Friday, 27 May 2022

Local collaboration leads to recognition of new tick-borne disease

LAKE COUNTY – A presentation to the Lake County Board of Supervisors this Tuesday, Feb. 16, will

summarize the characterization of a newly recognized infection in humans that is associated with tick bites.

The condition, which was characterized primarily by a skin ulcer, often with a dark scab, was first noted in Lake County by local internist, Dr. Marc Shapiro, several years ago, according to a report from the Lake County Department of Health Services and Lake County Vector Control.

State public health and tick experts suspected that this condition might be the result of a particular species (364D) of a microorganism known as a rickettsia.

A related species of rickettsia is known to cause Rocky Mountain Spotted Fever, a tick-borne illness that is rare in California.

A patient with a skin ulcer in August 2008 prompted the initiation of a public health investigation involving Lake County Public Health, California Department of Public Health, the federal Centers for Disease Control and Prevention, and the Lake County Vector Control District.

The resulting research and investigation has resulted in the first scientific confirmation of human disease associated with the 364D species of the spotted fever group of rickettsiae.

A summary of this investigation and findings to date appeared in the February issue of “Clinical Infectious Diseases.”

“This does not represent a new health threat, but it will help local doctors more accurately and quickly diagnose and treat an infection that has probably been around for many years,” said Lake County Health Officer Dr. Karen Tait.

Although the infection has been described to appear as an inflamed appearing skin ulcer at the probable site of a tick bite, the full range of symptoms and signs of infection that might occur have yet to be fully described. Additional research in this area will continue.

In addition, the Lake County Vector Control District is continuing to collect ticks for testing and to gain a better understanding of the environmental conditions that affect the ticks that transmit Rickettsia 364D.

Infection from the 364D organism is treatable with antibiotics, but health officials encourage everyone to protect themselves from tick bites by taking a few precautions:

  • Wear light-colored clothing to make it easier to see ticks;

  • Wear long pants and long-sleeved shirts, and tuck shirts into pants, and pantlegs into socks to make it harder for ticks to reach your skin;

  • Apply a tick repellant (always read and follow label directions);

  • Check your body for ticks after working or playing outdoors; have someone else check your back, neck, and head or other places that you can't see yourself.

  • Remove ticks promptly by grasping them as close to the skin as possible with tweezers and gently pulling. Save the tick in a Ziploc bag or other tightly sealed container and bring it to Lake County Vector Control District for identification and possible testing.

  • Talk with your veterinarian about tick protection for your pets.

More information on the prevention of tick-borne diseases can be found at .

Follow Lake County News on Twitter at and on Facebook at .

Upcoming Calendar

05.28.2022 9:00 am - 5:00 pm
Cobb Estate Sale
05.28.2022 9:00 am - 5:00 pm
12 Tribe yard sale and fundraiser
05.28.2022 10:00 am - 1:00 pm
Farmers' Market at Steele
05.28.2022 10:00 am - 2:00 pm
Rodman Preserve public hours
05.28.2022 10:00 am - 12:00 pm
Morning cemetery tour
05.28.2022 11:00 am - 1:00 pm
Weekly writing workshop
05.29.2022 9:00 am - 5:00 pm
Cobb Estate Sale
Memorial Day
05.30.2022 9:00 am - 10:00 am
Middletown Cemetery honors veterans

Mini Calendar



Responsible local journalism on the shores of Clear Lake.





Enter your email here to make sure you get the daily headlines.

You'll receive one daily headline email and breaking news alerts.
No spam.
Cookies! uses cookies for statistical information and to improve the site.