A New Tick Species Is Spreading Across the U.S.—But Here's What You Should Really Worry About
The new tick has not yet been found to carry any human illnesses in this country. The same can't be said for native species that carry the bacteria that cause Lyme disease and other dangerous infections.
The New York Times reported yesterday that a new-to-the-United-States tick species has been identified in seven states in recent months, after an infestation was first discovered last summer in New Jersey. The tick is native to Asia, where it is known to carry a dangerous virus that kills 15% of the people it bites. But it has spread in recent years—to Australia, New Zealand, several Pacific islands, and now to America.
An invasive tick species surely sounds like something out of a horror film, especially given the explosion of tick populations and tick-borne diseases here in the States in recent years. But before you start freaking out about this specific critter—Haemaphysalis longicornis, or the Asian longhorned tick, as it’s known—let’s put a few things into perspective.
First, none of the Asian longhorned ticks discovered here in the United States has been found to carry any human diseases. (According to the New York Times, the longhorned ticks are, at least for now, considered a greater threat to livestock than they are to people.)
“People should not extrapolate that just because this tick carries a potentially serious virus in the Far East, that next year everyone here will have that same disease,” John Aucott, MD, director of the Lyme Disease Research Center at Johns Hopkins University Medical Center, tells Health. "We don't want to connect dots that may never be connected in real life." Plus, he adds, the Asian longhorned tick has only been found in a few localities so far in the United States.
“We certainly don’t want it spreading all over the country, which is why public health officials should definitely be paying attention to this,” Dr. Aucott says. “But for the general public, there are a lot more important things—both having to do with tick-borne illnesses and other things—that should be of greater concern.”
One of those things is the “very real epidemic” of diseases being spread by ticks native to the United States. “Instead of focusing on the theoretical risk of some exotic imported tick species,” he says, “people should be paying more attention to actually protecting themselves from these much bigger threats.”
Deer ticks, for example (also known as blacklegged ticks), can spread Lyme disease, Powassan virus, and anaplasmosis, among other infections; they can also cause tick paralysis. Their numbers are on the rise throughout the United States, as are the diseases they carry.
According to a recent report from lab-testing service Quest Diagnostics, Lyme disease rates have skyrocketed in recent years. Positive test results have now been reported in all 50 states as well as Washington D.C., and several states reported sharp increases in positive test results between 2015 and 2017. (Yes, you may have seen that scary headline this week, too.)
That specific report may not offer the most scientifically reliable data, says Dr. Aucott: It hasn’t been published in a peer-reviewed medical journal, it’s based only on tests done by Quest Diagnostics and not by other facilities, and it can only show what state people were in when they tested positive for Lyme disease bacteria—not where they actually were when they were infected.
But in general, he says, the data is in line with other research. “It’s true that Lyme disease has been spreading relentlessly since the 1970s and that it has spread dramatically on the East Coast and in the Upper Midwest especially,” he says.
Other conditions spread by different types of native ticks—like Rocky Mountain Spotted Fever and alpha-gal syndrome (which involves a sudden allergy to red meat)—have also seen increases in recent years.
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These are the truly scary statistics, says Dr. Aucott, and the real reason people need to be vigilant about ticks that might be lurking in their yards and in nearby grasses and forests.
“Everyone loves to worry about these things, but very few people actually make the effort to protect themselves,” he says. For starters, he recommends wearing long pants when you’re out in the woods or tall grasses, using insect repellant containing DEET, and treating your clothing with permethrin.
“I know it’s no fun to wear long pants in Maryland when it’s 95 degrees, but I do it because I don’t want to get Lyme disease,” he says. “We’ve gotten across to people the importance of wearing a seatbelt and not drinking and driving, but we haven’t yet gotten the message across that tick-bite prevention is something that people should take just as seriously.”