PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION

Ultrasensitive, rapid diagnostic detects Ebola earlier than gold standard test

Portable platform detects early biomarkers of the Ebola virus faster than PCR, the current industry standard

Ultrasensitive, rapid diagnostic detects Ebola earlier than gold standard test
2021-04-07
(Press-News.org) DURHAM, N.C. -- An interdisciplinary team of scientists at Duke University has developed a highly sensitive and rapid diagnostic test for Ebola virus (EBOV) infection. In monkeys infected with Ebola, this diagnostic, called the D4-assay, proved to be 1000 times more sensitive than the currently approved rapid diagnostic test and capable of detecting the virus a full day earlier than the gold standard polymerase chain reaction (PCR) test.

This work, which appears in Science Translational Medicine on April 7, was done by biomedical engineers, molecular biologists, and immunologists at Duke University, and the University of Texas Medical Branch in Galveston and the Galveston National Laboratory.

Ebola virus gained global notoriety in early 2014 after an outbreak began spreading across the populous capital cities in Guinea, Liberia and Sierra Leone in Western Africa. By the time the pandemic was officially declared ended in 2016, more than 28,000 people had been infected and more than 11,300 people had died of the virus.

As of March 2021, there are two ongoing Ebola outbreaks in the Democratic Republic of the Congo that have resulted in more than 2,200 deaths, and Guinea declared a new outbreak of Ebola virus disease (EVD) after a cluster of cases appeared in February.

Early treatment and contact tracing of Ebola virus disease is critical for two reasons: First, patients are highly contagious once they begin showing symptoms, and early diagnosis can help contain the spread of EVD by make contact tracing and patient isolation easier. Second, the fatality rate of EVD can be as high as 90 percent if left untreated or treated late, but can be reduced to roughly 10 percent with monoclonal antibodies if patients are treated early in the infection.

The current gold standard for detecting Ebola virus is the reverse transcriptase polymerase chain reaction (RT-PCR) test, which identifies and amplifies viral RNA. Although RT-PCR has proven to be sensitive and capable of diagnosing Ebola infection much earlier than current alternatives, it has been difficult to implement in the remote settings where EVD outbreaks frequently originate.

Recent advances in RT-PCR test design have made it easier for untrained technicians to use the platform and reduced the need for expensive equipment. However, at $22.50 per test, the platform is expensive and, because it is lab-based, can be slow. In some studies, the median time required to confirm a diagnosis in the field is 6 days, making it a suboptimal tool when dealing with a highly contagious virus.

The current alternate diagnostic option is lateral flow assays, which detect antibodies or antigens that appear during an infection. These tests are cheaper, easy to use, and typically yield results in less than 30 minutes, but the trade-off is a greatly diminished sensitivity, so there is a greater possibility of the test missing an early infection.

To help address the shortcomings of both tests, the Duke team adapted the D4 assay, an ultrasensitive, point-of-care diagnostic previously developed by the Ahsutosh Chilkoti lab, to quickly and accurately detect secreted glycoprotein (sGP), a biomarker produced by the Ebola virus during the early stages of infection.

Besides Chilkoti, the Alan L. Kaganov Distinguished Professor of Biomedical Engineering, the team included Cassio Fontes, a former graduate student and now a senior research scientist in the Chilkoti lab, Michael Gunn, MD, a professor of medicine and immunology, and Barbara Lipes, an assistant professor of medicine at the Duke University School of Medicine.

"Prior studies suggested that Ebola virus produces secreted glycoprotein at high levels early in infection to act as a decoy and distract the immune system while the virus replicates and binds to the host cells," Fontes said. "We thought that if we could detect that, we could help facilitate earlier diagnosis, containment, and treatment during Ebola outbreak."

However, antibodies against sGP were not available, so Lipes, an antibody engineering expert in the Gunn lab, created a large library of antibodies that bind to sGP and screened for the antibodies that bound most strongly.

The two labs then worked together to identify the capture-detection antibody pair that provided the greatest sensitivity on the D4 platform.

The D4 assay for Ebola is made by inkjet printing these two antibodies against secreted glycoprotein onto a glass slide: detection antibodies, which are tagged with a fluorescent marker, and capture antibodies, which are primed to bind the target antigen. When a drop of blood or a throat or nose swab is placed on the slide, the detection antibodies separate from the array and bind to the target in the sample. These antibody-biomarker complexes then attach to the capture antibodies on the slide, which glow to indicate a capture.

To further improve sensitivity, the D4 assay is printed on a stealth polymer brush coating developed by the Chilkoti lab, which prevents non-target proteins from attaching to the slide's surface. This removes any 'background noise' on the chip, making it easier to detect very low levels of the target proteins, which makes the D4 assay very sensitive.

In parallel, the Chilkoti lab also developed a cheap but highly sensitive hand-held detector -- the D4Scope -- to read the results of the D4 assay.

"Jason Liu, a graduate student in my lab, worked to develop the D4Scope, which is a low-cost, battery-powered, compact, wide-field fluorescence reader that can image microarray spots with high sensitivity," Chilkoti said. "It was specifically designed using off-the-shelf components, so that parts could easily be replaced if the reader was damaged in the field."

To test their platform, the team worked with collaborators at the University of Texas Medical Branch in Galveston, where they showed that the D4 assay could detect EBOV in non-human primates a full day earlier than the RT-PCR.

"We've put the lateral flow assay to shame, sensitivity wise," said Fontes. "This is exciting because by understanding the biology of this virus, we've shown that there may be a target to look for where immunoassays like the D4 can outperform the PCR. It's really breaking new ground."

As the team moves forward, they aim to continue to refine their platform with the goal of shortening the time to results from 60 minutes to 30 minutes. Experiments are underway using molecular evolution to increase the sensitivity of the capture and detection antibodies.

They are also improving the design of the platform to make it a fully self-contained test. This would mean that users would only need to add a drop of blood to one port of a flow cell and a buffer solution to a second port to run the test under gravity flow. These changes would also allow for improved biocontainment and biosafety when handling potentially dangerous fluids.

Once these changes are made, the team hopes to coordinate clinical experiments in the field.

"I think it's a tremendous opportunity to really change the way Ebola testing works," Gunn said.

"When controlling an outbreak, it's key to identify the infected and be able to trace their contacts very quickly, and our hope is that test would allow you to do that," Gunn said. "With such a simple and rapid assay, you can also quickly screen people who are at risk of having contracted Ebola. It seems simple, but in the grand scheme of things could represent the difference between an outbreak and a pandemic."

INFORMATION:

This research was funded by the National Institutes of Health (NIH, R01AI150888; U19AI142785; UC7AI094660), the US Special Operations Command (w81XWH- 16C-0219), the National Council for the Improvement of Higher Education and the Science Without Borders project. Partial support was provided by the Department of Health and Human Services. The team also received the support of the Biosafety Level 4 (BSL-4) lab at the Galveston National Laboratory.

Competing Interests: The underlying technology of the D4 was developed by Angus Hucknall and Ashutosh Chilkoti, and was acquired by Immucor Inc (Norcross, GA) in 2014. The other authors declare no competing financial interests. CITATION: "Ultrasensitive Point-Of-Care Immunoassay for Secreted Glycoprotein Detects Ebola Infection Earlier Than PCR," Cassio Fontes, Barbara Lipes, Jason Liu, Krystle Agans, Aiwei Yan, Patricia Shi, Daniela Cruz, Garrett Kelly, Kelli Luginbuhl, Daniel Joh, Stephanie Foster, Jacob Heggestad, Angus Hucknall, Maiken Mikkelson, Carl Pieper, Roarke Horstmeyer, Thomas Geisbert, Michael Gunn, Ashutosh Chilkoti. Science Translational Medicine, April 7, 2021. DOI 10.1126/scitranslmed.abd9696


[Attachments] See images for this press release:
Ultrasensitive, rapid diagnostic detects Ebola earlier than gold standard test

ELSE PRESS RELEASES FROM THIS DATE:

Urolithin A shows effective against muscular dystrophy

Urolithin A shows effective against muscular dystrophy
2021-04-07
Progression of Duchenne Muscle Dystrophy (DMD) can be delayed in mice by supplementing their diets with Urolithin A, according to new results reported today. The findings, published in Science Translational Medicine, raise hopes that new treatment options could one-day be developed for DMD, an uncurable genetic condition characterized by progressive muscle degeneration. About 1 in 3,500 boys are born with DMD, which usually develops in childhood and significantly reduces life expectancy. The new research carried out at the laboratory of Professor Johan Auwerx, ...

Fungi are present in your lungs

2021-04-07
The lungs were for a long time considered to be sterile in health, while in diseases like chronic obstructive pulmonary disease (COPD) failure in immune mechanisms were thought to allow microorganisms to proliferate and persist. New sequencing techniques have shown that several microorganisms reside in the lungs of healthy individuals, as well. Few studies have examined the fungal community in COPD and compared it to healthy controls using such techniques. According to the study findings, the compositions of these environments seem to be unaffected by the use of inhaled steroids. Lungs have a unique fungal environment The Bergen COPD Microbiome study (short name "MicroCOPD") is the world's largest single-centre study on the fungal community in ...

Crohn's disease may be caused by immune signaling failure

Crohns disease may be caused by immune signaling failure
2021-04-07
JUPITER, FL - People with Crohn's disease are typically treated with powerful anti-inflammatory medications that act throughout their body, not just in their digestive tract, creating the potential for unintended, and often serious, side effects. New research from the lab of Mark Sundrud, PhD, at Scripps Research, Florida suggests a more targeted treatment approach is possible. Crohn's disease develops from chronic inflammation in the digestive tract, often the small intestine. More than half a million people in the United States live with the disease, which can be debilitating and require repetitive surgeries to remove irreversibly damaged intestinal tissue. Writing in the journal Nature on April 7, Sundrud's team finds that certain immune cells ...

Carbon dioxide levels reflect COVID-19 risk

Carbon dioxide levels reflect COVID-19 risk
2021-04-07
Tracking carbon dioxide levels indoors is an inexpensive and powerful way to monitor the risk of people getting COVID-19, according to new research from the Cooperative Institute for Research in Environmental Sciences (CIRES) and the University of Colorado Boulder. In any given indoor environment, when excess CO2 levels double, the risk of transmission also roughly doubles, two scientists reported this week in Environmental Science & Technology Letters. The chemists relied on a simple fact already put to use by other researchers more than a decade ago: Infectious people exhale ...

WHOI and NOAA release report on U.S. socio-economic effects of harmful algal blooms

WHOI and NOAA release report on U.S. socio-economic effects of harmful algal blooms
2021-04-07
Harmful algal blooms (HABs) occur in all 50 U.S. states and many produce toxins that cause illness or death in humans and commercially important species. However, attempts to place a more exact dollar value on the full range of these impacts often vary widely in their methods and level of detail, which hinders understanding of the scale of their socio-economic effects. In order to improve and harmonize estimates of HABs impacts nationwide, the National Oceanic and Atmospheric Administration (NOAA) National Center for Coastal Ocean Science (NCCOS) and the U.S. National Office for Harmful Algal Blooms at the Woods Hole Oceanographic Institution (WHOI) convened a workshop led by WHOI Oceanographer ...

Field guides: Argonne scientists bolster evidence of new physics in Muon g-2 experiment

Field guides: Argonne scientists bolster evidence of new physics in Muon g-2 experiment
2021-04-07
Scientists are testing our fundamental understanding of the universe, and there's much more to discover. What do touch screens, radiation therapy and shrink wrap have in common? They were all made possible by particle physics research. Discoveries of how the universe works at the smallest scale often lead to huge advances in technology we use every day. Scientists from the U.S. Department of Energy's (DOE) Argonne National Laboratory and Fermi National Accelerator Laboratory, along with collaborators from 46 other institutions and seven countries, are conducting an experiment to put our current understanding of the universe to the test. The first result points to the existence of undiscovered particles or forces. This new physics could help explain long-standing ...

First results from Fermilab's Muon g-2 experiment strengthen evidence of new physics

First results from Fermilabs Muon g-2 experiment strengthen evidence of new physics
2021-04-07
AMHERST Mass. - The long-awaited first results from the Muon g-2 experiment at the U.S. Department of Energy's Fermi National Accelerator Laboratory show fundamental particles called muons behaving in a way that is not predicted by scientists' best theory, the Standard Model of particle physics. This landmark result, made with unprecedented precision and to which UMass Amherst's David Kawall's research group made key contributions, confirms a discrepancy that has been gnawing at researchers for decades. "Today is an extraordinary day, long awaited ...

Surgical sutures inspired by human tendons

Surgical sutures inspired by human tendons
2021-04-07
Sutures are used to close wounds and speed up the natural healing process, but they can also complicate matters by causing damage to soft tissues with their stiff fibers. To remedy the problem, researchers from Montreal have developed innovative tough gel sheathed (TGS) sutures inspired by the human tendon. These next-generation sutures contain a slippery, yet tough gel envelop, imitating the structure of soft connective tissues. In putting the TGS sutures to the test, the researchers found that the nearly frictionless gel surface mitigated the damage typically ...

Research brief: Reflecting sunlight could cool the Earth's ecosystem

2021-04-07
Published in the Proceedings of National Academy of Sciences, researchers in the Climate Intervention Biology Working Group -- including Jessica Hellmann from the University of Minnesota Institute on the Environment -- explored the effect of solar climate interventions on ecology. Composed of climate scientists and ecologists from leading research universities internationally, the team found that more research is needed to understand the ecological impacts of solar radiation modification (SRM) technologies that reflect small amounts of sunlight back into space. The team focused on a specific proposed SRM strategy -- referred ...

Race and poverty appear to guide heart muscle DNA methylation in heart-failure patients

Race and poverty appear to guide heart muscle DNA methylation in heart-failure patients
2021-04-07
BIRMINGHAM, Ala. - Race associates with the risk of death from end-stage heart failure. So, identifying the molecular determinants of that risk may help the pursuit of the novel diagnosis and prognosis of heart failure, and its therapy. A University of Alabama at Birmingham study of end-stage heart-failure patients has found that cytosine-p-guanine, or CpG, methylation of the DNA in the heart has a bimodal distribution among the patients, and that race -- African American versus Caucasian -- was the sole variable in patient records that explained the difference. A subsequent ...

LAST 30 PRESS RELEASES:

Scientists model 'true prevalence' of COVID-19 throughout pandemic

New breakthrough to help immune systems in the fight against cancer

Through the thin-film glass, researchers spot a new liquid phase

Administering opioids to pregnant mice alters behavior and gene expression in offspring

Brain's 'memory center' needed to recognize image sequences but not single sights

Safety of second dose of mRNA COVID-19 vaccines after first-dose allergic reactions

Changes in disparities in access to care, health after Medicare eligibility

Use of high-risk medications among lonely older adults

65+ and lonely? Don't talk to your doctor about another prescription

Exosome formulation developed to deliver antibodies for choroidal neovascularization therapy

Second COVID-19 mRNA vaccine dose found safe following allergic reactions to first dose

Plant root-associated bacteria preferentially colonize their native host-plant roots

Rare inherited variants in previously unsuspected genes may confer significant risk for autism

International experts call for a unified public health response to NAFLD and NASH epidemic

International collaboration of scientists rewrite the rulebook of flowering plant genetics

Improving air quality reduces dementia risk, multiple studies suggest

Misplaced trust: When trust in science fosters pseudoscience

Two types of blood pressure meds prevent heart events equally, but side effects differ

New statement provides path to include ethnicity, ancestry, race in genomic research

Among effective antihypertensive drugs, less popular choice is slightly safer

Juicy past of favorite Okinawan fruit revealed

Anticipate a resurgence of respiratory viruses in young children

Anxiety, depression, burnout rising as college students prepare to return to campus

Goal-setting and positive parent-child relationships reduce risk of youth vaping

New research identifies cancer types with little survival improvements in adolescents and young adul

Oncotarget: Replication-stress sensitivity in breast cancer cells

Oncotarget: TERT and its binding protein: overexpression of GABPA/B in gliomas

Development of a novel technology to check body temperature with smartphone camera

The mechanics of puncture finally explained

Extreme heat, dry summers main cause of tree death in Colorado's subalpine forests

[Press-News.org] Ultrasensitive, rapid diagnostic detects Ebola earlier than gold standard test
Portable platform detects early biomarkers of the Ebola virus faster than PCR, the current industry standard