Respiratory cross-infection in non-invasive ventilation devices

Area of Science:

• Respiratory Medicine
• Infectious Disease Control
• Biomedical Engineering

Background:

• Non-invasive ventilation (NIV) is classified as an aerosol-generating procedure.
• Uncertainty exists regarding the actual risk of airborne pathogen transmission during NIV use.

Purpose of the Study:

• To assess bioaerosol generation during NIV.
• To evaluate NIV device contamination.
• To compare airborne particle dispersion during NIV versus other breathing/coughing methods.

Main Methods:

• Three studies were conducted using specialized rigs to measure aerosol particles and bacterial contamination.
• HEPA-filtered air ensured detection of NIV-generated particles.
• Study 3 compared aerosol dispersion during NIV, sham NIV, tidal breathing, and uncovered coughing.

Main Results:

• NIV generated aerosol particles, with viable bacteria detected at high concentrations (≥1 × 10^5 CFU/mL).
• Inline filters prevented bacterial emission, and NIV device contamination risk was low (1 in 10).
• NIV produced more aerosol particles than tidal breathing but fewer than uncovered coughing; infectious particle release was minimal.

Conclusions:

• NIV devices can become contaminated and aerosolize viable bacteria.
• Despite WHO classification, NIV poses a low risk for infectious particle release when using effective interfaces, leak control, and infection prevention measures.