How many days after a tick bite should blood be taken for encephalitis testing? - briefly
Blood should be collected roughly one to two weeks after the tick exposure to permit serologic detection of encephalitis antibodies; a follow‑up sample can be taken 2–3 weeks later if the initial test is negative.
How many days after a tick bite should blood be taken for encephalitis testing? - in detail
Blood for tick‑borne encephalitis (TBE) diagnostics should be collected in a staged manner. An initial specimen is taken as soon as the bite is recognized, ideally within 24 hours, to establish a baseline and to permit early polymerase chain reaction (PCR) if viral RNA is present. Because viremia is transient, PCR sensitivity declines after the first few days.
Serologic testing becomes reliable when the immune response develops. IgM antibodies usually appear 7–10 days after infection, and IgG follows shortly thereafter. Consequently, a second sample is recommended between day 7 and day 10 post‑exposure. If the first serology is negative and clinical suspicion persists, a third specimen collected at day 14–21 can confirm seroconversion.
Practical schedule:
- Day 0–1: Collect whole‑blood or serum for PCR; record date of bite.
- Day 7–10: Draw serum for IgM/IgG ELISA; repeat PCR if early sample was negative.
- Day 14–21 (optional): Obtain additional serum to verify rising antibody titers.
Testing should be repeated promptly if neurological symptoms (headache, fever, meningitis, or encephalitis) emerge, regardless of the predefined timeline. Early PCR is most useful before symptom onset; serology is the primary diagnostic tool after the first week. Adhering to this timing maximizes detection probability and guides appropriate clinical management.