Phase 3 Evaluation of an Innovative Simple Molecular Test for the Diagnosis of Malaria in Different Endemic and Health Settings in Sub-Saharan Africa (DIAGMAL)

Abstract Background: Rapid Diagnostic Tests (RDTs) have become the cornerstone for the management of malaria in many endemic settings. However, the use of RDTs in diagnostic strategies is constrained for several reasons: (i) persistent malaria antigen (histidine-rich protein 2; HRP2) leading to false positive test results; (ii) hrp2 deletions leading to false negative Pf HRP2 results; and (iii) limited sensitivity with a detection threshold of around 100 parasites/µl blood ( p LDH- and HRP2-based) leading to false negative tests. Microscopy is still the gold standard for malaria diagnosis, and allows for species determination and quantitation, but requires trained microscopists and well maintained microscopes. Furthermore, microscopy has also detection limit issues. Consequently, there is a pressing need to develop and evaluate more sensitive and accurate diagnostic tests that circumvent the above mentioned limitations of RDTs and microscopy. To address this need we have developed a direct on blood mini PCR-NALFIA test that combines the benefits of molecular biology with low infrastructural requirements and extensive training.Methods: This is a Phase 3 diagnostic evaluation being conducted in 5 African countries. Study sites (Sudan, Ethiopia, Burkina, Kenya and Namibia) were selected to ensure wide geographical coverage of Africa and to address various malaria epidemiological contexts ranging from high transmission to near elimination settings with different clinical scenarios and diagnostic challenges. Study participants (patients with clinically suspected malaria) will be enrolled at the study health facilities after obtaining written informed consent. Diagnostic accuracy will be assessed following the WHO/TDR guidelines for the evaluation of diagnostics and reported according to STARD principles. Due to the lack of a 100% specific and sensitive standard diagnostic test for malaria, the sensitivity and specificity of the new test will be compared to the available diagnostic practices in place at the selected sites (microscopy and/or RDT) and to quantitative PCR as the reference test. Discussion: This phase 3 study is designed to validate the clinical performance and feasibility of implementing a new diagnostic tool for the detection of malaria in real clinical settings. If successful, the proposed technology will improve the diagnosis of malaria. Enrolment started in November 2022 (Kenya) with assessment of long term outcome to be completed by 2023 at all recruitment sites. Trial registration: This trial is registered at the Pan African Clinical Trial Registry (www.pactr.org) under number PACTR202202766889963 on 1 February 2022 and at ISCRTN (www.isrctn.com/) under number ISRCTN13334317 on 22/02/2022.