Fungal Assessment of Indoor Air Quality in Wards and Operating Theatres in an Organ Transplantation Hospital

In the clinical management of organ transplant recipients, infectious diseases continue to be a major cause of morbidity and mortality. Every year about 1.7 million cases of nosocomial infections have been reported all around the world (1). In the past, pathogenic species have been limited in extent; however, recently, the number of pathogenic and opportunistic species is considerably increased (2). Studies have shown that there is a significant relationship between hospital infections and airborne bioaerosols (3). Fungi are present in indoor environments and play important roles in human diseases. These infections are increasing in immunosuppressed patients such as patients undergoing hematopoietic stem cell transplantation, chemotherapy for leukaemia, or AIDS (4). Aspergillus is a common fungus in invasive infections, however, other fungi are appearing as important pathogens in immunosuppressed patients (5). Most invasive infections are acquired from indoor air. For reducing concentrations of airborne fungal, it is necessary to control measures in clinical environments (6, 7). Opportunistic fungal infections are the main reason of death among transplant patients and the risk of nosocomial fungal infections after transplantation may increase (7, 8). Reduction in the patient’s defensive ability due to organ transplantation may lead to the uncontrolled multiplication of fungi and consequent onset of infection (9, 10). Also, we cannot completely eliminate fungi from indoor clinical environments. Fungi exposure in clinical units is unavoidable, however, for control measures, the air filtration systems can be used (11). The quality of the air in an organ transplant hospital is a significant role to control infections. One of the most important steps to reduce hospital infection is regular fungal monitoring (12). The present study is the first research about fungal contaminations in an organ transplant hospital in Iran. The results of this study can be used to describe the state of fungal contamination in operating theatres and wards of the hospital. Using an efficient ventilation system, reviewing the disinfection procedure, and controlling nosocomial infections are effective in decreasing fungal contamination.

The study was carried out in the organ transplantation hospital of Mashhad University of Medical Sciences, during spring, 2017. In this study, 96 samples were taken from three operating theatres and five wards; hemodialysis for women and men, kidney and liver transplant, and ICU. Air samples were collected from the operating theatres and wards once a week within three months.

In all three operating theaters there were ultraviolet lamps, while there was no ultraviolet (UV) lamp in any ward of this hospital.

According to the importance of controlling the disinfection efficiency and performance of ultraviolet lamps in operating theatres, sampling was conducted before and after disinfection and using UV radiation.

The sampling was done by an activate air sampling method based on the national institute for NIOSH-0800 instruction, by using a Quick Take SKC sampling pump and an Andersen bio-sampler, with a flow of 28.3 L per 2 minutes (13). In order to avoid any interference of germs or other contaminations, bio-sampler was sterilized before sampling by using disposable sterile gas and 70% ethanol based on device catalog, and then placed under a UV lamp for 20 minutes. After sterilization, to prevent contamination until reaching to the sampling location, bio-sampler was placed in a sterilized cold box and the box was opened in the sampling location. During sampling a 90-mm plate containing medium was placed inside the bio-sampler. The sampling circuit was established at a distance of 120 - 150 cm from the patient’s respiratory tract and any other obstacle and 100 - 150 cm from the floor (10, 14).

In this study, plates containing Saboro dextrose medium and chloramphenicol (SC) antibiotic were used for sampling. Sample plates were transported to the laboratory by cold boxes and incubated at 32°C for 7 - 10 days. For early differential diagnosis of fungal genera, macroscopic examination (colonies morphology, color, texture, shape and colony apparent diameter) and microscopic mycology tests (presence of mycelium, presence of specific productive structures, shape and Conidia structure) was used (15). Due to the need for more accurate diagnosis of fungal agents, the slide culture method was also used.

Sampling was done in standard temperature and air pressure conditions, therefore, according to the volume of sampled air and the number of cultured colonies, fungal density of the indoor air of different parts of hospital in a cubic meter of air was calculated and reported by colony forming unite (CFU/m³).

Due to the high sensitivity of transplantation recipients and immunocompromised patients to nosocomial fungal infections, comparison of the concentration of air fungal contamination in the hospital was necessary. The results of the present study were compared with guideline values. Good Manufacturing Practices (GMP) is a guideline of air cleaning requirements for medical device manufacturing. It recommends a total aerobic count limit of < 1 CFU/m³ in class A rooms (very clean), < 10 CFU/m³ in class B rooms (clean), < 100 CFU/m³ in class C rooms (medium) and 200 CFU/m³ in class D rooms (contaminated) (16).

The data was analyzed by the SPSS software and Chi-square test such as simple mean value, percentage, and test of significance.

In this study, 8 species of fungi were detected including Aspergillus spp., Penicillium spp., Ulocladium spp., Cladosporium spp., Mucor spp., Paecilomyces spp., Hyaline filamentous fungi, and Black filamentous fungi. The average concentration of fungi in operating theatres prior to disinfection was 7.37 ± 2.68 CFU/m³ and after disinfection has decreased to 3.82 ± 2.30 CFU/m³ that this rate of decline was statistically significant (P ≤ 0.001). According to the EU GMP, the average concentration of fungi in all the operating theatres were < 10 CFU/m³ in class B (clean state), (Table 1).

Figure 1 shows the airborne Aspergillus and Penicillium contamination in operating theatres depending on the type of fungus, before and after using UV radiation. The results show that the most important fungal contaminations in operating theatres respectively was related to Aspergillus and Penicillium, which decreased significantly after disinfection. In addition, according to the results, disinfection was more effective on Aspergillus than the Penicillium.

Figure 1.

Aspergillus and Penicillium contamination in operating theatres. AB, percent Aspergillus Before using UV radiation; AA, percent Aspergillus After using UV radiation; PB, percent Penicillium Before using UV radiation, PA, percent Penicillium After using UV radiation.

The highest fungal contamination in hospital wards was related to the hemodialysis ward for men with an average of 11.78 ± 8.31 CFU/m³ and the less contaminated wards were kidney transplantation, women’s hemodialysis, ICU, and liver transplantation wards, respectively. The most important fungal species in hospital wards was Aspergillus, that its contamination in the men’s hemodialysis, ICU, women’s hemodialysis, liver transplantation and kidney transplantation wards was 58.3, 50, 33.3, 33.3, and 16.7 percent, respectively.

With the exception of the Men’s Hemodialysis ward and the ICU, the mean of fungi in all the wards were in <10 CFU/m³ in class B (clean state), (Table 2).

Fungal concentration in all three operating theaters in after disinfection and using UV radiation was significantly lower (P ≤ 0.001) than before using UV radiation. Concentration of fungal in the sampling operating theaters was < 10 CFU/m³ and indicating a clean state of indoor air (Table 1). The minimum concentration of fungal (5.53 ± 4.08 CFU/m³) was found in liver transplantation and the maximum concentration (11.78 ± 8.31 CFU/m³) was found in men’s hemodialysis. With the exception of men’s hemodialysis and the ICU, the concentration of fungal in the sampling wards was < 10 CFU/m³, indicating a clean state of indoor air while the men’s hemodialysis and the ICU represented a middle contamination state for indoor air, as shown in Table 2. Studies suggested that levels be sustained under 10 CFU/m³ during surgery, which can be expected by decreasing it to 1 CFU/m³ (17, 18). Several studies around the world have evaluated indoor air quality in clinical facilities. Values of fungal airborne in clinical wards without high efficiency particulate air (HEPA) filters are commonly between 50 and 500 CFU/m³ (19). In clinical wards with air filtration, airborne fungal values are < 0 - 50 CFU/m³ (20-23). In the present study the concentration of total fungal was lower than the reported by Chuaybamroong et al., (24) (67 CFU/m³), Huang et al., (25) (12 CFU/m³ and 59 CFU/m³ in ICU I and ICU II, during sampling consistency study), and Fumaglli et al., (26) (250 - 300 CFU/m³ during restrictive visiting periods).

Nowadays, all efforts have been paid on designing effective programs and strategies to prevent nosocomial infections, especially infections caused by Aspergillus species in individuals who have been a candidate for an organ transplant, particularly bone marrow transplantation (27). In this study, the most important fungal contaminations in operating theatres, respectively, was related to Aspergillus and Penicillium.

In the study of Ekhaise and et al., in Nigeria, the average concentration of fungi in the air of the hospital was reported 10 to 53 CFU/m³ and the most species of fungi were Penicillium and Aspergillus (28). This study and another study conducted in the city of Damghan by Dehdashti (29) as well as a study conducted by Choobineh and et al., (30) were completely in accordance with the results of the current study.

Aspergillus species are a common cause of invasive fungal infections that are unable to make important invasive fungal infections in recipients. A total of 36% of nosocomial pneumonia is caused by Aspergillus species and the mortality rate of Aspergillus pneumonia has been 95% (15). However, several studies in different cities of Iran and other countries showed that diversity of fungi in different wards have great extents. For example, in the study of Nourian and et al., the main airborne fungal contamination in different wards was related to Aspergillus, Alternaria, Penicillium, Fusarium, Cladosporium, Rhizopus, and Phoma (31), where the results of this study, in terms of the diversity of fungi, is very similar to the present study.

Awosika, in his study, reported that the most common fungi found in hospital wards were Aspergillus flavus, Penicillium, Fusarium, Candida albicans, and Alternaria (17). Despite the fact that the current study was conducted in a different geographical area, fungal diversity was almost similar to Awosika’s results. In several studies conducted on samples of immunosuppression patients’ bronchial in different wards, various species of Aspergillus and Penicillium were identified (32, 33). Due to the similarity of the fungi obtained from the respiratory system of patients with fungal agents suspended in the air of the most units of hospitals, there can be a direct relationship between the fungal agents and fungal infections during the course of hospitalization in these wards.

In a study that was conducted by Hoseinzadeh et al., in Fatemie Hospital, the highest and lowest concentration of bioaerosols, respectively, was obtained in the maternity ward 1 (54.4 CFU/m³) and operating theatre (13.3 CFU/m³). The most common fungi identified in the hospital air were Penicillium (32.06%), Cladosporium (20.5%), Aspergillus fumigatus (14.61%), and Aspergillus niger (7.43%), respectively (34).