Pathlab update: Sputum culture in the community setting updated indications

Sputum culture is generally considered a low-value microbiology test, due to limited sensitivity and specificity in identifying bacterial pathogens. An analysis of 3,200 samples processed at Pathlab between July 2023 and June 2024 found that only 6 per cent grew a respiratory pathogen resistant to amoxycillin, and just 0.7 per cent grew a pathogen resistant to doxycycline (excluding Pseudomonas). In the majority of cases, results did not change patient management.

Despite this, the volume of sputum samples being processed has increased in recent years.

Sputum culture in the community setting is only indicated in the following circumstances:

• If the patient has clear clinical evidence of a bacterial infection of the lower respiratory tract and has failed empiric antibiotic therapy with either amoxycillin and/or doxycycline.
• Monitoring of patients with bronchiectasis or cystic fibrosis, or management of acute exacerbations of bronchiectasis or cystic fibrosis.

To ensure appropriate testing, Pathlab may decline requests for sputum culture in patients that do not fall into the above categories.

Read more on the Pathlab website.