Vaporized H 2 O 2 decontamination against surrogate viruses for the reuse of N95 respirators in the COVID-19 emergency

  1. Ebru Oral
  2. Keith K. Wannomae
  3. Rachel L. Connolly
  4. Joseph A. Gardecki
  5. Hui Min Leung
  6. Orhun K. Muratoglu
  7. John Durkin
  8. Ralph Jones
  9. Cassidy Collins
  10. Julian Gjore
  11. Amanda Budzilowicz
  12. Tareq Jaber

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Abstract

Decontamination of N95 respirators has become critical to alleviate PPE shortages for healthcare workers in the current COVID-19 emergency. The factors that are considered for the effective reuse of these masks are the fit, filter efficiency and decontamination/disinfection level both for SARS-CoV-2, which is the causative virus for COVID-19, and for other organisms of concern in the hospital environment such as Staphylococcus aureus or Clostridium difficile.

In its guidance entitled ‘Recommendations for Sponsors Requesting EUAs for Decontamination and Bioburden Reduction Systems for Surgical Masks and Respirators During the Coronavirus Disease 2019 (COVID19) Public Health Emergency’ (May 2020)[1], the FDA recommends a 6-log10 reduction in either the most resistant bacterial spores for the system or in a mycobacterium species to authorize the use of a decontamination method of N95 respirators for single or multiple users. While the goal is primarily inactivation against SARS-CoV-2, testing of decontamination methods against the virus may not always be available. For decontamination methods considered for only single users, the recommendation is a 6-log10 reduction in the infective virus concentration of 3 non-enveloped viruses or in the concentration of two Gram (+) and two Gram (-) bacteria. Based on these recommendations, we explored the efficacy of vaporized H2O2 (VHP) treatment of N95 respirators against surrogate viruses covering a wide range of disinfection resistance for emergency decontamination and reuse to alleviate PPE shortages for healthcare workers in the COVID-19 emergency.

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  1. ScreenIT

    SciScore for 10.1101/2020.06.25.20140269: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    The corresponding growth media were Complete MEM for CRFK, MDCK and StNeb cells, Complete RPMI for Vero76 cells, and Complete DMEM for BT cells.
    MDCK
    suggested: None
    Vero76
    suggested: IZSLER Cat# BS CL 101, RRID:CVCL_0603)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    These are technical limitations associated with viral infectivity studies for the purpose of determining the efficacy of a decontamination method on respirator surfaces. VHP decontamination of respirator surfaces spiked with PPV could be reliably quantified due to (1) high initial stock concentration and sustained concentration of infective units of PPV on surfaces; (2) high persistent concentration of infective units of PPV on the surfaces for a prolonged period of (hold) time; and (3) the detection of live infective units in culture after decontamination. VHP decontamination of respirator surfaces spiked with PPV ranged from 5.61 to 7.02 log10 reduction, showing a high level of disinfection/inactivation against this non-enveloped virus. We have previously shown inactivation of infective SARS-Cov-2 using VHP decontamination under similar conditions to those tested here [6], supporting the efficiency of this decontamination method against a wide range of pathogens. We have also previously shown that the filter efficiency and fit for the 3M 1860S N95 respirator was not detrimentally affected by VHP decontamination for at least one cycle of decontamination [6]. The results of our study only consider bioburden reduction, one of the many considerations that healthcare facilities need to consider in selecting a decontamination method to utilize during emergency use of N95 respirators. The results presented here are not meant to constitute a stand-alone recommendation.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  2. Version published to 10.1101/2020.06.25.20140269v1 on medRxiv