Published On Jun 13, 2017
Diagnosis on the Go
A portable detection system can identify disease-causing bacteria far from the laboratory.
Microbial infections are responsible for about 4.6 million deaths each year. To head these off, health workers need to identify the pathogen in the patient and offer the right treatment. But that first step—diagnosis—typically involves laboratory tests, and in the low-income countries where infectious disease deaths are most common, the labs available to do this are often far away or not equipped to handle the problem.
A team led by Douglas Weibel, professor of biochemistry at the University of Wisconsin, Madison, created an inexpensive portable system to identify bacterial pathogens. To test their approach, they focused on the six bacteria responsible for most hospital-related infections worldwide.
In the field, a user adds a sample from the patient—a swab from the mouth or a drop of blood or urine—to a cartridge. The sample gets isolated using a simple process called degas flow, Weibel says. It gets “sucked” into several microchambers that contain information about snippets of DNA unique to each of the bacteria that the device is testing for. The approach, moving the sample from chamber to chamber, enables many different tests to be performed simultaneously on a single sample.
The cartridge is loaded into a battery-powered reader that incubates it for about 20 minutes. If one of the organisms is present, the chamber containing it lights up with fluorescent dye. Results of the test can be displayed on a cell phone app connected to the reader via Bluetooth. “The app walks the user through the whole process,” says Weibel.
The next step for the device is to conduct patient trials at hospitals in India. “Our goal was to take assays that typically require laborious lab-based work and simplify them,” says Weibel. “This test can be performed anywhere, by pretty much anyone.”