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Updated: Aug 14, 2025
Author Spotlight: Advancing Rapid Detection of Respiratory Pathogens Using Microfluidic Chip
Published on: March 29, 2024
The rapid detection of respiratory pathogens in critically ill children
John A Clark1,2, Andrew Conway Morris3,4,5, Martin D Curran6
1Department of Paediatrics, Addenbrooke's Hospital, University of Cambridge, Level 8, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK. jac302@cam.ac.uk.
Insights
A new molecular diagnostic test accurately identifies pathogens in children with lower respiratory tract infections (LRTI). This rapid test aids in the appropriate use of antimicrobials in critically ill children.
Area of Science:
- Pediatric critical care medicine
- Infectious diseases
- Diagnostic microbiology
Background:
- Respiratory infections are a leading cause of pediatric intensive care unit (PICU) admissions.
- Empirical broad-spectrum antimicrobial use is common for lower respiratory tract infections (LRTI) in children, despite low pathogen confirmation rates.
- Optimizing antimicrobial therapy requires rapid and accurate diagnostics.
Purpose of the Study:
- To evaluate a novel molecular diagnostic test for identifying pathogens in pediatric lower respiratory tract infections (LRTI).
- To assess the accuracy and speed of the molecular test compared to standard microbiology.
- To determine the potential of the molecular test to guide antimicrobial stewardship in critically ill children.
Main Methods:
- A prospective, observational cohort study involving 100 mechanically ventilated children aged corrected 37/40 weeks to 18 years with suspected LRTI.
- Utilized a 52-pathogen custom TaqMan Array Card (TAC) for pathogen detection in bronchoalveolar lavage samples.
- Compared TAC results against routine bacterial and fungal cultures, analyzing sensitivity, specificity, and time to result.
Main Results:
- The TAC demonstrated high sensitivity (89.5%) and specificity (97.9%) compared to routine cultures.
- TAC provided results significantly faster (median 25.8 hours) than conventional culture methods (median positive 110.4 hours, median negative 69.4 hours).
- 91 patients had matching samples for comparative analysis.
Conclusions:
- The TaqMan Array Card (TAC) is a reliable and rapid diagnostic tool for LRTI in critically ill children.
- This molecular test has the potential to facilitate early and rational antimicrobial therapy adjustments.
- Improved diagnostics can lead to better patient outcomes and antimicrobial stewardship.
Purpose:
Respiratory infections are the most common reason for admission to paediatric intensive care units (PICU). Most patients with lower respiratory tract infection (LRTI) receive broad-spectrum antimicrobials, despite low rates of bacterial culture confirmation. Here, we evaluated a molecular diagnostic test for LRTI to inform the better use of antimicrobials.
Methods:
The Rapid Assay for Sick Children with Acute Lung infection Study was a single-centre, prospective, observational cohort study of mechanically ventilated children (> 37/40 weeks corrected gestation to 18 years) with suspected community acquired or ventilator-associated LRTI. We evaluated the use of a 52-pathogen custom TaqMan Array Card (TAC) to identify pathogens in non-bronchoscopic bronchoalveolar lavage (mini-BAL) samples. TAC results were compared to routine microbiology testing. Primary study outcomes were sensitivity and specificity of TAC, and time to result.
Results:
We enrolled 100 patients, all of whom were tested with TAC and 91 of whom had matching culture samples. TAC had a sensitivity of 89.5% (95% confidence interval (CI95) 66.9-98.7) and specificity of 97.9% (CI95 97.2-98.5) compared to routine bacterial and fungal culture. TAC took a median 25.8 h (IQR 9.1-29.8 h) from sample collection to result. Culture was significantly slower: median 110.4 h (IQR 85.2-141.6 h) for a positive result and median 69.4 h (IQR 52.8-78.6) for a negative result.
Conclusions:
TAC is a reliable and rapid adjunct diagnostic approach for LRTI in critically ill children, with the potential to aid early rationalisation of antimicrobial therapy.
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