Evidence map›Paper›PMID 40705833›Full record

ArticlePLoS neglected tropical diseases2025

Development and evaluation of a triplex real-time PCR assay for enhanced plague diagnostics in Madagascar.

Beza Ramasindrazana, Zoé A Rahalison, Philippe Gauthier, Guillain Mikaty, Zaina I Bodoarison, Lanto A Maminirina, Soloandry Rahajandraibe, Mamy G Randriamanantsoa, Gilbert Kayoko, Jean-Claude Manuguerra and 3 more

Abstract read
In one paragraph

Article in PLoS neglected tropical diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
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

2 citing papers in PubMed.

  1. Review
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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

13 authors.

Beza RamasindrazanaPlague Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.ORCID 0000-0002-8838-949X
Zoé A RahalisonPlague Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.
Philippe GauthierCBGP, IRD, INRAE, CIRAD, Institut Agro, Université de Montpellier, Montpellier, France.
Guillain MikatyInstitut Pasteur, Université Paris Cité, Unité Environnement et Risques infectieux, Cellule d'Intervention Biologique d'Urgence, Paris, France.
Zaina I BodoarisonPlague Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.
Lanto A MaminirinaPlague Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.
Soloandry RahajandraibeMinistry of Public Health, National Plague Control Program, Antananarivo, Madagascar.
Mamy G RandriamanantsoaMinistry of Public Health, National Plague Control Program, Antananarivo, Madagascar.
Gilbert KayokoWorld Health Organization, Emergency Preparedness and response, Antananarivo, Madagascar.
Jean-Claude ManuguerraInstitut Pasteur, Université Paris Cité, Unité Environnement et Risques infectieux, Cellule d'Intervention Biologique d'Urgence, Paris, France.
Anne-Sophie Le GuernInstitut Pasteur, Université Paris Cité, Yersinia Research Unit, National Reference Centre for Plague and other yersiniosis, Paris, France.
Andriamiliharison J RasamindrakotrokaFaculté de Médecine Humaine, Université d'Antananarivo, Antananarivo, Madagascar.
Minoarisoa RajerisonPlague Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar.

Funding

World Health Organization 001
6 · The paper itself

Abstract

backgroundThe plague, caused by Yersinia pestis, remains a critical public health issue, particularly in endemic regions like Madagascar. Rapid and accurate detection of this pathogen is essential for effective outbreak management and timely intervention. Following the urban plague outbreak of 2017, a new molecular diagnostic algorithm was developed and introduced into routine use. However, certain cases required combining real-time and conventional polymerase chain reaction (PCR) methods. While effective, this approach often delayed obtaining conclusive results, an issue that can hinder swift outbreak responses. The aim of this study is to design and optimize a three-target real-time PCR assay (qPCR) for the detection of Y. pestis in clinical samples.

methodsThe assay targeted three genes: caf1, pla, and yopM, located on the plasmids pMT1, pPCP1, and pCD1, respectively. Conducted at the Institut Pasteur de Madagascar (IPM), the study evaluated the assay using both pure bacterial cultures and clinical samples, including 50 bubonic aspirates and 50 respiratory specimens.

resultsUsing bacteriology technique as the reference standard, the triplex qPCR demonstrated a sensitivity of 100% (89-100%) and a specificity of 82%. The positive predictive value (PPV) was 73% and the negative predictive value (NPV) was 100% (91-100%). The coefficient of agreement kappa was 0.74, with a p-value of <0.0001. Notably, the new assay resolved 100% of previously inconclusive cases from the duplex qPCR test targeting only pla and caf1. DISCUSSION: While a new plague diagnostic algorithm has been set up after the outbreak in 2017, the present study suggests a real-time PCR assay based on three genes to improve the speed and accuracy of plague diagnostic. Furthermore, this new technique is a valuable tool for managing plague outbreaks and supporting field diagnostics not only in Madagascar but also in countries with plague.

conclusionsThe developed triplex assay to molecularly diagnose Y. pestis in human samples improves the standard already in place and allows to resolve ambiguities previously associated with inconclusive results from duplex qPCR tests, thereby reinforcing the reliability and accuracy of this new technique. Implementing this new method into routine will enable a faster, more effective response to plague outbreaks by reducing the time needed to confirm plague cases and limiting the spread of the diseases. This new technique is also flexible and can be undertaken close to human cases with adequate biosecurity and biosafety measures.

Indexed as

Molecular Diagnostic TechniquesMultiplex Polymerase Chain ReactionPlagueReal-Time Polymerase Chain ReactionYersinia pestisAlgorithmsBacterial Outer Membrane ProteinsBacterial ProteinsHumansMadagascarPlasminogen ActivatorsPredictive Value of TestsSensitivity and SpecificityBacterial Outer Membrane ProteinsBacterial Proteinscaf1 protein, Yersinia pestisPla protease, Yersinia pestisPlasminogen ActivatorsyopM protein, Yersinia

Identifiers

PMID40705833
PMCPMC12313063

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Registered trials

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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.