How many days after a tick bite should blood be taken for testing for borreliosis and encephalitis? - briefly
Blood should be collected about 2–3 weeks after the bite to detect Lyme disease antibodies, and 7–10 days after exposure for tick‑borne encephalitis IgM, with a follow‑up sample 2–4 weeks later for confirmation.
How many days after a tick bite should blood be taken for testing for borreliosis and encephalitis? - in detail
Blood should be drawn for Lyme disease testing no earlier than three to five days after the bite if polymerase chain reaction (PCR) is used to detect Borrelia DNA. Serologic assays that measure IgM and IgG antibodies become reliable only after the immune response has developed; the earliest detectable IgM appears around the end of the first week, with a typical rise at 10‑14 days. For definitive diagnosis, a second sample is recommended 2‑4 weeks after the initial draw to confirm seroconversion or rising titres.
For tick‑borne encephalitis (TBE), the first serum sample is recommended at 7‑10 days post‑exposure to capture the initial IgM response. A follow‑up specimen taken 2‑3 weeks later is necessary to document the transition to IgG and to verify a primary infection. In vaccinated individuals, the timing is the same, but the presence of IgG may reflect vaccine‑induced antibodies rather than natural infection; thus, paired samples remain essential.
Practical schedule
- Day 3‑5: PCR for Borrelia (if available) – early detection of bacterial DNA.
- Day 10‑14: First serology for Lyme disease – IgM/IgG assessment.
- Day 7‑10: First serology for TBE – IgM detection.
- Day 21‑28: Second serology for both pathogens – confirm seroconversion, evaluate IgG rise.
If the initial result is negative but clinical suspicion persists, repeat testing at the 2‑4‑week mark is advised. Cerebrospinal fluid analysis may be required for neurological manifestations, but peripheral blood sampling follows the timeline outlined above.