Plasma disinfection procedures for air and surfaces in emergency service vehicles - a field trial at the German red cross

Abstract

The need for disinfection in ambulances is high as medical procedures are performed inside the cars and patients may have open wounds that pose a high risk of infection. The application of reactive products from air's oxygen and water vapor, brought to reaction through cold plasma, can be a solution to the discrepancy in surface hygiene. The cell membrane of the microorganisms is perforated by the charged particles of the cold plasma. This is impossible in human cells because proteins in the form of enzymes break down the cold plasma and protect the cells. An ambulance was contaminated in 8 places. Samples were taken at each site and two surfaces of approximately 8x8 cm were sealed and marked. Both surfaces were contaminated with an Enterococcus faecium suspension of 8.5x107CFU/mL by applying the suspension with a sterile cotton swab. Then, the disinfection process was applied. The PLASMOCAR® device was placed in the front work surface and operated for 30 minutes using the vehicle's onboard voltage. During operation, doors and windows were closed and the vehicle's air conditioning was active. The surfaces for bacterial counts were sampled after the disinfection process was completed. A reduction of 3.73 log levels in initial bacteria was achieved in the rescue vehicle for Enterococcus faecium, equivalent to a 10-4-fold reduction in bacteria, eliminating up to 99.99% of the initial microorganisms. This makes the process suitable as a continuously "background" procedure to support and relieve established disinfection procedures. The established disinfection procedures per hygiene plan should be recognized as soon as mechanical cleaning of surfaces is needed. The use of PLASMOCAR® provides additional security and significantly reduces the background risk of transmitting microorganisms through cross-contamination and aerosols, a relevant benefit for staff and patients.