Reliability of malaria rapid diagnostic tests (RDTs) in imported malaria: implications for diagnostic preparedness in...

Climate change is increasing the environmental suitability of the Mediterranean basin for malaria transmission, raising concerns about the potential re-emergence of the disease in areas where it has long been eradicated. As imported cases represent the potential source of local transmission in receptive areas, the rapid and accurate identification of imported malaria cases is a major public health priority. This study evaluated the diagnostic performance of a point-of-care Rapid Diagnostic Test (RDT) compared with an automated Real-Time PCR assay in a clinical setting in Sicily, Italy.

A total of 119 samples from 117 patients with suspected malaria were analyzed. Blood samples were evaluated simultaneously using the Malaria P.f. /Pan Rapid Test Cassette and a fully automated Real-Time PCR assay, which served as the molecular reference standard.

Molecular analysis confirmed 32 imported malaria cases (93.75% Plasmodium falciparum, 3.1% P. vivax, 3.1% P. ovale). The RDT demonstrated a sensitivity of 96.87% and a specificity of 96.55%. Notably, the Negative Predictive Value (NPV) was 98.82%, with an overall diagnostic accuracy of 96.63%. Cohen's Kappa coefficient (κ = 0.916) indicated almost perfect agreement. Minor discrepancies (three false positives and one false negative) were consistent with known RDT limitations, such as prolonged HRP2 antigen persistence and detection limits.

The RDT showed high diagnostic accuracy as a first-line screening tool for the rapid triage of febrile travelers, facilitating timely clinical decision-making and initial patient management. However, Real-Time PCR remains essential for case confirmation and accurate species identification, supporting an integrated diagnostic strategy to manage imported malaria in climate-vulnerable, non-endemic regions.