

Diagnostics for filovirus detection: impact of recent outbreaks on the diagnostic landscape

Ebolaviruses and Marburg virus (MARV) both belong to the family Filoviridae and cause severe haemorrhagic fever in humans. Due to high mortality rates and potential for spread from rural to urban regions, they are listed on the WHO R&D blueprint of high-priority pathogens. Recent ebolavirus outbreaks in Western and Central Africa have highlighted the importance of diagnostic testing in epidemic preparedness for these pathogens and led to the rapid development of a number of commercially available benchtop and point-of-care nucleic acid amplification tests as well as serological assays and rapid diagnostic tests. Despite these advancements, challenges still remain. While products approved under emergency use licenses during outbreak periods may continue to be used post-outbreak, a lack of clarity and incentive surrounding the regulatory approval pathway during non-outbreak periods has deterred many manufacturers from seeking full approvals. Waning of funding and poor access to samples after the 2014–2016 outbreak also contributed to cessation of development once the outbreak was declared over. There is a need for tests with improved sensitivity and specificity, and assays that can use alternative sample types could reduce the need for invasive procedures and expensive equipment, making testing in field conditions more feasible. For MARV, availability of diagnostic tests is still limited, restricted to a single ELISA test and assay panels designed to differentiate between multiple pathogens. It may be helpful to extend the target product profile for ebolavirus diagnostics to include MARV, as the viruses have many overlapping characteristics.

Viral Haemorrhagic Fever (VHF) and Other Serious Viral Infections

Viral haemorrhagic fever—VHF—virus and a number of other special viruses are considered to cause the world’s most dangerous infections with very high mortality, lack of therapeutic possibilities and often absence of effective vaccines. Such viruses are identified as “biohazard-level 4” agents and are treated at the highest level of infection protection with strict isolation measures. At least 14 patients with Ebola disease were transported to Europe and the United States (11 patients) for hospital treatment during the African epidemic in 2014. There were no secondary spread of VHF import cases in Europe and the United States from 1999 until the Ebola outbreak in 2014. Then there were three cases of nosocomial spread to personnel in hospitals, two in the United States and one in Spain, despite alleged use of strict containment routines. This indicates a high risk of spread of infection through intensive treatment and handling of very sick persons with VHF like Ebola. In most cases vaccines are not available or specific antiviral drugs. Therefore, infection control must be based on a proper infection protection. This chapter is focused on practical means to handle and treat patients with suspect VHF or other dangerous agents to avoid spread to personnel and environment

Using physical contact heterogeneity and frequency to characterize dynamics of human exposure to nonhuman primate bodily fluids in central Africa

Emerging infectious diseases of zoonotic origin constitute a recurrent threat to global health. Nonhuman primates (NHPs) occupy an important place in zoonotic spillovers (pathogenic transmissions from animals to humans), serving as reservoirs or amplifiers of multiple neglected tropical diseases, including viral hemorrhagic fevers and arboviruses, parasites and bacteria, as well as retroviruses (simian foamy virus, PTLV) that are pathogenic in human beings. Hunting and butchering studies in Africa characterize at-risk human social groups, but overlook critical factors of contact heterogeneity and frequency, NHP species differences, and meat processing practices. In southeastern Cameroon, a region with a history of zoonotic emergence and high risk of future spillovers, we conducted a novel mixed-method field study of human physical exposure to multiple NHP species, incorporating participant-based and ecological methodologies, and qualitative interviews (n = 25). We find frequent physical contact across adult human populations, greater physical contact with monkeys than apes, especially for meat handling practices, and positive correlation of human exposure with NHP species abundance and proximity to human settlement. These fine-grained results encourage reconsideration of the likely dynamics of human-NHP contact in past and future NTD emergence events. Multidisciplinary social science and ecological approaches should be mobilized to generate more effective human and animal surveillance and risk communications around neglected tropical diseases. At a moment when the WHO has included "Disease X", a presumably zoonotic pathogen with pandemic potential, on its list of blueprint priority diseases as, new field-based tools for investigating zoonotic disease emergence, both known and unknown, are of critical importance.

The potential impact of a prophylactic vaccine for Ebola in Sierra Leone

The 2014 outbreak of Ebola virus disease (EVD) in West Africa was multinational and of an unprecedented scale primarily affecting the countries of Guinea, Liberia, and Sierra Leone. One of the qualities that makes EVD of high public concern is its potential for extremely high mortality rates (up to 90%). A prophylactic vaccine for ebolavirus (rVSV-ZEBOV) has been developed, and clinical trials show near-perfect efficacy. We have developed an ordinary differential equations model that simulates an EVD epidemic and takes into account (1) transmission through contact with infectious EVD individuals and deceased EVD bodies, (2) the heterogeneity of the risk of becoming infected with EVD, and (3) the increased survival rate of infected EVD patients due to greater access to trained healthcare providers. Using fitted parameter values that closely simulate the dynamics of the 2014 outbreak in Sierra Leone, we utilize our model to predict the potential impact of a prophylactic vaccine for the ebolavirus using various vaccination strategies including ring vaccination. Our results show that an rVSV-ZEBOV vaccination coverage as low as 40% in the general population and 95% in healthcare workers will prevent another catastrophic outbreak like the 2014 outbreak from occurring.

Determining the effect of different environmental conditions on Ebola virus viability in clinically relevant specimens

In 2013-2016, West Africa experienced the largest and longest Ebola virus disease outbreak ever documented. The wide geographic spread and magnitude of the outbreak often limited the timely and rapid testing of diagnostic samples from patients with suspected Ebola virus disease, raising questions regarding the optimal storage and shipping conditions of clinically relevant specimens, including EDTA-whole blood, plasma, capillary blood, urine and seminal fluid (associated with sexual transmission of the Ebola virus after recovery from the disease). Therefore, the aim of our study was to identify the extent to which storage temperature and clinical specimen type influence Ebola virus viability. Virus infectivity was determined using a fluorescent focus-forming assay. In our study, we show that Ebola virus was the most stable in EDTA-whole blood and plasma samples, whereas rapid decay of infectivity was observed in simulated capillary blood, urine and semen samples, especially when these samples were stored at higher temperatures. The analysis of variance results demonstrated that both temperature and clinical specimen type have significant effects on virus viability, whereas donor differences were not observed. Repeated freeze and thaw cycles of the samples also had a notable impact on virus viability in EDTA-whole blood and urine. Due to the rapid temperature- and specimen-dependent degradation of the virus observed here, our study highlights the importance of proper clinical sample storage at low temperatures during transportation and laboratory analysis.

Can Ebola virus evolve to be less virulent in humans?

Understanding Ebola virus (EBOV) virulence evolution not only is timely but also raises specific questions because it causes one of the most virulent human infections and it is capable of transmission after the death of its host. Using a compartmental epidemiological model that captures three transmission routes (by regular contact, via dead bodies and by sexual contact), we infer the evolutionary dynamics of case fatality ratio on the scale of an outbreak and in the long term. Our major finding is that the virus's specific life cycle imposes selection for high levels of virulence and that this pattern is robust to parameter variations in biological ranges. In addition to shedding a new light on the ultimate causes of EBOV's high virulence, these results generate testable predictions and contribute to informing public health policies. In particular, burial management stands out as the most appropriate intervention since it decreases the R0 of the epidemics, while imposing selection for less virulent strains.

Establishing Ebola Virus Disease (EVD) diagnostics using GeneXpert technology at a mobile laboratory in Liberia: Impact on outbreak response, case management and laboratory systems strengthening

The 2014-16 Ebola Virus Disease (EVD) outbreak in West Africa highlighted the necessity for readily available, accurate and rapid diagnostics. The magnitude of the outbreak and the re-emergence of clusters of EVD cases following the declaration of interrupted transmission in Liberia, reinforced the need for sustained diagnostics to support surveillance and emergency preparedness. We describe implementation of the Xpert Ebola Assay, a rapid molecular diagnostic test run on the GeneXpert platform, at a mobile laboratory in Liberia and the subsequent impact on EVD outbreak response, case management and laboratory system strengthening. During the period of operation, site coordination, management and operational capacity was supported through a successful collaboration between Ministry of Health (MoH), World Health Organization (WHO) and international partners. A team of Liberian laboratory technicians were trained to conduct EVD diagnostics and the laboratory had capacity to test 64-100 blood specimens per day. Establishment of the laboratory significantly increased the daily testing capacity for EVD in Liberia, from 180 to 250 specimens at a time when the effectiveness of the surveillance system was threatened by insufficient diagnostic capacity. During the 18 months of operation, the laboratory tested a total of 9,063 blood specimens, including 21 EVD positives from six confirmed cases during two outbreaks. Following clearance of the significant backlog of untested EVD specimens in November 2015, a new cluster of EVD cases was detected at the laboratory. Collaboration between surveillance and laboratory coordination teams during this and a later outbreak in March 2016, facilitated timely and targeted response interventions. Specimens taken from cases during both outbreaks were analysed at the laboratory with results informing clinical management of patients and discharge decisions. The GeneXpert platform is easy to use, has relatively low running costs and can be integrated into other national diagnostic algorithms. The technology has on average a 2-hour sample-to-result time and allows for single specimen testing to overcome potential delays of batching. This model of a mobile laboratory equipped with Xpert Ebola test, staffed by local laboratory technicians, could serve to strengthen outbreak preparedness and response for future outbreaks of EVD in Liberia and the region.

Marine Infectious Disease Ecology

To put marine disease impacts in context requires a broad perspective on the roles infectious agents have in the ocean. Parasites infect most marine vertebrate and invertebrate species, and parasites and predators can have comparable biomass density, suggesting they play comparable parts as consumers in marine food webs. Although some parasites might increase with disturbance, most probably decline as food webs unravel. There are several ways to adapt epidemiological theory to the marine environment. In particular, because the ocean represents a three-dimensional moving habitat for hosts and parasites, models should open up the spatial scales at which infective stages and host larvae travel. In addition to open recruitment and dimensionality, marine parasites are subject to fishing, filter feeders, dose-dependent infection, environmental forcing, and death-based transmission. Adding such considerations to marine disease models will make it easier to predict which infectious diseases will increase or decrease in a changing ocean.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): Ebola virus disease

Ebola virus disease has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of Ebola virus disease to be listed, Article 9 for the categorisation of Ebola virus disease according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to Ebola virus disease. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, Ebola virus disease can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria as in Sections 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (d) and (e) of Article 9(1). The animal species to be listed for Ebola virus disease according to Article 8(3) criteria are some species of non-human primates, pigs and rodents as susceptible species and some species of fruit bats as reservoir, as indicated in the present opinion.

Pathways to zoonotic spillover

Zoonotic spillover, which is the transmission of a pathogen from a vertebrate animal to a human, presents a global public health burden but is a poorly understood phenomenon. Zoonotic spillover requires several factors to align, including the ecological, epidemiological and behavioural determinants of pathogen exposure, and the within-human factors that affect susceptibility to infection. In this Opinion article, we propose a synthetic framework for animal-to-human transmission that integrates the relevant mechanisms. This framework reveals that all zoonotic pathogens must overcome a hierarchical series of barriers to cause spillover infections in humans. Understanding how these barriers are functionally and quantitatively linked, and how they interact in space and time, will substantially improve our ability to predict or prevent spillover events. This work provides a foundation for transdisciplinary investigation of spillover and synthetic theory on zoonotic transmission.

Rapid deployment of a mobile biosafety level-3 laboratory in Sierra Leone during the 2014 Ebola virus epidemic

Background

Ebola virus emerged in West Africa in December 2013. The high population mobility and poor public health infrastructure in this region led to the development of the largest Ebola virus disease (EVD) outbreak to date.

Methodology/Principal findings

On September 26, 2014, China dispatched a Mobile Biosafety Level-3 Laboratory (MBSL-3 Lab) and a well-trained diagnostic team to Sierra Leone to assist in EVD diagnosis using quantitative real-time PCR, which allowed the diagnosis of suspected EVD cases in less than 4 hours from the time of sample receiving. This laboratory was composed of three container vehicles equipped with advanced ventilation system, communication system, electricity and gas supply system. We strictly applied multiple safety precautions to reduce exposure risks. Personnel, materials, water and air flow management were the key elements of the biosafety measures in the MBSL-3 Lab. Air samples were regularly collected from the MBSL-3 Lab, but no evidence of Ebola virus infectious aerosols was detected. Potentially contaminated objects were also tested by collecting swabs. On one occasion, a pipette tested positive for EVD. A total of 1,635 suspected EVD cases (824 positive [50.4%]) were tested from September 28 to November 11, 2014, and no member of the diagnostic team was infected with Ebola virus or other pathogens, including Lassa fever. The specimens tested included blood (69.2%) and oral swabs (30.8%) with positivity rates of 54.2% and 41.9%, respectively. The China mobile laboratory was thus instrumental in the EVD outbreak response by providing timely and reliable diagnostics.

Conclusions/Significance

The MBSL-3 Lab significantly contributed to establishing a suitable laboratory response capacity during the emergence of EVD in Sierra Leone.

A Mobile Biosafety Level-3 Laboratory (MBSL-3 Lab) and a well-trained diagnostic team were dispatched to Sierra Leone to assist in Ebola virus disease (EVD) diagnosis when the largest outbreak of EVD to date emerged in West Africa in 2014. This setup allowed for the diagnosis of suspected EVD cases in less than 4 hours from the time of sample receiving. The laboratory was composed of three container vehicles and was equipped with advanced ventilation system, communication system, electricity and gas supply system. Multiple safety precautions were strictly applied to reduce exposure risks. A total of 1,635 suspected EVD cases were evaluated from September 28 to November 11, 2014, and none of the staff members was infected with Ebola virus or other pathogens. The China mobile laboratory was thus instrumental in the EVD outbreak response by providing timely and accurate diagnostics. Therefore, the MBSL-3 Lab played a significant role in establishing a suitable laboratory response capacity during the emergence of EVD in Sierra Leone.

Low potential for mechanical transmission of Ebola virus via house flies (Musca domestica)

BACKGROUND

Ebola virus (EBOV) infection results in high morbidity and mortality and is primarily transmitted in communities by contact with infectious bodily fluids. While clinical and experimental evidence indicates that EBOV is transmitted via mucosal exposure, the ability of non-biting muscid flies to mechanically transmit EBOV following exposure to the face had not been assessed.

RESULTS

To investigate this transmission route, house flies (Musca domestica Linnaeus) were used to deliver an EBOV/blood mixture to the ocular/nasal/oral facial mucosa of four cynomolgus macaques (Macaca fascicularis Raffles). Following exposure, macaques were monitored for evidence of infection through the conclusion of the study, days 57 and 58. We found no evidence of systemic infection in any of the exposed macaques.

CONCLUSIONS

The results of this study indicate that there is a low potential for the mechanical transmission of EBOV via house flies - the conditions in this study were not sufficient to initiate infection.

Disinfection of Ebola Virus in Sterilized Municipal Wastewater

Concerns have been raised regarding handling of Ebola virus contaminated wastewater, as well as the adequacy of proposed disinfection approaches. In the current study, we investigate the inactivation of Ebola virus in sterilized domestic wastewater utilizing sodium hypochlorite addition and pH adjustment. No viral inactivation was observed in the one-hour tests without sodium hypochlorite addition or pH adjustment. No virus was recovered after 20 seconds (i.e. 4.2 log10 unit inactivation to detection limit) following the addition of 5 and 10 mg L-1 sodium hypochlorite, which resulted in immediate free chlorine residuals of 0.52 and 1.11 mg L-1, respectively. The addition of 1 mg L-1 sodium hypochlorite resulted in an immediate free chlorine residual of 0.16 mg L-1, which inactivated 3.5 log10 units of Ebola virus in 20 seconds. Further inactivation was not evident due to the rapid consumption of the chlorine residual. Elevating the pH to 11.2 was found to significantly increase viral decay over ambient conditions. These results indicate the high susceptibility of the enveloped Ebola virus to disinfection in the presence of free chlorine in municipal wastewater; however, we caution that extension to more complex matrices (e.g. bodily fluids) will require additional verification.

Human transmission of Ebola virus

Ever since the first recognised outbreak of Ebolavirus in 1976, retrospective epidemiological analyses and extensive studies with animal models have given us insight into the nature of the pathology and transmission mechanisms of this virus. In this review focusing on Ebolavirus, we present an outline of our current understanding of filovirus human-to-human transmission and of our knowledge concerning the molecular basis of viral transmission and potential for adaptation, with particular focus on what we have learnt from the 2014 outbreak in West Africa. We identify knowledge gaps relating to transmission and pathogenicity mechanisms, molecular adaptation and filovirus ecology.

Long shadow of fear in an epidemic: fearonomic effects of Ebola on the private sector in Nigeria

Background

The already significant impact of the Ebola epidemic on Guinea, Liberia and Sierra Leone, was worsened by a fear of contagion that aggravated the health crisis. However, in contrast to other Ebola-affected countries, Nigeria fared significantly better due to its swift containment of the disease. The objective of our study was to describe the impact of Ebola on the Nigerian private sector. This paper introduces and defines the term fearonomic effect as the direct and indirect economic effects of both misinformation as well as fear-induced aversion behaviour, exhibited by individuals, organisations or countries during an outbreak or an epidemic.

Methods

This study was designed as a cross-sectional mixed-methods study that used semistructured in-depth interviews and a supporting survey to capture the impact of Ebola on the Nigerian private sector after the outbreak. Themes were generated from the interviews on the direct and indirect impact of Ebola on the private sector; the impact of misinformation and fear-based aversion behaviour in the private sector.

Results

Our findings reveal that the fearonomic effects of Ebola included health service outages and reduced healthcare usage as a result of misinformation and aversion behaviour by both patients and providers. Although certain sectors (eg, health sector, aviation sector, hospitality sector) in Nigeria were affected more than others, no business was immune to Ebola's fearonomic effects. We describe how sectors expected to prosper during the outbreak (eg, pharmaceuticals), actually suffered due to the changes in consumption patterns and demand shocks.

Conclusion

In a high-stressor epidemic-like setting, altered consumption behaviour due to distorted disease perception, misinformation and fear can trigger short-term economic cascades that can disproportionately affect businesses and lead to financial insecurity of the poorest and the most vulnerable in a society.

Ebola Virus Shedding and Transmission: Review of Current Evidence

BACKGROUND

The magnitude of the 2013-2016 Ebola virus disease outbreak in West Africa was unprecedented, with >28 500 reported cases and >11 000 deaths. Understanding the key elements of Ebola virus transmission is necessary to implement adequate infection prevention and control measures to protect healthcare workers and halt transmission in the community.

METHODS

We performed an extensive PubMed literature review encompassing the period from discovery of Ebola virus, in 1976, until 1 June 2016 to evaluate the evidence on modes of Ebola virus shedding and transmission.

FINDINGS

Ebola virus has been isolated by cell culture from blood, saliva, urine, aqueous humor, semen, and breast milk from infected or convalescent patients. Ebola virus RNA has been noted in the following body fluids days or months after onset of illness: saliva (22 days), conjunctiva/tears (28 days), stool (29 days), vaginal fluid (33 days), sweat (44 days), urine (64 days), amniotic fluid (38 days), aqueous humor (101 days), cerebrospinal fluid (9 months), breast milk (16 months [preliminary data]), and semen (18 months). Nevertheless, the only documented cases of secondary transmission from recovered patients have been through sexual transmission. We did not find strong evidence supporting respiratory or fomite-associated transmission.

Ebola Virus RNA Stability in Human Blood and Urine in West Africa's Environmental Conditions

We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa's environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly.

Secondary Infections with Ebola Virus in Rural Communities, Liberia and Guinea, 2014-2015

Persons who died of Ebola virus disease at home in rural communities in Liberia and Guinea resulted in more secondary infections than persons admitted to Ebola treatment units. Intensified monitoring of contacts of persons who died of this disease in the community is an evidence-based approach to reduce virus transmission in rural communities.

Ebola Virus Disease Diagnostics, Sierra Leone: Analysis of Real-time Reverse Transcription-Polymerase Chain Reaction Values for Clinical Blood and Oral Swab Specimens

During the Ebola virus outbreak of 2013-2016, the Viral Special Pathogens Branch field laboratory in Sierra Leone tested approximately 26 000 specimens between August 2014 and October 2015. Analysis of the B2M endogenous control Ct values showed its utility in monitoring specimen quality, comparing results with different specimen types, and interpretation of results. For live patients, blood is the most sensitive specimen type and oral swabs have little diagnostic utility. However, swabs are highly sensitive for diagnostic testing of corpses.

An Outbreak of Ebola Virus Disease in the Lassa Fever Zone

BACKGROUND

Kenema Government Hospital (KGH) has developed an advanced clinical and laboratory research capacity to manage the threat of Lassa fever, a viral hemorrhagic fever (VHF). The 2013-2016 Ebola virus (EBOV) disease (EVD) outbreak is the first to have occurred in an area close to a facility with established clinical and laboratory capacity for study of VHFs.

METHODS

Because of its proximity to the epicenter of the EVD outbreak, which began in Guinea in March 2014, the KGH Lassa fever Team mobilized to establish EBOV surveillance and diagnostic capabilities.

RESULTS

Augustine Goba, director of the KGH Lassa laboratory, diagnosed the first documented case of EVD in Sierra Leone, on 25 May 2014. Thereafter, KGH received and cared for numbers of patients with EVD that quickly overwhelmed the capacity for safe management. Numerous healthcare workers contracted and lost their lives to EVD. The vast majority of subsequent EVD cases in West Africa can be traced back to a single transmission chain that includes this first diagnosed case.

CONCLUSIONS

Responding to the challenges of confronting 2 hemorrhagic fever viruses will require continued investments in the development of countermeasures (vaccines, therapeutic agents, and diagnostic assays), infrastructure, and human resources.

Effectiveness of Four Disinfectants against Ebola Virus on Different Materials

The West Africa Ebola virus (EBOV) outbreak has highlighted the need for effective disinfectants capable of reducing viral load in a range of sample types, equipment and settings. Although chlorine-based products are widely used, they can also be damaging to equipment or apparatus that needs continuous use such as aircraft use for transportation of infected people. Two aircraft cleaning solutions were assessed alongside two common laboratory disinfectants in a contact kill assay with EBOV on two aircraft relevant materials representative of a porous and non-porous surface. A decimal log reduction of viral titre of 4 is required for a disinfectant to be deemed effective and two of the disinfectants fulfilled this criteria under the conditions tested. One product, Ardrox 6092, was found to perform similarly to sodium hypochlorite, but as it does not have the corrosive properties of sodium hypochlorite, it could be an alternative disinfectant solution to be used for decontamination of EBOV on sensitive apparatus.

Perspectives on West Africa Ebola Virus Disease Outbreak, 2013-2016

Many features of this outbreak reinforce the benefit of continued investment in global health security.

The variety of factors that contributed to the initial undetected spread of Ebola virus disease in West Africa during 2013–2016 and the difficulty controlling the outbreak once the etiology was identified highlight priorities for disease prevention, detection, and response. These factors include occurrence in a region recovering from civil instability and lacking experience with Ebola response; inadequate surveillance, recognition of suspected cases, and Ebola diagnosis; mobile populations and extensive urban transmission; and the community’s insufficient general understanding about the disease. The magnitude of the outbreak was not attributable to a substantial change of the virus. Continued efforts during the outbreak and in preparation for future outbreak response should involve identifying the reservoir, improving in-country detection and response capacity, conducting survivor studies and supporting survivors, engaging in culturally appropriate public education and risk communication, building productive interagency relationships, and continuing support for basic research.

Aerosol Transmission of Filoviruses

Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013–2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.

Utility of Oral Swab Sampling for Ebola Virus Detection in Guinea Pig Model

To determine the utility of oral swabs for diagnosing infection with Ebola virus, we used a guinea pig model and obtained daily antemortem and postmortem swab samples. According to quantitative reverse transcription PCR analysis, the diagnostic value was poor for antemortem swab samples but excellent for postmortem samples.