Decontamination of room air and adjoining wall surfaces by nebulizing hydrogen peroxide.

AIM: In 2010, the ASP GLOSAIR(TM) 400 was introduced in Germany for nebulizing hydrogen peroxide (H(2)O(2)). Since there were no results of practical experience, the new method was to be checked under practical conditions for its effectiveness in decontaminating air in rooms, infested with mold after water damage and, at the same time, under experimentally controlled conditions, test surfaces, contaminated with Aspergillus brasiliensis. METHOD: After the nebulizer was used in two rooms with a massive mold infestation, the air colony count was determined (MAS-100(®) Zinsser Analytik) and, at the same time, the mold infestation in samples of wall plaster.As part of this controlled study, test surfaces contaminated with Aspergillus brasiliensis were positioned vertically and horizontally in a test room. The effectiveness of the nebulization (5-6% H(2)O(2) for 2 hours) was tested on these surfaces according to EN 13697. RESULTS: In a massive mold infestation resulting from water damage (worst case), an approximately 9-fold decrease in the mold content and an approximately 13-fold decrease in the number of colony-forming units (sum of the bacteria + fungi) could be detected in the room air immediately after the nebulizing was finished. Even in samples of wall and joint plaster, the molds were reduced, although to a distinctly lesser extent. By indoor nebulization of 5-6% H(2)O(2), A. brasiliensis was reduced >4 log on vertical and horizontal surfaces. DISCUSSION: In rooms with a massive mold infestation, the ASP GLOSAIR(TM) 400 system is suitable for attaining a clear reduction in the fungal and bacterial room air load, lasting for a week. On vertical and horizontal surfaces, contaminated experimentally with A. brasiliensis, a reduction of >4 lg is achieved. As a load of 10(4) to 10(5) fungal spores is unlikely to occur on pre-cleaned surfaces, the GLOSAIR(TM) 400 can be considered a suitable complementary process for the substantial reduction of fungal contamination.

Impact of surface disinfection and sterile draping of furniture on room air quality in a cardiac procedure room with a ventilation and air-conditioning system (extrusion airflow, cleanroom class 1b (DIN 1946-4)).

In a cardiac procedure room, ventilated by a ventilation and air-conditioning system with turbulent mixed airflow, a protection zone in the operating area could be defined through visualization of airflows. Within this protection zone, no turbulence was detectable in the room air.Under the given conditions, disinfection of all surfaces including all furniture and equipment after the last operation and subsequent draping of furniture and all equipment that could not be removed from the room with sterile surgical drapes improved the indoor room air quality from cleanroom class C to cleanroom class B. This also allows procedures with elevated requirements to be performed in room class 1b.

Are laptop ventilation-blowers a potential source of nosocomial infections for patients?

Inadequately performed hand hygiene and non-disinfected surfaces are two reasons why the keys and mouse-buttons of laptops could be sources of microbial contamination resulting consequently in indirect transmission of potential pathogens and nosocomial infections. Until now the question has not been addressed whether the ventilation-blowers in laptops are actually responsible for the spreading of nosocomial pathogens. Therefore, an investigational experimental model was developed which was capable of differentiating between the microorganisms originating from the external surfaces of the laptop, and from those being blown out via the ventilation-blower duct. Culture samples were taken at the site of the external exhaust vent and temperature controls were collected through the use of a thermo-camera at the site of the blower exhaust vent as well as from surfaces which were directly exposed to the cooling ventilation air projected by the laptop. Control of 20 laptops yielded no evidence of microbial emission originating from the internal compartment following switching-on of the ventilation blower. Cultures obtained at the site of the blower exhaust vent also showed no evidence of nosocomial potential. High internal temperatures on the inner surfaces of the laptops (up to 73°C) as well as those documented at the site of the blower exhaust vent (up to 56°C) might be responsible for these findings.