After how many days can a tick be submitted for analysis? - briefly
Ticks can be submitted for laboratory analysis within seven days of removal if kept refrigerated and alive; after this period, viability and diagnostic accuracy decline sharply.
After how many days can a tick be submitted for analysis? - in detail
The interval between collection and laboratory examination of a tick is governed by pathogen survival, storage conditions, and the testing methodology.
For most bacterial and protozoan agents (e.g., Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti), viability declines rapidly at ambient temperature. Guidelines recommend:
- Dry, room‑temperature storage: submit within 7 days.
- Refrigerated (4 °C) storage: submit within 14 days; viability remains acceptable for most agents.
- Frozen (-20 °C or lower) storage: DNA remains detectable for several months, allowing submission up to 6 months for molecular assays.
Viral agents (e.g., tick‑borne encephalitis virus) are less stable; the recommended window is 5 days at room temperature, extending to 10 days under refrigeration.
Laboratories often impose a maximum acceptance period regardless of condition. Typical cut‑off points are:
- Standard diagnostic labs: 30 days from collection if the specimen is refrigerated or frozen.
- Specialist research facilities: up to 90 days for frozen specimens, provided the tick is intact and labeled correctly.
Key factors influencing the permissible delay:
- Temperature: lower temperatures slow degradation of nucleic acids and proteins.
- Moisture: excessive humidity promotes bacterial overgrowth, compromising results.
- Tick species and life stage: larger nymphs and adults retain pathogens longer than larvae.
- Testing method: culture requires live organisms (shorter window), while PCR tolerates longer storage.
To ensure reliable results, the safest practice is to place the tick in a sealed, dry container, refrigerate promptly, and ship to the laboratory within two weeks. If immediate analysis is not possible, freezing the specimen extends the acceptable submission period substantially.