As temperatures rise in California and people in search of respite head for the beach, there's a new concern beyond damaging sun rays and strong undercurrents: disease-carrying ticks that appear to be spreading all along the Golden State's coast.
The black-legged arachnids that carry Borrelia burgdorferi, the bacterium that causes Lyme, are common on the East Coast, where they usually are found in wooded areas and tall grass. But new research shows the blood-sucking critters are capable of thriving along the West Coast too, though experts don't exactly know why or how.
An unexpected home in California
Dan Salkeld, a biology researcher at Colorado State University in Fort Collins, led a four-year study that found the ticks on beaches along much of Northern California, from Mendocino County down to Monterey County. It appears they're also moving farther south, including to Malibu, Manhattan Beach and Newport Beach, Salkeld told NPR affiliate KCRW — though he notes that the threat of Lyme disease is minimal in those areas.
"Three combined studies done by other researchers ... found 1 out of 5,000-plus ticks are actually infected. So the risk in Southern California is really low," he said.
According to the research in Northern California, Salkeld said, about 4% of adult ticks — which are larger and easier to discover — are carriers of the bacterium.
Still, the coastal shrubs and grasses are surprising new habitat for the disease because those ecosystems are not home to the traditional reservoir hosts.
Ticks on their own do not carry the bacterium that causes Lyme. For that to happen, they need to draw blood from a mammal host that can harbor B. burgdorferi. On the East Coast, that is commonly deer and white-footed mice. In California, that would include deer, as well as western gray squirrels, voles and mice — none of which lives in seaside grasslands.
"We've known that there are more ticks in more places with more pathogens than most people have commonly known about," said Lia Gaertner, director of education and outreach for the Bay Area Lyme Foundation, which funded Salkeld's research.
Because of his work, Gaertner added, "Now we're able to match up what we're seeing from personal experience and hearing from doctors, and hearing from patients."
Ronald Owens, a spokesman with the state's Department of Public Health, told SFGate that there were fewer than 50 confirmed and probable Lyme disease cases in 2020. That's less than half of what is typically reported, he said.
But Gaertner believes that is a woefully inaccurate method of counting cases — which in many instances, she said, doctors are unable, unwilling or untrained to identify or treat.
A 2018 report by Quest on Lyme disease said that cases in California shot up by 195% from 2015 to 2017 and that the infection that causes the disease was found in all 50 states and the District of Columbia. The Centers for Disease Control and Prevention estimates that approximately 476,000 Americans are diagnosed and treated for Lyme disease each year.
Lyme disease symptoms and how to protect yourself
Typical symptoms of the illness include fever, chills, headache, fatigue, muscle and joint pain, swollen lymph nodes and a skin rash.
But in the case of the latter, Gaertner warns not to rely on the appearance of the bull's-eye shaped rash people have been told about for decades.
"It's a myth that every Lyme disease infection comes with that kind of rash. In fact, most rashes are solid red oval rashes, so people shouldn't think they don't have it if they don't see that bull's-eye," she said.
It can also be incredibly difficult to spot ticks, especially if they're in the nymph stage. Salkeld described them as being the size of a poppy seed, while Gaertner said they can be as tiny as a period on a computer screen.
In either case, they are just as dangerous as fully grown adult ticks in spreading a variety of diseases, and they can feast for three to four days. So it's imperative to do a full body and head check using a magnifying glass or a smartphone magnifier after an outing in the great outdoors, according to Gaertner.
She recommends swapping out dark leggings for light-colored clothing to make it easier to see even the tiniest creatures, and using permethrin tick repellent on bags, shoes and socks, which should always be pulled over pants cuffs to prevent direct access to one's legs. "And always walk on the designated path," she said, adding that ticks like to "quest" on the very tops of tall grasses, "waiting for a chance to hitch a ride."
Save the tick
Once home, put clothes in a dryer with high heat for about 15 minutes to kill any remaining tourist ticks. A thorough shower, scrubbing under armpits, behind the knees and in genital areas, also will help wash away any ticks that haven't yet latched on.
If you do find a tick, "the only proper way to take it out is using pointy nose tweezers, because you don't want it to vomit its bacteria into you," Gaertner said.
And after it's been removed, don't throw it away!
Instead, she said, wrap it in a moist paper towel, put it in a plastic sandwich bag, and drop it in the mail to a tick testing laboratory. Within three days, she said, they can tell what kind of tick it was, how long it had been feeding, and what kind of diseases it was carrying. "That's super important information for people to share with their doctors," Gaertner said.
Gaertner offered one last piece of advice for those who are now terrified to step outside: "I know it all sounds scary, but knowing how scary it is makes it much safer for you."