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.

Serological evidence of zoonotic filovirus exposure among bushmeat hunters in Guinea.

Human Ebola virus (EBOV) outbreaks caused by persistent EBOV infection raises questions on the role of zoonotic spillover in filovirus epidemiology. To characterise filovirus zoonotic exposure, we collected cross-sectional serum samples from bushmeat hunters (n = 498) in Macenta Prefecture Guinea, adjacent to the index site of the 2013 EBOV-Makona spillover event. We identified distinct immune signatures (20/498, 4.0%) to multiple EBOV antigens (GP, NP, VP40) using stepwise ELISA and Western blot analysis and, live EBOV neutralisation (5/20; 25%). Using comparative serological data from PCR-confirmed survivors of the 2013-2016 EBOV outbreak, we demonstrated that most signatures (15/20) were not plausibly explained by prior EBOV-Makona exposure. Subsequent data-driven modelling of EBOV immunological outcomes to remote-sensing environmental data also revealed consistent associations with intact closed canopy forest. Together our findings suggest exposure to other closely related filoviruses prior to the 2013-2016 West Africa epidemic and highlight future surveillance priorities.

Molecular characterization of the 2022 Sudan virus disease outbreak in Uganda.

IMPORTANCE: Ebola disease (EBOD) is a public health threat with a high case fatality rate. Most EBOD outbreaks have occurred in remote locations, but the 2013-2016 Western Africa outbreak demonstrated how devastating EBOD can be when it reaches an urban population. Here, the 2022 Sudan virus disease (SVD) outbreak in Mubende District, Uganda, is summarized, and the genetic relatedness of the new variant is evaluated. The Mubende variant exhibited 96% amino acid similarity with historic SUDV sequences from the 1970s and a high degree of conservation throughout the outbreak, which was important for ongoing diagnostics and highly promising for future therapy development. Genetic differences between viruses identified during the Mubende SVD outbreak were linked with epidemiological data to better interpret viral spread and contact tracing chains. This methodology should be used to better integrate discrete epidemiological and sequence data for future viral outbreaks.

Characterization of Ebola Virus Mucosal Challenge Routes in Cynomolgus Macaques.

Zaïre ebolavirus (EBOV) causes Ebola virus disease (EVD), a devastating viral hemorrhagic fever in humans. Nonhuman primate (NHP) models of EVD traditionally use intramuscular infection with higher case fatality rates and reduced mean time-to-death compared to contact transmission typical of human cases of EVD. A cynomolgus macaque model of oral and conjunctival EBOV was used to further characterize the more clinically relevant contact transmission of EVD. NHPs challenged via the oral route had an overall 50% survival rate. NHPs challenged with a target dose of 1 × 102 PFU or 1 × 104 PFU of EBOV via the conjunctival route had 40% and 100% mortality, respectively. Classic signs of lethal EVD-like disease were observed in all NHPs that succumbed to EBOV infection including viremia, hematological abnormalities, clinical chemistries indicative of hepatic and renal disease, and histopathological findings. Evidence of EBOV viral persistence in the eye was observed in NHPs challenged via the conjunctival route. IMPORTANCE This study is the first to examine the Kikwit strain of EBOV, the most commonly used strain, in the gold-standard macaque model of infection. Additionally, this is the first description of the detection of virus in the vitreous fluid, an immune privileged site that has been proposed as a viral reservoir, following conjunctival challenge. The oral and conjunctival macaque challenge model of EVD described here more faithfully recapitulates the prodrome that has been reported for human EVD. This work paves the way for more advanced studies to model contact transmission of EVD, including early events in mucosal infection and immunity, as well as the establishment of persistent viral infection and the emergence from these reservoirs.

Social mobilization, education, and prevention of the Ebola virus disease: A scoping review.

The Ebola Virus Disease (EVD) remains a global public health concern with multiple outbreaks over the last five years. This scoping review aimed to synthesize the current state of knowledge on awareness, education, and community mobilization programs on EVD prevention. A comprehensive search strategy was executed in October 2021 across eight databases (APA PsycInfo, CINAHL, Cochrane CENTRAL, Embase, Global Health, MEDLINE, Scopus, and Web of Science). According to the PRISMA flow diagram, out of the 4815 studies generated by the search, 33 were retained for extraction and were included in this scoping review. Findings revealed that cultural practices that increased the risk of Ebola transmission remain very prevalent, even educational and awareness campaigns. Levels of Ebola-related knowledge by community members varied widely. A large proportion of the Ebola-affected populations were not aware of modes of transmission and half were unaware of signs and symptoms. Interventions with deep community mobilization, collaboration and engagement were effective in changing cultural practices, and reducing rates of infection. Interventions in the health sector helped increase willingness to practice preventive methods and the maintenance of social distancing and patient handwashing. A majority of the population members received their information about EVD from the community and mass media (in most instances, through broadcasting stations). Community interventions with a collaborative approach are effective to prevent EVD. It is needed to build trust between communities and health care, but also to use local resources and cultural factors combined with the use of technologies of information to prevent EVD.

Risk perceptions and behaviors of actors in the wild animal value chain in Kinshasa, Democratic Republic of Congo.

In the Democratic Republic of Congo (DRC) which contains the greatest area of the second largest rainforest on Earth, people have long been connected to the forest for subsistence and livelihood from wild animals and bushmeat. This qualitative study sought to characterize the bushmeat movement-from hunting wild animals to market sale-and the roles of participants in the animal value chain, as well as their beliefs surrounding zoonotic disease and occupational risk. Actors in in eight bushmeat markets and two ports in Kinshasa, DRC completed semi-structured interviews between 2016 and 2018 in which they expressed belief in transmission of illness from domestic animals to humans, but not from wild animals to humans. Wild animals were viewed as pure and natural, in contrast to domestic animals which were considered tainted by human interference. Participants reported cutting themselves during the process of butchering yet did not consider butchering bushmeat to be a risky activity. Instead, they adopted safety practices learned over time from butchering experts and taught themselves how to butcher in a fashion that reduced the frequency of cutting. In general, butcherers rejected the idea of personal protective equipment use. Port markets were identified as important access points for meat coming from the Congo river and plane transport was identified as important for fresh and live meat coming from Équateur province. Most participants reported having heard about Ebola, but their mistrust in government messaging privileged a word-of-mouth story of witchcraft to be propagated about Ebola's origins. It is critical to better understand how public health messaging about outbreaks can successfully reach high risk communities, and to develop creative risk mitigation strategies for populations in regular contact with animal blood and body fluids. In this paper, we offer suggestions for formal and informal trusted channels through which health messages surrounding zoonotic risk could be conveyed to high-risk populations in Kinshasa.

Rapid establishment of a frontline field laboratory in response to an imported outbreak of Ebola virus disease in western Uganda, June 2019.

The Democratic Republic of the Congo (DRC) declared an Ebola virus disease (EVD) outbreak in North Kivu in August 2018. By June 2019, the outbreak had spread to 26 health zones in northeastern DRC, causing >2,000 reported cases and >1,000 deaths. On June 10, 2019, three members of a Congolese family with EVD-like symptoms traveled to western Uganda's Kasese District to seek medical care. Shortly thereafter, the Viral Hemorrhagic Fever Surveillance and Laboratory Program (VHF program) at the Uganda Virus Research Institute (UVRI) confirmed that all three patients had EVD. The Ugandan Ministry of Health declared an outbreak of EVD in Uganda's Kasese District, notified the World Health Organization, and initiated a rapid response to contain the outbreak. As part of this response, UVRI and the United States Centers for Disease Control and Prevention, with the support of Uganda's Public Health Emergency Operations Center, the Kasese District Health Team, the Superintendent of Bwera General Hospital, the United States Department of Defense's Makerere University Walter Reed Project, and the United States Mission to Kampala's Global Health Security Technical Working Group, jointly established an Ebola Field Laboratory in Kasese District at Bwera General Hospital, proximal to an Ebola Treatment Unit (ETU). The laboratory consisted of a rapid containment kit for viral inactivation of patient specimens and a GeneXpert Instrument for performing Xpert Ebola assays. Laboratory staff tested 76 specimens from alert and suspect cases of EVD; the majority were admitted to the ETU (89.3%) and reported recent travel to the DRC (58.9%). Although no EVD cases were detected by the field laboratory, it played an important role in patient management and epidemiological surveillance by providing diagnostic results in <3 hours. The integration of the field laboratory into Uganda's National VHF Program also enabled patient specimens to be referred to Entebbe for confirmatory EBOV testing and testing for other hemorrhagic fever viruses that circulate in Uganda.

Establishing Healthcare Worker Performance and Safety in Providing Critical Care for Patients in a Simulated Ebola Treatment Unit: Non-Randomized Pilot Study.

Improving the provision of supportive care for patients with Ebola is an important quality improvement initiative. We designed a simulated Ebola Treatment Unit (ETU) to assess performance and safety of healthcare workers (HCWs) performing tasks wearing personal protective equipment (PPE) in hot (35 °C, 60% relative humidity) or thermo-neutral (20 °C, 20% relative humidity) conditions. In this pilot phase to determine the feasibility of study procedures, HCWs in PPE were non-randomly allocated to hot or thermo-neutral conditions to perform peripheral intravenous (PIV) and midline catheter (MLC) insertion and endotracheal intubation (ETI) on mannequins. Eighteen HCWs (13 physicians, 4 nurses, 1 nurse practitioner; 2 with prior ETU experience; 10 in hot conditions) spent 69 (10) (mean (SD)) minutes in the simulated ETU. Mean (SD) task completion times were 16 (6) min for PIV insertion; 33 (5) min for MLC insertion; and 16 (8) min for ETI. Satisfactory task completion was numerically higher for physicians vs. nurses. Participants' blood pressure was similar, but heart rate was higher (p = 0.0005) post-simulation vs. baseline. Participants had a median (range) of 2.0 (0.0-10.0) minor PPE breaches, 2.0 (0.0-6.0) near-miss incidents, and 2.0 (0.0-6.0) health symptoms and concerns. There were eight health-assessment triggers in five participants, of whom four were in hot conditions. We terminated the simulation of two participants in hot conditions due to thermal discomfort. In summary, study tasks were suitable for physician participants, but they require redesign to match nurses' expertise for the subsequent randomized phase of the study. One-quarter of participants had a health-assessment trigger. This research model may be useful in future training and research regarding clinical care for patients with highly infectious pathogens in austere settings.

On the effectiveness of communication strategies as non-pharmaceutical interventions to tackle epidemics.

When pharmaceutical interventions are unavailable to deal with an epidemic outbreak, adequate management of communication strategies can be key to reduce the contagion risks. On the one hand, accessibility to trustworthy and timely information, whilst on the other, the adoption of preventive behaviors may be both crucial. However, despite the abundance of communication strategies, their effectiveness has been scarcely evaluated or merely circumscribed to the scrutiny of public affairs. To study the influence of communication strategies on the spreading dynamics of an infectious disease, we implemented a susceptible-exposed-infected-removed-dead (SEIRD) epidemiological model, using an agent-based approach. Agents in our systems can obtain information modulating their behavior from two sources: (i) through the local interaction with other neighboring agents and, (ii) from a central entity delivering information with a certain periodicity. In doing so, we highlight how global information delivered from a central entity can reduce the impact of an infectious disease and how informing even a small fraction of the population has a remarkable impact, when compared to not informing the population at all. Moreover, having a scheme of delivering daily messages makes a stark difference on the reduction of cases, compared to the other evaluated strategies, denoting that daily delivery of information produces the largest decrease in the number of cases. Furthermore, when the information spreading relies only on local interactions between agents, and no central entity takes actions along the dynamics, then the epidemic spreading is virtually independent of the initial amount of informed agents. On top of that, we found that local communication plays an important role in an intermediate regime where information coming from a central entity is scarce. As a whole, our results highlight the importance of proper communication strategies, both accurate and daily, to tackle epidemic outbreaks.

Resurgence of Ebola virus in 2021 in Guinea suggests a new paradigm for outbreaks.

Seven years after the declaration of the first epidemic of Ebola virus disease in Guinea, the country faced a new outbreak-between 14 February and 19 June 2021-near the epicentre of the previous epidemic1,2. Here we use next-generation sequencing to generate complete or near-complete genomes of Zaire ebolavirus from samples obtained from 12 different patients. These genomes form a well-supported phylogenetic cluster with genomes from the previous outbreak, which indicates that the new outbreak was not the result of a new spillover event from an animal reservoir. The 2021 lineage shows considerably lower divergence than would be expected during sustained human-to-human transmission, which suggests a persistent infection with reduced replication or a period of latency. The resurgence of Zaire ebolavirus from humans five years after the end of the previous outbreak of Ebola virus disease reinforces the need for long-term medical and social care for patients who survive the disease, to reduce the risk of re-emergence and to prevent further stigmatization.

Molecular analysis of the 2012 Bundibugyo virus disease outbreak.

Bundibugyo virus (BDBV) is one of four ebolaviruses known to cause disease in humans. Bundibugyo virus disease (BVD) outbreaks occurred in 2007-2008 in Bundibugyo District, Uganda, and in 2012 in Isiro, Province Orientale, Democratic Republic of the Congo. The 2012 BVD outbreak resulted in 38 laboratory-confirmed cases of human infection, 13 of whom died. However, only 4 BDBV specimens from the 2012 outbreak have been sequenced. Here, we provide BDBV sequences from seven additional patients. Analysis of the molecular epidemiology and evolutionary dynamics of the 2012 outbreak with these additional isolates challenges the current hypothesis that the outbreak was the result of a single spillover event. In addition, one patient record indicates that BDBV's initial emergence in Isiro occurred 50 days earlier than previously accepted. Collectively, this work demonstrates how retrospective sequencing can be used to elucidate outbreak origins and provide epidemiological contexts to a medically relevant pathogen.

Development and implementation of the Ebola Exposure Window Calculator: A tool for Ebola virus disease outbreak field investigations.

During an Ebola virus disease (EVD) outbreak, calculating the exposure window of a confirmed case can assist field investigators in identifying the source of infection and establishing chains of transmission. However, field investigators often have difficulty calculating this window. We developed a bilingual (English/French), smartphone-based field application to assist field investigators in determining the exposure window of an EVD case. The calculator only requires the reported date of symptoms onset and the type of symptoms present at onset or the date of death. Prior to the release of this application, there was no similar electronic capability to enable consistent calculation of EVD exposure windows for field investigators. The Democratic Republic of the Congo Ministry of Health endorsed the application and incorporated it into trainings for field staff. Available for Apple and Android devices, the calculator continues to be downloaded even as the eastern DRC outbreak resolved. We rapidly developed and implemented a smartphone application to estimate the exposure window for EVD cases in an outbreak setting.

Mapping of Ebola virus spillover: Suitability and seasonal variability at the landscape scale.

The unexpected Ebola virus outbreak in West Africa in 2014 involving the Zaire ebolavirus made clear that other regions outside Central Africa, its previously documented niche, were at risk of future epidemics. The complex transmission cycle and a lack of epidemiological data make mapping areas at risk of the disease challenging. We used a Geographic Information System-based multicriteria evaluation (GIS-MCE), a knowledge-based approach, to identify areas suitable for Ebola virus spillover to humans in regions of Guinea, Congo and Gabon where Ebola viruses already emerged. We identified environmental, climatic and anthropogenic risk factors and potential hosts from a literature review. Geographical data layers, representing risk factors, were combined to produce suitability maps of Ebola virus spillover at the landscape scale. Our maps show high spatial and temporal variability in the suitability for Ebola virus spillover at a fine regional scale. Reported spillover events fell in areas of intermediate to high suitability in our maps, and a sensitivity analysis showed that the maps produced were robust. There are still important gaps in our knowledge about what factors are associated with the risk of Ebola virus spillover. As more information becomes available, maps produced using the GIS-MCE approach can be easily updated to improve surveillance and the prevention of future outbreaks.

Knowledge, perceptions and effects of Ebola virus disease outbreak on the pig value chain in the agro-pastoralist district of Luwero, Central Uganda.

BACKGROUND: Ebola Virus Disease (EVD) outbreaks have a significant impact on the health and wellbeing, and livelihoods of communities. EVD response interventions particularly affect the food value chain, and income security of pig farmers in agro-pastoral communities. Despite the enormous effort of EVD response interventions, there is paucity of information towards EVD among those involved in the pig value chain, as well as the effect of EVD outbreaks on the pig value chain. This study therefore, assessed the knowledge, perceptions on the occurrence of Ebola and its effects on the pig value chain in the agro-pastoral district of Luweero, Central Uganda. METHODS: A cross sectional study was conducted in two parishes of Ssambwe and Ngalonkulu, Luwero district. A total of 229 respondents were included in the study. Structured questionnaires, key informant interviews and focus group discussions were conducted to collect data. Quantitative data was analysed using SPSS version 22 while qualitative data was analysed using thematic content analysis. RESULTS: Of the 229 respondents, 95.6% could recall the occurrence of the last EVD outbreak in their locality. About 24.5% associated EVD with touching pigs or eating pork. Regarding knowledge, 194 (84.7%) correctly associated EVD with handling Ebola infected persons, 191 (83.4%) with migration of people from endemic areas, 148 (64.9%) eating monkey meat, 127 (55.5%) with eating bats, and 198 (64.9%) with conducting public meetings where there is an Ebola infected person. Out of 142 farmers, 55 (38.7%) believed that Ebola outbreaks affected demand and sale of pigs. The EVD outbreak significantly led to a reduction in the average number of pigs sold (P = 0.001), the average number of pigs bought by traders (P = 0.04), and the number of pigs sold/ slaughtered by butcher men at pork eating places (P = 0.03). CONCLUSION: This study showed that EVD outbreak negatively affected the pig value chain i.e., the demand and supply of pigs and pork. Therefore, there is need to sensitize the stakeholders in the pig value chain on EVD in order to minimize the negative economic impacts associated with EVD outbreaks.

Emerging and Re-emerging Infections in Children: COVID/ MIS-C, Zika, Ebola, Measles, Varicella, Pertussis ... Immunizations.

The role of the emergency provider lies at the forefront of recognition and treatment of novel and re-emerging infectious diseases in children. Familiarity with disease presentations that might be considered rare, such as vaccine-preventable and non-endemic illnesses, is essential in identifying and controlling outbreaks. As we have seen thus far in the novel coronavirus pandemic, susceptibility, severity, transmission, and disease presentation can all have unique patterns in children. Emergency providers also have the potential to play a public health role by using lessons learned from the phenomena of vaccine hesitancy and refusal.

Infection Prevention and Control in Liberia 5 Years After Ebola: A Case Study.

BACKGROUND: Effective management of health emergencies is an important strategy to improve health worldwide. One way to manage health emergencies is to build and sustain national capacities. The Ebola epidemic of 2014 to 2015 resulted in greater infection prevention and control (IPC) capacity in Liberia, but few studies have investigated if and how that capacity was sustained. The purpose of this study was to examine the maintenance of IPC capacity in Liberia after Ebola. METHODS: For this case study, data were collected via direct observation of nurse practice, semistructured interviews, and document collection. Data were collected in two counties in Liberia. Data were analyzed using directed content and general thematic analysis using codes generated from the safety capital theoretical framework, which describes an organization's intangible occupational health resources. FINDINGS: Thirty-seven nurses from 12 facilities participated. Ebola was a seminal event in the development of safety capital in Liberia, particularly regarding nurse knowledge of IPC and facilities' investments in safety. The safety capital developed during Ebola is still being applied at the individual and organizational levels. Tangible resources, including personal protective equipment, however, have been depleted. CONCLUSIONS/APPLICATION TO PRACTICE: IPC capacity in Liberia had been sustained since Ebola but was threatened by under-investments in physical resources. Donor countries should prioritize sustained support, both financial and technical, in partnership with Liberian leaders. Occupational health nurses participating in disaster response should advocate for long-term investment by donor countries in personal protective equipment, access to water, and clinician training.

Integration of genomic sequencing into the response to the Ebola virus outbreak in Nord Kivu, Democratic Republic of the Congo.

On 1 August 2018, the Democratic Republic of the Congo (DRC) declared its tenth Ebola virus disease (EVD) outbreak. To aid the epidemiologic response, the Institut National de Recherche Biomédicale (INRB) implemented an end-to-end genomic surveillance system, including sequencing, bioinformatic analysis and dissemination of genomic epidemiologic results to frontline public health workers. We report 744 new genomes sampled between 27 July 2018 and 27 April 2020 generated by this surveillance effort. Together with previously available sequence data (n = 48 genomes), these data represent almost 24% of all laboratory-confirmed Ebola virus (EBOV) infections in DRC in the period analyzed. We inferred spatiotemporal transmission dynamics from the genomic data as new sequences were generated, and disseminated the results to support epidemiologic response efforts. Here we provide an overview of how this genomic surveillance system functioned, present a full phylodynamic analysis of 792 Ebola genomes from the Nord Kivu outbreak and discuss how the genomic surveillance data informed response efforts and public health decision making.

Assessing the determinants of Ebola virus disease transmission in Baka Community of the Tropical Rainforest of Cameroon.

BACKGROUND: Ebola virus disease (EVD) is a severe, often fatal illness in humans and nonhuman primates caused by the Ebola virus. The recently approved rVSV-EBOV vaccine is not available in many high-risk countries hence prevention is paramount. The design of effective prevention interventions requires an understanding of the factors that expose communities at risk. It was based on this that we investigated the Baka community of Abong-Mbang Health District in tropical rain forest of Cameroon. METHODS: A cross-sectional study was conducted with participants randomly selected from 13 villages in Abong-Mbang by multi-stage cluster sampling. A questionnaire was administered to them to collect demographic information, data on knowledge of EVD, their feeding and health-seeking behaviour. Data was analyzed using the chi-square test. Knowledge of EVD was assessed using an 8 item Morisky Scale. An adapted Threat Capability Basic Risk Assessment Guide was used to determine their risk of exposure to infection. RESULTS: A total of 510 participants, most of whom were hunters (31.4%), farmers (29.8%), and had primary education (62.7%), were included in this study. Although 83.3% participants had heard of EVD, most (71%) did not know its cause. Their source of information was mainly informal discussions in the community (49%). Misconceptions were identified with regards to the cause and mode of transmission. Only 43.1% accepted EVD could be transmitted from human-to-human. Generally, participants' knowledge of EVD was poor. Demographic factors such as level of education, occupation and ethnic group significantly affected knowledge of EVD. The majority of participants were at a very high risk of exposure to infection as they consumed various forms of bush meat and were involved in other risky practices such as scarification and touching of corpses. Although over half of participants seek medical care, most of them preferred traditional medicine. Socio-cultural and service-related factors were deterrent factors to medical care. CONCLUSION: Participants generally had poor knowledge of EVD and were at high risk of infection. We recommend rigorous sensitization campaigns in the study area to educate the population on EVD and clarify the misconceptions identified. EVD surveillance is recommended particularly as outbreaks have often been reported in the Congo Basin.

Ebola Virus Transmission Initiated by Relapse of Systemic Ebola Virus Disease.

During the 2018-2020 Ebola virus disease (EVD) outbreak in North Kivu province in the Democratic Republic of Congo, EVD was diagnosed in a patient who had received the recombinant vesicular stomatitis virus-based vaccine expressing a ZEBOV glycoprotein (rVSV-ZEBOV) (Merck). His treatment included an Ebola virus (EBOV)-specific monoclonal antibody (mAb114), and he recovered within 14 days. However, 6 months later, he presented again with severe EVD-like illness and EBOV viremia, and he died. We initiated epidemiologic and genomic investigations that showed that the patient had had a relapse of acute EVD that led to a transmission chain resulting in 91 cases across six health zones over 4 months. (Funded by the Bill and Melinda Gates Foundation and others.).