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.
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Authors | Marloes Heutmekers, Philippe Gillet, Lieselotte Cnops, Emmanuel Bottieau, Marjan Van Esbroeck, Jessica Maltha, Jan Jacobs |
Journal | Malaria journal
(Malar J)
Vol. 11
Pg. 359
(Oct 29 2012)
ISSN: 1475-2875 [Electronic] England |
PMID | 23107162
(Publication Type: Comparative Study, Evaluation Study, Journal Article)
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Chemical References |
- Antigens, Protozoan
- HRP-2 antigen, Plasmodium falciparum
- Protozoan Proteins
- L-Lactate Dehydrogenase
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Topics |
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Antigens, Protozoan
(blood)
- Child
- Child, Preschool
- Diagnostic Tests, Routine
(methods)
- Female
- Humans
- Infant
- L-Lactate Dehydrogenase
(blood)
- Malaria, Falciparum
(diagnosis)
- Male
- Middle Aged
- Plasmodium falciparum
(immunology, isolation & purification)
- Protozoan Proteins
(blood)
- Sensitivity and Specificity
- Young Adult
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