California health officials are reminding residents to stay vigilant against ticks after confirming a rare tick-borne illness in a Northern California resident earlier this year.
The patient was diagnosed in April with Rickettsia lanei, an extremely uncommon bacterial infection that shares similarities with Rocky Mountain spotted fever. According to the California Department of Public Health (CDPH), the individual was hospitalized but has since made a full recovery.
What makes this case particularly noteworthy is just how rare the illness is. Health officials say only four cases have ever been documented worldwide, with three of those occurring in California. Previous California cases were reported in 2004 and 2023.
Symptoms associated with Rickettsia lanei can include fever, headaches, skin rashes, and other potentially serious complications if left untreated. Officials have not released additional details about the patient's symptoms, length of hospitalization, or exact location, citing privacy concerns. They did confirm that the individual both lived and worked in Northern California.
The bacteria belong to the "spotted fever group" of Rickettsia, which are transmitted to humans through the bite of infected ticks. Experts warn that tick activity is especially high during the summer months, increasing the risk of exposure for people spending time outdoors.
In California, three tick species are known to carry bacteria capable of causing Rocky Mountain spotted fever in both humans and dogs:
- American dog tick
- Pacific Coast tick
- Brown dog tick
The Pacific Coast tick can also transmit Pacific Coast tick fever, another tick-borne illness found in the state.
Health officials emphasize that prevention is the best defense. If you're hiking, camping, gardening, or spending time in grassy or wooded areas, use tick repellent, wear protective clothing, and regularly check yourself, your children, and your pets for ticks. Because some ticks can transmit disease shortly after attaching, prompt removal is important.
While cases of Rickettsia lanei remain exceptionally rare, this latest diagnosis serves as a reminder that tick-borne diseases are a real concern in California, especially during peak tick season. Staying aware and taking simple precautions can help keep outdoor adventures safe this summer.
