How to give a blood test after a tick bite? - briefly
Collect a blood sample via standard venipuncture within 2–3 weeks of the bite, label it for Lyme disease serology, and send it to a certified laboratory following the lab’s specimen‑handling guidelines. Confirm the results with a healthcare professional to determine appropriate treatment.
How to give a blood test after a tick bite? - in detail
A tick bite can transmit pathogens that are detectable only through laboratory analysis. Prompt blood sampling, appropriate test selection, and correct handling are essential for accurate diagnosis.
After the bite, assess the risk based on tick species, duration of attachment, and geographic prevalence of tick‑borne diseases. If the tick was attached for more than 24 hours or the region is known for Lyme disease, anaplasmosis, babesiosis, or Rocky Mountain spotted fever, a blood draw should be arranged within 2–4 weeks of the encounter.
Sample collection
- Use a sterile vacutainer system; draw at least 5 mL of whole blood for serology and 2 mL of plasma/serum for PCR.
- Label each tube with patient identifier, date, and time of collection.
- Store serum and plasma at 2–8 °C if processing occurs within 24 hours; otherwise freeze at –20 °C for PCR assays.
Test panel
-
Serologic assays
- Enzyme‑linked immunosorbent assay (ELISA) for IgM and IgG antibodies against Borrelia burgdorferi.
- Immunofluorescence assay (IFA) for Anaplasma phagocytophilum and Ehrlichia spp.
- Indirect immunofluorescence or microagglutination for Rickettsia species.
-
Molecular detection
- Real‑time PCR targeting the 16S rRNA gene of Borrelia.
- PCR panels for Babesia microti and Rickettsia rickettsii.
-
Complete blood count
- Evaluate leukopenia, thrombocytopenia, or anemia, which may indicate systemic infection.
Interpretation guidelines
- Positive IgM with recent symptom onset suggests early infection; IgG persistence indicates past exposure.
- PCR positivity confirms active infection, even when serology is negative early in the disease course.
- Hematologic abnormalities support clinical suspicion but are not disease‑specific.
Follow‑up
- If initial results are negative but symptoms develop, repeat serology after 2–3 weeks to capture seroconversion.
- Positive findings require prompt antimicrobial therapy according to current clinical guidelines.
Adhering to these procedures maximizes diagnostic yield and enables timely treatment of tick‑borne illnesses.