Mobile Point of Care Diagnostic Testing for Ebola Virus Disease in DRC

In the Ebola outbreak in Guinea up to 90% of patients tested negative but were rarely diagnosed for differentials and Malaria and other diseases went under-diagnosed, which most likely lead to more deaths from these infectious agents. Another important aspect is that, the fear of the patients of having Ebola, while they are suffering from other disease must be overcome by providing the correct diagnosis of the type of the pathogen timely. [Dunbar NK et al.].

The RPA assay is six times faster than conventional real-time PCR while yielding the same analytical sensitivity and specificity. In addition, the RPA format (equipment size, cold-chain independent reagents) makes rapid on-site testing feasible and affordable. We developed a mobile laboratory, which consists of a hard plastic glovebox a Diagnostics-in-a-Suitcase (DiaS), and a solar panel and power pack set. The disassembled glovebox is kept in a metal box (80 × 60 × 41 cm) with other necessary materials (disinfectant solution, extraction kits, filter tips, racks, vortex, heat block, autoclavable plastic bags and personal protective equipment (PPE). The total weight is 28 kg for the box and 16 kg for the DiaS. Sample inactivation and RNA extraction using the SE kit so far were done in the glovebox. This allowed handling of hazard group 4 samples. The RT-RPA assay was performed in the DiaS containing the ESEQuant TS2 device with integrated touchscreen to operate the device and display the results without the need of a laptop, which is not easy to disinfect (Figure 1).The mobile lab was successfully deployed in Conakry when an increasing number of cases, due mainly to non-reporting, reticence, and infection transmission chains during burials developed towards the end of 2014. To provide quick results for the safe and dignified burial (SDB) programme two mobile laboratories were set up in the Matoto Gbessia Port II district. Altogether 928 post-mortem swab samples were tested. Overall, 120 samples (12.9%) scored positive. Positive results were obtained within 30-40 min and reported directly to the SDB teams [Faye O et al.].

APPROACH

Objective:

To assess the performances and operational characteristics of the differential RPA we will use i) a panel of well characterized EBOV sera from samples collected in Guinea and DRC ii) sera from EVD suspect cases, and iii) sera from routine diagnostics at IPD and NIBR.