A breakthrough in diagnostic technology could significantly impact the fight against mpox, a virus that has spread globally since 2022. Researchers from the University of California, San Diego (UCSD), and Boston University (BU) have developed an optical biosensor capable of rapidly detecting mpox, potentially transforming how the disease is diagnosed and controlled. This novel approach could enable point-of-care diagnoses and provide quicker results than current methods, which are slower and more expensive. The study, published in Biosensors and Bioelectronics on November 14, 2024, offers hope for more efficient detection of the virus, which has caused rising concern worldwide.
Mpox: A Growing Global Concern
Since 2023, a new variant of human mpox has claimed the lives of approximately 5% of those infected in the Democratic Republic of the Congo (DRC), particularly affecting children. This variant has since spread to multiple countries. The World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern on August 14, 2023. Additionally, another variant, although rarely fatal, has caused an outbreak affecting over 100 countries since 2022.
Urgent Need for Faster Diagnostics
There is a growing urgency for faster, more affordable diagnostic methods to contain the spread of mpox and prepare for future global health threats. The current standard for diagnosing mpox is polymerase chain reaction (PCR) testing, which is costly, laboratory-dependent, and can take days or even weeks to yield results. This delay is problematic in the face of a rapidly spreading epidemic or potential pandemic.
In response, researchers from UCSD and BU have developed a groundbreaking biosensor that could diagnose mpox on-site, dramatically improving speed and accessibility.
A Revolutionary Approach to Diagnostics
The new diagnostic technology leverages a digital detection platform called Pixel-Diversity interferometric reflectance imaging sensor (PD-IRIS), which uses light interference to detect the virus. Developed by a team led by Selim Ünlü, a distinguished engineering professor at BU, this optical biosensor can detect virus particles at the point of care without needing laboratory equipment.
“The challenge with diagnosing mpox in a clinical setting is that its symptoms—fever, pain, rashes, and lesions—are common to many other viral infections,” said Partha Ray, an associate project scientist at UCSD School of Medicine and co-principal investigator on the study. “It’s not easy to distinguish mpox from these other diseases just by looking at the patient.”
How the Technology Works
In the study, the team used samples from a patient at UCSD Health who had a laboratory-confirmed case of mpox. They incubated the samples with monoclonal antibodies that bind specifically to proteins on the surface of the virus. The virus-antibody complex was then introduced to tiny chambers on silicon chips treated to fix the nanoparticles.
Using precise wavelengths of red and blue light, the researchers created interference patterns, which changed when virus-antibody complexes were present. A color camera detected these minute changes, allowing the team to count individual particles with high sensitivity.
Ünlü compared the process to FM radio, where a weak signal is amplified by mixing it with a stronger carrier signal. In this case, the weak signal comes from the scattered light from the virus, while the stronger signal comes from the chip’s surface reflection.
Rapid Results and High Specificity
The biosensor can detect mpox in as little as two minutes, with the full process—collecting samples and obtaining real-time results—taking about 20 minutes. The speed of the test could significantly improve diagnosis, allowing healthcare providers to quickly identify mpox cases and take appropriate action, especially in regions with limited resources.
The test’s ability to distinguish mpox from other viruses, such as herpes simplex virus and cowpox virus, which have similar symptoms, underscores the high specificity of the technology.
“In a clinical setting, this rapid test could enable healthcare providers to start treatment much sooner, which is crucial in preventing the spread of the virus,” said Ray.
A Vision for Widespread Use
Ray and Ünlü envision the technology being mass-produced as diagnostic kits, potentially sold to clinics worldwide. A single kit could test for multiple viruses, such as syphilis or HIV, by swapping out the virus-specific antibody. This adaptability would help keep costs down, making the technology more accessible.
However, to bring this vision to fruition, the researchers emphasize the need for government support. They highlight that there is little commercial incentive to develop diagnostics for future threats without public backing.
“If we don’t address this epidemic now, it won’t be limited to Africa,” warned Ray.
Next Steps and Funding
The researchers are working towards commercialization, with the goal of addressing urgent needs in regions like the Democratic Republic of the Congo. Their efforts are supported by funding from the National Institute of Allergy and Infectious Diseases (NIAID) and the National Science Foundation (NSF), as well as other collaborators from UCSD, BU, and the Centers for Disease Control and Prevention (CDC).
By advancing this innovative technology, the team hopes to improve global health security and prevent the emergence of future pandemics.
Additional Contributors:
Howard Brickner, UCSD
Alex E. Clark, UCSD
Aaron F. Carlin, UCSD
Elif Seymour, iRiS Kinetics, BU
Michael B. Townsend, CDC
Panayampalli S. Satheshkumar, CDC
Iris Celebi, BU
Megan Riley, axiVEND
This research was supported by the National Institutes of Health (P30 AI036214) and the National Science Foundation (NSF-TT PFI 2329817).
Date:Nov 14 2024
Source:University of California – San Diego
