Aspergillus surveillance project at a large tertiary-care hospital

A one-year surveillance project was conducted at a large tertiary hospital, which had extensive indoor renovation and extensive demolition/building at several nearby sites. This study collected viable fungi samples in the hospital every six days and analysed 74 duct dust samples for Aspergillus fumigatus mycelial asp f1 protein. Mean total fungi were 257.8 cfu/m3 outdoors, 53.2 cfu/m3 in all indoor samples and 83.5 cfu/m3 in the bone marrow transplant patient rooms. Mean total aspergillus was 6.8 cfu/m3 outdoors, 12.1 cfu/m3 in all indoor samples and 7.3 cfu/m3 in the bone marrow transplant patient rooms. The five most prevalent Aspergillus species collected inside the hospital (mean cfu/m3) were Aspergillus niger 7.57 cfu/m3, Aspergillus candidus 1.72 cfu/m3, Aspergillus flavus 0.97 cfu/m3, A. fumigatus 0.88 cfu/m3 and Aspergillus glaucus 0.45 cfu/m3. In rooms undergoing duct cleaning, mean A. fumigatus concentrations were 11.0 cfu/m3. Forty-eight of 74 (65%) duct dust samples had measurable levels of asp f1 protein, with a mean level of 0.41 ppm and maximum level of 1.94 ppm. Three major incidents involved increased hospital aspergillus concentrations. A. niger levels reached 680 cfu/m3 in an organ transplant room after a water leak from a ceiling pipe. Total aspergillus concentrations rose to 77 cfu/m3 in a bone marrow transplant patient room after improper sealing and water infiltration of the unit's dedicated high-efficiency particulate air filter system. Total aspergillus levels of 160 cfu/m3 were recorded in a renovation area during wood cutting. The higher concentrations of aspergillus seen inside the hospital compared with outdoors and the various moisture/HEPA filter/renovation incidents suggest that numerous small to moderate sources of aspergillus exist in the hospital.     

Efficacy of prevention by high-efficiency particulate air filtration or laminar airflow against Aspergillus airborne contamination during hospital renovation.

OBJECTIVE: To evaluate efficacy of laminar airflow facilities plus high-efficiency particulate air (HEPA) filtration and HEPA filtration alone in preventing environmental Aspergillus contamination during hospital renovation. To show the usefulness of environmental surveillance to facilitate protection of patients at risk for invasive pulmonary aspergillosis. DESIGN: Prospective sampling of air and surfaces for Aspergillus conidia during 2-year period. SETTING: A hematological department adjacent to building renovation at a university hospital. RESULTS: 1,047 air samples and 1,178 surface samples were collected from January 1996 to December 1997. Significantly more air samples were positive for Aspergillus species during the period of building renovation than during the periods before and after renovation in a unit without a protected air supply adjacent to the building work area (51.5% vs 31.7%; odds ratio [OR], 2.3; 95% confidence interval [CI95], 1.4-3.7; P<.001). A major increase in the frequency of positive air samples was also found in another adjacent unit that was protected with HEPA filtration alone (from 1.8% to 47.5%; OR, 48.9; CI95, 12-229; P<10(-7)). In addition, in this unit, the mean count of Aspergillus conidia in positive air samples increased significantly during construction (4 colony-forming units [CFU]/m3 to 24.7 CFU/m3; P=.04) and the proportion of positive surface samples showed a significant increase during renovation (from 0.4% to 9.7%; OR, 28.3; CI95, 3.4-623; P=10(-4)). However, none of 142 air samples collected during renovation in the area protected with laminar airflow plus HEPA filtration showed Aspergillus conidia. In a unit distant from the building renovation site, the results of air and surface samples were not affected by renovation. CONCLUSION: This study showed a strong association between building renovation and an increase in environmental Aspergillus contamination. Results confirmed the high efficacy of laminar airflow plus HEPA filtration and a high air-change rate. Although filtration with HEPA was effective during normal conditions, it alone was unable to prevent the rise of Aspergillus contamination related to building renovation. This study emphasized the necessity of an environmental survey of airborne contamination related to construction, to facilitate prevention of nosocomial aspergillosis outbreaks. A standardized protocol for aerobiological surveillance is needed.     

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis((R))) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis((R)) hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.     

Eight-year surveillance of environmental fungal contamination in hospital operating rooms and haematological units

An eight-year fungal environmental surveillance was carried out in 15 operating theatres and two haematological units. Sampling was performed twice a year in each room, using contact plates for plane surfaces and sterile swabs for grids. From 1992 to 1999, individual rooms in the 17 units were sampled on 1094 occasions and 3822 samples were collected. The percentage of rooms without fungus increased regularly between 1992 and 1999 (41.1% and 74.8%, respectively). The units were classified according to the fungal contamination during the eight years: the operating theatres which required the highest protection (cardiological, thoracic, vascular, hand, orthopaedic and neurosurgery) and the adult haematological unit showed least contamination (71.8% rooms were negative). The most frequent species isolated were Penicillium spp. (28.4%), Cladosporium spp. (15.6%) and Aspergillus spp. (7.6%). Aspergillus fumigatus was rarely isolated (3.7%), and was mainly isolated at the beginning of the study. This study demonstrates that environmental control programmes are effective in reducing environmental mould contamination and could be useful in establishing exposure guidelines, especially by defining an acceptable level of biocontamination in zones at risk.     

Prospective survey of indoor fungal contamination in hospital during a period of building construction

An 18-month survey of indoor fungal contamination was conducted in one haematology unit during a period of construction work. Air was sampled with a portable Air System Impactor and surfaces with contact Sabouraud plates. During this survey the mean concentration of viable fungi in air was 4.2 cfu/m(3) and that for surfaces was 1.7 cfu/plate. At the beginning of construction work, there were increases in airborne fungal spores (from 3.0 to 9.8 cfu/m(3)) in the unit, but concentrations did not exceed 10 cfu/m(3) during the 18-month period. The most frequently recovered airborne fungi were Penicillium spp. (27-38%), Aspergillus spp. (25%) and Bjerkandera adusta, a basidiomycete identified with molecular tools (7-12%). Blastomycetes accounted for more than 50% of the fungal flora on surfaces. Investigating the impact of a new air-treatment system (mobile Plasmair units), there were significant reductions in fungal contamination for the Plasmer -treated rooms, and in these rooms we observed the same level of fungal load whether construction work was in progress or not.     

The surveillance of the aeraulic and hydraulic system reduce environmental Aspergillus contamination in hospital

The aim of this work was to value the evolution of environmental Aspergillus contamination in hospital with respect to aeraulic system and bathrooms works. An analysis on levels of air and surface Aspergillus contamination were determined in patient's rooms and various common sites in a ward of an hospital in Genoa in 1999. As high contamination levels were found, in summer 1999 a radical disinfection and revision of the aeraulic system was settled. In spite of these interventions some samples maintained an high contamination level, even if from only two rooms, so a further disinfection of bathrooms and surfaces became necessary. A period of sampling was conducted after this last intervention until November 2002. At the beginning of our surveillance 59% positive samples and about 50% of them with high contamination level (>1000 CFU/m3) were found. After the revision of the aeraulic system the reduction of positive samples was significative (14.2%), besides all the positive samples regarded only two rooms. In the last valuation period, after a further disinfection of bathrooms and surfaces of the above mentioned rooms, all the samples taken resulted with a contamination level lower than 10 CFU/m3. This findings underlines the importance of environmental surveillance looking for all the contaminated sources; in particular the aeraulic and hydraulic system as well as the proximity hospital building yard not sufficiently protected.     

Assessment of environmental and surgical mask contamination at a student health center — 2012–2013 influenza season

Increased understanding of influenza transmission is critical for pandemic planning and selecting appropriate controls for healthcare personnel safety and health. The goals of this pilot study were to assess environmental contamination in different areas and at two time periods in the influenza season and to determine the feasibility of using surgical mask contamination to evaluate potential exposure to influenza virus. Bioaerosol samples were collected over 12 days (two 6-day sessions) at 12 locations within a student health center using portable two-stage bioaerosol samplers operating 8?hr each day. Surface samples were collected each morning and afternoon from common high-contact non-porous hard surfaces from rooms and locations where bioaerosol samplers were located. Surgical masks worn by participants while in contact with patients with influenza-like illness were collected. A questionnaire administered to each of the 12 participants at the end of each workday and another at the end of each workweek assessed influenza-like illness symptoms, estimated the number of influenza-like illness patient contacts, hand hygiene, and surgical mask usage. All samples were analyzed using qPCR. Over the 12 days of the study, three of the 127 (2.4%) bioaerosol samples, 2 of 483 (0.41%) surface samples, and 0 of 54 surgical masks were positive for influenza virus. For the duration of contact that occurred with an influenza patient on any of the 12 days, nurse practitioners and physicians reported contacts with influenza-like illness patients >60?min, medical assistants reported 15–44?min, and administrative staff reported <30?min. Given the limited number of bioaerosol and surface samples positive for influenza virus in the bioaerosol and surface samples, the absence of influenza virus on the surgical masks provides inconclusive evidence for the potential to use surgical masks to assess exposure to influenza viruses. Further studies are needed to determine feasibility of this approach in assessing healthcare personnel exposures. Information learned in this study can inform future field studies on influenza transmission.     

A case study: surface contamination of cyclophosphamide due to working practices and cleaning procedures in two Italian hospitals

The efficacy of preventive and organisational measures implemented in Italy to prevent the contamination of cytotoxic drug preparation rooms has been investigated, and oncologic wards of two Italian hospitals were examined. The sampling strategy was based not only on potential sources of contamination but also on responses to detailed questionnaires on workplace practices and work organisation. Wipe samples were taken from different surfaces of preparation rooms, before and after the work shift, over a span of a month. Cyclophosphamide was taken as the marker drug that reflects exposure to cytotoxic drugs, being measurable by GC/MS. In one of the two hospitals (Hospital A), a large amount of cyclophosphamide was found, both before and after shift, on the workbench (median value, 2.55 microg dm(-2), before shift), on the floor between the operator working position and the waste bin (>10 microg dm(-2), after shift), as also on door handles and storage shelves. No quantifiable levels of cytotoxic drug were detected in the second hospital investigated (Hospital B). These results could be attributed to the efficacy of cleaning procedures and working practices. In fact, both hospitals were provided with vertical-laminar airflow hoods and the (male) nurses had attended special training courses; but in Hospital A, cleaning procedures were carried out without substances used specifically for the cleaning of surfaces contaminated by cytotoxic drugs such as sodium hypochlorite. Working practices did not include Luer Lock devices. Cyclophosphamide concentrations found in both hospitals, compared with the quantities of drug handled, gave evidence of the importance of the correct handling of cytotoxic agents as a major tool in reducing contamination levels. The results reveal the insufficiency of the risk management measures which do not take into account working practices that are prevailing, and stress the necessity for periodic environmental monitoring, indispensable for evolving effective procedures to prevent antineoplastic drug exposure.     

Refinements of environmental assessment during an outbreak investigation of invasive aspergillosis in a leukemia and bone marrow transplant unit.

OBJECTIVES: To investigate an outbreak of aspergillosis in a leukemia and bone marrow transplant (BMT) unit and to improve environmental assessment strategies to detect Aspergillus. DESIGN: Epidemiological investigation and detailed environmental assessment. SETTING: A tertiary-care university hospital with a 37-bed leukemia and BMT unit PARTICIPANTS: Leukemic or BMT patients with invasive aspergillosis identified through prospective surveillance and confirmed by chart review. INTERVENTIONS: We verified the diagnosis of invasive fungal infection by reviewing medical charts of at-risk patients, performing a case-control study to determine risk factors for infection, instituting wet mopping to clean all floors, providing N95 masks to protect patients outside high-efficiency particulate air (HEPA)-filtered areas, altering traffic patterns into the unit, and performing molecular typing of selected Aspergillus flavus isolates. To assess the environment, we verified pressure relationships between the rooms and hallway and between buildings, and we compared the ability of large-volume (1,200 L) and small-volume (160 L) air samplers to detect Aspergillus spores. RESULTS: Of 29 potential invasive aspergillosis cases, 21 were confirmed by medical chart review. Risk factors for developing invasive aspergillosis included the length of time since malignancy was diagnosed (odds ratio [OR], 1.0; P=.05) and hospitalization in a patient room located near a stairwell door (OR, 3.7; P=.05). Two of five A. flavus patient isolates were identical to one of the environmental isolates. The pressure in most of the rooms was higher than in the corridors, but the pressure in the oncology unit was negative with respect to the physically adjacent hospital; consequently, the unit acted essentially as a vacuum that siphoned non-HEPA-filtered air from the main hospital. Of the 78 samples obtained with a small-volume air sampler, none grew an Aspergillus species, whereas 10 of 40 cultures obtained with a large-volume air sampler did. CONCLUSIONS: During active construction, Aspergillus spores may have entered the oncology unit from the physically adjacent hospital because the air pressure differed. Guidelines that establish the minimum acceptable pressures and specify which pressure relationships to test in healthcare settings are needed. Our data show that large-volume air samples are superior to small-volume samples to assess for Aspergillus in the healthcare environment.     

An evaluation of hospital special-ventilation-room pressures.

OBJECTIVE: To quantitate the magnitude and consistency of positive (airflow out) and negative (airflow in) hospital special-ventilation-room (SVR) airflow. DESIGN: A room-pressure evaluation was conducted during two seasons on a total of 18 rooms: standard rooms, airborne infection isolation rooms, and protective environment rooms. The pressures were measured using a digital pressure gauge-piezoresistive pressure sensor that measured pressure differentials. With doors closed, the rooms were measured a minimum of 30 times each for a cooling season and a heating season. RESULTS: The standard rooms showed the least amount of variability in pressure differential, with an average of -0.2 Pa (median, -0.2 Pa), and an interquartile range (IQR) of 0.4 Pa. Airborne infection isolation rooms showed more variability in pressure, with an average of -0.3 Pa (median, -0.2 Pa) and an IQR of 0.5 Pa. Protective environment rooms had the greatest fluctuation in pressure, with an average of 8.3 Pa (median, 7.7 Pa) and an IQR of 8.8 Pa. Dramatic pressure changes were observed during this evaluation, which may have been influenced by room architectural differences (sealed vs unsealed); heating, ventilation, and air-conditioning zone interactions; and stack effect. CONCLUSION: The pressure variations noted in this study, which potentially affect containment or exclusion of contaminants, support the need for standardization of pressure requirements for SVRs. To maintain consistent pressure levels, creating an airtight seal and continuous pressure monitoring may be necessary.     

Demolition of a hospital building by controlled explosion: the impact on filamentous fungal load in internal and external air

The demolition of a maternity building at our institution provided us with the opportunity to study the load of filamentous fungi in the air. External (nearby streets) and internal (within the hospital buildings) air was sampled with an automatic volumetric machine (MAS-100 Air Samplair) at least daily during the week before the demolition, at 10, 30, 60, 90,120, 180, 240, 420, 540 and 660 min post-demolition, daily during the week after the demolition and weekly during weeks 2, 3 and 4 after demolition. Samples were duplicated to analyse reproducibility. Three hundred and forty samples were obtained: 115 external air, 69 'non-protected' internal air and 156 protected internal air [high efficiency particulate air (HEPA) filtered air under positive pressure]. A significant increase in the colony count of filamentous fungi occurred after the demolition. Median colony counts of external air on demolition day were significantly higher than from internal air (70.2 cfu/m(3) vs 35.8 cfu/m(3)) (P < 0.001). Mechanical demolition on day +4 also produced a significant difference between external and internal air (74.5 cfu/m(3) vs 41.7 cfu/m(3)). The counts returned to baseline levels on day +11. Most areas with a protected air supply yielded no colonies before demolition day and remained negative on demolition day. The reproducibility of the count method was good (intra-assay variance: 2.4 cfu/m(3)). No episodes of invasive filamentous mycosis were detected during the three months following the demolition. Demolition work was associated with a significant increase in the fungal colony counts of hospital external and non-protected internal air. Effective protective measures may be taken to avoid the emergence of clinical infections.     

Bacterial contamination of the air in different operating rooms

Bacteria air samples were taken in the operating rooms, with no people present, to specify the level of air contamination and suggest bacteriological standards for different operating rooms. In the first step of this study, for 5 months the air contamination mean value of operating rooms, ventilated at 15 changes/hour was 18.5 Cfu/m3 +/- 1.9. In the second part of the study, during two years, 1 381 air samples were taken in 8 different operating rooms. The mean values of air contamination range from 1.4 Cfu/m3 in a Charnley isolator system to 121 Cfu/m3 in an operating room ventilated at 7.5 changes per hour. As a general rule, the airborne contamination is more significant in the oldest operating rooms than in the new one with filtrated air. The variations observed between 1981 and 1982 are explained by technical modifications of the system or progress in control of operating room conditions. Measurements of the bacterial contamination of the air give useful informations, but it is however better to ensure that the specifications for volume air supply and positive air pressure in the operating theatres are being fulfilled. The airborne bacterial concentration in a modern ventilated operating room should not exceed 30 Cfu/m3.     

Relationship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients.

Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Spore inhalation is the usual route of Aspergillus infection, suggesting a determining role of environmental contamination by spores in the epidemiology of IA. We prospectively examined the relationship between environmental contamination by Aspergillus and other fungal species and the incidence of invasive nosocomial aspergillosis (INA) in a bone marrow transplantation unit and two haematology wards. During a four-year period, levels of air and surface fungal contamination were determined bi-monthly in patients' rooms (some equipped with HEPA filters and LAF systems), and various common sites in each ward (corridors, nursing stations, etc.). Results were compared to the incidence of INA. A total of 3100 air and 9800 surface samples were collected, and 79 cases of IA were diagnosed, of which 64 were probably or possibly INA. Patterns of fungal contamination were comparable in the three wards, with a gradient ranging from high levels in common sites to a virtual absence in rooms equipped with HEPA filters and LAF systems. Using a regression model, a significant relationship was found between the incidence of INA and the degree of fungal contamination of air and surfaces in conventional patient rooms (not equipped with HEPA) and common sites. This study shows that in a non-epidemic setting, there is a significant relationship between environmental fungal contamination in haematology wards and the incidence of INA. Our findings underline the importance of environmental surveillance and strict application of preventive measures.     

Environmental reservoirs of methicillin-resistant Staphylococcus aureus in isolation rooms: correlation with patient isolates and implications for hospital hygiene

Strategies to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) include early identification of positive patients through screening, patient isolation, hand hygiene, nasal and skin decontamination, and the adequate cleaning and decontamination of clinical areas. However, many national and other guidelines provide few details on environmental decontamination regimens, partly because the role of the environment in the spread of MRSA is not well documented. We prospectively studied the environment of the isolation rooms of 25 MRSA patients for up to four weeks, sampling horizontal surfaces and the air using settle plates as well as an air sampler, while continuing regular daily cleaning according to the hospital protocol. We then typed 20 patient isolates and the corresponding environmental isolates (N=35) to assess the similarity of strains. A high proportion of samples were positive for MRSA; 269/502 (53.6%) surface samples, 70/250 (28%) air samples and 102/251 (40.6%) settle plates. Over half of the surface samples taken from the beds and the mattresses were positive for MRSA. Identical or closely related isolates were recovered from the patient and their environment in 14 (70%) patients, suggesting possible environmental contamination of the isolation rooms, possibly contributing to endemic MRSA. More effective and rigorous use of current approaches to cleaning and decontamination is required as well as consideration of newer technologies to eradicate MRSA and other hospital-acquired pathogens.     

Reduced fungal contamination of the indoor environment with the Plasmair system (Airinspace)

Aspergillus spp. and other moulds cause life-threatening opportunistic infections in immunocompromised patients. Indoor contamination and construction work that liberate fungal spores are a major source of nosocomial aspergillosis. Dijon hospital is a tertiary care institution in northeast France undergoing construction work beside high-risk clinical units. To determine the impact of this activity, a surveillance programme was implemented one year before building work began in order to establish baseline levels of contamination. Air and surface fungal contamination in adult and paediatric haematology units were prospectively examined following use, or not, of a new air-treatment system with mobile Plasmair units (Airinspace). There were significant reductions in overall fungal contamination for the Plasmair treated rooms for air and surface samples in both clinical units. Plasmair treatment also significantly reduced A. fumigatus in the air. These data suggest that Plasmair units may provide an efficient method of reducing indoor fungal contamination in hospitals.     

Fungal contamination in hospital environments.

OBJECTIVES: To assess the degree of fungal contamination in hospital environments and to evaluate the ability of air conditioning systems to reduce such contamination. METHODS: We monitored airborne microbial concentrations in various environments in 10 hospitals equipped with air conditioning. Sampling was performed with a portable Surface Air System impactor with replicate organism detection and counting plates containing a fungus-selective medium. The total fungal concentration was determined 72-120 hours after sampling. The genera most involved in infection were identified by macroscopic and microscopic observation. RESULTS: The mean concentration of airborne fungi in the set of environments examined was 19 +/- 19 colony-forming units (cfu) per cubic meter. Analysis of the fungal concentration in the different types of environments revealed different levels of contamination: the lowest mean values (12 +/- 14 cfu/m(3)) were recorded in operating theaters, and the highest (45 +/- 37 cfu/m(3)) were recorded in kitchens. Analyses revealed statistically significant differences between median values for the various environments. The fungal genus most commonly encountered was Penicillium, which, in kitchens, displayed the highest mean airborne concentration (8 +/- 2.4 cfu/m(3)). The percentage (35%) of Aspergillus documented in the wards was higher than that in any of the other environments monitored. CONCLUSIONS: The fungal concentrations recorded in the present study are comparable to those recorded in other studies conducted in hospital environments and are considerably lower than those seen in other indoor environments that are not air conditioned. These findings demonstrate the effectiveness of air-handling systems in reducing fungal contamination.     

Contamination of room door handles by methicillin-sensitive/methicillin-resistant Staphylococcus aureus

We investigated the contamination of room door handles by Staphylococcus aureus in wards of a university hospital. Door handles in 53 (27.0%) of 196 rooms were contaminated by methicillin-sensitive Staphylococcus aureus (MSSA) and/or methicillin-resistant Staphylococcus aureus (MRSA); MSSA was detected on door handles of 41 rooms (20.9%), MRSA on door handles of 17 rooms (8.7%), and MSSA and MRSA on the same door handles of five rooms (2.6%). The density of MSSA contamination was 1-2.6x10(4) colony forming units (cfu)/door handle, and that of MRSA was 1-6.0x10(3) cfu/door handle. The MRSA contamination rate on door handles of rooms with patients with MRSA was 19.0% (4/21 rooms) while that on door handles of rooms with patients without MRSA was 7.4% (13/175); the difference was not significant. These results suggest extensive contamination of MSSA and MRSA in the hospital environment.     

Fungi growth in buildings

The results of research into occurrence of fungi in buildings are hereby presented. Indoor air pollution balanced between 10(2)-10(3) cfu/m3. Examined building surfaces have been found significantly mouldy. Total number of fungi ranged from 3.28 x 10(5) to 9.75 x 10(10) cfu/100 cm2. The results of the research show the active development of this group of microorganisms. In rooms, over 30 fungi species belonging to 11 genera have been detected. The most frequently occurring ones were fungi genera: Cladosporium, Penicillium, Aspergillus and Acremonium. Among those, potentially toxinogenic species have been separated (Aspergillus ochraceus, Cladosporium cladosporioides, Penicillium chrysogenum, Penicillium notatum). Apart from micotoxins they have been found to produce huge amounts of conidia which can cause allergy in sensitive people. Hence, people should definitely avoid fungi in their environment.     

Environmental investigations and molecular typing of Aspergillus flavus during an outbreak of postoperative infections

After an outbreak of sternal surgical-site infections (SSSI) with Aspergillus flavus following cardiac surgery, a mycological survey of air and surfaces (41 and 149 samples, respectively) was performed throughout the surgical ward (SW) and in other areas of the hospital. Results showed massive contamination by A. flavus: more than 100 cfu per contact plate were frequently observed in some areas of the SW. The distribution of the A. flavus spores in the building, and especially in the SW, enabled the location of a possible source within the non-medical part of the SW, but the true source could not be identified. Four other surveys were made to follow up the decontamination process; the contamination level did not fall rapidly, needing repetitive cleaning operations. Strains from patients and from the hospital environment selected all over the SW were typed by random amplification of polymorphic DNA (RAPD), using two different primers (ERIC-1, BG-2). All these strains showed the same genotype, proving the clonal single-source of the environmental contamination and the intra-operative acquisition of A. flavus in the SSSI outbreak.     

Environmental surveillance of filamentous fungi in three tertiary care hospitals in Greece

The environmental fungal load (FL) of three hospitals was studied in representative regions in Greece (Thessalonika, Northern Greece, Athens, Central Greece and Heraklion, Southern Greece). Air, surfaces and tap water from high-risk departments were sampled monthly during one year. Air FL was [median (range)] 10.6 (1.2-37), 5.5 (3-28.8) and 7.7 (3.1-12.1) cfu/m(3) at Thessalonika, Athens and Heraklion, respectively. Air FL was lower in winter and higher in summer and autumn but seldom above acceptable levels. Aspergillus spp. constituted 70.5% of the filamentous fungi isolated. Aspergillus niger was the most prevalent species in the air of all the hospitals followed by Aspergillus flavus and Aspergillus fumigatus. The least contaminated departments were the intensive care units, whilst most contaminated were the solid organ transplantation in Athens and haematology departments in Thessalonika. No correlation between fungal species, season, hospital or departments was observed. Sixty per cent of all surfaces examined yielded filamentous fungi and/or blastomycetes. While no fungi were recovered from water in Thessalonika and Athens, one-third of the samples in Heraklion (apart from those of ICU) yielded multiple fungal species. The higher air FL in Thessalonika and Athens was recorded in departments located close to renovation works. These findings suggest that the air and surface FL fluctuates over the year, is due to varying fungal species, but does not differ greatly among hospitals. The variation among hospitals, as well as the role of hospital water fungal contamination and appropriate measures to eliminate it, need further study.