Abstract
Rapid, low-cost, species-specific diagnosis, based upon DNA testing, is becoming important in the treatment of patients with infectious diseases. Here, we demonstrate an innovation that uses origami to enable multiplexed, sensitive assays that rival polymerase chain reactions (PCR) laboratory assays and provide high-quality, fast precision diagnostics for malaria. The paper-based microfluidic technology proposed here combines vertical flow sample-processing steps, including paper folding for whole-blood sample preparation, with an isothermal amplification and a lateral flow detection, incorporating a simple visualization system. Studies were performed in village schools in Uganda with individual diagnoses being completed in <50 min (faster than the standard laboratory-based PCR). The tests, which enabled the diagnosis of malaria species in patients from a finger prick of whole blood, were both highly sensitive and specific, detecting malaria in 98% of infected individuals in a double-blind first-in-human study. Our method was more sensitive than other field-based, benchmark techniques, including optical microscopy and industry standard rapid immunodiagnostic tests, both performed by experienced local healthcare teams (which detected malaria in 86% and 83% of cases, respectively). All assays were independently validated using a real-time double-blinded reference PCR assay. We not only demonstrate that advanced, low-cost DNA-based sensors can be implemented in underserved communities at the point of need but also highlight the challenges associated with developing and implementing new diagnostic technologies in the field, without access to laboratories or infrastructure.
Highlights
Rapid, low-cost, species-specific diagnosis, based upon DNA testing, is becoming important in the treatment of patients with infectious diseases
We recently reported a diagnostic platform that uses paper folding to integrate the different blood sample preparation steps that are required for Loop-mediated isothermal amplification (LAMP) onto a paper microfluidic device [25]
The readout was difficult to assess quantitatively in varying levels of ambient light. This optical detection method was ambiguous at low levels of infections, when the signal-to-background was small. To overcome this uncertainty in visual signal measurement, we present a format for a paper-based microfluidic device that uniquely combines our previously published vertical sampleprocessing steps of the origami device [25] with a microfluidic lateral flow LAMP amplification and detection platform
Summary
Low-cost, species-specific diagnosis, based upon DNA testing, is becoming important in the treatment of patients with infectious diseases. Point-of-care immunoassays, known under the generic term of rapid diagnostic tests (RDTs), are based upon a hand-held lateral flow technology and are widely used in low-resource areas They are able to detect the presence of species-specific antigens derived from the malarial parasites, Significance. The 2018 World Health Organization (WHO) malaria report [1] highlights that, after almost two decades of decline, malaria cases have significantly risen in 13 countries, stating that no significant progress has been made in reducing global malaria between 2015 and 2017 (before the number of people contracting the disease had been falling) This has prompted concern that more is needed to combat the epidemic, and the report highlights the need for species-specific diagnostics before treatment. Health workers are increasingly calling for low-cost, rapid diagnostic devices that require no refrigeration, laboratory equipment, or special training, but that can detect parasites even when they are not abundant
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call