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

Embedding treatment in stronger care systems

A key lesson from the west Africa (2014-16) Ebola disease epidemic was that outbreak responses fail when they respond to patients through a narrow clinical lens without considering the broader community and social context of care. Here, in the second of two Series papers on the modern landscape of Ebola disease, we review progress made in the last decade to improve patient-centred care. Although the biosafety imperatives of treating Ebola disease remain, recent advances show how to mitigate these so that patients are cared for in a safe and dignified manner that encourages early treatment-seeking behaviour and provides support after the return of patients to their communities. We review advances in diagnostics, including faster Ebola disease detection via real-time RT-PCR, and consider design improvements in Ebola disease treatment units that enhance patient safety and dignity. We also review advances in care provision, such as the integration of palliative care and mobile communication into routine care, and address how greater access to research is possible through harmonised clinical trials. Finally, we discuss how strengthened community engagement and psychosocial programmes are addressing stigma and providing holistic support for survivors.

Immunochromatographic Lateral Flow Assays to Detect Filovirus Nucleoproteins

The recent large outbreaks of Ebola virus disease in West Africa and the Democratic Republic of the Congo have highlighted the need for rapid diagnostic tests to control this disease. In this chapter, the development of immunochromatographic lateral flow assays to detect filovirus nucleoproteins is described as an example of designing rapid diagnostic tests.

Systematic review and meta-analysis of antigen rapid diagnostic tests to detect Zaire ebolavirus

We conducted a systematic review and meta-analysis of studies and reports comparing the performance of antigen rapid diagnostic tests (Ag RDT) for diagnosing Ebola disease (EVD). We searched PubMed, EMBASE, and Web of Science for diagnostic studies published between 1976 and 2023, evaluating them with QUADAS-2. Using a bivariate random-effects model, we estimated the pooled sensitivity and specificity of Ag RDTs. Of 64 eligible full studies and reports, 16 met the inclusion criteria. Pooled sensitivity and specificity were 82.1% (95%CI: 75.2 - 88.0) and 97.0% (95%CI: 95.1-98.2), respectively. We conducted subgroup analysis on 4 Ag RDTs, 3 RT-PCR tests, and 4 sample types, showing varied performance. The high specificity and positive predictive value of Ag RDTs support their use to "rule-in" patients with EVD. However, high-sensitivity RDTs suitable for field settings and capable of detecting multiple ebolavirus species are needed.

Development and evaluation of an antigen targeting lateral flow test for Crimean-Congo Haemorrhagic Fever

BACKGROUND

Crimean-Congo Haemorrhagic Fever (CCHF) is a viral haemorrhagic fever with a case fatality rate of 5-25% that has been prioritised for research and development by the World Health Organisation. There are no CCHF rapid diagnostic tests (RDTs) commercially available. We describe the development and evaluation of an antigen-targeting lateral flow immunoassay RDT for CCHF.

METHODS

Prospective clinical samples were collected and tested between July and October 2023 in Türkiye. Retrospective stored samples were obtained from the Central Public Health Laboratory, Baghdad, Iraq. The sensitivity and specificity of the CCHF RDT was compared to reverse transcription quantitative polymerase chain reaction assays.

FINDINGS

On prospective clinical samples in Türkiye, the sensitivity and specificity of the CCHF RDT was 90.4% [95% CI 81.5-95.3%] (n = 73) and 96.2% [95% CI 87.0-99.3%] (n = 52), respectively with a sensitivity of 92.9% [95% CI 84.3-96.9%] (n = 70) in samples with a cycle threshold (Ct) ≤30. On retrospective stored samples in Iraq, sensitivity and specificity of the RDT was 71.7% [95% CI 59.2-81.5%] (n = 60) and 92.5% [95% CI 80.1-97.8%] (n = 40), respectively with a sensitivity of 82.2% [95% CI 68.7-90.7%] (n = 45) in samples of Ct ≤30.

INTERPRETATION

The CCHF RDT was an effective rapid diagnostic test in this preliminary clinical evaluation, showing this RDT has the potential diagnostic capability for use at the point-of-care. Definitive evaluation is now required to ensure the RDT meets the regulatory requirements for commercialisation.

FUNDING

The Liverpool School of Tropical Medicine, National Institute for Health Research Health Protection Research Unit in Emerging Zoonotic Infections, The Medical Research Council and The Pandemic Institute.

Development of a clinical prediction score for Ebola virus disease screening at triage centers in the Democratic Republic of the Congo

The 2018-2020 Ebola virus disease (EVD) outbreak in the Democratic Republic of the Congo (DRC) was the largest since the disease's discovery in 1976. Rapid identification and isolation of EVD patients are crucial during triage. This study aimed to develop a clinical prediction score for EVD using clinical and epidemiological predictors. We conducted a retrospective cross-sectional study using surveillance data from EVD outbreak, collected during routine clinical care at the Ebola Transit Center (ETC) in Beni, DRC, from 2018 to 2020. The Spiegelhalter and Knill-Jones method was used for score development, including potential predictors with an adjusted likelihood ratio above 2 or below 0.50. Validation was performed using a dataset previously published in PLOSOne by Tshomba et al. Among 3725 patients screened, 3698 fulfilled the inclusion criteria, with 571 (15.4%) testing positive for EVD via RT-PCR Test. Seven predictive factors were identified: asthenia, sore throat, conjunctivitis, bleeding gums, hematemesis, contact with a sick person, and contact with a traditional healer. The prediction score achieved an Area under the receiver operating characteristic (AUROC) of 0.764, with 81.4% sensitivity and 53.6% specificity at a -1 cutoff. External validation demonstrated an AUROC of 0.766, with 80.8% sensitivity and 41.4% specificity at the -1 cutoff. Our study developed a screening tool to assess the risk of suspected patients developing EVD and being admitted to ETUs for RT-PCR testing and treatment. External validation results affirmed the model's reliability and generalizability in similar settings, suggesting its potential integration into clinical practice. Given the severity and urgency of EVD as well as the risk nosocomial EVD transmission, it is essential to continuously update these models with real-time data on symptoms, disease progression, patient outcomes and validated RDT during EVD outbreaks. This approach will enhance model accuracy, enabling more precise risk assessments and more effective outbreak management.

Sample-to-result molecular diagnostic platforms and their suitability for infectious disease testing in low- and middle-income countries

INTRODUCTION

Diagnostics are an essential, undervalued part of the health-care system. For many diseases, molecular diagnostics are the gold standard, but are not easy to implement in Low- and Middle-Income Countries (LMIC). Sample-to-result (S2R) platforms combining all procedures in a closed system could offer a solution. In this paper, we investigated their suitability for implementation in LMIC.

AREAS COVERED

A scorecard was used to evaluate different platforms on a range of parameters. Most platforms scored fairly on the platform itself, ease-of-use and test consumables; however, shortcomings were identified in cost, distribution and test panels tailored to LMIC needs. The diagnostic coverage for common infectious diseases was found to have a wider coverage in high-income countries (HIC) than LMIC. A literature study showed that in LMIC, these platforms are mainly used as diagnostic tools or evaluation of diagnostic performance, with a minority assessing the operational characteristics or the clinical utility. In this narrative review, we identified various points for adaptation of S2R platforms to LMIC conditions.

EXPERT OPINION

For S2R platforms to be suitable for implementation in LMIC some modifications by the manufacturers could be considered. Furthermore, strengthening health systems and digitalization are vital; as are smaller, cheaper, faster, and sustainable technologies.

Impact of Ebola epidemics on the daily operation of existing systems in Eastern Democratic Republic of the Congo: a brief review

AIMS

to provide insights into the recent Ebola virus disease (EVD) outbreaks on different aspects of daily life in the Democratic Republic of the Congo and propose possible solutions.

METHODS

We collected information regarding the effects of EVD outbreaks on existing systems in the eastern part of the Democratic Republic of the Congo (DRC). We searched the PubMed database using the terms "impact effect Ebola outbreak system", "Management Ebola Poor Resources Settings", "Health Economic Challenges Ebola" and "Economic impact Ebola systems." Only studies focusing on epidemiology, diagnostics, sequencing, vaccination, therapeutics, ecology, work force, governance, healthcare provision and health system, and social, political, and economic aspects were considered. The search included the electronic archives of EVD outbreak reports from government and partners.

RESULTS

EVD outbreaks negatively impacts the functions of countries. The disruption in activities is proportional to the magnitude of the epidemic and slows down the transport of goods, decreases the region's tourist appeal, and increases 'brain drain'. Most low- and medium-income countries, such as the DRC, do not have a long-term holistic emergency plan for unexpected situations or sufficient resources to adequately implement countermeasures against EVD outbreaks. Although the DRC has acquired sufficient expertise in diagnostics, genomic sequencing, administration of vaccines and therapeutics, clinical trials, and research activities, deployment, operation, and maintenance of these expertise and associated tools remains a concern.

LIMITATIONS

Despite the data search extension, additional reports addressing issues related to social aspects of EVD outbreaks in DRC were not retrieved.

CONCLUSION

National leadership has not yet taken the lead in strategic, operational, or financial aspects. Therefore, national leaders should double their efforts and awareness to encourage local fundraising, sufficient budget al.location, infrastructure construction, equipment provision, and staff training, to effectively support a holistic approach in response to outbreaks, providing effective results, and all types of research activities.

Development of an Immunochromatography Assay to Detect Marburg Virus and Ravn Virus

The recent outbreaks of Marburg virus disease (MVD) in Guinea, Ghana, Equatorial Guinea, and Tanzania, none of which had reported previous outbreaks, imply increasing risks of spillover of the causative viruses, Marburg virus (MARV) and Ravn virus (RAVV), from their natural host animals. These outbreaks have emphasized the need for the development of rapid diagnostic tests for this disease. Using monoclonal antibodies specific to the viral nucleoprotein, we developed an immunochromatography (IC) assay for the rapid diagnosis of MVD. The IC assay was found to be capable of detecting approximately 102-4 50% tissue culture infectious dose (TCID50)/test of MARV and RAVV in the infected culture supernatants. We further confirmed that the IC assay could detect the MARV and RAVV antigens in the serum samples from experimentally infected nonhuman primates. These results indicate that the IC assay to detect MARV can be a useful tool for the rapid point-of-care diagnosis of MVD.