Pertussis PCR NP Swab Storage
Yes—refrigerate the nasopharyngeal swab (2–8°C) if it cannot reach the lab within 2 hours; keep cold during transport. 1, 2
- Rationale and hierarchy
- IDSA/ASM 2018 utilization guide (most recent, high-quality): If delivery is not rapid (<2 hours) at room temperature, specimens should be refrigerated; most virology specimens on wet ice, and freeze at −80°C if testing is delayed >48 hours. While pertussis PCR targets bacteria, the same specimen-handling principles apply to preserve nucleic acids and clinical yield, minimizing false negatives that affect morbidity, mortality, and quality of life through delayed diagnosis and isolation/treatment. 1
- 2013 IDSA/ASM guidance is concordant: refrigerate after 2 hours if RT specified; prioritize cold transport. 2
- Older data for culture show superior recovery at 4°C vs 25°C, supporting cold storage to maintain organism/nucleic acid integrity. 3
Algorithm (practical steps)
- If specimen will arrive at lab:
- Within 2 hours: transport at room temp acceptable per lab policy; prefer cold pack if available. 1, 2
2 hours: refrigerate immediately (2–8°C) and transport on ice/cold pack. 1, 2
48 hours delay expected: freeze at −80°C if validated for your lab’s PCR; otherwise keep refrigerated and expedite. Confirm with your lab. 1
- Use appropriate swab and transport medium per lab protocol; label accurately. 1, 2
Pitfalls to avoid
- Leaving swabs at room temperature beyond 2 hours (risk of nucleic acid degradation → false negatives). 1, 2
- Freezing at −20°C (can degrade targets); use −80°C if freezing is required and validated. 1
- Using improper swab/media (e.g., cotton/calcium alginate) that can inhibit PCR—follow lab instructions. 1
Nuance