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.

Use of Ebola Vaccines - Worldwide, 2021-2023.

Ebola virus disease (Ebola) is a rare but severe illness in humans, with an average case fatality rate of approximately 50%. Two licensed vaccines are currently available against Orthoebolavirus zairense, the virus that causes Ebola: the 1-dose rVSVΔG-ZEBOV-GP (ERVEBO [Merck]) and the 2-dose regimen of Ad26.ZEBOV and MVA-BN-Filo (Zabdeno/Mvabea [Johnson & Johnson]). The Strategic Advisory Group of Experts on Immunization recommends the use of 1-dose ERVEBO during Ebola outbreaks, and in 2021, a global stockpile of ERVEBO was established to ensure equitable, timely, and targeted access to vaccine doses for future Ebola outbreaks. This report describes the use of Ebola vaccines and the role of the stockpile developed and managed by the International Coordinating Group (ICG) on Vaccine Provision during 2021-2023. A total of 145,690 doses have been shipped from the ICG stockpile since 2021. However, because outbreaks since 2021 have been limited and rapidly contained, most doses (139,120; 95%) shipped from the ICG stockpile have been repurposed for preventive vaccination of high-risk groups, compared with 6,570 (5%) used for outbreak response. Repurposing doses for preventive vaccination could be prioritized in the absence of Ebola outbreaks to prevent transmission and maximize the cost-efficiency and benefits of the stockpile.

Efficiency of Field Laboratories for Ebola Virus Disease Outbreak during Chronic Insecurity, Eastern Democratic Republic of the Congo, 2018-2020.

During the 10th outbreak of Ebola virus disease in the Democratic Republic of the Congo, the Institut National de Recherche Biomédicale strategically positioned 13 decentralized field laboratories with dedicated equipment to quickly detect cases as the outbreak evolved. The laboratories were operated by national staff, who quickly handed over competencies and skills to local persons to successfully manage future outbreaks. Laboratories analyzed ≈230,000 Ebola diagnostic samples under stringent biosafety measures, documentation, and database management. Field laboratories diversified their activities (diagnosis, chemistry and hematology, survivor follow-up, and genomic sequencing) and shipped 127,993 samples from the field to a biorepository in Kinshasa under good conditions. Deploying decentralized and well-equipped laboratories run by local personnel in at-risk countries for Ebola virus disease outbreaks is an efficient response; all activities are quickly conducted in the field.

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

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

Global Health Security in Vision Care: Health Systems Strengthening During Ebola Virus Disease Outbreak Responses.

During the last decade, global health security has been threatened by major Ebola virus disease outbreaks in Western Africa (2014 to 2016) and in eastern Democratic Republic of the Congo (2018 to 2020). Particularly in Western Africa, the outbreak initially overwhelmed health care capacity in already fragile health systems. Thousands of survivors were at risk of newly recognized postacute ocular complications, and their need for urgent ophthalmic care challenged national vision health systems with scarce eye care services. In these unprecedently large outbreaks with implications for global health security, agile eye care responses were challenging, including in regard to decision coordination and requisite logistical needs. In this report, we detail vision care initiatives implemented in response to these outbreaks and highlight the need to include vision care as a critical component of the response to infectious disease outbreaks with eye health implications.

Effect of anti-Ebola virus monoclonal antibodies on endogenous antibody production in survivors of Ebola virus disease in the Democratic Republic of the Congo: an observational cohort study.

BACKGROUND: The use of specific anti-Ebola virus therapy, especially monoclonal antibodies, has improved survival in patients with Ebola virus disease. We aimed to assess the effect of monoclonal antibodies on anti-Ebola virus antibody responses in survivors of the 2018-20 Ebola outbreak in the Democratic Republic of the Congo. METHODS: In this observational prospective cohort study, participants were enrolled at three Ebola survivor clinics in Beni, Mangina, and Butembo (Democratic Republic of the Congo). Eligible children and adults notified as survivors of Ebola virus disease (ie, who had confirmed Ebola virus disease [RT-PCR positive in blood sample] and were subsequently declared recovered from the virus [RT-PCR negative in blood sample] with a certificate of recovery from Ebola virus disease issued by an Ebola treatment centre) during the 2018-20 Ebola virus disease outbreak were invited to participate in the study. Participants were recruited on discharge from Ebola treatment centres and followed up for 12-18 months depending on recruitment date. Routine follow-up assessments were done at 1, 3, 6, and 12-18 months after inclusion. We collected sociodemographic (age, sex, visit site), clinical (anti-Ebola virus drugs), and laboratory data (RT-PCR and Ct values). The primary outcome was the antibody concentrations against Ebola virus glycoprotein, nucleoprotein, and 40-kDa viral protein antigens over time assessed in all participants. Antibody concentrations were measured by the multiplex immunoassay, and the association between anti-Ebola virus antibody levels and the relevant exposures, such as anti-Ebola virus disease drugs (ansuvimab, REGN-EB3, ZMapp, or remdesivir), was assessed using both linear and logistic mixed regression models. This study is registered at ClinicalTrials.gov, NCT04409405. FINDINGS: Between April 16, 2020, and Oct 18, 2021, 1168 survivors were invited to participate in the Les Vainqueurs d'Ebola cohort study. 787 survivors were included in the study, of whom 358 had data available for antibody responses. 85 (24%) of 358 were seronegative for at least two Ebola virus antigens on discharge from the Ebola treatment centre. The antibody response over time fluctuated but a continuous decrease in an overall linear evolution was observed. Quantitative modelling showed a decrease in nucleoprotein, glycoprotein, and VP-40 antibody concentrations over time (p<0·0001) with the fastest decrease observed for glycoprotein. The probability of being seropositive for at least two antigens after 36 months was 53·6% (95% CI 51·6-55·6) for participants who received ansuvimab, 73·5% (71·5-75·5) for participants who received REGN-EB3, 76·8% (74·8-78·8) for participants who received remdesivir, and 78·5% (76·5-80·5) for participants who received ZMapp. INTERPRETATION: Almost a quarter of survivors were seronegative on discharge from the Ebola treatment centre and antibody concentrations decreased rapidly over time. These results indicate that monoclonal antibodies might negatively affect the production of anti-Ebola virus antibodies in survivors of Ebola virus disease which could increase the risk of reinfection or reactivation. FUNDING: The French National Agency for AIDS Research-Emergent Infectious Diseases-The French National Institute of Health and Medical Research, the French National Research Institute for Development, and the European and Developing Countries Clinical Trials Partnership. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Screening for Eye Disease in Ebola Virus Disease Survivors: Program Implementation During an Active Outbreak in the North Kivu and Ituri Provinces, Democratic Republic of the Congo.

First identified in the Democratic Republic of the Congo (DRC, formerly Zaire) in 1976, Ebola virus disease (EVD) outbreaks have afflicted thousands of Congolese over the past several decades. The nation's largest outbreak of EVD in 2018-2020 was complicated by security challenges as well as large case numbers across an expansive geographic region. These factors provided challenges for logistical considerations as well as clinical coverage. In conjunction with the EVD survivor care program spearheaded by the Ministry of Health in DRC, the DRC Intitut National de Recherche Biomédicale, (DRC Institut National de Recherche Biomedicale, DRC National Institute of Biomedical Research) and others, we launched a multidimensional effort to provide ophthalmic care to EVD survivors. During the engagement period, 237 EVD survivors were screened, 56% of which were women. The 237 EVD survivors constituted ∼75% of the total EVD survivors who were discharged at the time of the intervention. The mean time from EVD symptom onset to evaluation was 4.6 months ± 1.8 SD (range: 24 d to 8.5 mo). Ninety-seven (41%) of EVD survivors screened reported ocular symptoms during or after acute illness, such as itchy eyes (49%), eye pain (25%), and tears (24%). Ophthalmic findings, including retinal scarring, active uveitis, dry eye disease, cataracts, and glaucoma, were also identified. The need for continued monitoring and longitudinal care for EVD survivors is evident from the expanding body of literature pertaining to post-acute sequelae, including ophthalmic manifestations. Initiatives for such care should be conducted across and in conjunction with multidisciplinary stakeholders for contextualization and effectiveness.

Fatal meningoencephalitis associated with Ebola virus persistence in two survivors of Ebola virus disease in the Democratic Republic of the Congo: a case report study.

BACKGROUND: During the 2018-20 Ebola virus disease outbreak in the Democratic Republic of the Congo, thousands of patients received unprecedented vaccination, monoclonal antibody (mAb) therapy, or both, leading to a large number of survivors. We aimed to report the clinical, virological, viral genomic, and immunological features of two previously vaccinated and mAb-treated survivors of Ebola virus disease in the Democratic Republic of the Congo who developed second episodes of disease months after initial discharge, ultimately complicated by fatal meningoencephalitis associated with viral persistence. METHODS: In this case report study, we describe the presentation, management, and subsequent investigations of two patients who developed recrudescent Ebola virus disease and subsequent fatal meningoencephalitis. We obtained data from epidemiological databases, Ebola treatment units, survivor programme databases, laboratory datasets, and hospital records. Following national protocols established during the 2018-20 outbreak in the Democratic Republic of the Congo, blood, plasma, and cerebrospinal fluid (CSF) samples were collected during the first and second episodes of Ebola virus disease from both individuals and were analysed by molecular (quantitative RT-PCR and next-generation sequencing) and serological (IgG and IgM ELISA and Luminex assays) techniques. FINDINGS: The total time between the end of the first Ebola virus episode and the onset of the second episode was 342 days for patient 1 and 137 days for patient 2. In both patients, Ebola virus RNA was detected in blood and CSF samples during the second episode of disease. Complete genomes from CSF samples from this relapse episode showed phylogenetic relatedness to the genome sequenced from blood samples collected from the initial infection, confirming in-host persistence of Ebola virus. Serological analysis showed an antigen-specific humoral response with typical IgM and IgG kinetics in patient 1, but an absence of an endogenous adaptive immune response in patient 2. INTERPRETATION: We report the first two cases of fatal meningoencephalitis associated with Ebola virus persistence in two survivors of Ebola virus disease who had received vaccination and mAb-based treatment in the Democratic Republic of the Congo. Our findings highlight the importance of long-term monitoring of survivors, including continued clinical, virological, and immunological profiling, as well as the urgent need for novel therapeutic strategies to prevent and mitigate the individual and public health consequences of Ebola virus persistence. FUNDING: Ministry of Health of the Democratic Republic of the Congo, Institut National de Recherche Biomédicale, Infectious Disease Rapid Response Reserve Fund, US Centers for Disease Control and Prevention, US National Cancer Institute (National Institutes of Health), French National Research Institute for Development, and WHO.

2020 Ebola virus disease outbreak in Équateur Province, Democratic Republic of the Congo: a retrospective genomic characterisation.

BACKGROUND: The Democratic Republic of the Congo has had 15 Ebola virus disease (EVD) outbreaks, from 1976 to 2023. On June 1, 2020, the Democratic Republic of the Congo declared an outbreak of EVD in the western Équateur Province (11th outbreak), proximal to the 2018 Tumba and Bikoro outbreak and concurrent with an outbreak in the eastern Nord Kivu Province. In this Article, we assessed whether the 11th outbreak was genetically related to previous or concurrent EVD outbreaks and connected available epidemiological and genetic data to identify sources of possible zoonotic spillover, uncover additional unreported cases of nosocomial transmission, and provide a deeper investigation into the 11th outbreak. METHODS: We analysed epidemiological factors from the 11th EVD outbreak to identify patient characteristics, epidemiological links, and transmission modes to explore virus spread through space, time, and age groups in the Équateur Province, Democratic Republic of the Congo. Trained field investigators and health professionals recorded data on suspected, probable, and confirmed cases, including demographic characteristics, possible exposures, symptom onset and signs and symptoms, and potentially exposed contacts. We used blood samples from individuals who were live suspected cases and oral swabs from individuals who were deceased to diagnose EVD. We applied whole-genome sequencing of 87 available Ebola virus genomes (from 130 individuals with EVD between May 19 and Sept 16, 2020), phylogenetic divergence versus time, and Bayesian reconstruction of phylogenetic trees to calculate viral substitution rates and study viral evolution. We linked the available epidemiological and genetic datasets to conduct a genomic and epidemiological study of the 11th EVD outbreak. FINDINGS: Between May 19 and Sept 16, 2020, 130 EVD (119 confirmed and 11 probable) cases were reported across 13 Équateur Province health zones. The individual identified as the index case reported frequent consumption of bat meat, suggesting the outbreak started due to zoonotic spillover. Sequencing revealed two circulating Ebola virus variants associated with this outbreak-a Mbandaka variant associated with the majority (97%) of cases and a Tumba-like variant with similarity to the ninth EVD outbreak in 2018. The Tumba-like variant exhibited a reduced substitution rate, suggesting transmission from a previous survivor of EVD. INTERPRETATION: Integrating genetic and epidemiological data allowed for investigative fact-checking and verified patient-reported sources of possible zoonotic spillover. These results demonstrate that rapid genetic sequencing combined with epidemiological data can inform responders of the mechanisms of viral spread, uncover novel transmission modes, and provide a deeper understanding of the outbreak, which is ultimately needed for infection prevention and control during outbreaks. FUNDING: WHO and US Centers for Disease Control and Prevention.

Head-to-head comparison of diagnostic accuracy of four Ebola virus disease rapid diagnostic tests versus GeneXpert® in eastern Democratic Republic of the Congo outbreaks: a prospective observational study.

BACKGROUND: Ebola virus disease (EVD) outbreaks have emerged in Central and West Africa. EVD diagnosis relies principally on RT-PCR testing with GeneXpert®, which has logistical and cost restrictions at the peripheral level of the health system. Rapid diagnostic tests (RDTs) would offer a valuable alternative at the point-of-care to reduce the turn-around time, if they show good performance characteristics. We evaluated the performance of four EVD RDTs against the reference standard GeneXpert® on stored EVD positive and negative blood samples collected between 2018 and 2021 from outbreaks in eastern Democratic Republic of the Congo (DRC). METHODS: We conducted a prospective and observational study in the laboratory on QuickNavi-Ebola™, OraQuick® Ebola Rapid Antigen, Coris® EBOLA Ag K-SeT, and Standard® Q Ebola Zaïre Ag RDTs using left-over archived frozen EDTA whole blood samples. We randomly selected 450 positive and 450 negative samples from the EVD biorepositories in DRC, across a range of GeneXpert® cycle threshold values (Ct-values). RDT results were read by three persons and we considered an RDT result as "positive", when it was flagged as positive by at least two out of the three readers. We estimated the sensitivity and specificity through two independent generalized (logistic) linear mixed models (GLMM). FINDINGS: 476 (53%) of 900 samples had a positive GeneXpert Ebola result when retested. The QuickNavi-Ebola™ showed a sensitivity of 56.8% (95% CI 53.6-60.0) and a specificity of 97.5% (95% CI 96.2-98.4), the OraQuick® Ebola Rapid Antigen test displayed 61.6% (95% CI 57.0-65.9) sensitivity and 98.1% (95% CI 96.2-99.1) specificity, the Coris® EBOLA Ag K-SeT showed 25.0% (95% CI 22.3-27.9) sensitivity and 95.9% (95% CI 94.2-97.1) specificity, and the Standard® Q Ebola Zaïre Ag displayed 21.6% (95% CI 18.1-25.7) sensitivity and 99.1% (95% CI 97.4-99.7) specificity. INTERPRETATION: None of the RDTs evaluated approached the "desired or acceptable levels" for sensitivity set out in the WHO target product profile, while all of the tests met the "desired level" for specificity. Nevertheless, the QuickNavi-Ebola™ and OraQuick® Ebola Rapid Antigen Test demonstrated the most favorable profiles, and may be used as frontline tests for triage of suspected-cases while waiting for RT-qPCR confirmatory testing. FUNDING: Institute of Tropical Medicine Antwerp/EDCTP PEAU-EBOV-RDC project.

Virus kinetics and biochemical derangements among children with Ebolavirus disease.

Background: A paucity of data is available on virologic and biochemical characteristics of paediatric Ebolavirus disease (EVD), compared to adults. Methods: We conducted a retrospective chart review of children (<16 years old) and a comparator group of young adults (16-44 years) from two treatment centres during the 2018-2020 EVD epidemic in Eastern Democratic Republic of the Congo. Statistical methods included chi-squared and Fisher's exact tests (dichotomous and categorical variables), Mann-Whitney U-test (continuous variables), multivariable linear regression (for determinants of admission viral load), linear mixed-effects models (for analysis of longitudinal viral load), and Cox proportional hazard models (to examine risk factors for mortality). Findings: We included 73 children and 234 adults admitted from April to October 2019. Paediatric patients commonly had electrolytes imbalances: hypokalaemia in 26/73 (36%), hyperkalaemia in 38/73 (52%), and hyponatraemia in 54/73 (74%). Hypoglycaemia occurred in 20/73 (27%), acute kidney injury in 43/73 (59%), and rhabdomyolysis in 35/73 (48%). Biochemical abnormalities were detected in a similar proportion of children and adults. The viral load (VL, log10 copies/mL) at admission (7.2 versus 6.5, p=0.0001), the peak viral load (7.5 versus 6.7, p=<0.0001), and the time for viraemia clearance (16 days versus 12 days, p=<0.0001) were significantly different in children. The duration of hospital stay was prolonged in children (20 versus 16 days, p=<0.0001). Risk factors for mortality in children were: VL >7.6 log10copies/mL, alanine transaminase >525 U/L, C-reactive protein >100 mg/L, blood urea nitrogen >7.5 mmol/L, rhabdomyolysis, and.acute kidney injury. Interpretation: Paediatric EVD patients, like adults, experience multiorgan dysfunction with life-threatening electrolyte imbalances, hypoglycaemia, kidney injury, liver injury, and rhabdomyolysis. Paediatric patients have significantly higher VLs throughout the course of EVD than adults. Funding: This study was not funded.

Ebola virus disease nosocomial infections in the Democratic Republic of the Congo: a descriptive study of cases during the 2018-2020 outbreak.

OBJECTIVES: To describe the characteristics of nosocomial cases of Ebola virus disease (EVD) in the Democratic Republic of the Congo between July 2018 and May 2020 in order to inform future interventions. METHODS: Nosocomial cases of EVD were identified during outbreak response surveillance, and a retrospective analysis of cases was conducted according to demographic characteristics and type of health facility (HF). RESULTS: Of 3481 cases of EVD, 579 (16.6%) were nosocomial. Of these, 332 cases occurred in women (57.3%). Patients and visitors accounted for 419 cases (72.4%), of which 79 (18.9%) were aged 6-≤18 years and 108 (25.8%) were aged ≤5 years. Health workers (HWs) accounted for the remaining 160 (27.6%) nosocomial cases. The case fatality rate (CFR) for HWs (66/160, 41.3%) was significantly lower than the CFR for patients and visitors (292/419, 69.7%) (P<0.001). The CFR was higher among cases aged 6-≤18 years (54/79, 68.4%) and ≤5 years (89/108, 82.4%). Referral HFs (>39 beds) had the highest prevalence of nosocomial EVD (148/579, 25.6%). Among HFs with at least one case of nosocomial infection, 50.0% (98/196) were privately owned. CONCLUSIONS: Nurses and traditional healers should be targeted for infection prevention and control training, and supportive supervision should be provided to HFs to mitigate EVD transmission.

Toward a transdisciplinary understanding and a global control of emerging infectious diseases.

The Franceville International Centre for Medical Research (CIRMF) organized a first international symposium on infectious diseases, environments, and biodiversity. Over 200 international experts gathered in Gabon to forecast and work to prevent the emergence of infectious diseases. This symposium aimed to strengthen the regional and international fight against the emergence of infectious diseases with high-level scientific debates. Toward this goal, it brought together experts in human and animal health, the environment, and ecology, including biologists, climatologists, microbiologists, epidemiologists, public health professionals, and human and social sciences specialists. National, regional and international participants were present to debate on the challenges related to the emergence of infectious diseases and on the responses to be implemented. The symposium was very successful, and plans for a second symposium of this kind to be held in the near future in another high-biodiversity area are already underway.