Simple ‘thread’ test diagnoses fever

The knotty problem of diagnosing fevers in poor, remote areas may be unraveled by a short length of cotton thread. A health worker roaming the outback of an impoverished developing nation—often on foot—must carry the diagnostic equipment and supplies needed to care for patients who cannot get to distant hospitals, say experts from Jhpiego, a Johns Hopkins University unit working around the world for maternal and child health. It would help, they say, to have a simple, lightweight test to easily and accurately determine the underlying cause of fever, which could be malaria, bacterial pneumonia or a virus. A team of graduate student inventors, working with Jhpiego mentors, has come up with such a test. “What makes this all work is a piece of thread,” says Omid Akhavan, a member of the team from the Center for Bioengineering Innovation and Design at Johns Hopkins’ Biomedical Engineering Department. The test the team is developing produces a diagnosis in about five minutes. It relies on the same basic science as an over-the-counter pregnancy test: a drop of blood from a patient’s finger is placed on one end of the thread. The blood is drawn through the thread, passing targeted biomarkers that indicate if an infection is present and whether it’s viral, bacterial, or malarial. “The future of medical device innovation is taking ordinary things and creating something lifesaving,” Akhavan says. “There had been some research done on thread as a microfluidic channel, and we found a way to take it to the next level.” The test, which the team calls FeverPoint, holds promise for developing countries because it does not require electricity, water, or sample preparation, and is inexpensive, at an estimated three cents per test. Similar tests exist, the team says, but some require plasma to be separated from blood cells before testing; others use much larger, pricier technology. FeverPoint is more efficient and less expensive because it accepts a whole-blood sample and uses just one thread. Malaria and bacterial pneumonia claim the lives of nearly 3 million children under the age of 5 each year, according to a 2010 study funded by the World Health Organization. Many of these deaths could be prevented if health care workers had the tools necessary to quickly and accurately diagnose the cause of fever and prescribe the correct medicine, the team says. Without adequate diagnostic tests, health care workers often treat viral infections with ineffective (but expensive) antibiotics, or prescribe drugs that don’t treat underlying illnesses. The student research team estimates that 90 percent of unnecessary antibiotic prescriptions occur in the developing world. “The great thing about this technology is that it can serve as a platform to feasibly tackle and diagnose many illnesses,” team member Luccie Wo says. “Our product is specifically targeting fever, but it can be applied to any number of other diseases.”