Tick-Borne Diseases

Photographs of six ticks - dorsal and ventral views of male and female adults and dorsal views of nymphs. All the ticks have eight legs and a darker brown upper part and lighter brown lower part.

Lyme Disease

Lyme disease is caused by a bacteria (Borrelia burgdorferi) which is transmitted by ticks. It may be cured by early diagnosis and appropriate antibiotic treatment, but it may persist in the human body for years, if not properly treated. Lyme disease was named for Old Lyme, Connecticut, where the first cases of Lyme disease were reported. The first case in California was reported in 1978. It is…

Anaplasmosis

Anaplasmosis is a disease caused by the bacteria Anaplasma phagocytophilum, transmitted to humans by tick bites. It is less common than Lyme disease in California but is transmitted by the same tick, the western black-legged tick (Ixodes pacificus). On the east coast of the United States, the tick vector is the deer tick (Ixodes scapularis). It is treatable with antibiotics and rarely fatal…

A dark brown and light brown colored tick, with a round body, 8 long legs, and a mouthpart extending from the body

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.

Tick-borne relapsing fever

Tick-borne relapsing fever refers to a type of illness caused by the bacteria Borrelia miyamotoi carried by ticks. In San Mateo County, the ticks that carry bacteria that cause this illness are Ixodes pacificus, the western black-legged tick. It is closely related to the bacteria that causes tick-borne relapsing fever. The infection is treatable with antibiotics. A person who has been bitten…

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever (RMSF) is a bacterial disease (Rickettsia rickettsii) transmitted by ticks of the genus Dermacentor. These ticks are most common during spring and summer. Rocky Mountain Spotted Fever is very rare in San Mateo County.

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