Ebola Virus-Specific Neutralizing Antibody Persists at High Levels in Survivors 2 Years After Resolution of Disease in a Sierra Leonean Cohort.

Ebola virus (EBOV) infection results in Ebola virus disease (EVD), an often severe disease with a nonspecific presentation. Since its recognition, periodic outbreaks of EVD continue to occur in sub-Saharan Africa. The 2013-2016 West African EVD outbreak was the largest recorded, resulting in a substantial cohort of EVD survivors with persistent health complaints and variable immune responses. In this study, we characterize humoral immune responses in EVD survivors and their contacts in Eastern Sierra Leone. We found high levels of EBOV IgG in EVD survivors and lower yet substantial antibody levels in household contacts, suggesting subclinical transmission. Neutralizing antibody function was prevalent but variable in EVD survivors, raising questions about the durability of immune responses from natural infection with EBOV. Additionally, we found that certain discrete symptoms-ophthalmologic and auditory-are associated with EBOV IgG seropositivity, while an array of symptoms are associated with the presence of neutralizing antibody.

Rhabdomyolysis, Acute Kidney Injury, and Mortality in Ebola Virus Disease: Retrospective Analysis of Cases From the Eastern Democratic Republic of the Congo, 2019.

BACKGROUND: Skeletal muscle injury in Ebola virus disease (EVD) has been reported, but its association with morbidity and mortality remains poorly defined. METHODS: This retrospective study included patients admitted to 2 EVD treatment units over an 8-month period in 2019 during an EVD epidemic in the Democratic Republic of the Congo. RESULTS: An overall 333 patients (median age, 30 years; 58% female) had at least 1 creatine kinase (CK) measurement (n = 2229; median, 5/patient [IQR, 1-11]). Among patients, 271 (81%) had an elevated CK level (>380 U/L); 202 (61%) had rhabdomyolysis (CK >1000 IU/L); and 45 (14%) had severe rhabdomyolysis (≥5000 U/L). Among survivors, the maximum CK level was a median 1600 (IQR, 550-3400), peaking 3.4 days after admission (IQR, 2.3-5.5) and decreasing thereafter. Among fatal cases, the CK rose monotonically until death, with a median maximum CK level of 2900 U/L (IQR, 1500-4900). Rhabdomyolysis at admission was an independent predictor of acute kidney injury (adjusted odds ratio, 2.2 [95% CI, 1.2-3.8]; P = .0065) and mortality (adjusted hazard ratio, 1.7 [95% CI, 1.03-2.9]; P = .037). CONCLUSIONS: Rhabdomyolysis is associated with acute kidney injury and mortality in patients with EVD. These findings may inform clinical practice by identifying laboratory monitoring priorities and highlighting the importance of fluid management.

Effects of Shock and Vibration on Product Quality during Last-Mile Transportation of Ebola Vaccine under Refrigerated Conditions1.

Analyzing vaccine stability under different storage and transportation conditions is critical to ensure that effectiveness and safety are not affected by distribution. In a simulation of the last mile in the supply chain, we found that shock and vibration had no effect on Ad26.ZEBOV/MVA-BN-Filo Ebola vaccine regimen quality under refrigerated conditions.

Psychological distress among healthcare professionals in Mbarara, following the 2022 Ebola Virus Disease outbreak in Uganda: a mixed methods study.

BACKGROUND: The 2022 Ebola Virus Disease (EVD) outbreak occurred at a time when Uganda was still battling the social and psychological challenges of the COVID-19 pandemic; placing health care professionals (HCPs) at a much higher risk of developing psychological distress. Psychological distress among HCPs can cause decreased workplace productivity and ineffective management of their patients. The current study aimed to investigate and understand psychological distress among HCPS in Mbarara city in Southwestern Uganda following the 2022 EVD outbreak. METHOD: We enrolled 200 HCPs through convenient sampling from one private and one public health facility in Mbarara city in Southwestern Uganda, in a cross-sectional convergent parallel mixed method approach where qualitative and quantitative data were collected concurrently. Quantitative data, utilizing the Kessler Psychological Distress (K10) Scale, provided us with a quantitative measure of the prevalence of psychological distress among HCPs, and were analyzed using STATA version 16. Qualitative data, on the other hand, offered deeper insights into the nature, perceptions, and contextual factors influencing this distress, and were analyzed using emergent theme analysis. RESULTS: The prevalence of psychological distress was 59.5% and it was higher among females (63.9%) compared to males (36.1%). HCPs vividly expressed distress and anxiety, with heightened suspicion that every patient might be an EVD carrier, creating a pervasive sense of unsafety in the workplace. However, the outbreak had an educational affect where concerns about the announcement of another EVD outbreak were diverse, with HCPs expressing anxiety, despair, and dissatisfaction with the country's management of potential outbreaks. CONCLUSION: High levels of psychological distress were experienced by HCPs in Southwestern Uganda as a result of the 2022 EVD pandemic. HCPs express a wide range of feelings, such as dread, anxiety, despair, pessimism, and discontent with the way the outbreaks are handled throughout the nation. We recommend implementation of comprehensive psychosocial support programs tailored to the unique needs of HCPs, including counseling services, stress management workshops, and peer support networks.

Prevention and control of Ebola virus transmission: mathematical modelling and data fitting.

The Ebola virus disease (EVD) has been endemic since 1976, and the case fatality rate is extremely high. EVD is spread by infected animals, symptomatic individuals, dead bodies, and contaminated environment. In this paper, we formulate an EVD model with four transmission modes and a time delay describing the incubation period. Through dynamical analysis, we verify the importance of blocking the infection source of infected animals. We get the basic reproduction number without considering the infection source of infected animals. And, it is proven that the model has a globally attractive disease-free equilibrium when the basic reproduction number is less than unity; the disease eventually becomes endemic when the basic reproduction number is greater than unity. Taking the EVD epidemic in Sierra Leone in 2014-2016 as an example, we complete the data fitting by combining the effect of the media to obtain the unknown parameters, the basic reproduction number and its time-varying reproduction number. It is shown by parameter sensitivity analysis that the contact rate and the removal rate of infected group have the greatest influence on the prevalence of the disease. And, the disease-controlling thresholds of these two parameters are obtained. In addition, according to the existing vaccination strategy, only the inoculation ratio in high-risk areas is greater than 0.4, the effective reproduction number can be less than unity. And, the earlier the vaccination time, the greater the inoculation ratio, and the faster the disease can be controlled.

Prevalence of somatic symptoms among Ebola Virus Disease (EVD) survivors in Africa: a systematic review and meta-analysis.

BACKGROUND: Many Ebola virus disease (EVD) survivors have reported somatic and neuropsychological symptoms after discharge from the Ebola Treatment Unit (ETU). Since the 2014-2016 Ebola epidemic in West Africa, various studies have investigated and identified these symptoms. Evidence on somatic symptoms is widely available in the literature, however, there is no concise overview of the prevalence across different time intervals. METHODS: This meta-analysis was conducted following the (PRISMA) guidelines. A database search was conducted to identify original studies that reported the prevalence of symptoms. The primary outcome measure was the prevalence rate of several somatic symptoms. Results were pooled, and prevalence rates were assessed over time, to elucidate any particular trends. RESULTS: We included 23 studies (5,714 participants). The pooled prevalence was: arthralgia 50% (95% CI: 41%-59%); headache 44% (95% CI: 36%-52%); myalgia 32% (95% CI: 26%-38%); abdominal pain 27% (95% CI: 15%-39%); fatigue 25% (95% CI: 19%-31%); numbness of feet 16% (95% CI: 14%-18%); numbness of hands 12% (95% CI: 10%-14%) and hearing loss 9% (95% CI: 5%-12%). Prevalence across different time intervals revealed significant patterns. All the symptoms persisted for more than 2 years after discharge except for abdominal pain. CONCLUSION: The pooled prevalence rates of somatic symptoms are notably high. Arthralgia and headache are the most prevalent of the symptoms, with hearing loss and numbness in hands and feet being the least. We found that arthralgia, myalgia, and abdominal pain decreased over time. However, headache, fatigue, numbness of hands and feet, and hearing loss increased over time.

"If I die for touching him, let me die": a rapid ethnographic assessment of cultural practices and Ebola transmission in high-risk border regions of Tanzania.

BACKGROUND: Ebola Virus Disease (EVD) is a rare but contagious disease caused by Ebola Virus (EBOV). The first Ebola outbreaks were reported in the Democratic Republic of Congo (DRC) before subsequent reported cases in Western and East African countries, including Uganda, which borders Tanzania. Proximity to EVD-infected countries raises the prospect of cross-border transmission, raising alarm in Tanzania. This study aimed to explore the cultural practices likely to prevent or escalate EVD transmission in the event of its outbreak in the country. METHODS: This rapid ethnographic assessment employed observation, interviews, and focus group discussions to collect data from people with diverse characteristics in five regions of Tanzania Mainland namely, Kagera, Kigoma, Mwanza and Songwe regions and Zanzibar Island. The qualitative data was then subjected to thematic analysis. FINDINGS: Cultural practices may escalate the transmission of EVD and hinder its prevention and control. These cultural practices include caring sick people at home, confirmation of death, mourning, and body preparation for burial. Communal life, ceremonies, and social gatherings were other aspects observed to have the potential for compounding EVD transmission and hindering its containment in case of an outbreak. CONCLUSION: Cultural practices may escalate EVD transmission as identified in the study settings. As such, Risk Communication and Community Engagement (RCCE) activities should be interventionist in transforming cultural practices that may escalate the spread of EVD as part of preparedness, prevention, and control efforts in the event of an outbreak.

A scoping review of ethics review processes during public health emergencies in Africa.

BACKGROUND: The COVID-19 pandemic forced governments, multilateral public health organisations and research institutions to undertake research quickly to inform their responses to the pandemic. Most COVID-19-related studies required swift approval, creating ethical and practical challenges for regulatory authorities and researchers. In this paper, we examine the landscape of ethics review processes in Africa during public health emergencies (PHEs). METHODS: We searched four electronic databases (Web of Science, PUBMED, MEDLINE Complete, and CINAHL) to identify articles describing ethics review processes during public health emergencies and/or pandemics. We selected and reviewed those articles that were focused on Africa. We charted the data from the retrieved articles including the authors and year of publication, title, country and disease(s) reference, broad areas of (ethical) consideration, paper type, and approach. RESULTS: Of an initial 4536 records retrieved, we screened the titles and abstracts of 1491 articles, and identified 72 articles for full review. Nine articles were selected for inclusion. Of these nine articles, five referenced West African countries including Liberia, Guinea and Sierra Leone, and experiences linked to the Ebola virus disease. Two articles focused on South Africa and Kenya, while the other two articles discussed more general experiences and pitfalls of ethics review during PHEs in Africa more broadly. We found no articles published on ethics review processes in Africa before the 2014 Ebola outbreak, and only a few before the COVID-19 outbreak. Although guidelines on protocol review and approval processes for PHEs were more frequently discussed after the 2014 Ebola outbreak, these did not focus on Africa specifically. CONCLUSIONS: There is a gap in the literature about ethics review processes and preparedness within Africa during PHEs. This paper underscores the importance of these processes to inform practices that facilitate timely, context-relevant research that adequately recognises and reinforces human dignity within the quest to advance scientific knowledge about diseases. This is important to improve fast responses to PHEs, reduce mortality and morbidity, and enhance the quality of care before, during, and after pandemics.

Performance and impact of contact tracing in the Sudan virus outbreak in Uganda, September 2022-January 2023.

BACKGROUND: Contact tracing (CT) is critical for ebolavirus outbreak response. Ideally, all new cases after the index case should be previously-known contacts (PKC) before their onset, and spend minimal time ill in the community. We assessed the impact of CT during the 2022 Sudan Virus Disease (SVD) outbreak in Uganda. METHODS: We collated anonymized data from the SVD case and contacts database to obtain and analyze data on CT performance indicators, comparing confirmed cases that were PKC and were not PKC (NPKC) before onset. We assessed the effect of being PKC on the number of people infected using Poisson regression. RESULTS: There were 3844 contacts of 142 confirmed cases (mean: 22 contacts/case). Forty-seven (33%) confirmed cases were PKC. PKCs had fewer median days from onset to isolation (4 vs 6; P<0.007) and laboratory confirmation (4 vs 7; P<0.001) than NPKC. Being a PKC vs NPKC reduced risk of transmitting infection by 84% (IRR=0.16, 95% CI 0.08-0.32). CONCLUSION: Contact identification was sub-optimal during the outbreak. However, CT reduced the time SVD cases spent in the community before isolation and the number of persons infected in Uganda. Approaches to improve contact tracing, especially contact listing, may improve control in future outbreaks.

Factors Associated with Reliable Contact Tracing During the 2021 Ebola Virus Disease Outbreak in Guinea.

BACKGROUND: In 2021, an Ebola virus disease (EVD) outbreak was declared in Guinea, linked to persistent virus from the 2014-2016 West Africa Epidemic. This paper analyzes factors associated with contact tracing reliability (defined as completion of a 21-day daily follow-up) during the 2021 outbreak, and transitively, provides recommendations for enhancing contact tracing reliability in future. METHODS: We conducted a descriptive and analytical cross-sectional study using multivariate regression analysis of contact tracing data from 1071 EVD contacts of 23 EVD cases (16 confirmed and 7 probable). RESULTS: Findings revealed statistically significant factors affecting contact tracing reliability. Unmarried contacts were 12.76× more likely to miss follow-up than those married (OR = 12.76; 95% CI [3.39-48.05]; p < 0.001). Rural-dwelling contacts had 99% lower odds of being missed during the 21-day follow-up, compared to those living in urban areas (OR = 0.01; 95% CI [0.00-0.02]; p < 0.01). Contacts who did not receive food donations were 3× more likely to be missed (OR = 3.09; 95% CI [1.68-5.65]; p < 0.001) compared to those who received them. Contacts in health areas with a single team were 8× more likely to be missed (OR = 8.16; 95% CI [5.57-11.96]; p < 0.01) than those in health areas with two or more teams (OR = 1.00; 95% CI [1.68-5.65]; p < 0.001). Unvaccinated contacts were 30.1× more likely to be missed compared to vaccinated contacts (OR = 30.1; 95% CI [5.12-176.83]; p < 0.001). CONCLUSION: Findings suggest that contact tracing reliability can be significantly influenced by various demographic and organizational factors. Considering and understanding these factors-and where possible addressing them-may be crucial when designing and implementing contact tracing strategies during future outbreaks in low-resource settings.

Kenyan Free-Tailed Bats Demonstrate Seasonal Birth Pulse Asynchrony with Implications for Virus Maintenance.

Ecological information on wildlife reservoirs is fundamental for research targeting prevention of zoonotic infectious disease, yet basic information is lacking for many species in global hotspots of disease emergence. We provide the first estimates of synchronicity, magnitude, and timing of seasonal birthing in Mops condylurus, a putative ebolavirus host, and a co-roosting species, Mops pumilus (formerly Chaerephon pumilus). We show that population-level synchronicity of M. condylurus birthing is wide (~ 8.5 weeks) and even wider in M. pumilus (> 11 weeks). This is predicted to promote the likelihood of filovirus persistence under conditions of bi-annual birthing (two births per year). Ecological features underlying the magnitude of the birth pulse-relative female abundance (higher than expected for M. condylurus and lower for M. pumilus, based on literature) and reproductive rate (lower than expected)-will have countering effects on birthing magnitude. Species-specific models are needed to interpret how identified birth pulse attributes may interact with other features of molossid ebolavirus ecology to influence infection dynamics. As a common feature of wildlife species, and a key driver of infection dynamics, detailed information on seasonal birthing will be fundamental for future research on these species and will be informative for bat-borne zoonoses generally.

Assessment of health care workers preparedness to epidemics: A case of Ebola virus disease preparedness in private hospitals in Kampala, Uganda.

INTRODUCTION: Unrecognized Ebola Virus Disease (EVD) can lead to multiple chains of transmissions if the first caretakers are not trained and prepared. This study aimed to assess healthcare workers (HCWs) preparedness in private hospitals located in Kampala, to detect, respond and prevent EVD. METHODOLOGY: A descriptive cross-sectional study was carried out among HCWs in direct clinical care provision in four private hospitals, and in one Ebola Treatment Unit (ETU) using a self-administered questionnaire from March to June 2020. RESULTS: 222 HCWs agreed to participate aged from 19 to 64 years and with 6 months to 38 years of practice where most were nurses (44%). 3/5 hospitals did not have written protocols on EVD case management, and only one (ETU) had an exclusive emergency team. 59% were not sure whether contact tracing was taking place. Private hospitals were not included in EVD trainings organized by the Ministry of Health (MoH). In addition, HCWs in private hospitals were not empowered by the MoH to take part in EVD case management. Despite these shortcomings, only 66% of HCWs showed an interest to be immunized. Knowledge about potential Ebola vaccines was generally poor. CONCLUSIONS: In Kampala, Uganda, establishment of a more comprehensive preparedness and response strategy for EVD outbreaks is imperative for HCWs in private facilities, including a wide vaccination educational program on Ebola vaccination. The findings from this study if addressed will likely improve the preparedness and management of future Ebola outbreaks in Uganda.

Readiness To Manage Ebola Virus Disease Among Emergency Healthcare Workers in Uganda: A Nationwide Multicenter Survey.

Background: Emerging infectious diseases like the Ebola Virus Disease (EVD) pose significant global public health threats. Uganda has experienced multiple EVD outbreaks, the latest occurring in 2022. Frontline healthcare workers (HCWs) are at increased risk, yet there isn't sufficient evidence of existing knowledge of EVD of these health workers. We aimed to assess the readiness of Uganda's emergency healthcare workers to manage Ebola virus disease (EVD) and identify their training needs to inform targeted capacity-building interventions for future outbreaks. Methods: This multicentre nationwide cross-sectional study was conducted from July to August 2023 among 691 HCWs providing emergency care in 14 secondary and tertiary hospitals across Uganda. Participants were consecutively recruited using the probability-proportional-to-size sampling technique, and data was collected using a self-reported questionnaire. Factors associated with EVD knowledge were identified through a mixed-effect linear model. Results: Data from 691 eligible HCWs with a median age of 32 (IQR: 28-38) was analyzed (response rate: 92%). Only one-third (34.4%, n = 238) had received EVD training in the past year. The median EVD knowledge score was 77.4% (IQR: 71.2% - 83.4%). EVD knowledge was associated with longer professional experience in years (ß: 0.21, 95% CI: 0.03 to 0.39, p = 0.024) and higher level of education: diploma (ß: 3.37, 95% CI: 1.49 to 5.25, p < 0.001), undergraduate degree (ß: 6.45, 95% CI: 4.11 to 8.79) and postgraduate degree (ß: 7.13, 95% CI: 4.01 to 10.25, p < 0.001). Being a doctor (ß: 2.55, 95% CI: 0.35 to 4.74, p = 0.023), providing care in the obstetrics/gynecology department (ß: -1.90, 95% CI: -3.47 to - 0.32, p = 0.018), previous EVD training (ß: 2.27, 95% CI: 0.96 to 3.59, p = 0.001) and accessing EVD information through social media (ß: 2.52, 95% CI: 1.17 to 3.88, p < 0.001) were also significantly associated with EVD knowledge. Conclusion: Our study reveals that Ugandan HCWs' EVD response readiness varies by individual factors and information sources. We recommend targeted training and suggest future research on educational innovations and social media's potential to fill knowledge gaps.

The potential risk components and prevention measures of the Ebola virus disease outbreak in Liberia: An in-depth interview with the health workers and stakeholders.

Background: The Ebola virus, a highly infectious and deadly pathogen, has posed a significant public health threat in West Africa for several decades. Liberia is one of the most severely affected countries. Healthcare personnel, including nurses, are on the front lines of patient care, and their perspectives are invaluable in understanding the challenges that arise during outbreaks, especially in implementing prevention measures. Objective: This study aimed to explore the potential risk components and prevention measures of the Ebola virus disease (EVD). Methods: This study used an exploratory descriptive qualitative design. Five stakeholders, ten doctors and five nurses who had suffered from EVD during the outbreak in Liberia participated in semi-structured interviews to provide their experience and comprehensive perspectives on EVD. Data were collected from February 2022-August 2023. NVivo 12 plus was used for inductive thematic analysis. Results: Six themes and several subthemes emerged: 1) transmission modes (body contact, body fluid, sexual intercourse, traditional burial), 2) funeral attendance (traditional practices and crowded gatherings), 3) community-led prevention (promoting good hygiene practices, increasing awareness, contact tracing, and surveillance), 4) Ebola virus vaccine (false sense of security, potential side effects, and limited data), 5) challenges in implementing prevention measures (inadequate health infrastructures, difficulty of tracing infected people, lack of resources, and cultural-social barriers), 6) Liberia's health systems (a weak, underfunded, fragile health infrastructure, lack of health facilities and shortage of health workers). Conclusion: Several potential risk components contributing to the EVD outbreak should be a public concern. Strengthening the current healthcare system supported by local community and international aid providers (multidisciplinary teams) is needed to anticipate behavioral problems and to improve the efficacy of the prevention measures appropriate to the conditions in Liberia. Accordingly, the nurses' compliance with the recommended prevention practices is necessary.

Derivation and Internal Validation of a Mortality Prognostication Machine Learning Model in Ebola Virus Disease Based on Iterative Point-of-Care Biomarkers.

Background: Although multiple prognostic models exist for Ebola virus disease mortality, few incorporate biomarkers, and none has used longitudinal point-of-care serum testing throughout Ebola treatment center care. Methods: This retrospective study evaluated adult patients with Ebola virus disease during the 10th outbreak in the Democratic Republic of Congo. Ebola virus cycle threshold (Ct; based on reverse transcriptase polymerase chain reaction) and point-of-care serum biomarker values were collected throughout Ebola treatment center care. Four iterative machine learning models were created for prognosis of mortality. The base model used age and admission Ct as predictors. Ct and biomarkers from treatment days 1 and 2, days 3 and 4, and days 5 and 6 associated with mortality were iteratively added to the model to yield mortality risk estimates. Receiver operating characteristic curves for each iteration provided period-specific areas under curve with 95% CIs. Results: Of 310 cases positive for Ebola virus disease, mortality occurred in 46.5%. Biomarkers predictive of mortality were elevated creatinine kinase, aspartate aminotransferase, blood urea nitrogen (BUN), alanine aminotransferase, and potassium; low albumin during days 1 and 2; elevated C-reactive protein, BUN, and potassium during days 3 and 4; and elevated C-reactive protein and BUN during days 5 and 6. The area under curve substantially improved with each iteration: base model, 0.74 (95% CI, .69-.80); days 1 and 2, 0.84 (95% CI, .73-.94); days 3 and 4, 0.94 (95% CI, .88-1.0); and days 5 and 6, 0.96 (95% CI, .90-1.0). Conclusions: This is the first study to utilize iterative point-of-care biomarkers to derive dynamic prognostic mortality models. This novel approach demonstrates that utilizing biomarkers drastically improved prognostication up to 6 days into patient care.

Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014-16 Ebola outbreak in Bo District, Sierra Leone.

BACKGROUND: There is a lack of empirical data on design effects (DEFF) for mortality rate for highly clustered data such as with Ebola virus disease (EVD), along with a lack of documentation of methodological limitations and operational utility of mortality estimated from cluster-sampled studies when the DEFF is high. OBJECTIVES: The objectives of this paper are to report EVD mortality rate and DEFF estimates, and discuss the methodological limitations of cluster surveys when data are highly clustered such as during an EVD outbreak. METHODS: We analysed the outputs of two independent population-based surveys conducted at the end of the 2014-2016 EVD outbreak in Bo District, Sierra Leone, in urban and rural areas. In each area, 35 clusters of 14 households were selected with probability proportional to population size. We collected information on morbidity, mortality and changes in household composition during the recall period (May 2014 to April 2015). Rates were calculated for all-cause, all-age, under-5 and EVD-specific mortality, respectively, by areas and overall. Crude and adjusted mortality rates were estimated using Poisson regression, accounting for the surveys sample weights and the clustered design. RESULTS: Overall 980 households and 6,522 individuals participated in both surveys. A total of 64 deaths were reported, of which 20 were attributed to EVD. The crude and EVD-specific mortality rates were 0.35/10,000 person-days (95%CI: 0.23-0.52) and 0.12/10,000 person-days (95%CI: 0.05-0.32), respectively. The DEFF for EVD mortality was 5.53, and for non-EVD mortality, it was 1.53. DEFF for EVD-specific mortality was 6.18 in the rural area and 0.58 in the urban area. DEFF for non-EVD-specific mortality was 1.87 in the rural area and 0.44 in the urban area. CONCLUSION: Our findings demonstrate a high degree of clustering; this contributed to imprecise mortality estimates, which have limited utility when assessing the impact of disease. We provide DEFF estimates that can inform future cluster surveys and discuss design improvements to mitigate the limitations of surveys for highly clustered data.

Main findings: For humanitarian organizations it is imperative to document the methodological limitations of cluster surveys and discuss the utility.Added knowledge: This paper adds new knowledge on cluster surveys for highly clustered data such us in Ebola virus disease.Global health impact of policy and action: We provided empirical estimates and discuss design improvements to inform future study.

Preparing for another Ebola Outbreak: The impact of viral inactivation methods on commonly measured biochemistry analytes in plasma and urine.

INTRODUCTION: Infectious specimens containing viruses like Ebola require sample manipulation to ensure the safety of laboratory staff, which may negatively impact biochemistry test results. We evaluated the impact of viral inactivation methods on 25 biochemistry analytes in plasma, and seven biochemistry analytes in urine. METHODS: Fifteen lithium heparinized plasma specimens with and without gel underwent the following viral inactivation methods: 1) untreated, 2) Triton X-100 treatment, 2) heated for 60 min then Triton X-100 treatment, 3) heated for 60 min, 4) heated for 75 min, and 5) heated for 90 min. Electrolytes, protein, enzymes, glucose, as well as hepatic and renal markers were measured on the Roche Cobas e601, c502 or c702. Urinalysis analytes were measured on the Siemens CLINITEK. Acceptable recovery was based on Institute for Quality Management in Healthcare 2021 guidelines or ± 1 for urinalysis. RESULTS: Potassium and lactate dehydrogenase were impacted by the presence of gel. Viral inactivation with Triton X-100 had minimal impact on the biochemistry results. Heat inactivation resulted in significant negative bias in alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, creatinine, total protein, amylase, lactate dehydrogenase and creatine kinase. Positive bias in phosphate, aspartate transaminase, total bilirubin, and uric acid were observed after heat inactivation. CONCLUSION: Reliable results for commonly measured electrolytes, enzymes and proteins can be obtained after viral inactivation by Triton X-100 treatment at room temperature. However, heat inactivation has significant negative impact on routine biochemistry enzymes and alternative testing processes should be explored.

Ebola virus circulation in a non-epidemic Guinean rural area: A mixed-method approach to assessing endemicity.

OBJECTIVES: This study aimed to investigate the prevalence of orthoebolavirus antibodies in Madina Oula, a non-epidemic rural area in Guinea, in 2022. METHODS: A cross-sectional study was conducted from March 14 to April 3, 2022 involving recording household and socio-demographic characteristics, lifestyle data, and collecting dried blood spots from 878 individuals in 235 households. Dried blood spots were tested using multiplex serology to detect antibodies to different orthoebolaviruses: Ebola virus, Bundibugyo virus, Sudan virus, Reston virus, and Bombali virus. Seroprevalence was estimated with a 95% confidence interval and a Z-test was performed to compare the seropositivity between children aged under 15 years and those over 15 years. Household and participant characteristics were analyzed using descriptive statistic, and socio-historical conditions were discussed. RESULTS: The serological analysis conducted in 2022 on 878 participants revealed varying reactivity to orthoebolavirus antigens, notably, with glycoprotein antigens, particularly, glycoprotein Sudan virus (16%). A total of 21 samples exhibited reactivity with at least two antigens, with a median age of 27 years (interquartile range 10.00-35.00), ranging from 2 to 80 years. There is no significant difference between seropositivity in children aged under 15 (2.86%) years and those over 15 (2.14%) years. The antibody presence varied per village, with the highest prevalence observed in Ouassou and Dar-es-Salam. CONCLUSIONS: Serological data in a region unaffected by recent Ebola outbreaks indicate possible orthoebolavirus endemicity, emphasizing the need for preparedness against known or novel orthoebolaviruses with potential cross-reactivity.

National burden of Ebola virus disease in Democratic Republic of the Congo: the urgency to act.

Ebola virus disease (EVD) has long been a major public health concern for Democratic Republic of the Congo (DR Congo). First identified in DR Congo in 1976, the country has witnessed more than 25 outbreaks of this deadly disease, which has a case fatality rate of nearly 90% and manifesting with symptoms such as diarrhoea, vomiting, stomachache and haemorrhagic fever. African fruit bats have been speculated to be the reservoir of this virus. DR Congo is currently facing another EVD outbreak simultaneously with other communicable diseases, rendering it vulnerable to a shortage of medical and paramedical staff along with distrust among remote communities towards local authorities due to armed conflict and political instability. Moreover, lack of ring vaccinations and inefficient surveillance of suspected individuals are some other significant hurdles in disease control. Despite the availability of rVSV-ZEBOV/Erbevo vaccine and many antibody-based vaccines, challenges including politicization, low access to remote communities, and illiteracy have limited their effectiveness. Recently, the Congolese govt. has put in efforts such as building local capacities at the health zone level, outbreak control intervention, community engagement and social mobilization to counter the rising EVD cases. Four successive Strategic Response Plans have been implemented to increase resource mobilization by DR Congo and her partners. The Spread of zoonotics such as EVD can be confronted by implementing the One Health approach, which involves medical staff, veterinarians and public health officials.

Fully human monoclonal antibodies against Ebola virus possess complete protection in a hamster model.

AbstractEbola disease is a lethal viral hemorrhagic fever caused by ebolaviruses within the Filoviridae family with case fatality rates of up to 90%. Monoclonal antibody (mAb) based therapies have shown great potential for the treatment of EVD. However, the potential emerging ebolavirus isolates and the negative effect of decoy protein (secreted glycoprotein, sGP) on the therapeutic efficacy of antibodies highlight the necessity of developing novel antibodies to counter the threat of Ebola. Here, 11 fully human mAbs were isolated from transgenic mice immunized with mucin-like domain-deleted GP ectodomain (EBOV GPΔmuc) and recombinant vesicular stomatitis virus-bearing GP (rVSV-EBOV GP). These mAbs were divided into five groups according to their germline genes and exhibited differential binding activities and neutralization capabilities. In particular, three antibodies, 8G6, 2A4, and 5H4 were cross-reactive and could bind at least three ebolavirus glycoproteins. mAb 4C1 not only exhibited neutralizing activity but no cross-reaction with sGP. mAb 7D8 exhibited the strongest neutralizing capacity. Further analysis on the critical residues for the bindings of 4C1 and 8G6 to GPs was conducted using antibodies heavy- and light-chains complementarity-determining regions (CDRs) alanine scanning. It has been shown that light chain CDR3 plays a crucial role in binding and neutralization and that any mutation in CDRs could not improve the binding of 4C1 to sGP. Importantly, mAb 7D8, 8G6, and 4C1 provided complete protection against EBOV infection in a hamster lethal challenge model when administered 12 hours post-infection. These results support mAb 7D8, 8G6, and 4C1 as potent antibody candidates for further investigations and pave the way for further developments of therapies and vaccines.