Development and implementation of a customised rapid syndromic diagnostic test for severe pneumonia

Area of Science:

• Clinical microbiology
• Infectious diseases
• Molecular diagnostics

Background:

• Traditional bacterial cultures for pneumonia diagnosis are slow and often yield negative results, leading to broad-spectrum antibiotic use.
• Empiric antibiotic prescribing in critically ill patients compromises antimicrobial stewardship.
• There is a need for rapid, accurate diagnostic tools for pneumonia.

Purpose of the Study:

• To evaluate the performance of a syndromic molecular diagnostic approach using a custom TaqMan array card (TAC) for 52 respiratory pathogens.
• To assess the impact of this molecular diagnostic approach on antimicrobial prescribing in pneumonia patients.

Main Methods:

• The TaqMan array card (TAC) was validated retrospectively and then prospectively used in patients with suspected pneumonia.
• A comparator group received conventional microbiological investigation.
• Outcomes included diagnostic sensitivity, time to result, and antibiotic-free days (AFD). Metagenomic sequencing was used for validation.

Main Results:

• The TAC demonstrated high sensitivity (97% retrospectively, 92% prospectively) compared to conventional microbiology.
• TAC provided results significantly faster (51 hours) than culture.
• The TAC group experienced more antibiotic-free days (AFD) and were more likely to undergo antimicrobial de-escalation.

Conclusions:

• The syndromic molecular diagnostic approach offers a rapid and sensitive method for pneumonia diagnosis.
• Implementation of TAC impacts antimicrobial prescribing, promoting better stewardship.
• This molecular approach enhances patient management by enabling quicker, more informed treatment decisions.