Bacterial indoor air contaminations in hospitals in MENA region: a systematic review

Poor indoor air quality in healthcare settings has been tied with the increase in hospital-acquired infections. Thus, this systematic review was conducted to assess the levels and compositions of bacteria in indoor hospital air in the Middle East and North Africa (MENA) region. We examined results provided by different search engines published between 2000 and 2021. Our data showed that most studies were conducted in Iran (80.9%) with a bacterial concentration mean of 172.9 CFU/m3. Comparing sensitive and non-sensitive areas of hospitals, no significant difference was detected in the mean bacterial concentration. The most investigated sensitive hospital areas were operating rooms and intensive care units with mean indoor bacterial concentrations of 180.3 CFU/m3 and 204.6 CFU/m3, respectively. Staphylococcaceae, Enterobacteriaceae, Pseudomonadaceae, and Bacillaceae were commonly identified bacterial families. In conclusion, the mean concentrations of the airborne bacteria were within the acceptable limit compared to WHO standards (300 CFU/m3) for the air in areas occupied by immunosuppressed people.

Bacterial Diversity on Historical Audio-Visual Materials and in the Atmosphere of Czech Depositories

Microbial contamination in cultural heritage storage facilities is undoubtedly still a huge problem and leads to the biodeterioration of historical objects and thus the loss of information for future generations. Most studies focus on fungi that colonize materials, which are the primary agents of biodeterioration. However, bacteria also play crucial roles in this process. Therefore, this study focuses on identifying bacteria that colonize audio-visual materials and those present in the air in the archives of the Czech Republic. For our purposes, the Illumina MiSeq amplicon sequencing method was used. Using this method, 18 bacterial genera with an abundance of higher than 1% were identified on audio-visual materials and in the air. We also evaluated some factors that were assumed to possibly influence the composition of bacterial communities on audio-visual materials, of which locality was shown to be significant. Locality also explained most of the variability in bacterial community structure. Furthermore, an association between genera colonizing materials and genera present in the air was demonstrated, and indicator genera were evaluated for each locality. IMPORTANCE The existing literature on microbial contamination of audio-visual materials has predominantly used culture-based methods to evaluate contamination and has overlooked the potential impact of environmental factors and material composition on microbial communities. Furthermore, previous studies have mainly focused on contamination by microscopic fungi, neglecting other potentially harmful microorganisms. To address these gaps in knowledge, our study is the first to provide a comprehensive analysis of bacterial communities present on historical audio-visual materials. Our statistical analyses demonstrate the critical importance of including air analysis in such studies, as airborne microorganisms can significantly contribute to the contamination of these materials. The insights gained from this study are not only valuable in developing effective preventive measures to mitigate contamination but also valuable in identifying targeted disinfection methods for specific types of microorganisms. Overall, our findings highlight the need for a more holistic approach to understanding microbial contamination in cultural heritage materials.

Application of nanotechnology in air purifiers as a viable approach to protect against Corona virus

The outbreak of COVID-19 disease, the cause of severe acute respiratory syndrome, is considered a worldwide public health concern. Although studies indicated that the virus could spread through respiratory particles or droplets in close contact, current research have revealed that the virus stays viable in aerosols for several hours. Numerous investigations have highlighted the protective role of air purifiers in the management of COVID-19 transmission, however, there are still some doubts regarding the efficiency and safety of these technologies. According to those observations, using a proper ventilation system can extensively decrease the spread of COVID-19. However, most of those strategies are currently in the experimental stages. This review aimed at summarising the safety and effectiveness of the recent approaches in this field including using nanofibres that prevent the spread of airborne viruses like SARS-CoV-2. Here, the efficacy of controlling COVID-19 by means of combining multiple strategies is comprehensively discussed.

Markers of Chemical and Microbiological Contamination of the Air in the Sport Centers

This study aimed to assess the markers of chemical and microbiological contamination of the air at sport centers (e.g., the fitness center in Poland) including the determination of particulate matter, CO₂, formaldehyde (DustTrak™ DRX Aerosol Monitor; Multi-functional Air Quality Detector), volatile organic compound (VOC) concentration (headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry), the number of microorganisms in the air (culture methods), and microbial biodiversity (high-throughput sequencing on the Illumina platform). Additionally the number of microorganisms and the presence of SARS-CoV-2 (PCR) on the surfaces was determined. Total particle concentration varied between 0.0445 mg m^-3 and 0.0841 mg m^-3 with the dominance (99.65-99.99%) of the PM_2.5 fraction. The CO₂ concentration ranged from 800 ppm to 2198 ppm, while the formaldehyde concentration was from 0.005 mg/m³ to 0.049 mg m^-3. A total of 84 VOCs were identified in the air collected from the gym. Phenol, D-limonene, toluene, and 2-ethyl-1-hexanol dominated in the air at the tested facilities. The average daily number of bacteria was 7.17 × 10² CFU m^-3-1.68 × 10³ CFU m^-3, while the number of fungi was 3.03 × 10³ CFU m^-3-7.34 × 10³ CFU m^-3. In total, 422 genera of bacteria and 408 genera of fungi representing 21 and 11 phyla, respectively, were detected in the gym. The most abundant bacteria and fungi (>1%) that belonged to the second and third groups of health hazards were: Escherichia-Shigella, Corynebacterium, Bacillus, Staphylococcus, Cladosporium, Aspergillus, and Penicillium. In addition, other species that may be allergenic (Epicoccum) or infectious (Acinetobacter, Sphingomonas, Sporobolomyces) were present in the air. Moreover, the SARS-CoV-2 virus was detected on surfaces in the gym. The monitoring proposal for the assessment of the air quality at a sport center includes the following markers: total particle concentration with the PM_2.5 fraction, CO₂ concentration, VOCs (phenol, toluene, and 2-ethyl-1-hexanol), and the number of bacteria and fungi.

Microbial Air Contamination in a Dental Setting Environment and Ultrasonic Scaling in Periodontally Healthy Subjects: An Observational Study

The risk of microbial air contamination in a dental setting, especially during aerosol-generating dental procedures (AGDPs), has long been recognized, becoming even more relevant during the COVID-19 pandemic. However, individual pathogens were rarely studied, and microbial loads were measured heterogeneously, often using low-sensitivity methods. Therefore, the present study aimed to assess microbial air contamination in the dental environment, identify the microorganisms involved, and determine their count by active air sampling at the beginning (T0), during (T1), and at the end (T2) of ultrasonic scaling in systemically and periodontally healthy subjects. Air microbial contamination was detected at T0 in all samples, regardless of whether the sample was collected from patients treated first or later; predominantly Gram-positive bacteria, including Staphylococcus and Bacillus spp. and a minority of fungi, were identified. The number of bacterial colonies at T1 was higher, although the species found were similar to that found during the T0 sampling, whereby Gram-positive bacteria, mainly Streptococcus spp., were identified. Air samples collected at T2 showed a decrease in bacterial load compared to the previous sampling. Further research should investigate the levels and patterns of the microbial contamination of air, people, and the environment in dental settings via ultrasonic scaling and other AGDPs and identify the microorganisms involved to perform the procedure- and patient-related risk assessment and provide appropriate recommendations for aerosol infection control.

Air contamination of therapeutic drug monitoring assay reagents results in falsely high plasma ammonia levels

BACKGROUND

Accumulating evidence shows that contamination of blood samples by atmospheric ammonia affects blood ammonia test levels; however, reports on the effect of ammonia contamination of assay reagents are limited. Here, we aimed to clarify the effect of ammonia contamination of assay reagents, particularly the therapeutic drug monitoring (TDM) reagents, on the detection levels of blood ammonia using enzymatic assays.

METHODS

Ammonia gas was measured in the refrigerator compartment of the automatic analyser and the reaction tank water, probe wash water and drain outlets connected to the automatic analyser. At different time points following the closure of the cold storage, ammonia levels in quality control plasma samples were measured using three commercial assay reagents to evaluate the effect of air contamination. The distribution of evaporated ammonia in the reagent was measured using the CicaLiquid NH3 assay kit containing the assay reagent most affected by air contamination.

RESULTS

It was confirmed that ammonia gas was generated in the cold storage of the automatic analyser. More than half of the reagents detected >0.25 ppm ammonia, and the highest concentration was detected in the TDM reagent. The ammonia levels obtained using all three reagents increased significantly after 3 h of air contamination. The effect was resolved by measuring a 'dummy' sample or mixing the reagents by inversion.

CONCLUSIONS

We demonstrated that air contamination by TDM reagents placed in cold storage could result in significantly falsely high ammonia measurements. Preventing this effect would improve the accuracy of ammonia measurements.

Investigating Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Surface and Air Contamination in an Acute Healthcare Setting During the Peak of the Coronavirus Disease 2019 (COVID-19) Pandemic in London

BACKGROUND

We evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surface and air contamination during the coronavirus disease 2019 (COVID-19) pandemic in London.

METHODS

Prospective, cross-sectional, observational study in a multisite London hospital. Air and surface samples were collected from 7 clinical areas occupied by patients with COVID-19 and a public area of the hospital. Three or four 1.0-m3 air samples were collected in each area using an active air sampler. Surface samples were collected by swabbing items in the immediate vicinity of each air sample. SARS-CoV-2 was detected using reverse-transcription quantitative polymerase chain reaction (PCR) and viral culture; the limit of detection for culturing SARS-CoV-2 from surfaces was determined.

RESULTS

Viral RNA was detected on 114 of 218 (52.3%) surfaces and in 14 of 31 (38.7%) air samples, but no virus was cultured. Viral RNA was more likely to be found in areas immediately occupied by COVID-19 patients than in other areas (67 of 105 [63.8%] vs 29 of 64 [45.3%]; odds ratio, 0.5; 95% confidence interval, 0.2-0.9; P = .025, χ2 test). The high PCR cycle threshold value for all samples (>30) indicated that the virus would not be culturable.

CONCLUSIONS

Our findings of extensive viral RNA contamination of surfaces and air across a range of acute healthcare settings in the absence of cultured virus underlines the potential risk from environmental contamination in managing COVID-19 and the need for effective use of personal protective equipment, physical distancing, and hand/surface hygiene.

Cytostatics in Indoor Environment: An Update of Analytical Methods

Periodic and adequate environmental monitoring programs are crucial to assess and reduce the occupational exposure of healthcare workers to cytostatics. The analytical methods employed should be rapid, reliable, sensitive, standardized, and include multiple compounds. A critical overview of recent overall procedures for surface and air contamination with cytostatics in workplace settings is presented, with a focus on sampling, sample preparation, and instrumental considerations. Limitations are also addressed and some recommendations and advice are provided. Since dermal absorption is the main exposure route, surface contamination is the preferred indicator of biological uptake and its methods have significantly improved. In contrast, cytostatics’ inhalation is rare; thus, air contamination has been poorly studied, with little improvement. Still, some elements of the analytical methods have not been extensively explored, namely: the amount of wetting solution, the extraction procedure, surface chemistry and roughness, recovery studies from specific surfaces, and cytostatics stability (in surfaces and during shipping and storage). Furthermore, complete validation data (including precision, accuracy, and instrumental and method detection limits) and estimation of global uncertainty are still lacking in most studies, thus preventing method comparison and proposal of standardized procedures.

Assessment of Microbial Load and of Antimicrobial Susceptibility

Air contamination in the hospital setting can be a reason for the spread of nosocomial infection among susceptible patients. The aim of this study was to identify bacterial species, and their load and drug resistance, in the air of a tertiary hospital. Air samples were collected on a monthly basis for 12 consecutive months in four different departments of the hospital (Intensive Care Unit (ICU), Internal Medicine Ward (IMW), Surgical Ward (SW), and Neonatal Unit (NU)). In total, 101 samples were collected, out of which 158 Gram-positive (GP) and 44 Gram-negative (GN) strains were isolated. The majority of GP isolates were Staphylococcus spp. (n = 100). The highest total microbial load was reported in the IMW (p = 0.005), while the highest Staphylococcus load was observed in the ICU (p = 0.018). GP bacterial load was higher in autumn, while GN load was higher in spring. Regarding drug resistance, four multi-drug-resistant (MDR) strains and one extensively drug-resistant (XDR) strain were isolated in the ICU, two MDR strains and one XDR strain in the SW, one MDR strain in the IMW and one MDR strain in the NU samples. Air in hospital settings is contaminated with various microbes; some of them are MDR, consisting a potential cause of hospital-acquired infection.

Reduction of Contamination with Antibiotics on Surfaces and in Environmental Air in Three European Hospitals Following Implementation of a Closed-System Drug Transfer Device

PURPOSE

Occupational exposure of nurses to antibiotics may result in adverse health effects such as hypersensitivity, allergic reactions, resistance, and anaphylactic shock. The purpose of this study was to measure surface and air contamination with antibiotics in three hospitals during the preparation of the drugs using conventional techniques or using the Tevadaptor® closed-system drug transfer device (CSTD).

METHODS

Surface contamination was measured by taking wipe samples. Stationary air samples were collected in preparation areas and personal air samples were collected in the working environment of the nurses. Contamination was reassessed after several weeks following implementation of the CSTD. Surface contamination was compared before and after CSTD introduction. Vancomycin, meronem, augmentin, ceftriaxone, cefotaxime, piperacillin, and benzylpenicillin were monitored. Wipe and air samples were analyzed using liquid chromatographytandem mass spectrometry (LC-MS/MS).

RESULTS

Using conventional preparation techniques, widespread contamination with antibiotics up to 767 ng cm-2 was detected. After implementation of the CSTD, contamination levels significantly decreased for the most frequently prepared antibiotics in the three hospitals.Using the conventional preparation technique, three antibiotics were detected in environmental air of seven nurses in two hospitals (0.01-5 µg m-3), and one antibiotic was found in environmental air above a preparation surface (0.02 µg m-3). After implementation of the CSTD, the same antibiotic was detected in environmental air above the same preparation surface (1.39 µg m-3) but no antibiotics were detected in environmental air of the nurses in the three hospitals.

CONCLUSIONS

Using the conventional preparation techniques, surfaces and air were widely contaminated with antibiotics whereas the use of the CSTD significantly reduced contamination. Systematic use of a CSTD significantly reduces exposure to hazardous antibiotics and consequently reduces potential adverse health effects for healthcare providers.

Particle and Carbon Dioxide Concentration Levels in a Surgical Room Conditioned with a Window/Wall Air-conditioning System

One of the most important functions of air conditioning systems in operating rooms is to protect occupants against pathogenic agents transported by air. This protection is done by simultaneously controlling the air distribution, temperature, humidity, filtration and infiltration from other areas etc. Due to their low price, simple installation, operation and maintenance, window/wall air conditioning system have largely been used in operating rooms in Brazil, even if these types of equipment only recirculate the air inside the room without appropriate filtration and renovation with outdoor air. In this context, this work aims to analyse the performance of the window/wall air conditioning systems on indoor air ventilation in operating rooms by measuring particle number concentrations and carbon dioxide concentrations during different surgical procedures, in a single surgical room and in the nearby areas (corridor) for two cases: single surgery and two subsequent surgeries. In addition, the efficiency of the analysed air conditioning system was evaluated by comparing the ventilation level calculated in the surgical room with the ventilation required in order to maintain the carbon dioxide concentration within acceptable levels. The results showed that this type of air conditioning system is not appropriate for use in operating rooms since it cannot provide an adequate level of ventilation. The CO₂ concentrations during surgeries, in fact, significantly exceeded acceptable values and a simultaneous increase in particle number concentration was observed. The results also showed that there is a high risk of contamination between subsequent surgeries in the same surgical room, due to residues of contaminants transported by the particles emitted during the surgeries that were not removed from the operating room by the air conditioning system. The particle number concentration measured in the second surgery, in fact, was approximately six times higher than in the first surgery.

Imaging features of fungal infection in immuno-suppressed patients in a local ward outbreak

Purpose of study

To examine the role of imaging in diagnosing and assessing fungal infections in paediatric patients undergoing chemotherapy in a facility, which had high fungal air contamination due to adjacent building construction work.

Materials and method

Nineteen patients aged five months to 12 years with various malignancies, mainly leukaemia, along with probable fungal infection were referred for imaging over a period of 12 months. The imaging findings from their CT and chest radiographs were reviewed by two radiologists and correlated with the clinical findings. Blood culture and/or biopsy of relevant lesions were performed for all patients.

Results

Fungus was positively isolated in 11 out of 19 patients, but the remaining patients clinically had fungal infection. The most common species isolated was Candida sp. (five patients), followed by Aspergillus sp. The most common site of fungal infection was the lungs (10 out of 19 patients), where consolidation or cavitating nodules were seen on CT or the plain chest radiograph. One patient developed pulmonary artery aneurysm as a complication. The other sites affected were the intra-abdominal organs (liver, kidneys, and spleen) and the paranasal sinuses, shown on CT. Two patients with clinical evidence of infection and Candida sp. isolated from their blood, however, showed no abnormal findings on imaging.

Conclusion

Early diagnosis of fungal infections in oncology patients undergoing chemotherapy is important, but diagnosis may be difficult through imaging because of the non-specific changes and the presence of abnormalities from the underlying disease. Even if a specific diagnosis cannot be reached, imaging is useful to monitor response to treatment and detect complications.