Wednesday, July 28

‘Infestation can occur in California’: What to know about the tick time-bomb – SFGate

The Weather Channel recently announced that most of the U.S. will be a “a tick time-bomb” in 2021, and displayed a map showing that in California, the threat ticks pose this year is slightly above average. And despite the drought — which would normally be a deterrent for ticks — scientists are noticing more of those bloodsuckers on the coast than ever.

To better understand how weather patterns this year might affect tick season in California, SFGATE spoke with Colorado State University tick researcher Daniel Salkeld, who sits on the board of the Bay Area Lyme Foundation and authored a recent and terrifying study concerning suitable tick habitats in California.

The study found that disease-carrying ticks once thought to mostly inhabit woodlands are also abundant near Northern California’s coastline, lying in wait within the grassy areas on sand dunes that people walk through to get to the beach. And here’s the kicker: in these coastal environments around the Bay Area, the study found that as many as 31% of the ticks carried harmful bacteria.

“The high rate of disease-carrying ticks in the coastal chaparral was really surprising to us,” Salkeld says. “When looking at all the tick-borne pathogens simultaneously, it makes you rethink the local disease risk.”

A tick sits on the tip of a blade of grass, waiting for its prey. 

A tick sits on the tip of a blade of grass, waiting for its prey. 

picture alliance/dpa/picture alliance via Getty I

Salkeld has been studying ticks for the better part of 15 years. On a research trip to Northern California in late May, he found numerous western black-legged ticks — the ones that carry the bacteria that causes Lyme disease — at collection points in Marin, San Mateo and Santa Clara counties, he says, and they were particularly abundant in the Marin Headlands.

In the vegetation near Stinson Beach, he collected ticks in all stages of development — larvae, nymphs, and adults. “I had never found that before,” he says.

It’s not possible to say why all were present, he emphasizes, and you can place that on a long list of other mysteries involving ticks, particularly in regards to how the climate impacts their populations. There are a couple of things we do know for sure, though.

In general, ticks prefer warm weather and high humidity. So while the drought might be keeping their numbers in check in California this year, the shorter winter may extend the period in which they are active. In looking at the spread of tick-borne illnesses, though, there are other factors in play, Salkeld says. For instance, due to warmer weather and pent-up demand for recreation due to the pandemic, people are spending more time outdoors. Warmer weather also promotes more activity among other tick hosts like squirrels, lizards and deer.

Another thing we do know, thanks to a study by the Environmental Protection Agency, is that warming temperatures associated with climate change are projected to expand the range of habitat favorable to ticks, which in turn will contribute to the spread of Lyme disease.

Of the 48 species of ticks in California, only six have demonstrated serious interest in sucking human blood. Just one of those, the aforementioned western black-legged, is known to carry the bacteria that causes Lyme disease, an infection characterized by fever, headache, fatigue and sometimes a skin rash. Left untreated, it can spread to joints, the heart and the nervous system. In rare cases it can be fatal.

Scientist Dan Salkeld found more western black-legged ticks than ever while researching the insects at Stinson Beach and the Marin Headlands this year.

Scientist Dan Salkeld found more western black-legged ticks than ever while researching the insects at Stinson Beach and the Marin Headlands this year.

Smith Collection/Gado/Getty Images

In response to a public records request from SFGATE, California Department of Public Health Information Officer Ronald Owens relayed that in 2020, there were just under 50 confirmed and probable Lyme disease cases in the state. “In contrast, typically about 100 confirmed cases and 40 probable cases are reported each year,” Owens wrote.

Pacific Coast ticks and American dog ticks are also rampant on the California coast, and known to carry spotted fever pathogens and occasionally transmit tularemia, a rare infectious disease that attacks the skin, eyes, lymph nodes and lungs.

To amuse Salkeld, I showed him a photograph involving dog ticks that recently went viral on Facebook. The guy who posted it, Hunter Cornick, lives in rural Nova Scotia where dog tick populations have been exploding in recent years. An outdoorsman with a diploma in forest and wildlife technology, Cornick invented a pretty effective tick prevention method.

Tick researcher Dan Salkeld found numerous western black-legged ticks in all life stages on a recent trip to the Bay Area. 

Tick researcher Dan Salkeld found numerous western black-legged ticks in all life stages on a recent trip to the Bay Area. 

Courtesy of Bay Area Lyme Foundation

“If you tuck your pants into your socks, and tuck your shirt into your pants, a tick will climb the entire length of your body to get to your hairline almost every time, and usually the back of the neck,” Cornick says. “So I figured If I wrapped duct tape sticky side out around my legs, so long as my pants were tucked in it would force them to climb over the tape.”

The method trapped 99% of the insects, Cornick says, which in many cases added up to dozens of ticks. The photo he posted on Facebook shows an all-time record: 27 ticks stuck to the tape.

Salkeld deemed the method “cool,” and added that “that kind of infestation can occur in California if you walk through the wrong section of brush.” He knows of a San Mateo vector control biologist who would get ticks trapped in his shirt collar “in large numbers,” he says.

So what is a Californian without a shirt collar or the desire to duct tape his pants to do?

A substance called permethrin tends to work pretty well, according to experts. You spray it on your clothes and let them dry for a day. Ticks will die when they come in contact with the sprayed clothing, and you can also buy clothes pre-treated with the chemical.

If you or your dog is bitten by a tick, grab the tick’s head with a pair of tweezers. Pull it straight out and don’t twist the tick’s body, which might cause the head to detach while still embedded in the skin.

Ticks may be scary, but Salkeld hopes they won’t deter people from spending time outside.

“This is a manageable problem if you try to prevent tick bites,” he says. “Wear repellent. Do tick checks. Shower when you get home. And watch your health. If you do have fevers or headaches, advocate to a physician that there’s potential for tick-borne disease.”

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