Limitations of Rapid Diagnostic Testing in Patients with Suspected Malaria: A Diagnostic Accuracy Evaluation from Swaziland, a Low-Endemicity Country Aiming for Malaria Elimination

Abstract

SummaryIn a low-endemicity/malaria elimination setting, we demonstrate limited sensitivity of Plasmodium falciparum–specific rapid diagnostic testing for suspected malaria, owing to unexpected low-density infections. Positive predictive value was also low, requiring further investigation. More accurate diagnostics may be needed.

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

“…In conclusion, the present study complements the previous findings by Ranadive [1]. In particular, it grants more accuracy to the RDT in terms of PPV (89.0% vs 67.3%).…”

“…To the Editor-We thank Rossi and colleagues for sharing their findings from Cambodia [1], which complement our recent article reporting limitations of rapid diagnostic testing in patients with suspected malaria from Swaziland, a low-endemic country in southern Africa aiming to eliminate malaria [2]. Using polymerase chain reaction (PCR) as gold standard, they performed a diagnostic accuracy evaluation of rapid diagnostic testing (RDT) to diagnose Plasmodium falciparum in subjects with suspected malaria.…”

“…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%).…”

“…Low-density infection, defined as <100 parasites/μL, explained 75% of false-negative results (compared to 76% in our study). With the large sample size of 4382 patients, sampling of all RDT negatives (vs selective sampling employed in our study), and use of quantitative PCR, the study is a useful addition to the few published studies on performance of RDT to assess symptomatic malaria in low-transmission settings [1,3,4]. As malaria transmission declines, the proportion of low-density infection among symptomatic as well as asymptomatic individuals increases [5][6][7].…”

Effect of Artificial Intelligence-Based Technology in Malaria Diagnosis

“…5 Rapid diagnostic tests are very good options in remote areas for diagnosis but they have their own disadvantages like persistence of HRP-2 in blood, low sensitivity at initial stages of lower parasitaemia and inability to give quantitative results and results very significantly across brands and batches. 6 So, overall misdiagnosis remains a challenge in curbing the antimalarial resistance due to unnecessary prescriptions 7 and preventing the morbidity and mortality secondary to missed malaria detection. 8 Recent advances in molecular diagnostics like PCR and LAMP have shown very good results in accurate diagnosis but they are time consuming, costly and not feasible at all places.…”