Orange County vector control warns of increased tick detections; offers prevention guidance

Tyler Gerber, an assistant vector ecologist with the Orange County Mosquito and Vector Control District, told the San Clemente Parks and Recreation Commission that field surveillance this year has found more ticks at multiple sites across the county than in recent years and urged residents who use trails to take precautions.

Gerber said district staff use fabric flags to sweep brush and collect ticks; he described one recent sweep that yielded about a dozen ticks at a site that historically has produced positive ticks and said other collections elsewhere in the county have been much larger. "We have seen more in this area, and that's why we go there time and time again," he said.

The district highlighted the species and biology most relevant to local trail users. Gerber identified Ixodes pacificus (the western black-legged tick) as the species that can transmit Lyme disease in the region, described its roughly three-year life cycle and "questing" behavior, and noted that not all individual ticks carry pathogens. He said other local ticks can transmit Rocky Mountain spotted fever, Pacific Coast tick fever, tularemia and anaplasmosis but that those detections are rare in the county.

Why it matters: ticks that transmit disease typically must feed for many hours or days for transmission probability to rise. Gerber told commissioners that according to CDC guidance the risk after a brief attachment is "very minimal" and that "anything less than 24 hours [is] very minimal risk," while stressing there is never a zero chance. He advised quick and proper removal when a tick is attached and discouraged folk remedies such as nail polish or heat, which can cause a tick to regurgitate and increase exposure.

Practical guidance given in the presentation included wearing light-colored, long clothing to make ticks easier to see, walking in the middle of trails to avoid brush, using EPA- or CDC-recommended repellents (and permethrin on clothing when used as directed), performing tick checks on people and pets after outdoor activity, and promptly removing attached ticks with a tick key, forceps or tweezers by grabbing the tick at the base and lifting straight out. Gerber said the district does not accept ticks from the public for testing and recommended clinicians or commercial labs such as Quest for individual tick testing.

Commissioners and members of the public asked about public education and signage. Gerber and staff said targeted trail signage and seasonally posted notices are possible and that the district’s website and state and federal pages (California Department of Public Health, CDC) are sources of additional information. Gerber provided contact information for the district and the district website (ocvector.org).

Ending: The presentation concluded with public questions about outreach, park signage and seasonal messaging. Staff said they would consider options for informational signage and brochure distribution, with the caveat that many local trails are county-managed and would require interagency coordination.