Catch Me If You Can: Diagnosing Ebola
WHY YOU SHOULD CARE
When it comes to the Ebola virus, an ounce of detection is worth 20 pounds of cure.
By Nathan Siegel
Before you race to a cure, you have to know what ails you.
Anxiety is mounting as the Ebola virus continues its deadly ricochet around the globe, taking victims in countries rich and poor. Already, two American nurses have been infected — and this month, the World Health Organization warned that the number could shoot up to 10,000 people per week (yes, per week) by December. That’s 10 times the current rate of infection. With prospects like that looming, it’s not surprising that researchers are scrambling for treatments and cures.
You aren’t going to invest in a new sprinkler system if your house is on fire. You’re going to keep tossing buckets of water.
But the real answer to stopping Ebola? It could be diagnostics. With standard Ebola testing machines in short supply — reportedly fewer than a dozen in Liberia, Guinea and Sierra Leone combined — and a lag between testing and results, experts say quick, cheap Ebola tests could seriously stanch the disease’s spread. When it comes to an epidemic, an ounce of detection is worth 20 pounds of cure.
“Diagnostics certainly plays a central role in stemming the spread of Ebola,” says Anurag Mairal, the global program leader for PATH, a humanitarian organization.
No one would gainsay him. Yet humanitarian organizations and governments are wary of shelling out for untested tech during a crisis. Though they’ve spent or committed more than $1 billion on the epidemic so far, diagnostics are nowhere near the top of the list. “You aren’t going to invest in a new sprinkler system if your house is on fire,” says Selim Unlu, a biomedical engineer who’s helping develop an on-the-spot Ebola test. “You’re going to keep tossing buckets of water.”
People can’t stand waiting for test results. They get anxious and disappear, or return home, only to infect family and neighbors.
Nonetheless, Unlu and other developers intend to see their products get serious use, crisis mode be damned. Unlu’s test uses silicon chips and nanotechnology, but you don’t need that: A Tulane University researcher has developed a finger prick antibody test that could deliver results in minutes. And across the Atlantic, a team of British researchers is building a machine that could diagnose Ebola weeks before symptoms appear.
The antibody test is the brainchild of Robert Garry, a microbiologist at Tulane University, who’s been on Ebola’s front lines since day one, and sort of Cassandra besides. At Kenema Government Hospital in Sierra Leone, Garry and his team processed almost every Ebola patient in the first 24 hours of the outbreak — and it quickly became clear that people can’t stand waiting for test results. They get anxious and disappear, or return home unknowing, only to infect family and neighbors.
Garry’s big idea: a quick-result Ebola litmus test. Garry’s device draws blood and dabs it onto a paper doused with antibodies that react with Ebola proteins. If there’s a reaction, the paper turns color — that’s a positive result. The process takes five to 15 minutes, and at $5 to $10, it’s cheaper than the standard testing machine, the qPCR, which costs about $20,000. Garry says he plans to bring the device back to Sierra Leone in a few weeks.
But Garry’s test, not yet named, lacks bells, whistles and early-detection capability. Not the qPCR’s sleeker, cheaper, faster rival, the Q16, being tested in Britain now. It’s comparatively cheap, at $6,000, and weighs less than 5 pounds, which makes diagnosis possible even in remote, rural areas. Results take 90 minutes, but the best part is this: The Q16 can diagnose the virus within five days of infection, weeks before patients start showing symptoms, says Jim Wicks, managing director of Primerdesign, which makes the machine. It’s slated to test live human samples soon.
Then there’s Unlu, the nanotechnologist, and his team at Boston University. Their invention could beat all of them: It draws blood “straight from the vein,” dabs it on a silicon chip and shines a single-colored LED through it. The Ebola-specific particles appear as bright dots on the chip, if present. Like the Primerdesign machine, it will be able to detect Ebola in asymptomatic patients. And it’ll also be able to test for the Marburg virus, also a hemorrhagic fever, and bacterial infections like E. coli.
But his nanotechnology machine will take at least six months to hit the market, Unlu says. Nonetheless, Unlu hopes that this year’s outbreak will yield some lessons for governments and humanitarian organizations alike — including the importance of investing in cheap, easy, quick diagnostics.
So does Mairal, of the humanitarian organization PATH, who notes that authorities in developed countries didn’t kick into high gear with research until it became clear that Ebola would reach them, too. In the future, he says, we’ll need to better incorporate diagnostics into the health care system, instead of “simply rolling out new technology when an outbreak occurs,” he says.
So the next time the house catches fire, the sprinkler system will be ready.