Evaluating Field Performance of NxTek™ Eliminate Malaria Pf a highly Sensitive Malaria RDT: Detection of infection among febrile patients, asymptomatic pregnant women and household contacts in Mpigi, Uganda

Abstract

Abstract Background: The World Health Organisation recommends that malaria case management is based on parasite-based diagnosis in all cases. However, currently available tools for clinical use have limitations, including the inability to detect low-level infections. Next-generation highly sensitive rapid diagnostic tests (HS-RDT) for Plasmodium falciparum (Pf) are commercially available but require field-based validation. This study evaluated the performance of the highly sensitive NxTek™ Eliminate Malaria Pf (NxTek) diagnostic test in health facilities and community settings in Mpigi district, Uganda, compared to the conventional rapid diagnostic tests (cRDTs) and evaluated a real-time data capture and transmission tools. Methods: Between April and December 2019, we randomly enrolled symptomatic participants from the outpatient department (OPD), community settings and asymptomatic Antenatal Care (ANC) women. The participants were tested with both cRDTs and an HS-RDT to detect Plasmodium falciparum HRP2 antigen and quality-assured results with qPCR as a reference. All results were transmitted as geo-coded real-time data using a smartphone with custom-designed software. Results: Among symptomatic participants at OPD, HS-RDTs showed 13.1% (110/8418) positive with the P.falciparum compared to 7.1% (612/8585) proportion positive for cRDTs. HS-RDTs detected 11% (384/3,490) positives among asymptomatic pregnant women at ANC. At iCCM testing points 79.7% (2,397/3,009) of the under-five age group were positive for malaria parasites on cRDTs. Follow-up to the homes of confirmed positive index contacts, HS-RDTs resulted in the detection of 21.1% (1,877) asymptomatic positive of different age groups. Acceptability of new technology was observed and demonstrated by the users. All health workers effectively performed HS-RDT testing after a one-day training session and transmitted real-time results through the 'Sympheos Collect' customized Android telephone application provided. Conclusion: Using HS-RDTs increased case findings of low parasite density infections compared to cRDTs in study populations and allowed the elimination of malaria reservoirs through treatments. The introduction of HS-RDTs and Sympheos CollectTM data collecting systems are feasible, acceptable, easy to use and require minimal additional training. Further evidence is required to demonstrate the wide population impact of HS-RDTs on asymptomatic infections in various age groups.