Malaria rapid diagnostic tests in endemic settings

Maltha, Jessica; Gillet, Philippe; Jacobs, Jan

doi:10.1111/1469-0691.12151

Cited by 129 publications

(142 citation statements)

References 94 publications

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“…Although microscopic examination of thick and thin blood smears remains the diagnostic gold standard, this technique requires considerable technologist training and ongoing internal and external proficiency assessments, and it is insensitive at very low parasitemia. RDTs have the advantage of rapid turnaround, but their excellent performance characteristics are limited to P. falciparum, with suboptimal diagnostic sensitivity for non-falciparum species, especially P. ovale and P. malariae, as reported in this study and other studies (10,11). Molecular methods do not require highly specialized technologists and have the advantage of sensitivity and rapidity; however, their practicality is limited to well-resourced reference centers, typically in settings of nonendemicity.…”

Section: Discussionmentioning

confidence: 79%

Sequence-Based Optimization of a Quantitative Real-Time PCR Assay for Detection of Plasmodium ovale and Plasmodium malariae

et al. 2014

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Although microscopic examination of Giemsa-stained blood smears remains the gold standard for the diagnosis of malaria, molecular detection using PCR is becoming increasingly popular. Due to discrepant PCR and microscopy results, we aimed to optimize our detection assays for Plasmodium malariae and Plasmodium ovale by sequencing the 18S rRNA region and developing a new primer and probe set for real-time quantitative PCR (qPCR). Clinical specimens positive for P. malariae (n ‫؍‬ 15) or P. ovale (n ‫؍‬ 33) underwent amplification and sequencing of the 18S rRNA region. Based on sequence discrepancies between our current primer/probe and clinical isolates, degenerate P. ovale primer and probe were developed to determine if their performance characteristics improved. The reference (gold) standard was microscopy. No 18S sequence heterogeneity was observed among the P. malariae isolates, and the sensitivity and specificity of our current P. malariae qPCR assay were both 100%. Compared to microscopy, the sensitivity and specificity of our current P. ovale qPCR assay were 72.7% and 100%, respectively. Five single nucleotide polymorphisms (SNPs) were identified in P. ovale. The sensitivity of the new P. ovale assay increased to 100% with 100% specificity. We therefore improved the performance characteristics of our P. ovale molecular detection assay through the development of a degenerate primer and probe set which accommodates 18S SNPs among the 2 subspecies of P. ovale. Given the suboptimal sensitivity of rapid diagnostic tests for non-falciparum malaria and the typically low parasitemia of P. malariae and P. ovale, a well-performing confirmatory molecular assay is imperative for clinical laboratories.

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Section: Discussionmentioning

confidence: 79%

Sequence-Based Optimization of a Quantitative Real-Time PCR Assay for Detection of Plasmodium ovale and Plasmodium malariae

et al. 2014

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“…e . risks that cannot be mitigated by adaptations and improvement of product design) of product failure and test limitations [27, 28]. …”

Section: Discussionmentioning

confidence: 99%

Photo-based External Quality Assessment of Malaria rapid diagnostic tests in a non-endemic setting

et al. 2018

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IntroductionIn non-endemic settings, expertise in malaria microscopy is limited and rapid diagnostic tests (RDTs) are an adjunct to malaria diagnosis.AimWe performed an External Quality Assessment (EQA) on reading and interpretation of malaria RDTs in a non-endemic setting.MethodsParticipants were medical laboratories in Belgium and the Grand Duchy of Luxembourg using malaria RDTs; they received (i) 10 high-resolution photographs presenting test line combinations of RDTs with interpretations listed in a multiple choice format and (ii) a questionnaire about their practices of malaria diagnosis.ResultsAmong 135 subscribing laboratories, 134 (99.3%) used 139 RDT products (11 different products from 8 brands). After exclusion of the results of one laboratory, analysis was done for 133 laboratories using 137 RDT products. Scores of 10/10, 9/10 and 8/10 were achieved for 58.4%, 13.1% and 8.0% of 137 RDT products respectively. For three-band P. falciparum–pan-Plasmodium RDTs (113 (82.5%) products, 6 brands), most frequent errors were (1) disregarding faint test lines (18.6%), (2) reporting invalid instead of P. falciparum (16.8%) and (3) reporting “Plasmodium spp., no further differentiation possible” without mentioning the presence or absence of P. falciparum (11.5%). For four-band RDTs (21 (15.3%) products, 1 brand), errors were (4) disregarding faint P. vivax test lines (47.6%) and (5) reporting “Plasmodium spp., no further differentiation possible” without mentioning the presence of P. falciparum and P. vivax (28.6%). Instructions for use (IFU) of only 4 out of 10 RDT products mentioned to interpret faint-intensity test lines as positive (conducive to errors 1 and 4) and IFU of 2 products displayed incorrect information (conducive to errors 2 and 5). Outside of office hours, 36.1% of participants relied on RDTs as the initial diagnostic test; 13.9% did not perform microscopic confirmation.ConclusionReading and interpretation of malaria RDTs was satisfactory, but errors were embedded in the instructions for use of the products. Relying on RDTs alone for malaria diagnosis (about one third of participants) is not a recommended practice.

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“…The composition of the target antigen varies between malaria RDTs. HRP-2-based RDTs are more sensitive than aldolase-or PfLDH-based RDTs for P. falciparum, whereas pLDH-based RDTs are more sensitive than aldolase-based RDTs for P. vivax (2,10). Nevertheless, specificity is also important for selecting malaria RDTs, and our study suggests new points for consideration for malaria RDTs to reduce false-positive results.…”

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confidence: 99%

False-Positive Results for Rapid Diagnostic Tests for Malaria in Patients with Rheumatoid Factor

et al. 2014

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c Four different rapid diagnostic tests (RDTs) for malaria were evaluated by testing 82 healthy control patients, 89 Plasmodium vivax-infected patients, and 92 rheumatoid factor (RF)-positive nonmalaria patients. The false-positive rate ranged from 2.2% to 13% in RF-positive patients. High RF levels are associated with malaria RDT false positivity. M alaria remains a major global health problem in tropical and subtropical countries, with high morbidity and mortality and extensive economic loss (1). Malaria rapid diagnostic tests (RDTs) are becoming the clinical diagnostic method of choice due to their quick results and ease of use, even by inexperienced personnel (2). However, false-positive results may be observed in patients with rheumatoid factor (RF), hepatitis C, toxoplasmosis, human African trypanosomiasis, dengue, leishmaniasis, Chagas disease, and schistosomiasis (2). Iqbal et al. (3) reported that 33 of the 35 false-positive specimens were negative when the RF was absorbed in the immunochromatographic test (ICT). The goal of this study was to use four different malaria RDTs to explore the relationship between false-positive malaria RDT results and RF.Between April 2010 and August 2013, a total of 263 wholeblood samples with EDTA were collected from South Korean patients at the Korea University Guro Hospital, Republic of Korea. Of these 263 samples, 89 were infected with malaria, as confirmed by Giemsa-stained microscopic examination, 92 did not have malaria but did have RF, and 82 had neither malaria nor RF. Both microscopy and PCR were used to rule out malaria. Each patient provided informed consent under the protocol for human use, which was approved by the Human Use Ethical Committee, Korea University Guro Hospital.Thick and thin blood films were prepared when blood was drawn in accordance with standard procedures. These films were stained with Giemsa and examined by trained microscopists who did not have prior knowledge of the patients' clinical history. Plasmodium species and the parasite density were determined. The circumsporozoite protein (CSP) gene of Plasmodium vivax was amplified by PCR using previously established methods (4). Four commercial malaria RDT kits were selected based on the multiple target antigens (Ags) detected, the BinaxNOW malaria kit (Binax Inc., Scarborough, ME, USA), the OptiMAL-IT malaria kit (BioRad, Marnes la Coquette, France), the SD Bioline malaria Ag Pf/ Pan rapid test (Standard Diagnostics, Inc., Yongin, South Korea), and the Humasis malaria P.f/Pan antigen test (Humasis, Anyang, South Korea). BinaxNOW detects both histidine-rich protein 2 (HRP-2), which is specific to Plasmodium falciparum, and aldolase, which is a pan-malarial enzyme found in the five human pathogenic Plasmodium species (5). OptiMAL-IT differentiates P. falciparum-specific lactate dehydrogenase (PfLDH) and pan-Plasmodium lactate dehydrogenase (pLDH) by immunological detection (6). The SD Bioline and Humasis tests target HRP-2 for P. falciparum and pLDH for other human malaria species (7,8). All te...

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Malaria rapid diagnostic tests in endemic settings

Cited by 129 publications

References 94 publications

Sequence-Based Optimization of a Quantitative Real-Time PCR Assay for Detection of Plasmodium ovale and Plasmodium malariae

Sequence-Based Optimization of a Quantitative Real-Time PCR Assay for Detection of Plasmodium ovale and Plasmodium malariae

Photo-based External Quality Assessment of Malaria rapid diagnostic tests in a non-endemic setting

False-Positive Results for Rapid Diagnostic Tests for Malaria in Patients with Rheumatoid Factor

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