When should blood be drawn for tests for tick-borne encephalitis and Lyme disease after a tick bite? - briefly
Blood for tick‑borne encephalitis should be collected 7–14 days after the tick attachment (or at symptom onset) to allow IgM/IgG detection. For Lyme disease, serologic testing is recommended no earlier than 2–4 weeks post‑exposure, when specific antibodies are typically present.
When should blood be drawn for tests for tick-borne encephalitis and Lyme disease after a tick bite? - in detail
Blood samples for laboratory confirmation of tick‑borne encephalitis (TBE) and Lyme borreliosis should be taken according to the kinetics of the specific antibody response and the clinical context.
For TBE, IgM antibodies become detectable 5–10 days after the onset of neurological symptoms, while IgG appears 2–3 weeks later. In a person who is asymptomatic after a tick attachment, the optimal schedule is:
- a first draw as soon as possible after removal of the tick (baseline), primarily to document pre‑exposure status;
- a second draw 10–14 days later, when seroconversion is likely to be evident if infection has occurred;
- a third draw 3–4 weeks after the bite if the second sample is negative but clinical suspicion persists or if the patient develops fever, headache, or meningitic signs.
For Lyme disease, the serologic response follows a biphasic pattern. IgM antibodies to Borrelia burgdorferi surface proteins appear 2–4 weeks after infection; IgG antibodies rise from 4–6 weeks onward and persist for months. The recommended timing is:
- an initial sample at the time of the bite or within the first week to serve as a reference;
- a follow‑up sample at 2–3 weeks to capture the early IgM response;
- a third sample at 4–6 weeks to detect IgG, especially if the earlier test was negative and the patient exhibits erythema migrans, arthralgia, or other early manifestations.
If clinical symptoms develop earlier (e.g., fever, meningitis, facial palsy, or expanding skin lesions), blood should be drawn immediately, regardless of the preset schedule, and the specimen should be sent for both serology and, when appropriate, polymerase chain reaction (PCR) testing of blood or cerebrospinal fluid.
In summary, a baseline sample, a second collection 10–14 days post‑exposure, and a third collection 3–6 weeks after the bite provide the most reliable detection window for both TBE and Lyme disease, with earlier sampling reserved for acute symptom onset.