## 3 Results and Discussion
This preparatory work allowed the laboratory team and trainees to become acquainted with BFA-specific biosafety procedures and analytical flow, including hydration of the cassette, preparation and loading of the sample in the glovebox, loading the cassette into the reader outside the glovebox, and use of the BFA software (Figure 6). In conjunction with the B-LiFE team, the trainees implemented additional BFA-specific biosafety procedures for the analysis of Ebola samples. The method included the following steps: (i) thermal inactivation of viral samples according to the WHO-recommended protocol (60 \({}^{\circ}\)C for 60 min) using a thermoblock inside the glovebox, (ii) preparation of the cassette in the glovebox (i.e., hydration of the reagents, preparation, and loading of the sample), (iii) decontamination of the cassette inside the glovebox with 1% sodium hypochlorite, and (iv) transfer of the cassette outside the glovebox and loading it into the BFA analyser placed on a bench near the glovebox. Figure 5: A breakdown by EVD status of the total cases and samples analysed during the B-LiFE Ebola mission in Guinea. We compared the BFA results for sixteen archived samples (11 plasma and 5 urine samples) with previously acquired qPCR results for the same samples. Almost all of the BFA results (15/16) concurred with the qPCR results (Table 1). The only discordant result (i.e., BFA-negative/qPCR-positive) was observed in sample 04 collected from patient-1 in the convalescence phase. For this sample, 2 of 3 replicates were qPCR-positive, with a high mean Cq value (37.8), indicating a very low viral load. Although qPCR tests were only performed on fresh samples, all BFA tests were performed on archived samples stored at \(-20\)\({}^{\circ}\)C with a mean interval period of 13.6 days (range: 3-46 days). Interestingly, performing BFA on previously frozen samples did not affect the quality of the results. Testing urine samples enabled us to evaluate the analytical efficiency of the BFA test on non-plasma body fluids, which is relevant since infectious Ebola virus is known to persist in semen, urine, and breast milk, with evidence of infectivity up to 531 days after initial diagnosis of infection [30; 31]. Moreover, follow-up with patient-1 enabled us to compare BFA and qPCR test results on 7 successive plasma samples and 1 urine sample. Except for sample 04, as previously stated, the BFA and qPCR results agreed for all subsequent samples, demonstrating that the BFA test can be used for EVD diagnosis. Most importantly, the data confirmed that the BFA test was easy to implement and user-friendly for local trainees working in a laboratory tent. Therefore, this method can be used for rapid and reliable EVD screening under field conditions in remote areas with weakened, disrupted, or totally lacking laboratory resources and without highly trained personnel. Notwithstanding the reagent costs, this type of automated assay platform can quickly strengthen the diagnostic capacity of deployed laboratories, contributing to national capacity building in terms of identification and surveillance of endemic and epidemic agents [10]. Data on BFA testing for EVD diagnosis have become available [15; 16; 17] since our deployment in N'Zerekore. However, in contrast with our field conditions, previous validation studies were performed in fixed and reasonably well-equipped laboratory facilities: the first in the haemorrhagic fever laboratory of the Donka National Hospital (Conakry, Guinea) [15], the second in a small private hospital (Bo, Sierra Leone) [16], and the last at the Public Health England and the United Kingdom Ministry of Defence Laboratory at the Kerry Town ETC (Sierra Leone) [17]. Interestingly, while processing a much larger  
Figure 6: The BioFine FilmArray (BFA) system. (**a**) The BFA reader was installed inside the laboratory tent, (**b**) but outside the glovebox. (**c**) The BFA instrument was installed and connected to a computer with the adequate software-hardware.