However, in a single trial designed by CDC and involving one machine, The Children's Hospital of Philadelphia subjected a Vapotherm device and used filter cartridge to the new chlorine dioxide disinfection protocol. The device and cartridge were known to be contaminated with Ralstonia spp., and the unit had been out of service and not disinfected for multiple weeks. Samples obtained immediately after disinfection grew no organisms. The trial was initially designed to run for 30 days; however, after 7 days of continuous operation of the unit with no patient contact, samples from both the vapor condensate and the filter cartridge grew Ralstonia spp. in culture at CDC.