Evaluation of the malaria rapid diagnostic test SDFK90: detection of both PfHRP2 and Pf-pLDH

• Published in: Malaria Journal
• Main Authors: Heutmekers Marloes, Gillet Philippe, Cnops Lieselotte, Bottieau Emmanuel, Van Esbroeck Marjan, Maltha Jessica, Jacobs Jan
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2012
• Subjects: Malaria; Plasmodium falciparum; Diagnosis; Rapid diagnostic test; Histidine-rich protein; Plasmodium falciparum -specific Plasmodium lactate dehydrogenase; Evaluation; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-11-359; https://doaj.org/article/2bcbf5bcdec44f2aac6a4a56fd8c07cc

Abstract Background Rapid diagnosis of Plasmodium falciparum infections is important because of the potentially fatal complications. SDFK90 is a recently marketed malaria rapid diagnostic test (RDT) targeting both histidine-rich protein 2 (PfHRP2) and P . falciparum -specific Plasmodium lactate dehydrogenase (Pf-pLDH). The present study evaluated its diagnostic accuracy. Methods SDFK90 was tested against a panel of stored whole blood samples (n= 591) obtained from international travellers suspected of malaria, including the four human Plasmodium species and Plasmodium negative samples. Microscopy was used as a reference method, corrected by PCR for species diagnosis. In addition, SDFK90 was challenged against 59 P . falciparum samples with parasite density ≥4% to assess the prozone effect (no or weak visible line on initial testing and a higher intensity upon 10-fold dilution). Results Overall sensitivity for the detection of P . falciparum was 98.5% and reached 99.3% at parasite densities >100/μl. There were significantly more PfHRP2 lines visible compared to Pf-pLDH (97.3% vs 86.9%), which was mainly absent at parasite densities <100/μl. Specificity of SDFK90 was 98.8%. No lot-to-lot variability was observed ( p = 1.00) and test results were reproducible. A prozone effect was seen for the PfHRP2 line in 14/59 (23.7%) P . falciparum samples tested, but not for the Pf-pLDH line. Few minor shortcomings were observed in the kit’s packaging and information insert. Conclusions SDFK90 performed excellent for P . falciparum diagnosis. The combination of PfHRP2 and Pf-pLDH ensures a low detection threshold and counters potential problems of PfHRP2 detection such as gene deletions and the prozone effect.