.Tick Talk: Blood-sucking arachnids spread disease in Northern California

What the heck is that thing in the photo? A hazelnut? A small dumpling with eight legs? Perhaps an odd seed pod? Nope.

Behold the engorged tick, swollen with blood stolen from its host. Not only do the little suckers feast on our vital red fluid, but they can also leave behind parting gifts, including the bacteria that causes Lyme disease and other tick-borne illnesses. It’s possible for ticks found in California to transmit seven different diseases to humans, according to the California Department of Public Health.

Exactly a decade ago, I wrote an article about Lyme disease featuring “Jane,” a Marin County native who had been suffering from a myriad of debilitating symptoms for three years.

music in the park san jose
music in the park san jose

“It started with a violent flu—the worst flu I ever had in my entire life,” Jane told me in 2013. “Then, I would wake up with numb arms and hands. My vision was slightly blurry.”

New symptoms continued to emerge. Severe headaches, extreme fatigue, joint and bone pain, memory loss and dizziness. Jane spent more and more time in bed.

She trudged to 14 doctors, who poked, prodded and misdiagnosed her. Finally, in May of 2013, the 15th doctor tested her for Lyme disease. Although Jane didn’t recall being bitten by a tick, nor had she noticed the tell-tale bullseye rash some people develop, she had Lyme.

While she was relieved to finally have a diagnosis, she was also confused—and rightfully so.

“First, I was told there was no Lyme in Northern California,” Jane said. “Then, I was diagnosed with chronic Lyme, a disease that I was told didn’t exist.”

In 2012, about a year before Jane’s diagnosis, a group of women in Silicon Valley started the Bay Area Lyme Foundation and convinced a couple of tick ecologists to conduct a study. The results, which came out in 2014, caused a stir in the science community. Sure enough, Borrelia burgdorferi, the bacterium that causes Lyme, was present in 1% to 7% of the western blacklegged ticks collected from Bay Area trails and parks, depending on the location.

“We found ticks carrying B. burgdorferi in nearly every park that we looked, and not just in wooded areas …” said Dr. Dan Salkeld, an ecologist and epidemiologist who was one of the study’s lead authors.

Based on this study and others, the medical community no longer quarrels about whether Lyme exists in Northern California. However, there are still many controversies surrounding the disease.

“No one is denying that Lyme disease is real,” said Dr. Matt Willis, Marin County’s public health officer. Willis contracted the disease years ago and had a bullseye rash. Fortunately, he was diagnosed and cured rather quickly.

“Lyme disease has been well established,” he continued. “The debate is around its prevalence.”

The Marin/Sonoma Mosquito and Vector Control District collects ticks year-round from trails, parks and recreation areas in both counties. The adult and young ticks, called nymphs, are tested for the bacterium that causes Lyme disease, and Borrelia miyamotoi, a bacterium that causes tick-borne relapsing fever.

In conjunction with the state, the district also tests for other pathogens, including the bacterium that causes anaplasmosis, a disease that is on the rise in Marin County, according to Willis.

About 2% of the adult ticks in Marin are infected with the bacteria that causes Lyme. Sonoma County fares a bit better at 1.5%.

Those percentages more than double when looking at the infection rate for the nymphs, which are about the size of poppy seeds. In Marin, almost 4.2% of the nymphs harbor Lyme-causing bacteria. The rate is 4.1% in Sonoma County.

“We’re in nymphal season now, from spring through summer,” said Dr. Kelly Liebman, an entomologist and the scientific programs manager for the Marin/Sonoma Mosquito and Vector Control District. “The ticks are out there, and the pathogens are there at low levels.”

But hotspots exist in certain areas, where a much higher percentage of the ticks carry pathogens, said Wendy Adams, research grant director for the Bay Area Lyme Foundation. And those locations can change from year to year.

In a Bolinas Lagoon study, 31% of the collected ticks harbored at least one pathogen, including the bacteria that causes Lyme, tick-borne relapsing fever and anaplasmosis, according to a 2021 research article by Salkeld that was published in the American Society for Microbiology Journal.

While the number of reported cases of Lyme disease remains low in the Bay Area—eight in Marin County and seven in Sonoma County in the last two years—experts agree underreporting occurs.

Consider the backflips by the Centers for Disease Control and Prevention, which states that “many cases do not get reported” because health care providers are “busy.” The CDC receives 35,000 reports of Lyme disease cases annually, yet the agency uses insurance records to estimate that approximately 476,000 Americans are diagnosed and treated for Lyme disease each year.

It’s no wonder that the Bay Area Lyme Foundation is funneling millions of dollars into research at dozens of esteemed institutions, such as Stanford University, Johns Hopkins University and the Massachusetts Institute of Technology. The organization aims to make Lyme disease easy to diagnose and simple to cure.

Diagnosis is difficult because the two-tiered Lyme antibody test recommended by the CDC, which has been around for 29 years, is known to provide false negatives. It often takes a few weeks for the body to produce enough antibodies to measure, causing a delay in treatment, according to the National Institute of Allergy and Infectious Diseases.

“Accurate diagnostics are the linchpin for being treated appropriately for Lyme Disease,” said Adams, the research grant director. “We are hoping that with new, more sensitive detection technologies, we will be able to detect the bacteria itself in a blood sample, and not just the immune response which varies from infection to infection.” 

Adams knows firsthand the importance of early and accurate diagnostics. She went five years before being diagnosed with Lyme disease, and it took her several more years to fully recover.

Many Lyme patients and their doctors believe delayed treatment plays a factor in chronic Lyme, a condition the CDC refers to as Post-treatment Lyme Disease Syndrome. Even after the prescribed course of antibiotics, some people are still plagued by illness.

Last week, I revisited Jane, whose name is actually Kirsten Seifert-Stein. During our first interview, she insisted on a pseudonym because she feared her family’s health coverage would be canceled due to her Lyme diagnosis.

Ten years post diagnosis, Seifert-Stein, now 53, has not fully recovered. Her health insurance was never canceled, but it doesn’t cover much anyway. She stopped tallying her out-of-pocket medical expenses years ago when the total hit $100,000.

“I’m concentrating on my health and getting better,” she said. “But I’ve sacrificed a lot to do that, Including my career, education and relationships with friends and family.”

Ditto for Sarah Reid, 59, who was also diagnosed with Lyme in 2013. The Santa Rosa resident’s experience is eerily similar to Seifert-Stein’s. Reid doesn’t remember removing a tick or having a bullseye rash. Despite a decade of treatment, she hasn’t been cured.

“I have a persistent disease that pretty much is with me constantly,” Reid said. “Lyme has caused me a lot of trauma, both financially and emotionally, in trying to get diagnosed and treated.”

Remarkably, both women still venture into the great outdoors when they feel up to it. Reid volunteers for the horse trail patrol and rides in Sonoma County parks and preserves, while Seifert-Stein mountain bikes and walks her dog throughout Marin. They agree that preventing tick borne illnesses is the key.

“Take precautions,” Seifert-Stein said. “Use tick repellent, wear the right clothing and do tick checks. It’s OK to go outside.”

For tips on preventing tick bites, visit the Marin/Sonoma Mosquito and Vector Control District and the Bay Area Lyme Foundation.

Nikki Silverstein
Nikki Silverstein is an award-winning journalist who has written for the Pacific Sun since 2005. She escaped Florida after college and now lives in Sausalito with her Chiweenie and an assortment of foster dogs. Send news tips to [email protected].


  1. This sounds awful! I get bit by ticks all the time (live in Northern California mountains and outside a lot). I usually have some kind of a reaction. I’ve had the bullseye rash twice, and always have a large area of swelling around the bite, but thank God nothing too bad. The last few years I’ve gotten bit, I just take goldenseal root for a few days after the bite as an antibiotic, since antibiotics are what are prescribed for Lyme disease. Figure It’ll nip it in the bud. Garlic would also work I’m sure. ♥️

  2. The most important thing I can recommend is killing the tick and saving its body! Your Doc can then send it in and they can so much more easily diagnose what you have contracted! I got anaplasmosis, one of the lesser known 7….
    The Infectious Disease specialist at the hospital ended up in was thrilled we’d saved the body!

  3. There are 16 reportable tick borne diseases, not just 7 (where did that bogus # come from?) And the reason Sonoma county only has single digit cases each year is because Public Health – and I quote Karen Holbrook, PH officer in 2015: “we plan to continue counting 8-10 cases per year”. Yes, pre selected count and they flat out refused to say how many case reports get “lost” each year. My best guess:hundreds. This is fraud. There’s more, but I’ll stop here. Do better research please.

    • Hi Karen,

      The number of tick-borne illnesses came from the California Department of Public Health and refers to California only, which is stated in the article. There are other tick-borne illnesses found in different areas. If you click on the link where that statistic is cited, it will take you to the information on the California Department of Health’s website.

      The number of cases cited in Sonoma County was provided by the County. There is also information in the article from the Centers for Disease Control, which states that cases are underreported. The statistics provided in that paragraph demonstrate that Lyme cases may be more than 10 times higher than reported cases.

      I hope that gives you a better understanding of the data and research cited in the article.


  4. About 8 years ago I successfully used doxycycline for 3 weeks after bullseye rash, as per my research. Test on tick’s body came back negative, from county lab, but since I had the classic rash, I wanted to treat for Lyme and not take any chances.


Please enter your comment!
Please enter your name here

North Bay Bohemian E-edition North Bay Bohemian E-edition
boheme magazine e-edition