WHO: Rapid, Sensitive, Safe and Simple Ebola Diagnostic Tests Urgently Needed

The goal of interrupting chains of Ebola virus transmission depends heavily on laboratory support. This support is needed to confirm or discard suspected cases, guide triage and clinical decisions, aid contact tracing, and facilitate the early detection of cases in people with an exposure history. The WHO goal of aggressive case detection and isolation likewise depends on laboratory support.

Efforts to contain the Ebola outbreaks in West Africa are currently hampered by cumbersome, slow and complex diagnostic tests that impose a number of additional logistical challenges, including requirements for a high level of laboratory biosafety and staff expertise in using sophisticated machines.

The standard molecular assays currently used in mobile and other laboratories supporting the Ebola response include the reverse-transcriptase polymerase chain reaction, or RT-PCR test. The test, which involves a number of laborious procedures, provides very accurate results when performed by trained staff. Each test requires a full tube of blood, takes from 2 to 6 hours, and costs around $100. These requirements are difficult to meet in resource-constrained West African settings, thus severely limiting testing capacity.

Lost time – for patients and treatments

The time lost transporting patient samples over bad roads to West Africa’s limited number of laboratories means that anxious patients and their families may need to wait several days for test results.

Lost time means that infected people may remain in the community, with a severe risk of unknowingly transmitting the virus to others. Moreover, in the absence of rapid laboratory support, people with other common infectious diseases, such as malaria and dengue, that have similar early symptoms may be unjustifiably held in an Ebola “transit” centre as a precautionary measure. If they did not have Ebola when entering the centre, they may unfortunately get it there.

Apart from posing a severe risk to families and communities, undiagnosed and unmanaged patients contribute to the cyclical transmission pattern currently being seen, whereby cases begin to fall as control measures take effect, only to spike again as new chains of transmission are ignited.

Perhaps most importantly, a recent research study, based on the management of more than 700 Ebola patients in Monrovia, Liberia, strongly suggests that clinical decisions guided by results from rapid point-of-care diagnostic tests could significantly improve treatment outcomes.

Moreover, having such tests readily available could restore some order to West African health systems, which have been devastated by fear of contagion as well as by the demands of managing a deadly and dreaded disease.

Apart from expediting the immediate outbreak response, rapid diagnostic tests will have enduring value in countries where many other endemic diseases mimic the early symptoms of Ebola. Having such tests in hand will also leave health services better prepared for a possible recurrence of Ebola in West Africa and elsewhere.

WHO initiatives to stimulate diagnostic innovation and deployment of suitable tests

For all these reasons, WHO has launched two urgent initiatives to stimulate diagnostic innovation and expedite the delivery of better and faster tests to West African countries – compressed into months instead of years.

The first initiative aims to minimize the barriers faced by diagnostic companies to develop and deploy their tests by clearly defining the needs, by identifying channels to access early validation materials and clinical samples for research and development, and by preparing the deployment of these new tests in the affected countries. It is moving forward in close collaboration with manufacturers, academic researchers, staff from Médecins sans Frontières (MSF), and the non-profit organization Foundation for Innovative New Diagnostics, or FIND.

The “ideal” assay

To clearly define the needs and thus guide the development of tests, WHO issued a detailed profile of the “ideal” rapid, sensitive, safe and simple diagnostic test considered most likely to accelerate interruption of virus transmission in severely resource-constrained settings.

For example, the ideal test should be suited for use in peripheral health clinics with no laboratory infrastructure in place. Testing procedures should involve fewer than 3 steps, produce results in less than 30 minutes, and have no biosafety requirements beyond the wearing of personal protective equipment.

Additional operational specifications pertain to the easy storage and reconstitution of reagents and staff training that takes less than half a day. The ideal test and related portable equipment should need no power supply and require no maintenance.

In the absence of regulatory oversight of most commercial Ebola tests, WHO is also assessing the quality of these tests. To date, no rapid tests, either on the market or under development, have undergone full regulatory assessment, underscoring the need for an independent review of these products before they are used in the field. Some tests are marketed for research use only, and not for use with patients.

A new mechanism for emergency quality assessment

The second WHO initiative comes with the establishment of an emergency quality assessment mechanism. This is a rapid review process for assessing a diagnostic’s quality, safety and performance.

In early October, an invitation was sent to manufacturers, known to be working on diagnostic tests for Ebola virus, to submit documentation setting out the evidence they have compiled on the safety, quality and performance of the test. Information to be submitted includes the recommended specimen types; evidence of test performance, including sensitivity and specificity; suppliers of critical components or raw materials and services, and data on current inventory and manufacturing capacity and quality.

Sixteen sets of documentation were received by mid-October. These include conventional RT-PCR diagnostic kits, automated “desktop” PCR systems with integrated specimen processing, and new point-of-care tests that could – within minutes – detect Ebola virus infection with blood from a finger-prick instead of a full tube. The documentation is independently assessed for WHO by expert virologists; the performance of the most promising tests will be verified through a rapid laboratory evaluation using clinical specimens.

The emergency quality assessment mechanism is currently assessing the first 5 of the 16 documentation sets submitted to date. Australian, Belgian and Dutch reviewers are participating in the evaluation, together with staff from the WHO Prequalification of In Vitro Diagnostics Programme.

The overarching objective is to guide bulk procurement decisions by WHO and other partners that will get the best tests to West Africa within the next few months.

The good news

As WHO has noted, the development of rapid and simple to use assays is technically readily achievable. Their commercial price is expected to be less costly than conventional PCR tests. Biomarkers already exist. No significant technical hurdles stand in the way.

Further progress and outstanding needs will be discussed during a WHO expert consultation on innovative Ebola diagnostic tests to be held in Geneva in December.

Source: WHO

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The Next Generation Rapid Ebola Diagnostic Tests

Responsible for almost 5000 deaths, the Ebola epidemic has ravaged West Africa and acted as a catalyst for global health initiatives. More recently, it has surfaced in the United States, prompting blaring, dramatic headlines and mounting fears of the dangerous disease. And with cases of Ebola—not to mention panic—on the rise, researchers and IVD manufacturers are scrambling for better methods of early detection and tests that yield faster results in order to slow the spread of disease.

SP-IRIS Label-Free, On-Site Rapid Diagnostic Test

A cross-functional team of researchers at Boston University (BU) has developed a prototype of a label-free, chip-scale photonics device designed to provide rapid, accurate, on-site detection of Ebola and other infectious diseases. Dubbed the single-particle interferometric reflectance imaging sensor (SP-IRIS), the device has the potential to minimize or possibly eliminate sample preparation time and to reduce processing time from two or more hours down to approximately one hour, according to an article on the university's Web site. If commercialized, the device would also offer a low-cost, relatively simple-to-use alternative to current label-based lab equipment, according to the team.

"To detect and size nanoparticles, SP-IRIS shines light from visible LED sources on nanoparticles bound to the sensor surface, which consists of a silicon-dioxide layer on top of a silicon substrate," Selim Ünlü, a BU professor of biomedical engineering, electrical and computer engineering, and materials science and engineering, told MD+DI. "Interference of light reflected from the sensor surface is modified by the presence of particles producing a distinct signal that reveals the size of the particle."

"We have successfully detected low-index dielectric particles down to 60 nm and various viruses—H1N1, VSV, Ebola—with accurate size discrimination," Ünlü added. "Single nanoparticle detection with IRIS led to virus detection as well as  protein and DNA arrays with attomolar detection sensitivity in serum and unprocessed whole blood." The developers are currently working on further reducing the time the device takes to yield results—with an aim of 30 minutes—and anticipate that a field-ready version of the device may be available in five years.

Recombinant Diagnostic Tests

Backed by a three-year, $2.9-million NIH grant, Colorado-based diagnostic test kit company Corgenix Medical Corp., in collaboration with the Viral Hemorrhagic Fever Consortium, is tackling the challenge of developing rapid diagnostic tests for Ebola. "We have developed prototype lateral flow (LFI) and ELISA diagnostic tests for detecting Ebola," Corgenix CEO Douglass Simpson told MD+DI. "Our LFI prototypes are currently in testing—clinical testing in Africa and analytical testing in controlled lab settings here in the United States."

In the face of the escalating Ebola crisis, the company has ramped up its efforts; however, it has been quick to quell speculation and misguided expectations about when a rapid, point-of-care test capable of diagnosing or ruling out Ebola will be available. "I want to strongly emphasize that this is a new three-year project, building off work commenced in 2010,” Simpson said in an August statement. “We understand the critical nature of this virus and are doing everything possible to accelerate efforts to develop reliable and rapid result diagnostic kits in order to be ready for the next outbreak.”

The company announced in August that it had entered into an agreement to be acquired by German specialty diagnostics company Orgentec Diagnostika.

Firefly Dx

Leveraging real-time polymerase chain reaction (PCR) chemistry, Florida-based PositiveID Corp.'s handheld Firefly Dx system also aims to deliver faster test results, thereby expediting diagnosis, containment, and quarantine of infected patients. "Unlike currently available technologies that are labor intensive, very expensive, and often limited to laboratory or clinical settings—thus falling short of truly effective point-of-need or timely site-specific monitoring—Firefly Dx can be used at the point of need and derive an accurate test result in less than 20 minutes," according to Allison Tomek, senior vice president, corporate development, at PositiveID. "Currently used lab tests for Ebola can take hours or even days to provide a result, and require trained personnel with the appropriate lab equipment to process."

In contrast, the Firefly system does not require any specific training to use and, in turn, can be used in remote areas where trained personnel can be scarce. The system is also not limited to blood; it can yield a diagnosis using saliva, a cheek swab, and urine, among other sample types.

The company is making progress tailoring its current platform for Ebola. "The system is currently in bench-top prototype development, but the cartridge has already demonstrated the ability to detect and identify common pathogens and diseases using DNA and RNA analysis, which is how they currently test for pathogens ranging from influenza to Ebola," Tomek said. "Firefly Dx is built to test for pathogens using any assay, and the assay currently used in labs to detect Ebola will run on Firefly. We expect to have units to test in the field in late 2015."

N-Assay Rapid Test

Last month, Ohio-based biotech company NanoLogix Inc. announced that it, too, would enter the fray by exploring how to adapt its N-Assay Rapid diagnostic kits to detect Ebola. “The company has been aware of the virus detection capabilities of the technology since the N-Assay development. Viruses viewed as public health concerns prior to Ebola and Enterovirus were Influenza, the common cold, and HIV, none of which have an immediate or near-immediate threat of mortality," NanoLogix CEO Bret Barnhizer said in an October statement. "Until recently, NanoLogix has been focused solely on the use of their N-Assay kit for bacteria detection and identification. Now, with the recent outbreaks of both Ebola and Enterovirus, there is an immediate need for configuration of the N-Assay for viruses."

The roadblock for NanoLogix, however, is that its facilities are not equipped for virus testing. In light of this barrier, the company is seeking a corporate partner that has the necessary facilities to help bring the N-Assay for Ebola to market. If the company is able to find a suitable partner, it believes that the N-Assay ELISA could yield results for Ebola in 30 minutes to several hours and could be used in both developed and remote areas.

NESDEP IU

Earlier this year, F Cubed LLC was awarded the 2014 North America Frost & Sullivan Award for Technology Innovation Leadership for its portable NESDEP IU MRSA test kit, for which it is about to start clinical trials. Now, the Indiana-based molecular diagnostics company is examining how it can extend the technology and apply the system, fueled by the company's F3 microfluidic biochip, to Ebola detection.

"We know we can test for any molecular material," Les Ivey, president and CEO of F Cubed told WNDU last month. "Ebola is an RNA virus, so it has a strand of RNA and we can detect that. The job of our NESDEP device is to extract that RNA from the virus. If it matches with the Ebola then we know we had a successful detection."

As its first step, the company is working on developing a test kit that identifies whether or not Ebola is present in objects or surfaces that a potentially infected person may have touched. However, the company hopes to then progress the test kit and navigate the more demanding regulatory hurdles involved with detecting and diagnosing Ebola in patients. The company expects that its technology could deliver test results in about 90 minutes. It's also portable—although not exactly lightweight at 50 lbs—and doesn't require highly skilled professionals to operate, according to the company. The device also carries a hefty price tag, WNDU reported, costing $50,000 while test kits range from $20 to $50 each.

Gene-RADAR

The emerging field of nanobiophysics—combining physics, nanotechnology, and biomedicine—has spawned development of the GENE-Radar device by Massachusetts-based Nanobiosym Diagnostics. Led by CEO and founder Anita Goel and featuring influential advisors such as MDEA Lifetime Achievement Award winner and MIT professor Robert Langer, Nanobiosym was established to "commercialize the Gene-RADAR technology platform to empower people worldwide with portable, rapid, and accurate information about their own health," according to the company's Web site. "Employing the latest advances in nanotechnology, Gene-RADAR is a fully portable, chip-based diagnostic that can recognize any disease with a genetic fingerprint from a single drop of blood or saliva without the need for lab infrastructure, trained health care personnel, electricity, or running water."

The technology has generated a great deal of buzz for its potential to rapidly and easily diagnose HIV and other diseases. But the company has also stated that it is investigating the possibility of adapting the platform to test for Ebola. If successful, the technology could diagnose the disease within an hour for a mere several dollars per test, according to the company.

BioThreat-E Test

While most rapid diagnostic tests for Ebola are still in development, the BioThreat-E test quickly became a technology to watch upon receiving FDA Emergency Use Authorization (EUA) for Ebola last month. Manufactured by Utah-based BioFire Diagnostics—which was acquired by bioMerieux earlier this year—the test is currently available to high and moderate complexity clinical laboratories in the United States, and can deliver results in one hour. The company's previously cleared BioFire FilmArray system, on which the fast-tracked EUA Ebola test runs, is a PCR molecular diagnostic instrument designed to identify infectious diseases.

“This EUA and FilmArray test for Ebola are the result of a long collaboration and close working relationship with U.S. Department of Defense. The FDA has been an excellent working partner, providing the feedback needed to ensure the efficacy of such an important diagnostic test,” Kirk Ririe, CEO of BioFire Defense, said in a statement last month. “It is our mission to help improve public health and the rapid turnaround and ease-of-use of FilmArray will certainly be a great help for the healthcare professionals in the context of the Ebola outbreak.”

Source: Medical Device and Diagnostic Industry Online

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Researchers Continue to Seek a Fast, Finger-Prick Ebola Test

Searching for a new way to attack Ebola, companies and academic researchers are now racing to develop faster and easier tests for determining whether someone has the disease.

Such tests might require only a few drops of blood rather than a test tube of it, and provide the answer on the spot, without having to send the sample to a laboratory.

The tests could be essential in West Africa, where it can take days for a sample to travel to one of the relatively few testing laboratories, leaving those suspected of having the disease in dangerous limbo.

Rapid tests might also be used to screen travelers at airports, providing a more definitive answer than taking their temperatures.

“There’s a great deal of interest in a technology that can screen large numbers of people from a finger prick in only a few minutes,” said Cary Gunn, chief executive of Genalyte, a company in San Diego that says its approach can do just that. “You can imagine testing an entire planeload of passengers and screening through them cost-effectively.”

The World Health Organization is encouraging development of rapid tests, as is the federal government. The Food and Drug Administration is giving emergency authorization for use of qualified Ebola tests. On Oct. 25, it gave such a clearance for a one-hour test developed by BioFire Defense, although that test requires more than a few drops of blood and is typically sent to a laboratory. “It would have taken years to get this product approved through the traditional process,” said Kirk Ririe, chief executive of the company, which is based Salt Lake City and owned by the French diagnostics firm BioMérieux.

Companies are hoping to get their tests into the field in Africa in the next few months, but it is not clear how many will be in time to make a difference in the outbreak. And some health specialists caution that while one company after another is announcing an Ebola test, there is little information about their accuracy.

“It’s a wild, wild West a little bit in development,” said Dr. Mark Perkins, chief scientific officer of FIND, or the Foundation for Innovative New Diagnostics, a nonprofit organization working with the World Health Organization to assess Ebola tests. “Eight Ebola products on the market with no one knowing how they work is not helpful.”

The need for better testing is most acute in West Africa, which has too few testing labs. Dr. Perkins said testing capacity needed to be more than doubled to about 12,000 tests a week in Guinea, Liberia and Sierra Leone and labs placed closer to where people with symptoms are coming for care.

Samples now sometimes have to be transported for hours or days over rutted roads to a laboratory. People suspected of having Ebola must wait in holding rooms until the results come back. If they do not have Ebola when they enter the room, they might have it by the time they leave.

“People are waiting four to five days,” for test results, said Dr. J. Daniel Kelly, who is working in Sierra Leone for the aid group Wellbody Alliance. “They are watching people around them die. Horrible experience. You are locked in there at night.”

Even in the United States, delays can occur, with samples being sent to the Centers for Disease Control and Prevention in Atlanta or some state public health laboratories.

It took about two days for the confirmation that Thomas Eric Duncan was infected after his second visit to a Dallas hospital.

With flu season coming, hospitals might benefit from having a quick way to rule out Ebola for certain patients as their emergency rooms fill with people with fevers and other symptoms that overlap with those of Ebola.

The standard testing technique for Ebola is known as reverse transcription polymerase chain reaction, or RT-PCR. It amplifies the genetic material of the virus, allowing even tiny quantities to be detected. It is very accurate if done correctly.

But PCR generally requires a tube of blood and is performed by trained personnel on a sophisticated machine. A test can take two to six hours or more and cost about $100.

BioFire’s FilmArray test, the one authorized for emergency use by the FDA, is a PCR test that can be done in one hour.

More than 300 hospitals already have one of BioFire’s $39,000 machines, which they have been using to test for other diseases. Now they can test for Ebola on site, though positive findings are supposed to be confirmed by the CDC.

A BioFire machine is in a special isolation ward used to treat Ebola patients at Emory University Hospital, and an instrument was delivered to Bellevue Hospital Center in New York after Dr. Craig Spencer was admitted for treatment.

Still, some say that in Africa, reducing PCR testing time by a couple of hours is not that important.

“The bottleneck is not the speed of the technology,” but the transport time and lack of testing capacity, said Rob Powell, director of research and development at Primerdesign, a British company. It is developing a PCR test using materials that do not require refrigeration, so that it can get “to more far-flung places,” he said.

What would be most valuable in Africa, some health specialists say, is a test that takes a few minutes, as the person awaits results, and costs a few dollars at most.

Various companies and organizations are working to develop such tests, including France’s Atomic Energy Commission, the Institut Pasteur, the German company Senova and the American companies Corgenix, NanoBioSym, Nanomix and others.

“We have been working since March, shoulders against the wheel, to be ready to roll these out in quantities that would make a difference in the outbreak,” said Dr. Robert Garry, a professor of microbiology at the Tulane University School of Medicine.

The test he is working on, which is being manufactured by Corgenix, is similar to a home pregnancy test. It uses antibodies that bind to one of the proteins of the Ebola virus. A finger prick blood sample is put on a test strip, which is then put into a tube containing a solution. After about 15 minutes, a line appears if the virus is present.

Because they do not amplify the viral genes as PCR does, such rapid tests are not expected to be as sensitive in detecting the virus. Using inaccurate tests would be a “perilous endeavor,” said Brian Bird, a veterinary medical officer at the CDC.

If a test falsely says someone has Ebola, that person would be put into an Ebola treatment center, where he or she might catch the disease. And missing an infection would allow a person to return to the community and possibly infect others.

Airport screening is also tricky. A fast test would presumably be more accurate, albeit slower, than thermometers, because body temperature can be raised for many reasons or suppressed by fever-relieving medicines.

But the main problem with screening is not that thermometers are inaccurate. Rather it is that people typically do not develop fever or other symptoms until six days or more after being infected. So they can pass through airport screening, as Mr. Duncan and Dr. Spencer did.

Yet health specialists say the rapid tests probably will not reliably detect the virus until the person has symptoms, because viral levels in the blood will be too low. Even the PCR test has trouble detecting infection much before symptoms appear.

Still, Dr. Garry of Tulane said even detecting the virus in people with mild symptoms might help. He said his test probably would have picked up the infection in Amber Vinson, the Dallas nurse who flew from Cleveland back to Dallas with a slight temperature and was later found to have Ebola.

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