Evidence map›Paper›PMID 29310651›Full record

ArticleMalaria journal2018

Stabilization of RDT target antigens present in dried Plasmodium falciparum-infected samples for validating malaria rapid diagnostic tests at the point of care.

Collins Morang'a, Cyrus Ayieko, George Awinda, Rachel Achilla, Caroline Moseti, Bernhards Ogutu, John Waitumbi, Elizabeth Wanja

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Malaria journal, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.2field-weighted citation impact, top 39% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 7 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 4 institutions in 3 countries.

Collins Morang'aMaseno University, P.O Box Private Bag, Maseno, Kenya. collinsmisita@gmail.com.
Cyrus AyiekoMaseno University, P.O Box Private Bag, Maseno, Kenya.
George AwindaUnited States Army Medical Research Directorate, P.O Box 54, Kisumu, 40100, Kenya.
Rachel AchillaUnited States Army Medical Research Directorate, P.O Box 54, Kisumu, 40100, Kenya.
Caroline MosetiUnited States Army Medical Research Directorate, P.O Box 54, Kisumu, 40100, Kenya.
Bernhards OgutuKenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya.
John WaitumbiUnited States Army Medical Research Directorate, P.O Box 54, Kisumu, 40100, Kenya.
Elizabeth WanjaUnited States Army Medical Research Directorate-Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand.
United States Army Medical Research Directorate - Africa · KEKenya Medical Research Institute · KEMaseno University · KEUnited States Army · US

Funding

Military Infectious Diseases Research Program L0324_13_WR_OC
6 · The paper itself

Abstract

backgroundMalaria rapid diagnostic tests (RDTs) are a great achievement in implementation of parasite based diagnosis as recommended by World Health Organization. A major drawback of RDTs is lack of positive controls to validate different batches/lots at the point of care. Dried Plasmodium falciparum-infected samples with the RDT target antigens have been suggested as possible positive control but their utility in resource limited settings is hampered by rapid loss of activity over time.

methodsThis study evaluated the effectiveness of chemical additives to improve long term storage stability of RDT target antigens (HRP2, pLDH and aldolase) in dried P. falciparum-infected samples using parasitized whole blood and culture samples. Samples were treated with ten selected chemical additives mainly sucrose, trehalose, LDH stabilizer and their combinations. After baseline activity was established, the samples were air dried in bio-safety cabinet and stored at room temperatures (~ 25 °C). Testing of the stabilized samples using SD Bioline, BinaxNOW, CareStart, and First Response was done at intervals for 53 weeks.

resultsStability of HRP2 at ambient temperature was reported at 21-24 weeks while that of PAN antigens (pLDH and aldolase) was 2-18 weeks of storage at all parasite densities. The ten chemical additives increased the percentage stability of HRP2 and PAN antigens. Sucrose alone and its combinations with Alsever's solution or biostab significantly increased stability of HRP2 by 56% at 2000 p/µL (p < 0.001). Trehalose and its combinations with biostab, sucrose or glycerol significantly increased stability of HRP2 by 57% (p < 0.001). Unlike sucrose, the stability of the HRP2 was significantly retained by trehalose at lower concentrations (500, and 200 p/µL). Trehalose in combination biostab stabilizer increased the percentage stability of PAN antigens by 42, and 32% at 2000 and 500 p/µL respectively (p < 0.01). This was also the chemical combination with the shortest reconstitution time (~ < 20 min).

conclusionsThese findings confirm that stabilizing RDT target antigens in dried P. falciparum-infected samples using chemical additives provides field-stable positive controls for malaria RDTs.

Indexed as

Point-of-Care SystemsReference StandardsAntigens, ProtozoanChromatography, AffinityDiagnostic Tests, RoutineHumansL-Lactate DehydrogenaseMalaria, FalciparumPlasmodium falciparumProtozoan ProteinsTemperatureTime FactorsAntigens, ProtozoanHRP-2 antigen, Plasmodium falciparumL-Lactate DehydrogenaseProtozoan ProteinsChemical additivesMalariaPositive controlsRapid diagnostic testsStability

Identifiers

PMID29310651
PMCPMC5759799
OpenAlexW2783480532

What OpenQuestion holds

Textmetadata
LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.