Field validation of the performance of paper-based tests for the detection of the Zika and chikungunya viruses in serum samples Flashcards
Purpose
The purpose of developing the paper-based diagnostic technology is to provide rapid and cost-effective testing for infectious diseases, particularly Zika and chikungunya viruses, in regions where access to centralized clinical labs is limited.
Target: The primary aim is to detect the presence of Zika and chikungunya viruses in patient samples using a simplified and portable diagnostic method.
Challenge: Traditional PCR-based testing methods are often difficult, expensive, and bottlenecked in large-scale testing efforts, hindering timely diagnosis and treatment of infectious diseases.
Technology
Technology: The paper-based diagnostic technology utilizes synthetic gene networks, including toehold switch-based sensors, to target specific RNA sequences of the Zika and chikungunya viruses.
Components: These sensors are combined with recombinant enzymes of transcription and translation from Escherichia coli to transcribe and translate viral RNA sequences into reporter proteins.
Enhancement: The technology incorporates an isothermal RNA amplification reaction (NASBA) to increase sensitivity, allowing detection of viral RNA down to the low-femtomolar range.
Portable Reader: Optical measurements are performed using a low-cost, computer vision-enabled, automated plate reader known as the PLUM reader, designed for ease of use in decentralized settings.
limitations Addressed
Limitations Addressed: The technology addresses several limitations of traditional PCR-based testing, including:
High cost and complexity, making it inaccessible in resource-limited settings.
Dependency on centralized clinical labs, resulting in delayed diagnosis and treatment.
Need for refrigeration during distribution, limiting deployment in remote areas with inadequate infrastructure.
results
Process: The diagnostic process involves transcribing and translating viral RNA sequences into reporter proteins, which generate an optical signal upon detection of the target RNA. This signal is produced through enzymatic cleavage, resulting in a color change from yellow to purple.
Detection Sensitivity: The addition of NASBA allows for highly sensitive detection of viral RNA, even at extremely low concentrations, enabling accurate diagnosis.
Diagnostic Accuracy: The paper-based diagnostic technology achieves a diagnostic accuracy of 98.5% for the Zika virus, equivalent to traditional RT-qPCR methods.
Portability: The PLUM reader facilitates on-site testing, eliminating the need for centralized lab facilities and enabling rapid deployment in the field.
strengths
Analytical Sensitivity: The technology demonstrates equivalent sensitivity to RT-qPCR, ensuring reliable detection of viral RNA.
Diagnostic Accuracy: With a diagnostic accuracy of 98.5% for Zika virus, the paper-based diagnostic method provides highly accurate results.
Portability: The PLUM reader enables decentralized testing, making it suitable for use in remote and resource-limited settings.
Ease of Use: The system is designed to be user-friendly, automated, and self-contained, requiring minimal technical expertise for operation.
weaknesses
Liquid Handling: Skilled users are required for sample preparation, including RNA extraction from patient samples, which may pose challenges in settings with limited laboratory expertise.
Manual Intervention: The need for manual intervention increases the risk of cross-contamination and human error, particularly during sample preparation and assay setup.
Cost: While lower in cost compared to traditional PCR methods, the paper-based diagnostic technology may still be expensive for some resource-limited settings, hindering widespread adoption.
Technical Challenges: Ensuring affordability, scalability, and maintaining consistent performance across different settings are ongoing challenges that need to be addressed for successful implementation of the technology.
