Evaluation of the rapid diagnostic test CareStart pLDH Malaria (Pf-pLDH/pan-pLDH) for the diagnosis of malaria in a reference setting

Malar J. 2012 Jun 18:11:204. doi: 10.1186/1475-2875-11-204.

Abstract

Background: The present study evaluated CareStart pLDH Malaria, a three-band rapid diagnostic test detecting Plasmodium falciparum-specific parasite lactate dehydrogenase (Pf-pLDH) and pan Plasmodium-specific pLDH (pan-pLDH) in a reference setting.

Methods: CareStart pLDH was retrospectively and prospectively assessed with a panel of stored (n=498) and fresh (n=77) blood samples obtained in international travelers suspected of malaria. Both panels comprised all four Plasmodium species; the retrospective panel comprised also Plasmodium negative samples. The reference method was microscopy corrected by PCR. The prospective panel was run side-to-side with OptiMAL (Pf-pLDH/pan-pLDH) and SDFK60 (histidine-rich protein-2 (HRP-2)/pan-pLDH).

Results: In the retrospective evaluation, overall sensitivity for P. falciparum samples (n=247) was 94.7%, reaching 98.7% for parasite densities>1,000/μl. Most false negative results occurred among samples with pure gametocytaemia (2/12, 16.7%) and at parasite densities ≤ 100/μl (7/12, 58.3%). None of the Plasmodium negative samples (n=96) showed visible test lines. Sensitivities for Plasmodium vivax (n=70), Plasmodium ovale (n=69) and Plasmodium malariae (n=16) were 74.3%, 31.9% and 25.0% respectively. Wrong species identification occurred in 10 (2.5%) samples and was mainly due to P. vivax samples reacting with the Pf-pLDH test line. Overall, Pf-pLDH test lines showed higher line intensities compared to the pan-pLDH lines (67.9% and 23.0% medium and strong line intensities for P. falciparum). In the prospective panel (77 Plasmodium-positive samples), CareStart pLDH showed higher sensitivities for P. falciparum compared to OptiMAL (p=0.008), lower sensitivities for P. falciparum as compare to SDFK60 (although not reaching statistical significance, p=0.08) and higher sensitivities for P. ovale compared to both OptiMAL (p=0.03) and SDFK60 (p=0.01). Inter-observer and test reproducibility were good to excellent.

Conclusion: CareStart pLDH performed excellent for the detection of P. falciparum, well for P. vivax, but poor for P. ovale and P. malariae.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antigens, Protozoan / analysis
  • Child
  • Child, Preschool
  • Diagnostic Tests, Routine / methods*
  • Female
  • Humans
  • Immunoassay / methods
  • Infant
  • L-Lactate Dehydrogenase / analysis
  • Malaria / diagnosis*
  • Malaria / parasitology
  • Male
  • Middle Aged
  • Plasmodium / enzymology*
  • Plasmodium / isolation & purification
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Antigens, Protozoan
  • L-Lactate Dehydrogenase