Microbial contamination of powered air purifying respirators (PAPR) used by healthcare staff during the COVID-19 pandemic: an in situ microbiological study

Chakladar, Abhijoy; Jones, Claire G; Siu, Jimmy; Hassan-Ibrahim, Mohammed Osman; Khan, Mansoor

BACKGROUND: Powered air purifying respirators (PAPR) are an option for healthcare workers requiring respiratory protection during Covid-19; during the current pandemic, they are shared between multiple people. PAPR hoods are intended for multiple uses by a single user and may pose an infection risk between wearers. METHODS: Internal components of PAPR hoods and corrugated air supply hoses were swabbed for evidence of bacterial, fungal, common respiratory viruses and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) contamination. RESULTS: 25 PAPR hoods were swabbed; ten (40%) returned positive results. Bacterial growth was detected on six PAPR; five of the PAPR tested positive for fungal growth; all tested negative for SARS-CoV-2 and common respiratory viruses. CONCLUSIONS: Bacteria and fungi can remain on internal components of PAPR hoods and air supply hoses despite following recommended disinfection procedures. PAPR hoods have the potential to act as fomites, cross-infecting wearers and patients. Current guidelines for disinfecting PAPR hoods may not be effective for use in high risk healthcare environments.