American virologist David Safronetz carries buckets containing blood samples from... Read More
Sometimes it takes two days for the samples taken from patients to arrive there, often in worn coolers carried on motorbike. By then, healthy people awaiting results may have been confined to virus-ridden Ebola wards. Sick people could have been accidentally diagnosed with other, less-harmful diseases and sent back, contagious, into healthy communities.
Scientists working on the West Africa outbreak said reliance on the overworked labs far from patients has opened an opportunity for several companies that are d
eveloping quicker, mobile Ebola tests. The diagnostics, including some that work like a pregnancy test assessing a finger prick of blood, can produce results within minutes.
“A rapid test would make a world of difference,” said Andrew Hoskins, country director for MTI Liberia, an aid group helping to fight the Ebola crisis.
Hoskins, whose organization helps ready Ebola treatment units, said the absence of new, faster tests is holding back efforts to control the outbreak, which has infected almost 14,000 people and killed about 5,000 in West Africa.
Ebola symptoms such as fever, headache and body pains are common in the region, especially during malaria season. Health-care workers who mistook Ebola for something relatively minor in the past have contaminated hospitals, sickening some doctors and nurses and causing others to flee, Hoskins said. So every facility has to treat people with a fever like they have the deadly virus, straining resources.
Testing Delay
Some areas in Liberia are hundreds of miles from the nearest testing lab and it takes a week to get results. By then, the answer usually is clear anyway because the sick person has improved, or died, Hoskins said.Medical technology companies are taking note.
“It seems like everybody’s got an Ebola test these days,” John Connor, an assistant microbiology professor at Boston University, said by telephone. “It may be something where there is the nice sort of silver lining to this particular outbreak.”
In the Monrovia lab, partially run by the U.S. Army Medical Research Institute of Infectious Diseases, technicians test for Ebola by running a process called a polymerase chain reaction, a gold standard for virus identification.
Genetic Clues
The procedure includes breaking open the virus and amplifying a piece of the genetic material to decipher whether it contains the code distinct to Ebola. Results arrive in four hours, maybe three if the sample is particularly dense with virus particles, said Connor, who doesn’t work in West Africa, but is familiar with the technique.The lack of labs and the time it takes to analyze the samples means the number of people getting sick probably outpace the capacity to diagnosis the virus, Connor said.
The World Health Organization has said there are probably two to three times the number of actual Ebola cases than confirmed infections in West Africa, for a multitude of reasons, including diagnostic challenges.
At least four more labs will be built to handle the influx of blood samples, said Dave Norwood, head of the diagnostics division at the U.S. Army Medical Research unit. Hoskins said he didn’t know how many labs there were at any one time because people are constantly working to build “mobile labs.”
Quicker Results
Rapid, mobile tests could provide results on-site and pare the diagnosis time to a few minutes. They could also offer a reprieve for lab workers who spend all day decked head-to-toe in stifling protective gear, processing many samples from people who only have malaria or other, relatively minor diseases, Connor said.“Everybody agrees that a quick test, there’s a certain advantage to it,” said Doug Simpson, chief executive officer of Corgenix Medical Corp., a Broomfield, Colorado, company working on a portable Ebola test. “We’ve been on the fast track; we’ve tried to really accelerate our program.”
Corgenix’s test looks like a pregnancy test and works about the same. A sick person provides a finger prick of blood and within minutes a result appears on the testing strip -- two lines means positive for Ebola, one line means negative.
Getting such tests to market is hardly as simple. Quick tests are less sensitive than those conducted in a lab and may generate false positives, Norwood said. Government regulators and labs in West Africa are too busy fighting the outbreak to evaluate new rapid tests for accuracy, he said.
Device Trials
To surmount the challenges, Corgenix is carrying out trials as quickly as possible, hoping to get permission for field workers to throw the tests in their backpacks and start using them. Simpson said Corgenix will seek emergency authorization to use the test soon, possibly by the end of November. Other companies are working toward similar goals.The U.S. Food and Drug Administration gave emergency approval on Oct. 27 for a faster lab test that takes about 45 minutes. It costs either $185 a test or $39,500 for the shoebox-sized machine that does the work and is made by a Salt Lake City-based BioFire Defense LLC, a unit of the French biotechnology company BioMerieux. (BIM)
Automated Analysis
“Normally the technician would take the sample and process it by hand by pulling out nucleic acid, the genetic material, purifying it and setting up the chemistry,” Mark Scullion, vice president for sales and marketing at BioFire. “The machine does all the work the technician would do all in one hour.”BioFire’s test needs to be plugged into a wall and used by a technician, rather than by a health-care worker in the field.
It’s unclear whether the rapid tests like the one made by Corgenix could be useful during this outbreak or if companies will wait until the next Ebola epidemic.
“One of the challenges that we face and public faces with things like Ebola and Anthrax, or other rarer diseases that have very high consequences, is there is no incentive for therapeutics to bring expertise to bear,” Norwood said. “Unfortunately the events of this outbreak will probably bring some folks to the table.”
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