Diagnosing Disease On A 'Postage Stamp'

By Cristina Quinn

Jan. 18, 2012

CAMBRIDGE, Mass. — Paper: It’s everywhere. From the pre-dawn thud of the newspaper landing on your front porch to the filter in the coffeemaker and the pile on your desk: Paper’s ubiquity speaks to its value in our world — while also making it remarkably mundane.
What if that mundane material could save lives?

DFA paper
A detail of a DFA device. (Courtesy of Diagnostics For All)

Medical advances the size of a postage stamp

Tucked inside an office building on Memorial Drive is a small nonprofit called Diagnostics For All. The waiting area doubles as an office space; upon entry, its lean décor of plain white walls lined with tables and a handful of computers make it look like a fly-by-night operation.
DFA was founded in 2007 by a group of scientists and entrepreneurs who wanted to make low-cost, portable diagnostic devices to help people living in poor countries.
Una Ryan is the CEO of Diagnostics For All. She said the idea was to keep the devices cheap — very cheap.
“You’ve got to have something that is infinitely scalable, extremely cheap — almost free and be very easy to use.” Ryan said.
The use of paper in diagnostics has been around since the mid-1970s. The best-known use is the home pregnancy kit. What DFA does is more complicated and very small… like the size of a stamp.
Led by the innovative research of renowned Harvard professor George Whitesides, DFA takes advantage of the way a liquid spreads when it comes into contact with paper.
Picture what happens when you spill coffee on a napkin: The coffee spreads out into a big blob. But by creating pathways to split and pool that fluid into different sections on paper, and with a technique called "multi-plexing," DFA can test for any number of diseases and the potential causes for those diseases.
Imagine spitting on paper and finding out within moments if the medicine you’ve been taking is causing liver damage.
Printer + paper + oven + reagent = diagnosis

DFA ink
Fluid wicking on a piece of DFA paper. (Courtesy of Diagnostics For All)

Inside the lab, reporters are not allowed to take any photos because of the top-secret patents DFA is developing. The lab looks like any other: people in white coats, bottles, tubes, trays. Ryan pointed out what she calls “the workhorse of DFA,” which is a printer.
That’s right: a Xerox printer. DFA prints the test pattern, with those pathways, on a sheet of chromatography paper. Then the paper goes through a couple more steps that include a small oven and a machine that injects reagents (the substances that indicate some feature of the fluid tested by changing color).

After that, all it takes is a single drop of any bodily fluid such as blood, urine, sweat or spit to yield results.
Ryan demonstrated what happens after the fluid is applied.
“You turn it over and watch the color change. And we have positive and negative controls on every device, so we know if the device is working. It can have a serial number, it can have a bar code, it can have an RFID on it," Ryan said. But the goal, again, is cheapness and simplicity. "So in the simplest case, you just read it by eye.”
So in an instant, if you are in the African savannah, you can find out if you have malaria. But then what? Because all of a sudden, you’re in the middle of the African savannah… and you just learned that you have malaria.
“You take a picture of it. And email the picture, just as people do day in and day out. Everyone has a phone — there’s at least one in a village," Ryan said. That photo can then be sent to another doctor for an opinion if needed. It creates a permanent patient record.
DFA is working with a large telecom company on building a phone app that can read test results accurately. Their tests currently have an accuracy rate of over 96 percent. That’s not bad for the price tag, which comes to about $0.01 per test.
The what-ifs of easy diagnoses

This approach to health care puts a whole new meaning to Do-It-Yourself. But do we really want to be able to diagnose ourselves with potentially lethal diseases?
Ryan said proper training is essential to administering these tests.
“You can’t have people out there telling their friends that they’ve got some dread disease. This has to be properly managed," she said. "And people’s identities have to be clear, and that’s quite easy to do with these.”
Ryan emphasized the importance of teaching people in developing countries to use the tests properly — perhaps even training children in schools. But some experts think there are risks to having something like this so accessible. One in particular is Art Caplan, director of the Center for Bioethics at the University of Pennsylvania.
Caplan supported making tests affordable and easy-to-use for resource-poor countries but believed things could potentially get ugly.
“If somebody wants to find out if you’re using drugs or HIV-positive or have some other condition that maybe you don’t want them to know about — if they can get a bit of your urine, which is not hard to do, or they can get a bit of your spit, there are ways to collect those tissues and then surreptitiously see what’s going on,” Caplan said.
And what if the tests got into the wrong hands? Caplan envisioned governments testing their citizens for diseases they consider morally wrong — and punishing the afflicted.
“There’s stigma with HIV. There are certainly governments around the world who would say, 'You’re headed off to a labor camp' or 'headed off to a quarantine,'” Caplan said.
Next steps for the stamp

DFA page
Many DFA devices can fit on a single sheet. (Courtesy of Diagnostics For All)

DFA’s liver function tests have been tested in the U.S. and in India, and they are currently being used in a field study at a hospital in Ho Chi Minh City, Vietnam. The one-cent price tag is hard to beat, and the U.S. Navy and several non-governmental organizations have expressed strong interest in working with DFA. But diagnosing people doesn’t stop there. Right now, Diagnostics For All is working on agricultural tests: tests that will let a farmer know when his cow is in heat or if there is bacteria in the milk, or fungus in grain.
Ryan said the health of people and agriculture are closely tied.
“I think all the agricultural and livestock things are going to be incredibly important to the major problem, which is alleviation of poverty. If people have a livelihood, they can better manage their health. If they have better health, they can better manage their jobs,” she said.
DFA hopes to launch its paper tests for widespread use in 2013. First, the company must meet each country’s regulations, and intends to do so. While the focus is to serve developing countries, Ryan said there is no reason why DFA's affordable diagnostic testing couldn’t be made available in the U.S. The ultimate goal is to be able to diagnose any disease and to empower people to take care of their own health.
“I see people using them," she said. "Just using them. I want them to be part of the health care landscape.”

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