If you’ve ever been prescribed antibiotics to fight the flu, you’ve experienced first-hand how difficult it is for doctors to distinguish between bacterial infections and viral infections (the flu is the latter). Oftentimes, doctors will prescribe antibiotics just in case it’s a bacterial infection so the patient will recover sooner. Early administration of antibiotics can halt bacterial infections before they spiral out of control, but the practice has led to the overuse of our most precious drugs.
Fortunately, a team of researchers announced yesterday that they may have solved this problem in the form of a blood test. It works by detecting the proteins produced by a patient’s own body in response to infection to quickly determine whether they have been sickened by a bacterial strain or a virus. It returns a result within minutes rather than the hours or days required with typical clinical tests.
Today’s tests aren’t just slow, they also require that the infectious agent has multiplied enough inside the patient’s body that the levels are high enough to be detected, and can misidentify the root cause when a person has concurrent infections. To overcome these hurdles, scientists from Israeli biotech company MeMed looked to the patient’s own body to see which molecules the immune system produces when fighting off different kinds of infections.
The test performed well, properly identifying the type of infection most of the time. The researchers even report that it is more accurate than typical clinical diagnostics. Here’s Smitha Mundasad, reporting for BBC News on the new test:
It relies on the fact that bacteria and viruses can trigger different protein pathways once they infect the body.
A novel one, called TRAIL, was particularly high in viral infections and depleted during bacterial ones. They combined this with two other proteins – one is already used in routine practice.
The rapid test could slow the rampant spread of antibiotic resistance in bacteria. Inappropriately prescribing antibiotics to to combat a virus like the flu or using too low of a dose of antibiotics encourages bacteria to evolve traits that protect them from commonly used drugs.
Antibiotic misuse is not a small problem. The CDC estimates that nearly half of all antibiotics should never have been prescribed in the first place, and antibiotic resistant bacteria infect around 2 million people each year in the United States, killing over 23,000 of those infected.
Virus expert Jonathan Ball from the University of Nottingham is cautiously optimistic, telling the BBC’s Mundasad that while MeMed’s new test might reduce inappropriate antibiotic use, “It will be important to see how it performs in the long term.”