Virucidal Efficacy of Disinfectants in Soil Loads

Ethanol, absolute for analysis (Merck Millipore, Grogg Chemie AG, Stettlen, Switzerland) was diluted to 87.5% v/v, 35% sodium hypochlorite (NaOCl, Honeywell Fluka, Fischer Scientific, Reinach Switzerland) was diluted to 0.625% v/v, and 40% peracetic acid (PAA, Sigma Aldrich, Buchs, Switzerland) was diluted to 0.25% v/v in 800 µl WSH. Virucidal activity of these decontamination solutions was assessed in two different biological soil types. Tripartite soil, intended as a substitute for mucosal secretions, containing 100 µl 5% bovine serum albumin (BSA), 400 µl 0.4% mucin, and 140 µl 5% tryptone (all sourced from Sigma Aldrich, Buchs, Switzerland) representing a medium soil load as previously described^{13 (link)–15 (link)}. For a heavier soil load, whole blood was drawn with informed consent from a healthy 24-year-old donor never exposed to Ebola virus using BD Vacutainer K2E (EDTA) Plus Blood Collection Tubes (BD Switzerland Sàrl, Eysins, Switzerland) and used within 72 h. 1 ml concentrated Ebola virus was added to 640 µl of each soil load.