When somebody gets a fever in a poor country, there is no quick or easy way to tell whether it’s a symptom of flu, malaria, a bacterial invader, or some other bug.
And if you don’t what it is, then it’s hard to treat.
So it’s only natural that shrinking modern diagnostic tools into a lightweight box that’s fast, accurate, cheap, and rugged enough for the African bush is one of the big ideas the Bill & Melinda Gates Foundation has supported in the past five years. The instrument is now starting to take shape under the direction of a team at the University of Washington, through what’s called the DxBox, which looks a little like the popular video game console with a similar name. And this particular box is entering a delicate phase in which big decisions are being made about whether it is really ready for a prime time commercial push, in which it could help healthcare workers better diagnose millions of people.
The original Gates grant, worth $15.4 million over five years, went to a diverse collaboration between a pair of bioengineering labs at the University of Washington, global health experts at Seattle-based PATH, and a couple of commercial partners in Redmond, WA-based Micronics and what used to be called Bothell, WA-based Nanogen (now part of ELITech Group). Four years have now passed by since the first check arrived. As the lead scientist on the project, UW bioengineering chair Paul Yager, put it in a recent UW symposium, “it’s put up or shut up time.”
What he really meant is that enough work has been done that it’s time to size up the real-world commercial potential of the product, or maybe spend some more time back at the drawing board. “You have to take what’s in a lab here in Seattle and scrunch it down to that,” Yager said, pointing to a prototype sitting on a shelf in his office, when I followed up recently. “It’s probably about two years away.”
So after all of the long hours from 40 UW graduate students and postdocs, another 60 professionals outside the UW, and a lot of trial and error to meet all the demanding requirements of a portable diagnostic, what can this DxBox really do?
It is made to take a pinprick of blood, which a health worker squeezes onto a cartridge that slides into an 8-pound prototype device. All the health worker needs to do is hit “run,” and the pumps and valves inside the little box perform two kinds of automatic diagnostic tests. One is an immunoassay test that uses conventional antibodies, not all that different from a pregnancy test, that are made to bind with certain microbial invaders or antibodies that people produce in response to a certain infection. The other test is a more precise nucleic acid assay, which is supposed to identify microbes at the DNA level. Both tests are made to spit out an answer on an LCD screen in whatever the worker’s native language is, within 30 minutes, to identify the patient’s illness, Yager says. And the machine can run a full day on a laptop battery in places without electricity, Yager says.
The DxBox was designed to screen for six common illnesses that are associated with high fevers—flu, malaria, typhoid, rickettsial infections, measles, and dengue. Even from the start, the machine wasn’t made to be comprehensive, since it doesn’t screen for two of the biggest killers
