Ticks Carrying Disease Found to Be Abundant in Beach Areas, Similar to Woodlands, According to New Study

PORTOLA VALLEY, Calif., April 23, 2021 /PRNewswire/ -- Bay Area Lyme Foundation, a leading sponsor of Lyme disease research in the US, today announced results of a study demonstrating that adult Western black-legged ticks (Ixodes pacificus) carrying Borrelia burgdorferi, the bacterium that causes Lyme disease, were found in beach areas at equal rates to the woodland habitats in parts of northwestern California. Further, researchers, who were testing ticks for up to 5 species of tick-borne bacteria, found that the collective infection rate of all species was as high as 31% in at least one area, which offers a different perspective from previous studies that tested for a single species of bacteria in a specific area or areas. Conducted by researchers at Colorado State University, Northern Arizona State University and Translational Genomics Research Institute (TGen), and published in the June 2021 issue of the peer-reviewed journal Applied and Environmental Microbiology (AEM), the research points to the need for greater education for both the community at large and healthcare providers about the risks of tick-borne disease.

"The high rate of disease-carrying ticks in the coastal chaparral was really surprising to us. And when looking at all the tick-borne pathogens simultaneously, it makes you rethink the local disease risk," said Lead Author Daniel Salkeld, PhD, Colorado State University. "Previously, we, along with other researchers, may have missed the big picture when we focused our attention on investigating the risk of one pathogen at a time. Now, we have a new imperative to look at the collective risk of all tick-borne pathogens in an area."

Researchers sought to quantify the prevalence of five species of bacteria – Borrelia burgdorferi, Borrelia americana, Borrelia bissettiae, Borrelia miyamotoi and Anaplasma phagocytophilum -- in Western black-legged ticks (I. pacificus ) across multiple habitats. Habitats included woodlands and grasslands as well as coastal chaparral, which is a habitat that has not previously been studied. Ticks may also carry viruses and parasites, however only bacteria were included in this study.

"Beaches and lizard habitats can no longer be considered havens from ticks. Based on this new data, we are now encouraging residents to take preventative measures in beach areas and encouraging healthcare providers to learn the symptoms of tick-borne infections beyond Lyme disease," said Linda Giampa, executive director at Bay Area Lyme Foundation. "Prevention of tick-borne disease is critical and ecology studies like this highlight the need to be vigilant anytime we are in the outdoors."

This was the first study to characterize bacteria carried by ticks in the chaparral in beach areas. Coastal chaparral is a natural habitat for fence lizards, which have previously been found to carry a blood protein that kills Borrelia bacteria, although studies over the past 20 years have offered differing results.

Authors note that more research is necessary to better understand which animals may be hosts for the ticks in beach areas. It is speculated that the hosts may be rabbits, voles and/or the white-footed mouse. The grey squirrel, which has been known to be the primary tick host in northwestern California, doesn't live in coastal areas. Additionally, the prevalence and role of the fence lizard should be further explored.

More information about preventing tick bites can be found here, and here is the link to the study: https://doi.org/10.1128/AEM.00319-21 

About the Study

Researchers conducted tick drags of public and private areas including California State Parks (SP), County and Regional Parks, and National Parks in in Marin, Mendocino, Monterey, Napa, Santa Clara, Santa Cruz and Sonoma Counties.

Aggregated across all sites, prevalence of Borrelia burgdorferi sensu lato alone was 2.9% (95% CI = 2.3-3.7%), and Borrelia miyamotoi in adult ticks occurred at a lower prevalence than B. burgdorferi sensu lato: 1.3% (95% CI = 0.8-1.8%). However, prevalence of B. miyamotoi in nymphal ticks reached as high as 17.8% (95% CI = 10.5-27.3, n = 90) in some areas. Presence of Anaplasma phagocytophilum was sporadic throughout the area with highest rates observed up to 7.8% (95% CI = 3.2-15.4%.).

About Tick-borne Disease
The CDC recognizes 15 tick-borne diseases, and there are at least 9 different types of ticks that carry these diseases. Tick-borne disease has been diagnosed in every state in the country. The most common vector-borne infectious disease in the country, Lyme disease is a potentially disabling infection caused by the Borrelia burgdorferi bacteria. If caught early, most cases of Lyme disease can be effectively treated, but it is commonly misdiagnosed due to lack of awareness and unreliable diagnostic tests. According to the CDC, there are nearly 500,000 new cases of Lyme disease each year. As a result of the difficulty in diagnosing and treating Lyme disease, more than one million Americans may be suffering from the impact of its debilitating long-term symptoms and complications, according to Bay Area Lyme Foundation estimates.

About Bay Area Lyme Foundation
Bay Area Lyme Foundation, a national organization committed to making Lyme disease easy to diagnose and simple to cure, is the leading public not-for-profit sponsor of innovative Lyme disease research in the US. A 501c3 non-profit organization based in Silicon Valley, Bay Area Lyme Foundation collaborates with world-class scientists and institutions to accelerate medical breakthroughs for Lyme disease. It is also dedicated to providing reliable, fact-based information so that prevention and the importance of early treatment are common knowledge. A pivotal donation from The LaureL STEM Fund covers overhead costs and allows for 100% of all donor contributions to Bay Area Lyme Foundation to go directly to research and prevention programs. For more information about Lyme disease or to get involved, visit www.bayarealyme.org or call us at 650-530-2439.

Media contact:
Tara DiMilia
Phone: 908-369-7168
[email protected]

SOURCE Bay Area Lyme Foundation

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