科学美国人60秒:Quick Test Could Tell If Patient Needs Antibiotics

When patients show up in a hospital with a respiratory illness, they’re usually given an antibiotic, which do not work against viral infections. Even though most of these respiratory infections are viral.

It’s estimated that in these cases antibiotics are incorrectly prescribed nearly three quarters of the time. And the overuse of antibiotics is a huge problem, helping to drive the development of strains of bacteria that are resistant to our antibiotics.

So scientists have been searching for a tool that would quickly allow doctors to diagnose whether a patient has a viral or bacterial infection—and thus know for sure whether to prescribe an antibiotic.

“The new approach that we take rests on the premise that any time we are exposed to something in our environment—whether it’s cigarette smoke, changes in our diet, an infection—our bodies react to that.”

Ephraim Tsalik of Duke University. He and colleagues investigated gene expression—which genes are activated and which remain dormant—in 273 emergency room patients. Some had a bacterial infection, some had a viral one, some had both and some had no communicable disease at all. The researchers also studied 44 healthy adults as a control.

“And what we found are some elements, certain genes, that are turned on and off in a certain way that is very characteristic of a response to a viral infection. Other genes that are turned on and off in such a way that is very characteristic of a bacterial infection. And then other genes that are turned on and off in a way that is indicative of no infection at all.”

They then tested these genetic activation signatures against publicly available data sets of patient infections. And the method was 87 percent accurate. The study is in the journal Science Translational Medicine. [Ephraim L. Tsalik et al, Host gene expression classifiers diagnose acute respiratory illness etiology]

Right now, such gene tests would take perhaps 10 hours to return a diagnosis. And so the researchers are working to develop a diagnostic tool that would cut that turnaround time to just one hour, so that doctors could quickly prescribe antibiotics. But only to patients who would get a benefit, because they have a bacterial and not a viral infection. Which ultimately benefits everyone.

“Decreasing the amount of antibiotics that are used in general is one of the strategies to try and improve the antibacterial-resistance problem.”

—Cynthia Graber