When you're hacking up a lung and it's not getting better, you know you're going to have to visit the doctor. What you (and even the doctor) often don't know is whether that antibiotic Rx you may get is going to work, simply because it's often hard to tell the difference between a viral and bacterial infection. But a study published in PLOS One says that may all change with a blood test that can quickly differentiate between the two, the BBC reports. And if MeMed's ImmunoXpert proves to work as scientists say it does, it could not only get antibiotics more quickly to patients with bacterial infections (the only ones antibiotics work on), but also cut down on patients who don't have bacterial infections from taking them. That's big, because overuse is linked to widespread antibiotic resistance.
The study in Israel examined some 1,000 patients, scrutinizing the body's immune response to the sickness and honing in on protein trails that are activated depending on whether an infection is viral or bacterial. In particular, levels in blood of one protein called TRAIL significantly shot up in subjects who had been infected with viruses, while it dropped in patients with bacterial illnesses. The CEO of MeMed says the test works—a post at EurekAlert touts "highly accurate results, with sensitivity and specificity greater than 90%"—and offers results within two hours for most patients, per the BBC. "It is not perfect and it does not replace a physician's judgment, but it is better than many of the routine tests used in practice today," Eran Eden says. (A newly discovered antiobiotic may help fight superbugs.)