What is tularemia?

Tularemia, rabbit or deerfly fever, is a relatively rare bacterial disease transmitted to humans and animals by the bite of ticks. It is much less common that Lyme disease in California and is primarily transmitted by summer ticks, the American dog tick (Dermacentor variablis). It may be cured by early diagnosis and appropriate antibiotic treatment.

How is tularemia transmitted?

• Through the bite of an infected tick or deerfly
• Handling infected animal carcasses, most likely rodents or rabbits
• Exposure of contaminated water
• Breathing in tularemia bacteria

This disease can be fatal if not treated immediately and with the appropriate antibiotics. If you think you have tularemia, seek medical attention. Tularemia does not spread from person to person.

If I am bitten by a tick, will I get tularemia?

Tularemia is very rare among ticks in San Mateo County. Less than 1% of the adult ticks tested were found to be infected with the bacterium that causes this disease.

What are the signs and symptoms of tularemia?

• Sudden fever
• Chills
• Headaches
• Diarrhea
• Muscle aches
• Joint pain
• Dry cough
• Progressive weakness

Symptoms vary depending on the method of transmission.

Visit the CDC website to learn more about Tularemia.

Page last reviewed: February 20, 2025