Performance of Rapid Diagnostic Testing in Patients with Suspected Malaria in Cambodia, a Low-Endemicity Country Aiming for Malaria Elimination

To the Editor—We read with interest the article by Ranadive et al [1] assessing the performance of malaria rapid diagnostic testing (RDT) vs polymerase chain reaction (PCR) in Swaziland, a low-transmission country aiming at elimination. Through a large regional data set collected from 37 health facilities over 2 years, they demonstrated the poor sensitivity of RDT (First Response Malaria Ag P. falciparum HRP-2 Detection Rapid Card Test, Premier Medical) for Plasmodium falciparum (Pf) diagnosis (51.7%), due to a high proportion of low-density infections among symptomatic subjects (54/162 [33.3%]), along with a low positive predictive value (PPV) (67.3% for all samples and 62.3% for ≥100 parasites/µL samples), due to the high proportion of false positivity (32.4%). To overcome some of the limitations of the study (eg, the decision to include only 10% of negative RDTs samples), the authors called for more inclusive analyses.