Hospital Indoor Environment Research Articles

Possible Environmental Origin of Resistance of Aspergillus fumigatus to Medical Triazoles

We reported the emergence of resistance to medical triazoles of Aspergillus fumigatus isolates from patients with invasive aspergillosis. A dominant resistance mechanism was found, and we hypothesized that azole resistance might develop through azole exposure in the environment rather than in azole-treated patients. We investigated if A. fumigatus isolates resistant to medical triazoles are present in our environment by sampling the hospital indoor environment and soil from the outdoor environment. Antifungal susceptibility, resistance mechanisms, and genetic relatedness were compared with those of azole-resistant clinical isolates collected in a previous study. Itraconazole-resistant A. fumigatus (five isolates) was cultured from the indoor hospital environment as well as from soil obtained from flower beds in proximity to the hospital (six isolates) but never from natural soil. Additional samples of commercial compost, leaves, and seeds obtained from a garden center and a plant nursery were also positive (four isolates). Cross-resistance was observed for voriconazole, posaconazole, and the azole fungicides metconazole and tebuconazole. Molecular analysis showed the presence of the dominant resistance mechanism, which was identical to that found in clinical isolates, in 13 of 15 environmental isolates, and it showed that environmental and clinical isolates were genetically clustered apart from nonresistant isolates. Patients with azole-resistant aspergillosis might have been colonized with azole-resistant isolates from the environment.

Hospital Indoor Environment: Screening for Micro-Organisms and Particulate Matter

The concentrations of air-borne micro-organisms and particulate matter were measured in the air and on solid surfaces in five rooms in a hospital. For comparison the same measurements were also made outdoors. The rooms were chosen because of their different needs in terms of indoor environment quality. The highest bacterial concentrations were found in the air of a patient's room that was `unventilated' other than through its doorway. Some of the rooms were supplied with filtered air. Compared to the rest, these rooms had the lowest microbial concentrations in their air but the highest on surfaces. A correlation was found between the count of the particulate size-range ≥1.0 μm and that of bacteria ( r=0.76) and between the count of the particulate size range ≥5.0 μm and those of bacteria ( r=0.88) and staphylococci ( r=0.80) in indoor air. No correlation was found between the particulate count and the mould count in the indoor air.

Integrated Environmental Management for Hospitals

The hospital indoor environment includes several unwanted elements including a mix of chemical pollutants, biological contaminants and a high physical and mental stress for all the staff offering medical services. Infection risks are increased by direct contact with sick people in addition to needle and medical equipment punctures conveying blood-transmitted diseases. Although infection control measures are considered seriously they are often inadequate because of concomitant construction problems and ingress of outdoor pollutants. This is especially so in metropolitan areas where the hospitals are engulfed in an urban environment and surrounded by small scale industrial pollution and traffic air emissions. Every country and indeed every hospital has its own problems and this paper describes the progress of an environmental integrated management scheme initiated for the indoor environment of hospitals to provide greater control to protect the hospital staff from occupational hazards impacting their health, their home contacts and their patients. The scheme started with the preparation of an environmental assessment for newly built hospitals. For those hospitals currently operating the scheme comprised the organisation of an environmental health group and the preparation of a checklist of the environmental sources of indoor pollutants, contaminants and sources of infection and occupational health hazards. An environmental audit was conducted with monitoring for sources of environmental deterioration. There was a follow up for the adoption of hazardous waste management and cleaning and disinfection protocols. A reporting system was set up within the scheme which included follow up actions. The problems of adopting the system are discussed with methodologies for their solutions.