Paper II — 2024 March (Supplementary) (2019 Scheme) — Q12
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Paper II
2024 March (Supplementary) (2019 Scheme) · 100 marks · 180 min
Question
A CSF sample for culture was refrigerated and sent to microbiology laboratory. Write the
correct decision and the appropriate action to be taken
Q124 marksShort Answers
Answer
The correct decision is that this CSF sample is unacceptable for standard bacterial culture processing under normal circumstances — CSF for bacterial culture should never be refrigerated, since common fastidious organisms causing bacterial meningitis (e.g., Neisseria meningitidis, Haemophilus influenzae, and to a lesser extent Streptococcus pneumoniae) are cold-sensitive and may not survive refrigeration, potentially causing a false-negative culture result. (This is distinct from CSF for viral studies, where refrigeration is often appropriate/recommended — the correct handling instruction depends specifically on the intended test.)
Appropriate action:
Process the sample as soon as it arrives — do not delay further — but document the refrigeration/inappropriate storage explicitly and interpret/report the culture result with this caveat clearly communicated.
Communicate promptly with the requesting clinician, explaining that the refrigeration may have compromised the viability of fastidious organisms and reduced the sensitivity of the culture, so a negative result should be interpreted with caution and correlated closely with the clinical picture and other CSF findings (cell count, protein, glucose, Gram stain).
Given that antibiotic treatment for suspected bacterial meningitis should never be delayed pending laboratory confirmation, ensure the clinical team is proceeding with empirical antibiotic therapy based on clinical suspicion regardless of this culture’s outcome.
Use this incident as an opportunity to reinforce correct CSF handling/transport protocol with ward staff — CSF intended for bacterial culture should be transported to the laboratory immediately, at room temperature, without delay or refrigeration.
