Read condition-specific symptoms and clinical context for Borrelia burgdorferi. The corkscrew-shaped bacterium behind Lyme disease, carried by ticks rather than passed between people.
PHAC describes B. burgdorferi as a Gram-negative spirochete — a group of highly motile corkscrew-shaped bacteria — measuring 10 to 30 micrometres in length and 0.2 to 0.5 micrometres in width, microaerophilic, oxidase negative and non-spore-forming, with a linear chromosome of about 950 kilobases plus circular and linear plasmids. Transmission is by bites from selected species of ticks, primarily Ixodes scapularis and I. pacificus in North America, and humans are described as dead-end hosts. CDC reports that more than 80,000 Lyme disease cases are reported to it each year, while an estimate using insurance claims suggests 476,000 people are treated for Lyme disease each year.
CDC describes early signs and symptoms appearing 3 to 30 days after a tick bite. PHAC calls this stage I, early localized disease.
Possible symptoms: Erythema migrans rash; Fever; Chills; Headache; Fatigue; Muscle and joint aches; Swollen lymph nodes.
CDC’s early symptom list explicitly allows for illness without a rash, so the absence of a bull’s-eye does not rule Lyme disease out. Diagnosis and treatment are clinical decisions; this app does not assess a rash or a tick bite.
CDC describes later signs and symptoms appearing days to months after a tick bite. PHAC describes stage II early disseminated disease and stage III late disease, in which migratory polyarthropathy is the most common clinical manifestation.
Possible symptoms: Severe headaches and neck stiffness; Additional rashes on other areas of the body; Facial palsy; Arthritis with severe joint pain and swelling; Heart palpitations or an irregular heartbeat; Episodes of dizziness or shortness of breath; Nerve pain; Shooting pains, numbness or tingling in the hands or feet.
These features appear days to months after a bite, so they can arise in people who never noticed a tick or a rash. Assessment and treatment are clinical decisions.
A tick bite is not the same as an infection.
The bundled sources give no symptom list for a tick bite that does not transmit infection, and none is invented here. PHAC records transmission by bites from selected species of ticks, primarily Ixodes scapularis and I. pacificus in North America, with disease onset peaking in spring and summer during nymphal tick activity — so most ticks encountered are the wrong species, the wrong stage or uninfected. PHAC also describes humans as dead-end hosts, so a person with Lyme disease does not pass it to anyone else. This profile assigns no human carriage state.
Tick removal and decisions about whether a bite warrants assessment are clinical and local-guidance matters. This app gives no bite advice.
Source check: 2026-09-20. Educational content; independent scientific review remains pending.