Skip to main content
Thursday, October 29, 2026Oct 29

This story is free to read.

Is it really Lyme? Researchers developing a new test to tell

WASHINGTON (AP) – Diagnosing if a tick bite caused Lyme or another disease can be difficult but scientists are developing a new way to do it early – using a “signature” of molecules in patients’ blood.

It’s still highly experimental, but initial studies suggest the novel tool just might uncover early-stage Lyme disease more accurately than today’s standard test, researchers reported Wednesday. And it could tell the difference between two tick-borne diseases with nearly identical early symptoms.

“Think about it as looking at a fingerprint,” said microbiology professor John Belisle of Colorado State University, who helped lead the research.

Lyme disease is estimated to infect 300,000 people in the U.S. every year. Lyme-causing bacteria are spread by blacklegged ticks – also called deer ticks – primarily in the Northeast and Midwest, although their range is spreading. Lyme typically starts as a fever, fatigue and flu-like symptoms – often but not always with a hallmark bulls-eye rash – and people usually recover quickly with prompt antibiotics. But untreated, Lyme causes more serious complications, including swollen joints and arthritis, memory and concentration problems, even irregular heartbeat.

Yet today’s best available test often misses early Lyme. It’s considered no more than 40 percent accurate in the first few weeks of infection. It measures infection-fighting antibodies the immune system produces. Those take a while to form, making the test more useful a month or more after infection sets in than when people first start feeling ill.