The 2014 West Africa Ebola outbreak saw a substantial number of healthcare workers (HCWs) being infected, despite the use of personal protective equipment (PPE). PPE is intended to protect HCWs when caring for patients with Ebola virus disease (EVD), but PPE may play a role in the spread of Ebola in healthcare environments. Before the removal of PPE, chemical disinfection may prevent the transfer of pathogens to HCWs, but the efficacy of common disinfectants against enveloped viruses, such as Ebola, on PPE surfaces is relatively unknown. The purpose of this study is to assess the efficacy of two common disinfectants, chlorine bleach (Clorox® bleach) and quaternary ammonium (Micro-Chem Plus®), used in healthcare settings for inactivation of enveloped viruses on PPE. The virucidal activity of the two disinfectants were tested against bacteriophage Φ6, an enveloped, non-pathogenic surrogate for enveloped viruses, on Tyvek suit surfaces. Virus was dried onto Tyvek suit surface, exposed to the disinfectants at use-dilution for a contact time of one minute, and the surviving virus was quantified using a double agar layer (DAL) assay. The Clorox® bleach and Micro-Chem Plus® produced a >3.21 log10 reduction and >4.33 log10 reduction, respectively, in Φ6 infectivity. The results of this study suggest that chlorine bleach and quaternary ammonium are effective in the inactivation of enveloped viruses on Tyvek suit surfaces. Chemical disinfection of PPE should be considered as a viable method to reduce the spread of pathogenic, enveloped viruses to HCWs, patients, and other environmental surfaces in healthcare settings.

Background: Bacteriophage Φ6 is a lipid-enveloped dsRNA bacteriophage. The limitations in our knowledge of how this bacteriophage occurs in the environment are limited by non-selective isolation techniques. Research on finding phages in the environment in the past has employed the Double Agar Layer (DAL) plaque assay using Tryptic Soy Agar (TSA), a non-selective media. The bacterial host for bacteriophage Φ6 is Pseudomonas syringae. In this study, we tested Pseudomonas Agar, a selective media that suppresses the growth of bacteria except Pseudomonas species, in the standard double agar layer plaque assay for Φ6. Methods: DAL plaque assays were performed to determine the sensitivity of both Tryptic Soy Agar (TSA) and Pseudomonas Agar (PA) for determining the titer of pure bacteriophage Φ6 stocks. We used Pseudomonas syringae (HB10Y) as the host, and the plaque formation on both agars was compared. Following the evaluation of PA with pure Φ6 stocks, PA effectiveness for Φ6 isolation from environmental samples was tested in spiked waters obtained from irrigation ponds at an agricultural farm. Results: Comparison of TSA and PA using pure Φ6 cultured in the laboratory and spiked environmental samples showed that PA agar can detect bacteriophage Φ6 as well as the standard DAL assay using TSA. On PA, formation of clear visible plaques comparable to the plaques formed using TSA was observed. Conclusions: Pseudomonas Agar can be used for the isolation of bacteriophage Φ6 in environmental samples. This may enhance the detection of these phages in the environment.