Photo courtesy of Ervic Aquino
Western black-legged ticks carry the bacteria that transmit Lyme disease to humans in California.
Ticks carrying the bacteria that causes Lyme disease are widely distributed throughout the Bay Area and in this county, according to a recent study by California researchers.
The study will be published in the March issue of “Emerging Infectious Disease,” the peer-review journal of the Centers for Disease Control and Prevention. It explains how researchers including Dan Salkeld, a research associate at the Stanford Woods Institute for the Environment, found the bacterium, Borrelia miyamotoi, as well as Borrelia burgdorferi, the bacterium that causes Lyme disease, in ticks they sampled in San Mateo and Santa Clara counties. They found ticks infected with one or both bacteria in nearly every park they examined, surprising since until now the Northeast has been the focus of the disease.
“The study underscored the importance of awareness and prevention,” said Ana Thompson, executive director of the Bay Area Lyme Foundation. “What surprised us the most is we found ticks with Lyme disease in places we didn’t expect, like in drier areas like chaparral and grasses, not just in the forest.”
She said exposure to Borrelia miyamotoi causes side effects similar to Borrelia burgdorferi, but researchers don’t know as much about it. Health consequences of Lyme disease are fever, headache, fatigue and sometimes a telltale rash that looks like a bull’s-eye centered on the tick bite. If left untreated, the infection can cause arthritis, joint pain, immune deficiencies and a persistent cognitive fog. Most people recover with antibiotic treatment but, for unknown reasons, some patients who suffer from a variety of Lyme-like symptoms find no relief from the normally prescribed therapy.
“People who have difficulty getting diagnoses — maybe this is involved,” Salkeld said in an official statement, and she believes Borrelia miyamotoi could be the culprit.
Changes in climate and the movement of infected animals may be partly to blame for the move of Lyme disease west. Last summer, the Centers for Disease Control and Prevention reported as many as 300,000 Americans contract Lyme disease annually, a rate 10 times higher than previously reported. The new figure, the result of national laboratory surveys and a review of insurance information, reflects that Lyme disease is not well diagnosed or reported by many doctors, a press release stated.
Salkeld’s research is funded by the nonprofit Bay Area Lyme Foundation, which was founded by residents of Portola Valley who were alarmed by the number of people with the disease in their community. Bonnie Crater, the group’s vice president, said she and others were frustrated with an apparent lack of regional medical knowledge on the issue, along with the difficulty of diagnosing and treating the disease.
“This is not cancer,” she said in an official statement. “It’s bacteria, and we’ve had antibiotics for over 100 years.”
Meanwhile, Kathleen O’Rourke, a co-founder and advisory board member of the foundation, was diagnosed with Lyme disease along with her 9-year-old son after being told for months the disease didn’t exist in California. She caught the disease in her backyard in Woodside.
“Diagnostics is the number one thing in terms of getting care,” she said in an official statement.
After a year and a half of heavy antibiotic doses, her son was back to normal, but she suffered through four years of treatment and lingering symptoms. She said the pain of unmedicated childbirth was nothing compared to the excruciating pain she felt, describing it as “liquid fire in the joints.”
When someone is infected, it can take weeks before blood tests detect antibodies. Additionally, tests sometimes return false positives and false negatives. Current testing capabilities make it hard to determine whether the infection has been cured. An interdisciplinary Lyme Disease Working Group at the Stanford School of Medicine is exploring ways to improve diagnostic tests and medical understanding, evaluate the effectiveness of new therapies, expand clinical services and build greater public awareness.
“Tick season is year-round,” Thompson said. “Know the importance of prevention. Also, documenting where you might have been bitten helps get the diagnostic.”
The Stanford Woods Institute for the Environment does have tips for avoiding exposure to the disease including staying in the middle of trails; avoiding brush, wood piles and logs; checking thoroughly for ticks (especially in hair) after spending time outdoors; checking pets who can bring ticks indoors; and if you develop symptoms (fever, headache, fatigue or rash), consider consulting a doctor knowledgeable about Lyme. Thompson also recommends applying any insect repellent with DEET in it.
For more information about the Bay Area Lyme Foundation visit bayarealyme.org.
(650) 344-5200 ext. 105