Effect of refrigeration, room temperature, and processing time on serum immunofluorescent antibody titers for Sarcocystis neurona.
Authors: Valderrama-Martinez Claudia, Packham Andrea, Zheng Shichen, Smith Woutrina, Plancarte Magdalena, Aleman Monica
Journal: Journal of veterinary internal medicine
Summary
# Sarcocystis neurona Antibody Testing: Storage Conditions Don't Compromise Results Diagnosing equine protozoal myeloencephalitis (EPM) routinely involves serum antibody testing for *Sarcocystis neurona*, yet clinical reality often prevents immediate refrigeration of samples. Valderrama-Martinez and colleagues prospectively evaluated whether storage temperature affects immunofluorescent antibody (IFA) titre accuracy by testing 22 serum samples at baseline, day 5, and day 10 under both room temperature (20–23.3°C) and refrigerated (4°C) conditions. Results demonstrated no statistically significant differences in IFA titres between any storage conditions or timepoints over the 10-day period, with p-values ranging from 0.5 to 0.964 across comparisons. This finding substantially simplifies sample handling protocols in practice: practitioners can confidently send unrefrigerated serum samples without compromising diagnostic accuracy, provided testing occurs within 10 days of collection—a particularly valuable outcome for field-based practitioners, remote facilities, and situations where maintaining cold chain integrity proves logistically challenging.
Read the full abstract on PubMed
Practical Takeaways
- •Serum samples for S. neurona IFA testing can be safely stored at room temperature for up to 10 days, eliminating the need for immediate refrigeration in field or remote situations
- •This finding improves diagnostic accessibility for equine protozoal myeloencephalitis in practices without reliable cold chain capacity
- •Practitioners can collect samples without urgent shipping requirements, allowing more flexible sampling protocols and reduced diagnostic delays
Key Findings
- •IFA titers for S. neurona remain stable at room temperature (20-23.3°C) for up to 10 days with no significant difference from baseline (P=0.741 at Day 5, P=0.677 at Day 10)
- •IFA titers stored at 4°C show no significant degradation over 10 days compared to baseline (P=0.964 at Day 5, P=0.573 at Day 10)
- •No statistical difference exists between room temperature and refrigerated storage conditions at Days 5 and 10 (P=0.688 and P=0.104 respectively)
- •Serum samples for S. neurona antibody testing do not require immediate refrigeration and remain reliable for diagnostic purposes for at least 10 days