What is rapid syndromic testing for respiratory infections?

Acute respiratory infection has always been a huge burden of disease, as one of the most common causes of mortality worldwide. Dr Kay Roy explores the use of syndromic testing in respiratory infections.

Rapid syndromic testing in respiratory infections impacts greatly on clinical decision making, improving the de-escalation, and narrowing down of antibiotics for patients with susceptible pathogens when compared to conventional methods.

Conventional methods are often slower, with poorer pathogen recovery, and so present a delay in initiating active therapy for those with particularly resistant pathogens. This is a key performance indicator in the delivery of best care in pneumonia and ultimately leads to:

• Delay in patient recovery
• Increased mortality
• Prolonged hospital stay
• Addition to healthcare costs
• Adverse effects

Image: Depending on where the patient is (i.e. the healthcare setting), there is a huge diversity in the organisms seen

If you require a text version of the above image, this is available as a PDF.

Respiratory infections

For respiratory infections, syndromic testing provides the greatest potential benefit in being able to utilise antibiotics in an improved manner due to its superior diagnostic yield. Pathogens are detected both rapidly and in a greater proportion of patients so that therapy can be quickly tailored to the responsible organism.

In some situations, its use results in a narrowing down of broad-spectrum antimicrobial therapy that may have been initiated empirically at the start. In other cases, it facilitates escalation of antimicrobial therapy.

Unnecessary antibiotics can also be avoided through the absence of detection, allowing clinicians to confidently stop (or de-escalate) antibiotics. Its use is particularly important in patients with chronic lung disease, who thus require personalised care.

Effects of syndromic testing

Below are studies evaluating the effects of syndromic testing (and other molecular POCT approaches):

1 A pragmatic randomised controlled trial (RCT), enrolling >700 patients, showed that there was a significant reduction in LOS in patients who were randomised to the ‘POCT’ arm, as opposed to the ‘conventional methods’ arm.

Findings also highlighted shorter/discontinued antibiotic courses in patients where POCT was used. Duration of antibiotic treatment and the proportion treated with IV antibiotics did not differ between the two arms, perhaps highlighting the need to endorse these methods much earlier in the patient journey:

2 A study looking at patients with small airways disease observed the positive impact of POCT in identifying other viruses and influencing the reduction or rationalisation of antibiotic use:

3 A multi-centre evaluation looking at the use of syndromic testing in adapting antimicrobial therapy in adults with pneumonia showed positive impacts in antimicrobial therapy prescription when compared to non-PCR-guided therapy: Rapid syndromic molecular platforms significantly improve the use of antibiotics and clinical outcomes in patients with pneumonia. Click here for a closer look