Indications for Sputum Culture in the Community Setting
Sputum culture is in general a low value microbiology test, where the vast majority of results do not change patient management.
We analysed 3200 sputum samples between July 2023 and June 2024. The results are illustrated in the pie chart below. In summary, only 6% of the total samples grew a respiratory pathogen that was resistant to amoxycillin. Only 0.7% of the sample cohort grew a respiratory pathogen resistant to doxycycline. (excluding Pseudomonas)
Sputum culture suffers from both poor sensitivity and specificity in identifying bacterial pathogens.
Sputum culture in the community setting is only recommended if one of the following apply:
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The patient has clear clinical evidence of a bacterial infection of the lower respiratory tract and has failed empiric antibiotic therapy with amoxycillin and/or doxycycline.
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The patient is undergoing monitoring for bronchiectasis. Guidelines suggest 6 monthly monitoring for moderate to severe disease and annually for mild disease.
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Under direction from a respiratory specialist, including for CF patients.
In order to support good diagnostic stewardship principles, we would be grateful if you could adhere to the recommendations above before sending a sputum sample to the laboratory.