Key Elements Affecting the Library's CFU Concentration in Taiwan

Public libraries are popular gathering places, so understanding the factors that contribute to colony-forming unit (CFU) concentrations and how to minimize them is essential. This study aimed to investigate the factors that affect CFU concentrations in a public library, using air sampling (Bioluminescent ATP-assay) and statistical analysis software (SPSS) to collect and analyze data. The findings indicated that the CFU concentration in the library was significantly influenced by the air quality surrounding the building, the number of library visitors, and the hygiene and health of both visitors and employees. Additionally, indoor temperature and humidity were found to be key factors affecting CFU concentration. These findings suggest the need for better ventilation and air filtration systems, as well as regular cleaning and disinfection in public libraries. Furthermore, research is recommended to investigate other potential factors that may impact indoor air quality in public spaces.

Airborne virus shedding of the alpha, delta, omicron SARS-CoV-2 variants and influenza virus in hospitalized patients.

Airborne transmission is an important transmission route for the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological data indicate that certain SARS-CoV-2 variants, like the omicron variant, are associated with higher transmissibility. We compared virus detection in air samples between hospitalized patients infected with different SARS-CoV-2 variants or influenza virus. The study was performed during three separate time periods in which subsequently the alpha, delta, and omicron SARS-CoV-2 variants were predominant. In total, 79 patients with coronavirus disease 2019 (COVID-19) and 22 patients with influenza A virus infection were included. Collected air samples were positive in 55% of patients infected with the omicron variant in comparison to 15% of those infected with the delta variant (p < 0.01). In multivariable analysis, the SARS-CoV-2 omicron BA.1/BA.2 variant (as compared to the delta variant) and the viral load in nasopharynx were both independently associated with air sample positivity, but the alpha variant and COVID-19 vaccination were not. The proportion of positive air samples patients infected with the influenza A virus was 18%. In conclusion, the higher air sample positivity rate of the omicron variant compared to previous SARS-CoV-2 variants may partially explain the higher transmission rates seen in epidemiological trends.

The effects of enhanced formaldehyde clearance in a gross anatomy laboratory by floor plan redesign and dissection table adjustment.

Formaldehyde has carcinogenic properties. It is associated with nasopharyngeal cancer and causes irritation of the eyes, nose, throat, and respiratory system. Formaldehyde exposure is a significant health concern for those participating in the gross anatomy laboratory, but no learning method can substitute cadaver dissection. We performed a formaldehyde level study in 2018, which found that most of the breathing zone (S-level) and environment (R-level) formaldehyde levels during laboratory sessions at the Faculty of Medicine Siriraj Hospital exceeded international ceiling standards. In the academic year 2019, we adapted the engineering rationale of the NIOSH hierarchy of controls to facilitate formaldehyde clearance by opening the dissection table covers and increasing the area per dissection table, then measured formaldehyde ceiling levels by formaldehyde detector tube with a gas-piston hand pump during (1) body wall, (2) upper limb, (3) head-neck, (4) thorax, (5) spinal cord removal, (6) lower limb, (7) abdomen, and (8) organs of special senses dissection sessions and comparing the results with the 2018 study. The perineum region data were excluded from analyses due to the laboratory closure in 2019 from the COVID-19 outbreak. There were statistically significant differences between the 2018 and 2019 S-levels (p < 0.001) and R-levels (p < 0.001). The mean S-level decreased by 64.18% from 1.34 ± 0.71 to 0.48 ± 0.26 ppm, and the mean R-level decreased by 70.18% from 0.57 ± 0.27 to 0.17 ± 0.09 ppm. The highest formaldehyde level in 2019 was the S-level in the body wall region (1.04 ± 0.3 ppm), followed by the S-level in the abdomen region (0.56 ± 0.08 ppm) and the spinal cord removal region (0.51 ± 0.29 ppm). All 2019 formaldehyde levels passed the OSHA 15-min STEL standard (2 ppm). The R-level in the special sense region (0.06 ± 0.02 ppm) passed the NIOSH 15-min ceiling limit (0.1 ppm). Three levels for 2019 were very close: the R-level in the head-neck region (0.11 ± 0.08 ppm), the abdomen region (0.11 ± 0.08), the body wall region (0.14 ± 0.12 ppm), and the S-level in the special sense region (0.12 ± 0.04 ppm). In summary, extensive analysis and removal of factors impeding formaldehyde clearance can improve the general ventilation system and achieve the OSHA 15-min STEL standard.

Characterising SARS-CoV-2 transmission via aerosols and effective sampling methods for surveillance

Background: There is increasing evidence for aerosol-based transmission of SARS-CoV-2, with particulate matter (PM) a possible vector. Air surveillance is necessary to safeguard public spaces. Aim(s): To characterise SARS-CoV-2 distribution in aerosols collected in hospital and public spaces and determine best sampling methods for surveillance. Method(s): Over 8 months in 2021, 8 samplers collected liquid bioaerosols and size-fractioned particulate matter(PM) in hospitals (ICU, Respiratory ward and communal waiting areas), a London railway and underground station, a university, and a primary school. RNA was extracted from samples and RT-qPCR targeting the N-gene of SARSCoV-2 was performed. Samples were cultured on Vero cells. Result(s): 209 air samples were obtained with 20 positive for SARS-CoV-2. 15 positive samples were from hospitals, 10 from outpatient waiting areas (ED waiting area, Chemotherapy Day Unit), 2 of which had the B.1.1.7 mutation (alphavariant) on sequencing, and 5 positive samples from rooms housing SARS-CoV-2 positive patients on ICU and respiratory wards. 5 positive samples were obtained via a portable sampler on two separate journeys in a London underground carriage. SARS-CoV-2 was detected mostly in PM samplers (n=17) compared to liquid bioaerosol samplers (positive sample pick-up 13% vs 4%respectively), in fine particles <=2.5mum(PM2.5) in diameter (n=14). No samples were cultured on Vero cells. Conclusion(s): Size-fractioned particulate matter samplers may be more efficient than liquid bioaerosol samplers in detecting and monitoring SARS-CoV-2 in the air. SARS-CoV-2 is most detected on fine particles, giving support to PM2.5 acting as a vector for aerosol-based transmission.

Detection of hospital environmental contamination during SARS-CoV-2 Omicron predominance using a highly sensitive air sampling device.

Background and objectives: The high transmissibility of SARS-CoV-2 has exposed weaknesses in our infection control and detection measures, particularly in healthcare settings. Aerial sampling has evolved from passive impact filters to active sampling using negative pressure to expose culture substrate for virus detection. We evaluated the effectiveness of an active air sampling device as a potential surveillance system in detecting hospital pathogens, for augmenting containment measures to prevent nosocomial transmission, using SARS-CoV-2 as a surrogate. Methods: We conducted air sampling in a hospital environment using the AerosolSenseTM air sampling device and compared it with surface swabs for their capacity to detect SARS-CoV-2. Results: When combined with RT-qPCR detection, we found the device provided consistent SARS-CoV-2 detection, compared to surface sampling, in as little as 2 h of sampling time. The device also showed that it can identify minute quantities of SARS-CoV-2 in designated "clean areas" and through a N95 mask, indicating good surveillance capacity and sensitivity of the device in hospital settings. Conclusion: Active air sampling was shown to be a sensitive surveillance system in healthcare settings. Findings from this study can also be applied in an organism agnostic manner for surveillance in the hospital, improving our ability to contain and prevent nosocomial outbreaks.

SARS-CoV-2 in outdoor air following the third wave lockdown release, Portugal, 2021.

Aiming to contribute with more data on the presence of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) in outdoor environments, we performed air sampling in outdoor terraces from restaurants in three major cities of Portugal in April 2021, following the third wave lockdown release in the country. Air samples (n=19) were collected in 19 restaurant terraces during lunch time. Each air sample was collected using a Coriolis Compact air sampler, followed by RNA extraction and real-time quantitative PCR for the detection of viral RNA. Viral viability was also assessed through RNAse pre-treatment of samples. Only one of the 19 air samples was positive for SARS-CoV-2 RNA, with 7337 gene copies m-3 for the genomic region N2, with no viable virus in this sample. The low number of positive samples found in this study is not surprising, as sampling took place in outdoor settings where air circulation is optimal, and aerosols are rapidly dispersed by the air currents. These results are consistent with previous reports stating that transmission of SARS-CoV-2 in outdoor spaces is low, although current evidence shows an association of exposures in settings where drinking and eating is possible on-site with an increased risk in acquiring SARS-CoV-2 infection. Moreover, the minimal infectious dose for SARS-CoV-2 still needs to be determined so that the real risk of infection in different environments can be accurately established.

Viable SARS-CoV-2 detected in the air of hospital rooms of patients with COVID-19 with an early infection.

OBJECTIVES: This study assessed the concentration of SARS-CoV-2 in the air of hospital rooms occupied by patients with COVID-19 who had viable SARS-CoV-2 in nasopharyngeal (NP) samples in early infection. METHODS: Between July and October 2021, NP swabs were collected from 20 patients with early SARS-CoV-2 infection admitted to a tertiary hospital in Japan. Air samples were collected from their rooms, tested for SARS-CoV-2 RNA, and cultured to determine potential infectivity. RESULTS: The NP swab samples of 18 patients were positive for viable SARS-CoV-2 (median concentration: 4.0 × 105 tissue culture infectious dose 50/ml). In the air samples, viral RNA (median concentration: 1.1 × 105 copies/m3) was detected in 12/18 (67%) patients, and viable virus (median concentration: 8.9 × 102 tissue culture infectious dose 50/m3) was detected in 5/18 (28%) patients. The median time between illness onset and sampling was 3 days. The RNA concentration was significantly higher in samples wherein viable SARS-CoV-2 was detected than in samples in which viable virus was not detected (P-value = 0.027). CONCLUSION: Viable SARS-CoV-2 can be detected in the air surrounding patients with early SARS-CoV-2 infection. Health care workers should pay attention to infection control when caring for patients with early SARS-CoV-2 infection.

Environmental Dissemination of SARS-CoV-2 in a University Hospital during the COVID-19 5th Wave Delta Variant Peak in Castile-León, Spain.

The dominant SARS-CoV-2 Delta variant (B.1.617.2) became the main circulating variant among countries by mid 2021. Attention was raised to the increased risk of airborne transmission, leading to nosocomial outbreaks even among vaccinated individuals. Considering the increased number of COVID-19 hospital admissions fueled by the spread of the variant, with Spain showing the highest COVID-19 rates in mainland Europe by July 2021, the aim of this study was to assess SARS-CoV-2 environmental contamination in different areas of a University Hospital in the region of Castile-León, Spain, during the peak of the 5th wave of COVID-19 in the country (July 2021). Air samples were collected from sixteen different areas of the Hospital using a Coriolis® µ air sampler. Surface samples were collected in these same areas using sterile flocked plastic swabs. RNA extraction followed by a one-step RT-qPCR were performed for detection of SARS-CoV-2 RNA. Of the 21 air samples, only one was positive for SARS-CoV-2 RNA, from the emergency waiting room. Of the 40 surface samples, 2 were positive for SARS-CoV-2 RNA, both from the microbiology laboratory. These results may be relevant for risk assessment of nosocomial infection within healthcare facilities, thus helping prevent and minimize healthcare staff's exposure to SARS-CoV-2, reinforcing the importance of always wearing appropriate and well-fit masks at all times and proper PPE when in contact with infected patients.

COVID-19 pandemic lesson learned- critical parameters and research needs for UVC inactivation of viral aerosols.

The COVID-19 pandemic highlighted public awareness of airborne disease transmission in indoor settings and emphasized the need for reliable air disinfection technologies. This increased awareness will carry in the post-pandemic era along with the ever-emerging SARS-CoV variants, necessitating effective and well-defined protocols, methods, and devices for air disinfection. Ultraviolet (UV)-based air disinfection demonstrated promising results in inactivating viral bioaerosols. However, the reported data diversity on the required UVC doses has hindered determining the best UVC practices and led to confusion among the public and regulators. This article reviews available information on critical parameters influencing the efficacy of a UVC air disinfection system and, consequently, the required dose including the system's components as well as operational and environmental factors. There is a consensus in the literature that the interrelation of humidity and air temperature has a significant impact on the UVC susceptibility, which translate to changing the UVC efficacy of commercialized devices in indoor settings under varying conditions. Sampling and aerosolization techniques reported to have major influence on the result interpretation and it is recommended to use several sampling methods simultaneously to generate comparable and conclusive data. We also considered the safety concerns and the potential safe alternative of UVC, far-UVC. Finally, the gaps in each critical parameter and the future research needs of the field are represented. This paper is the first step to consolidating literature towards developing a standard validation protocol for UVC air disinfection devices which is determined as the one of the research needs.

A pseudo-outbreak of COVID-19 associated pulmonary aspergillosis: a microbiological investigation of both the patients and the environment.

Background: We experienced a pseudo-outbreak of aspergillosis in a newly constructed COVID-19 ward. Within the first 3 months from the commencement of the ward, six intubated patients of COVID-19 developed probable or possible pulmonary aspergillosis. We suspected an outbreak of pulmonary aspergillosis associated with ward construction and launched air sampling for the investigation of the relationship between these. Methods: The samples were collected at 13 locations in the prefabricated ward and three in the general wards, not under construction, as a control. Results: The results from samples revealed different species of Aspergillus from those detected by the patients. Aspergillus sp. was detected not only from the air samples in the prefabricated ward but also in the general ward. Discussion: In this investigation, we could not find evidence of the outbreak that links the construction of the prefabricated ward with the occurrence of pulmonary aspergillosis. It might suggest that this series of aspergillosis was more likely occurred from fungi that inherently colonized patients, and was associated with patient factors such as severe COVID-19 rather than environmental factors. Once an outbreak originating from building construction is suspected, it is important to conduct an environmental investigation including an air sampling.

Risk factors for COVID-19 associated pulmonary aspergillosis (CAPA) in severe COVID-19 and impact of airborne fungal contamination within negative pressure isolation room

Background. COVID-19 increase the risk of invasive pulmonary aspergillosis. However, the risk factors and fungal origin of COVID-19 associated pulmonary aspergillosis (CAPA) is not fully defined yet. We aim to identify the risk factors for CAPA in severe COVID-19 and evaluate association between fungal contamination within the air of negative pressure rooms and diagnosis of CAPAs. Methods. We performed a retrospective case-control study to identify risk factors for CAPA with 420 severe COVID-19 patients from March 2020 to January 2022 who admitted to a tertiary care hospital in South Korea. CAPA was defined with modified AspICU criteria. Control, matched by admission date and severity of COVID-19 at admission, was selected for each case. Air sampling and fungal culture was done on Jan 2022 with a microbial air sampler (MAS-100NT) at 11 spaces in the COVID-19 designated isolation ward including 9 negative pressure isolation rooms (IRs). A cross-sectional comparison between rooms with and without airborne fungal contamination was performed. Results. A total of 420 COVID-19 patients were hospitalized during the study period, and 51 patients were diagnosed with CAPA (prevalence 12.14%, incidence 6.26 per 1000 patient.day). Multivariate analysis showed that older age (odds ratio [OR] 1.051, 95% confidence intervals [CI] 1.006-1.009, p=0.025), mechanical ventilator use (OR 2.692, 95% CI 1.049-6.911, p=0.04), and lymphopenia (OR 4.353, 95% CI 1.727-10.975, p=0.02) were independent risk factors for CAPA. (Table 1, 2) Aspergillus spp. was identified within the air from 7 out of 11 spaces including 6 IRs and 1 doctors' room. (Figure 1). All 6 IRs with positive aspergillus culture were being occupied by patients at least 8 days. Among 6 patients, 3 had already been diagnosed with CAPA whereas the other 3 were not diagnosed with CAPA through the observation period. Among 4 patients in isolation rooms without airborne aspergillus contamination, one patient had been diagnosed as CAPA before air sampling. (Table 3). Conclusion. Association between CAPA and airborne aspergillus contamination within the negative pressure room could not be demonstrated in this study. Rather than environmental factors, patient factors such as older age, ventilator care, and lymphopenia were found to be associated with CAPA diagnosis.

Evaluation of environmental Mucorales contamination in and around the residence of COVID-19-associated mucormycosis patients.

Introduction: Recently, India witnessed an unprecedented surge of coronavirus disease 2019 (COVID-19)-associated mucormycosis (CAM) cases. In addition to patient management issues, environmental Mucorales contamination possibly contributed to the outbreak. A recent study evaluated environment contamination by Mucorales in the hospital setting. However, a considerable number of CAM patients were never admitted to a hospital before the development of the disease. The present study, therefore, planned to evaluate Mucorales contamination of patients' residences. Methods: The residential environment of 25 patients with CAM living in north India was surveyed. Air samples were collected from indoor and immediate outdoor vicinity of the patients' residence and cultured on Dichloran Rose-Bengal Chloramphenicol (DRBC) agar with benomyl for selective isolation of Mucorales. Surface swab samples were also collected from the air coolers fitted in those residences and cultured on DRBC agar. The isolates were identified by phenotypic and genotypic methods. Amplified fragment length polymorphism (AFLP) was employed to evaluate the genetic relatedness of the environmental and patients' clinical isolates. Results: The median spore count (mean ± SD, cfu/m3) of Mucorales in the air of patients' bedrooms was significantly higher than in the air in other rooms in those residences (3.55 versus 1.5, p = 0.003) or the air collected directly from the front of the air cooler (p < 0.0001). The Mucorales spore count in the environment did not correlate with either ventilation of the room or hygiene level of the patients' residences. Rhizopus arrhizus was isolated from the environment of all patients' residences (n = 25); other Mucorales species isolated were Cunninghamella bertholletiae (n = 14), Rhizopus microsporus (n = 6), Rhizopus delemar (n = 6), Syncephalastrum racemosum (n = 1), Lichtheimia corymbifera (n = 1), and Mucor racemosus (n = 1). Genetic relatedness was observed between 11 environmental isolates from the patients' bedrooms and respective clinical isolates from patients. Discussion: The study supported the view that the patients might have acquired Mucorales from the home environment during the post-COVID-19 convalescence period. Universal masking at home during patients' convalescence period and environmental decontamination could minimize exposure in those susceptible patients.

Compendium of analytical methods for sampling, characterization and quantification of bioaerosols

Bioaerosols are suspensions of airborne particulate matter of biological origin (BioPM) which includes microorganisms and the products of these organisms. Bioaerosols are ubiquitous in indoor and outdoor environments and can become dispersed by attaching to other particles. Bioaerosols are diverse in terms of their size, composition and biological properties and are an important transmission route for infectious and sensitization agents. More recently, bioaerosols have received significant scientific and societal attention from industry, academia, government and the wider public due to the emergence and global spread of COVID-19 and the threat of bioterrorism. Yet despite their importance for human health, the microbiological components of aerosols and their species dispersal from various environments remains poorly understood. Moreover, there is a lack of understanding of the ecology and role that bioaerosols play in the environment. As a result of these knowledge gaps, health officials and regulators have been hindered in their assessment of public and occupational health exposures and risk. For example, a better understanding of the concentrations and composition of bioaerosols in a particular environment, and the transmission dynamics of pathogens and their components, can inform on the appropriate ventilation rates and hygiene procedures to maintain good air quality and reduce human health risk. However, there are currently many uncertainties still remaining with regard to exposure assessment. To better understand the impact of bioaerosol exposure on human health, comprehensive methods to detect, characterise and quantify bioaerosols are needed. Although significant advances in technologies for bioaerosol sampling and analysis have been achieved over the last two decades or so, a consensus on air sampling methods for a particular context or environment and a universal analysis method still does not exist. This makes it difficult for researchers to compare data across studies, and for regulators to set meaningful exposure limits. BioAirNet is a UKRI NERC-funded project which acts as a leading voice for the UK BioPM science community and operates around four themes: Theme (1) BioPM sources and dynamics;Theme (2) BioPM sampling and characterisation;Theme (3) Human health, behaviour and wellbeing;and Theme (4) Policy and public engagement. As part of Theme 2, researchers, regulators, and public health officials have developed this compendium and Fig. 1 presents an overview of BioAirNet Theme 2. This compendium aims to provide a comprehensive toolbox of current techniques, workflows, and technologies for bioaerosol sampling, characterisation, and monitoring across different environments for researchers, epidemiologists, regulators, public health officials and regulators involved in bioaerosols. The overall goal of this text is to support the development of useful standards to better regulate and monitor bioaerosols worldwide.

Detection of SARS-CoV-2 Contamination in the Operating Room and Birthing Room Setting: Risks to Attending Health Care Workers

Objectives: The exposure risks to front-line health care workers (HCWs) who are in close proximity for prolonged periods of time, caring for COVID-19 patients undergoing surgery or obstetrical delivery, is unclear. Understanding of sample types that may harbour virus is important for evaluating risk. The objectives are as follows: to determine if SARS-CoV-2 viral RNA from patients with COVID-19 undergoing surgery or obstetrical delivery is present in: 1) the peritoneal cavity of males and females 2) the female reproductive tract, 3) the environment of the surgery or delivery suite (surgical instruments, equipment used, air or floors) and 4) inside the masks of the attending health care workers. Methods: In this cross-sectional study, conducted at 2 Toronto hospitals, 32 patients with COVID-19 underwent urgent surgery or obstetrical delivery and the presence of SARS-CoV-2 viral RNA in patient, environmental and air samples was identified by real time reverse transcriptase polymerase chain reaction. Air samples were collected using both active and passive sampling techniques. The primary outcome was the proportion of HCW masks positive for SARS-CoV-2 RNA. Results: SARS-CoV-2 RNA was detected in 20/332 (6%) patient and environmental samples collected: 4/24 (16.7%) patient, 5/60 (8.3%) floor, 1/5 (1.9%) air, 10/23 (43.5%) surgical instruments/equipment, 0/24 cautery filters and 0/143 (95% CI 0–0.026) inner surface of mask samples. Conclusions: While there is evidence of SARS-CoV-2 RNA in the surgical and obstetrical operative environment, the finding of no detectable virus inside the masks worn by the medical teams would suggest a low risk of infection for our health care workers using appropriate personal protective equipment. Keywords: SARS-CoV-2 viral RNA;PPE;exposure risk;health care workers;real time RT-PCR;environmental and air sampling;operating room exposure;delivery room exposure

SARS-CoV-2 air sampling: A systematic review on the methodologies for detection and infectivity.

This systematic review aims to present an overview of the current aerosol sampling methods (and equipment) being used to investigate the presence of SARS-CoV-2 in the air, along with the main parameters reported in the studies that are essential to analyze the advantages and disadvantages of each method and perspectives for future research regarding this mode of transmission. A systematic literature review was performed on PubMed/MEDLINE, Web of Science, and Scopus to assess the current air sampling methodologies being applied to SARS-CoV-2. Most of the studies took place in indoor environments and healthcare settings and included air and environmental sampling. The collection mechanisms used were impinger, cyclone, impactor, filters, water-based condensation, and passive sampling. Most of the reviewed studies used RT-PCR to test the presence of SARS-CoV-2 RNA in the collected samples. SARS-CoV-2 RNA was detected with all collection mechanisms. From the studies detecting the presence of SARS-CoV-2 RNA, fourteen assessed infectivity. Five studies detected viable viruses using impactor, water-based condensation, and cyclone collection mechanisms. There is a need for a standardized protocol for sampling SARS-CoV-2 in air, which should also account for other influencing parameters, including air exchange ratio in the room sampled, relative humidity, temperature, and lighting conditions.

EVALUATION OF THE TWO IN-PATIENT HOSPITALS ON POTENTIAL ENVIRONMENTAL HAZARD DURING THE PERIOD OF NEW CORONAVIRUS INFECTION IN THE KHABAROVSK CITY (DECEMBER 2020 — MARCH 2021)

Microbiological monitoring after infectious diseases in the system of epidemiological surveillance implies simultaneous pathogen identification both among patients and in hospital environment. Our aim is to assess potential hospital environmental hazard for the two in-patient infectious disease hospitals of the Khabarovsk city by using bacteriological and epidemiological analysis during new coronavirus disease pandemic. Materials and methods. Bacteriological assessment of nasopharyngeal microflora in 241 patients suffering from community-acquired pneumonia that were hospitalized in the two prevention and treatment facilities of the Khabarovsk city was performed. Sanitary-bacteriological control of hospital environment (428 hospital environment samples and 91 air samples) was carried out in parallel. Bacteriological assessment was performed with classical methods. Identification of isolated bacteriological pathogens and evaluation of drug-resistant strains were carried out by utilizing bacteriological analyzer Vitek 2 Compact. Results. Nine different pathogens (Pseudomonas aeruginosa, Pseudomonas stutzeri, Acinetobacter baumannii, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Pantoea, Enterococcus faecium, Staphylococcus haemolyticus) were isolated in 20 out of 428 samples — 4.7% [2.7–6.7]. Half of isolated agents — 2.3% [0.9–3.8] — were represented by drug-resistant isolates (10 out of 20 isolates) including 5 carbapenem-resistant isolates (Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae) and 5 isolates with multiple drug resistance (Enterobacter cloacae, Pantoea, Enterococcus faecium, Staphylococcus haemolyticus). Air samples contained pathogenic biological agents found in 6 out of 91 samples — 6.6% [1.5–11.7], and half of them — 3.3% [0.6–7.9] — were identified as drug-resistant variants, including S. aureus и S. haemolyticus. One of the surveyed hospitals was recognized as more hazardous due to microflora isolated from intensive care unit (A. baumannii and P. aeruginosa were resistant to 3rd–4th generation cephalosporins and carbapenems). Conclusion. Revealed circulation of wide range of microorganisms isolated from environment of two in-patient hospitals indicates high risk of healthcare-associated infections formation. Intensive care units can serve as a reservoir of healthcare-associated infections due to high percentage of patients with severe disease cases (“main reservoir” of drug-resistant strains).

Novel aerosol detection platform for SARS­CoV­2: Based on specific magnetic nanoparticles adsorption sampling and digital droplet PCR detection.

The SARS­CoV­2 virus is released from an infectious source (such as a sick person) and adsorbed on aerosols, which can form pathogenic microorganism aerosols, which can affect human health through airborne transmission. Efficient sampling and accurate detection of microorganisms in aerosols are the premise and basis for studying their properties and evaluating their hazard. In this study, we built a set of sub-micron aerosol detection platform, and carried out a simulation experiment on the SARS­CoV­2 aerosol in the air by wet-wall cyclone combined with immunomagnetic nanoparticle adsorption sampling and ddPCR. The feasibility of the system in aerosol detection was verified, and the influencing factors in the detection process were experimentally tested. As a result, the sampling efficiency was 29.77%, and extraction efficiency was 98.57%. The minimum detection limit per unit volume of aerosols was 250 copies (102 copies/mL, concentration factor 2.5).

SARS-CoV-2 Surveillance in Indoor Air Using Electrochemical Sensor for Continuous Monitoring and Real-Time Alerts.

The severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) has spread globally and there is still a lack of rapid detection techniques for SARS-CoV-2 surveillance in indoor air. In this work, two test rigs were developed that enable continuous air monitoring for the detection of SARS-CoV-2 by sample collection and testing. The collected samples from simulated SARS-CoV-2 contaminated air were analyzed using an ultra-fast COVID-19 diagnostic sensor (UFC-19). The test rigs utilized two air sampling methods: cyclone-based collection and internal impaction. The former achieved a limit of detection (LoD) of 0.004 cp/L in the air (which translates to 0.5 cp/mL when tested in aqueous solution), lower than the latter with a limit of 0.029 cp/L in the air. The LoD of 0.5 cp/mL using the UFC-19 sensor in aqueous solution is significantly lower than the best-in-class assays (100 cp/mL) and FDA EUA RT-PCR test (6250 cp/mL). In addition, the developed test rig provides an ultra-fast method to detect airborne SARS-CoV-2. The required time to test 250 L air is less than 5 min. While most of the time is consumed by the air collection process, the sensing is completed in less than 2 s using the UFC-19 sensor. This method is much faster than both the rapid antigen (<20 min) and RT-PCR test (<90 min).

Air Sampling for Fungus around Hospitalized Patients with Coronavirus Disease 2019.

The risk of developing coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) depends on factors related to the host, virus, and treatment. However, many hospitals have modified their existing rooms and adjusted airflow to protect healthcare workers from aerosolization, which may increase the risk of Aspergillus exposure. This study aimed to quantitatively investigate airborne fungal levels in negative and slightly negative pressure rooms for COVID-19 patients. The air in neutral pressure rooms in ordinary wards and a liver intensive care unit with high-efficiency particulate air filter was also assessed for comparison. We found the highest airborne fungal burden in recently renovated slightly negative air pressure rooms, and a higher airborne fungal concentration in both areas used to treat COVID-19 patients. The result provided evidence of the potential environmental risk of CAPA by quantitative microbiologic air sampling, which was scarcely addressed in the literature. Enhancing environmental infection control measures to minimize exposure to fungal spores should be considered. However, the clinical implications of a periodic basis to determine indoor airborne fungal levels and further air sterilization in these areas remain to be defined.

Variability of near-surface aerosol composition in Moscow in the spring of 2020

The paper studies variability in mass concentration and elemental composition of near-surface aerosol in Moscow in March-April 2020. During the study period, noticeable fluctuations in concentration of surface aerosol caused by atypical synoptic and meteorological conditions were revealed. Sharp increase in PM10 particle concentration (March 25-29, April 13) is associated with anticyclonic activity and advection of air containing combustion aerosols from the areas with biomass fires. In April as a whole, anomalously low values of aerosol particle concentrations were recorded in comparison with the long-term average. The prevailing dry Arctic air masses significantly decreased the atmospheric aerosol pollution. The decrease of anthropogenic load during COVID-19 non-proliferation actions affected on daily variations of the surface aerosol, smoothing out its typical daily maximal concentration values. Results of spring experiment at the IAP RAS showed good agreement with the data of the Obuchi nearest station of State Budgetary Institution "Mosecomonitoring". We analyzed geochemical spectrum of chemical elements in aerosol and its variability under different synoptic and weather conditions in Moscow. Possible sources and sinks of aerosols are discussed taking into account both abnormal weather conditions and decreased anthropogenic load during a lockdown period in the spring of 2020.