Ticks Are Spreading in the US—and Taking New Diseases With Them

The vast majority of tick-borne disease goes unrecorded, meaning life-threatening pathogens are traveling under the radar to new locations.

A DISEASE THAT is so rare in the United States that it is recognized in only about 40 people each year has taken the life of a person living in Maine. The cause, Powassan virus, is transmitted by ticks, which can pass it on within 15 minutes of biting. The virus causes neurological damage; one out of every 10 people who develop severe symptoms die of brain inflammation, and about half of those who recover experience long-term problems with memory, balance, and speech.

One death is always a tragedy, but one death in a country of hundreds of millions can feel like no more than a statistical blip. But to tick experts, the person in Maine—who hasn’t been identified or described—is a warning. Other than Lyme disease, tick-borne diseases are little known to the public and under-recognized by health care. That’s a problem, because research shows tick species are expanding into new areas and carrying greater amounts of pathogens as they move. And it’s especially a problem because the US has not set up a nationwide monitoring system that could identify where tick species exist, how they are traveling, and what diseases they carry.


Maryn McKenna
10 May 2022