Clinical trials in settings with intermittent or non-existent internet and power connectivity, for example during humanitarian emergencies, present challenges in the synchronisation of data across different sites, in addition to accessing a centralised database in real-time. To overcome these, we designed a novel hybrid analogue/digital data management system which was deployed during the rapid implementation of a Phase III evaluation of a two-dose preventative vaccine for Ebola virus disease in Goma, Democratic Republic of the Congo, from 2019 to 2022. We provided study participants with an Enhanced Participant Record Card (EPRC) that served as eligibility for, and confirmation of, vaccination and was used in combination with Open Data Kit (ODK) electronic case report forms to create an off-grid study participant management system. To understand the utility of the EPRC, we analysed data from 15,327 study participants who received both vaccines and various types of prompts or reminders to return for dose 2, including home visits, telephone calls, or short messaging service (SMS). A total of 53% participants referred to the date on the EPRC as a prompt to return for dose 2 and 36.1% mentioned this as the only prompt. A multivariable generalised linear mixed-effects model showed that those who were not working, those aged 45–64 years or who had a chronic medical condition identified prior to receiving dose 2 were more likely to use the date on the EPRC as a prompt. Our findings demonstrate the utility of this system in the facilitation of decentralised data collection in off-grid locations that may be useful for future trials in complex humanitarian settings.
The west Africa Ebola disease epidemic (2014-16) marked a historic change of course for patient care during emerging infectious disease outbreaks. The epidemic response was a failure in many ways-a slow, cumbersome, and disjointed effort by a global architecture that was not fit for purpose for a rapidly spreading outbreak. In the most affected countries, health-care workers and other responders felt helpless-dealing with an overwhelming number of patients but with few, if any, tools at their disposal to provide high-quality care. These inadequacies, however, led to attention and innovation. The decade since then has seen remarkable achievements in clinical care for Ebola disease, including the approval of the first vaccines and treatments. In this paper, the first in a two-part Series, we reflect on this progress and provide expert summary of the modern landscape of Ebola disease, highlighting the priorities and ongoing activities aimed at further improving patient survival and wellbeing in the years ahead.
Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria.
METHODS
We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity.
FINDINGS
Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read.
INTERPRETATION
The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings.
Lassa fever (LF), a haemorrhagic illness caused by the Lassa fever virus (LASV), is endemic in West Africa causing an estimated 300 000 to 500 000 cases and 5 000 fatalities every year. Due to its pandemic potential, LF has been placed on the WHO's list of priority pathogens in order to speed up the development of a safe and effective vaccine. However, the design of successful vaccine trials depends on the true prevalence and incidence rates of LF, which are unknown as infections are often asymptomatic and clinical presentations are varied. The aim of the Enable Lassa research programme is to estimate the incidences of LASV infection and LF disease in five West African countries.
METHODS
We conducted a prospective cohort study in Benin, Guinea, Liberia, Nigeria (three sites), and Sierra Leone from 2020 to 2023, with 24 months of follow-up. Each site assessed the incidence of LASV infection, LF disease, or both. When both incidences are assessed the LASV cohort (n = 1 000 per site) was drawn from the LF cohort (n = 5 000 per site). During recruitment participants completed questionnaires on household composition, socioeconomic status, demographic characteristics, and LF history, and blood samples were collected to determine IgG LASV serostatus. LF disease cohort participants were contacted biweekly to identify acute febrile cases, from whom blood samples were drawn to test for active LASV infection using RT-PCR. LASV infection cohort participants were asked for a blood sample every six months to assess LASV IgG serostatus.
RESULTS
Interim results were obtained in October 2022 using partial data. We focus here on the Nigeria-Edo cohort with a follow-up period of 22 months and 3 serological time-points available (T0, T6, T12). We found a baseline seroprevalence of 43% (95% CI: 42% - 45%), an incidence rate of LASV infection of 13% (10% - 16%) and an incidence rate of LF disease of 0.2% (0.1% - 0.3%). These results suggest that LASV infection is common, but LF disease is rare in hotspot communities. Furthermore, our results suggest that pre-exposure to LASV may temporarily reduce the risk of LF disease. Finally, we found evidence that children may be at greater risk of LF disease than adults due to lower pre-exposure.
CONCLUSION
This is the first epidemiological study to measure the incidence of LF disease and LASV infection in West Africa. The estimates will serve as a basis for the design of future vaccine efficacy trials. The interim results, although limited due to partial data, already suggest that a large sample of several tens of thousands of participants will be required and that children should be included, provided that the candidate vaccine is safe and immunogenic in this group.
KEY MESSAGE
Incidence of Lassa fever is needed to inform vaccine trials. Preliminary results show frequent infections but rare disease, suggesting the need for large vaccine trials.
This abstract is not to be quoted for publication.
Only one recommendation currently exists for the treatment of Lassa fever (LF), which is ribavirin administered in conjunction with supportive care. This recommendation is primarily based on evidence generated from a single clinical trial that was conducted more than 30 years ago-the methodology and results of which have recently come under scrutiny. The requirement for novel therapeutics and reassessment of ribavirin is therefore urgent. However, a significant amount of work now needs to be undertaken to ensure that future trials for LF can be conducted consistently and reliably to facilitate the efficient generation of evidence.
METHODOLOGY
We convened a consultation group to establish the position of clinicians and researchers on the core components of future trials. A Core Eligibility Criteria (CEC), Core Case Definition (CCD), Core Outcome Set (COS) and Core Data Variables (CDV) were developed through the process of a multi-stakeholder consultation that took place using a modified-Delphi methodology.
RESULTS
A consensus position was achieved for each aspect of the framework, which accounts for the inclusion of pregnant women and children in future LF clinical trials. The framework consists of 8 core criteria, as well as additional considerations for trial protocols.
CONCLUSIONS
This project represents the first step towards delineating the clinical development pathway for new Lassa fever therapeutics, following a period of 40 years without advancement. Future planned projects will bolster the work initiated here to continue the advancement of LF clinical research through a regionally-centred, collaborative methodology, with the aim of delineating a clear pathway through which LF clinical trials can progress efficiently and ensure sustainable investments are made in research capacity at a regional level.