A new tool can quickly and reliably determine the presence of the Ebola virus in a blood sample, according to a study by researchers at Washington University School of Medicine in St. Louis and colleagues at other institutions.
Pictured is a color scanning electron microscope image depicting Ebola virus particles budding from the cell surface. A new study from researchers at Washington University School of Medicine in St. Louis and colleagues at other institutes have detailed a new tool that can quickly identify the presence of Ebola virus in blood samples. This technology has the potential to be developed into a rapid diagnostic test. Image credit: National Institute of Allergy and Infectious Diseases
The technology uses so-called optical microchip resonators, which could potentially be developed into a rapid diagnostic test for the dead Ebola virus disease, killing 89% of those infected. Since its discovery in 1976, the Ebola virus has caused dozens of outbreaks, mainly in central and west Africa. An outbreak that began in 2014 and killed more than 11,000 people in Guinea, Sierra Leone and Liberia; In the US, the virus has caused 11 cases and two deaths. Rapid, early diagnosis can help public health workers monitor the spread of the virus and implement strategies to limit outbreaks.
The study – which also involved researchers from the University of Michigan, Ann Arbor, and Integrated Biotherapeutics, a biotechnology company – was published in the journal Cell Reports Method.
“Anytime you can diagnose an infection earlier, you can allocate health care resources more efficiently and promote better outcomes for individuals and communities,” said first co-author said Abraham Qavi, MD, PhD, a postdoctoral researcher at the University of Washington. “Using Ebola infection biomarkers, we have demonstrated that we can detect Ebola infection during the critical early days after infection. A few days makes a big difference in getting people the medical care they need and breaking the cycle of transmission. “
The Ebola virus is transmitted by contact with bodily fluids. It causes fever, body aches, diarrhea, and bleeding – nonspecific symptoms that are easily confused with other viral infections or malaria. In recent years, vaccines and effective treatments for Ebola have been developed, but they are not yet widely available. Instead, health officials control the deadly virus by containing outbreaks. This strategy relies on quickly identifying those infected and preventing transmission by encouraging caregivers to wear protective gear.
Qavi previously worked with Dr. Ryan C. Bailey, Robert A. Gregg Professor of Chemistry at the University of Michigan and senior co-author of this paper, to jointly develop optical microtubule resonators. , a type of whispering library-mode device used for molecular detection. The name comes from the Whispering Gallery at St. Paul in London. You can hear whispers in the archway above the nave more than 100 feet away because the sound waves increase in amplitude as they bounce around the circular wall. 18th century builders inadvertently constructed a giant demonstration of the principle of acoustic resonance, in which sound waves increase in amplitude if they interact exactly in the right way. The same phenomenon occurs with light waves on a much smaller scale.
When Qavi joined the co-author’s lab Gaya K. Amarasinghe, Ph.D. – an Ebola expert and Former Distinguished Professor of Pathology & Immunology and a professor of biochemistry & molecular biophysics and molecular microbiology at the University of Washington – they decided to apply the technology this to create a better diagnostic test for Ebola. Qavi collaborated with Bailey, first co-author Krista Meserve, a PhD student in Bailey’s lab. Same author Lan Yang, Ph.D.Edwin H. and Florence G. Skinner, Professor of Electrical & Systems Engineering at the University of Washington’s McKelvey School of Engineering, have developed a tool to detect small amounts of Ebola-related molecules in blood samples using how to use a micro resonator.
“We trap the light in the resonator and use the resonance to improve and enhance our signal,” says Qavi. “By tracking where this resonant wavelength occurs, we can tell how many molecules we have.”
The key is to find the right molecule. Current diagnostic tests detect the genetic material of the virus or the glycoprotein – a protein covered with sugar – made by the virus. But they are not reliable until the virus has multiplied to high levels in the body, a process that can take days. Senior co-author Frederick Holtsberg, PhD, vice president of manufacturing and bioanalysis at Integrated Biotherapeutics, has developed a highly sensitive antibody capable of detecting low levels of viral soluble glycoproteins. .
The researchers incorporated the antibody into their device and tested it using blood from infected animals. They found that their technique could detect glycoproteins as early or earlier than the most sensitive test for viral genetic material. Importantly, the technology also allowed them to quantify the amount of viral glycoproteins in the blood. The higher the level, the more severely infected the animal. Furthermore, the test takes only 40 minutes from start to finish.
“Looking at these data, we can say, ‘If you’re above these levels, your chances of survival are low; If you are below that, your chances of survival are very high,” said Qavi. “We still have to validate this in infected individuals, but if it is appropriate, doctors can use this information to tailor treatment plans to individual patients and allocate scarce drugs. for the patients most likely to benefit.
He added: “We demonstrated basic science work. “Now it’s just a matter of miniaturizing the devices and putting them in the field.”
Source: Washington University in St. Louis
