The Food and Drug Administration (FDA) approved two new diagnostic tests that can detect Ebola from blood, urine or saliva samples in as little as an hour. The tests are made by BioFire Defense, a Salt Lake City-based company, and can be used in the company’s FilmArray machine, a device that can look for Ebola virus genes in the blood. In the U.S., 300 hospitals already use the machine to detect a range of infectious agents.
One test is designed for commercial use in hospitals and laboratories, while the other is approved only for labs designated by the Department of Defense.
The company said it sent a FilmArray machine with the newly approved Ebola kit to Bellevue Hospital, where Dr. Craig Spencer, the fourth person to be diagnosed with Ebola in the U.S., is being treated. But because the approval came so quickly, and the device was rushed to the hospital at the FDA’s request, proper New York city and state regulations have not been met yet, so the machine is still not in use. The company says the paperwork should be completed soon. “We are working through the process of being able to deliver [it] to Bellevue Hospital and hope that happens soon,” says Kirk Ririe, CEO of BioFire Defense, which worked with the U.S. military to develop the Ebola test kit. “We just got out ahead of ourselves.”
The two tests were approved under the agency’s Emergency Use Authorization powers, which allows the FDA to permit use of unapproved tools or drugs to be used to diagnose, treat or prevent “serious or life-threatening diseases or conditions caused by [chemical, biological, radiological or nuclear] threat agents when there are no adequate, approved and available alternatives.”
While quick diagnosis of Ebola is critical to identifying patients infected with the virus and providing them with health care that can save their lives, officials at Doctors Without Borders (Medecins Sans Frontieres, or MSF) say that the BioFire tests do come with some disadvantages in the field. Currently, lab technicians use a gene-based assay to pick up genetic fingerprints of the Ebola virus. The test takes four hours, but the current technologies can run multiple samples from different patients at the same time, allowing clinics like MSF to test up to 70 people a day. While the BioFire platform can spit out results in one hour, it can only run one sample at a time, so to maintain the high volume of testing at outbreak centers, says Erwan Piriou, laboratory advisor at MSF, “we would need multiple devices to reach the same throughout in a day. I feel in that sense the device doesn’t solve everything.”
That could be tricky in the resource-poor settings where Ebola typically emerges. Each machine costs around $39,000, and the price of each test is about $189.
The big advantage to the BioFire platform, however, is that it requires less handling of the samples that could potentially be infectious. At field clinics in West Africa, testing currently occurs in small tents or facilities outside of the Ebola treatment areas. Ebola treatment areas require health care workers to don full personal protective equipment that reveals no skin that could potentially be exposed to virus. Health care workers draw blood and sterilize the outside of the vial with chlorine to kill any virus that may have contaminated it. The vial is then brought to the testing area, where technicians work in glove boxes—transparent, sealed boxes with built-in gloves so that technicians can destroy the virus. Once the virus is deactivated, the sample is put through a molecular process to amplify the viral genes and then analyzed for presence of Ebola RNA.
The BioFire platform, while welcome, is also a bit of overkill for the immediate needs of the Ebola health care community in West Africa. It was designed to test for an array of pathogens—from malaria to anthrax—so the cost includes the ability to test for all of those agents, which isn’t urgently needed in West Africa.
A diagnostic that can quickly detect Ebola—or rule it out in cases of diseases like malaria—is critical for containing the outbreak and maintaining strong health care in the region, even as the outbreak peters out in coming months and years. “It’s the malaria season now, and what is happening is that some non-Ebola cases need to be treated as well,” says Dr. Arlene Chua, policy advisor on diagnostics for MSF, citing patients with undefined fever or post-partum bleeding. “Health care workers are afraid they might have Ebola, so we need to a test to exclude Ebola quickly so we can take care of non-Ebola cases.”
WHO is soliciting submissions from companies interested in receiving expedited approval from WHO for their diagnostics; some have been in development for years but have stalled because of lack of funding. From MSF’s perspective, top priorities in an Ebola test would include a device that can take smaller samples of blood—such as from a finger stick rather than a blood draw, which exposes health care workers to more risk of infection—or samples of saliva. Also helpful would be a device that remains completely contained that does not require technicians performing the test to wear personal protective equipment, and lower power requirements, such as a battery, that can be recharged so the test can be used anywhere and under any conditions.
Those are tall orders, but such a dream diagnostic should be possible, says Piriou. “The BioFire technology is amazing technology for sure. So the technology is there,” he says. “It’s not more or less difficult than developing a test for any other disease. There is no reason it can’t happen.”