Differential Diagnosis of Malaria on Truelab Uno®, a Portable, Real-Time, MicroPCR Device for Point-Of-Care Applications

Abstract

BackgroundSensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings.MethodsTruenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec’s Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system.ResultsThe limit of detection of the Truenat Malaria assay was found to be <5 parasites/μl for both P. falciparum and P. vivax. The Truenat® Malaria test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5–99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively.ConclusionThe Truenat® Malaria microPCR test is a valuable diagnostic tool and implementation should be considered not only for malaria diagnosis but also for active surveillance and epidemiological intervention.

<em>Plasmodium knowlesi</em> malaria: current research perspectives

“… 51 Truelab Uno, based on TaqMan chemistry, has 100% sensitivity and specificity compared to the nested PCR. 52 Other point-of-care molecular tools for malaria include Illumigene Malaria LAMP work-flow, nanomal, and nucleic acid lateral flow immunoassay DIAGMAL. 53 However, these molecular methods were not tested specifically for P. knowlesi .…”

Chagas Disease Diagnostic Applications

“…Several rapid diagnostic and PoC tests to detect infection based on immunochromatography, particle agglutination, immunofiltration, immunodot, lateral-flow immunochromatographic assays (LFIA) or DNA detection are available for a variety of infectious diseases (Nair et al, 2016; Natoli et al, 2014; Teles and Fonseca, 2015). These may be either qualitative or semi-quantitative and are characterized by the delivery of quick results, in most cases without the need for electrical equipment.…”

High prevalence of malaria in a non-endemic setting: comparison of diagnostic tools and patient outcome during a four-year survey (2013–2017)

“…The molecular detection of malaria parasites is highly accurate and sensitive, and remains the best method for detecting multiple species and sub clinical infections [ 6 , 16 ]. The barriers to adoption of PCR include its high cost and the amount of infrastructure required in terms of equipment and a sophisticated laboratory setup with stable power and refrigerators for reagent storage [ 17 ]. Thus, its availability is limited to well-resourced reference facilities.…”