Transmission of Omicron (B.1.1.529) - SARS-CoV-2 Variant of Concern in a designated quarantine hotel for travelers: a challenge of elimination strategy of COVID-19

The Lancet Regional Health - Western Pacific, Journal Year: 2021, Volume and Issue: 18, P. 100360 - 100360

Published: Dec. 23, 2021

Language: Английский

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Indoor air surveillance and factors associated with respiratory pathogen detection in community settings in Belgium

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: March 11, 2023

Currently, the real-life impact of indoor climate, human behaviour, ventilation and air filtration on respiratory pathogen detection concentration are poorly understood. This hinders interpretability bioaerosol quantification in to surveil pathogens transmission risk. We tested 341 samples from 21 community settings Belgium for 29 using qPCR. On average, 3.9 were positive per sample 85.3% at least one. Pathogen varied significantly by pathogen, month, age group generalised linear (mixed) models estimating equations. High CO2 low natural independent risk factors detection. The odds ratio was 1.09 (95% CI 1.03-1.15) 100 parts million (ppm) increase CO2, 0.88 0.80-0.97) stepwise (on a Likert scale). portable independently associated with concentration. Each 100ppm qPCR Ct value decrease 0.08 -0.12 -0.04), 0.58 0.25-0.91) increase. effects occupancy, sampling duration, mask wearing, vocalisation, temperature, humidity mechanical not significant. Our results support importance reduce transmission.

Language: Английский

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Persistence of Phi6, a SARS-CoV-2 surrogate, in simulated indoor environments: Effects of humidity and material properties

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(1), P. e0313604 - e0313604

Published: Jan. 6, 2025

The SARS-CoV-2 virus caused the COVID-19 pandemic and brought major challenges to public health. It is transmitted via aerosols, droplets, fomites. Among these, viral transmission through fomites not well understood although it remains a very important route. This motivated us study how play role in within controlled indoor environments. To achieve this, we investigated aerosol persistence on under different humidity levels mimic built environment. We developed protocol effect of infectivity using full-scale environmental chamber. results show that aerosolized Phi6 air decreased by ≥ 1 log 10 as relative (RH) increased from 25% 75% but then RH further 85%, resulting characteristic V-shape curve which varied with exposure time. Consistently, material properties may impact persistence, changes local more significantly influence These provide new insights into fomite-mediated conditions. findings will help guide design effective strategies for control

Language: Английский

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Detection of SARS‐CoV‐2 Virions and RNA in Aerosols From COVID‐19 Environments

Indoor Air, Journal Year: 2025, Volume and Issue: 2025(1)

Published: Jan. 1, 2025

Background: Characterizing aerosols produced by SARS‐CoV‐2 patients is crucial for understanding disease transmission. The appearance and dispersal patterns of viral particles in airborne samples are not yet well understood. Knowing what look like just before they pass from one person to another can provide valuable insights into the mechanism transmission through air. Methods: Samples upper respiratory tract environmental were collected 39 SARS‐CoV‐2–positive at different stages symptom onset two distances source: 1 2 m. In addition, nasopharyngeal non‐COVID‐19 aerosol empty rooms healthy individuals taken as controls. analyzed RT‐PCR detect RNA field emission scanning electron microscopy (FESEM) visualize particles. Part was studied immunoelectron using nanogold against spike protein confirm specific method. Results: detected 59.18% environments COVID‐19 patients, with no significant differences based on distance. Higher detection rates noted when patient’s load Ct ≤ 25. Intact observed asymptomatic or those early progression disease, either free clumped well‐defined spikes. contrast, symptomatic had mucus without visible Virus‐like visualized both distances. Conclusion: Virions exhibited a better‐conserved samples. Although virions up m away only virion components, rather than complete virions, observed. To our knowledge, this first report showing three‐dimensional air

Language: Английский

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Portable air cleaners and residential exposure to SARS‐CoV‐2 aerosols: A real‐world study

Indoor Air, Journal Year: 2022, Volume and Issue: 32(4)

Published: April 1, 2022

Individuals with COVID-19 who do not require hospitalization are instructed to self-isolate in their residences. Due high secondary infection rates household members, there is a need understand airborne transmission of SARS-CoV-2 within We report the first naturalistic intervention study suggesting reduction such risk using portable air cleaners (PACs) HEPA filters. Seventeen individuals newly diagnosed completed this single-blind, crossover, randomized study. Total and size-fractionated aerosol samples were collected simultaneously self-isolation room PAC (primary) another (secondary) for two consecutive 24-h periods, one period filtration other filter removed (sham). Seven out sixteen (44%) primary rooms positive RNA during sham period. With operated at its lowest setting (clean delivery rate [CADR] = 263 cfm) minimize noise, decreased four residences (25%; p 0.229). A slight decrease was also observed room. As world confronts both new variants limited vaccination rates, our supports practical reduce presence viral aerosols real-world setting.

Language: Английский

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Outbreak investigation of airborne transmission of Omicron (B.1.1.529) - SARS-CoV-2 variant of concern in a restaurant: Implication for enhancement of indoor air dilution

Journal of Hazardous Materials, Journal Year: 2022, Volume and Issue: 430, P. 128504 - 128504

Published: Feb. 16, 2022

Language: Английский

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Evaluation of SARS-CoV-2 transmission in COVID-19 isolation wards: On-site sampling and numerical analysis

Journal of Hazardous Materials, Journal Year: 2022, Volume and Issue: 436, P. 129152 - 129152

Published: May 14, 2022

Language: Английский

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Spatiotemporal impact of COVID-19 on Taiwan air quality in the absence of a lockdown: Influence of urban public transportation use and meteorological conditions

Journal of Cleaner Production, Journal Year: 2022, Volume and Issue: 365, P. 132893 - 132893

Published: June 27, 2022

Language: Английский

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Airborne Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitals: Effects of Aerosol-Generating Procedures, HEPA-Filtration Units, Patient Viral Load, and Physical Distance

Clinical Infectious Diseases, Journal Year: 2022, Volume and Issue: 75(1), P. e89 - e96

Published: Feb. 28, 2022

Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation fine droplets or aerosols containing infectious virus. The objective this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome 2 (SARS-CoV-2)

Language: Английский

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Review of an intelligent indoor environment monitoring and management system for COVID-19 risk mitigation

Frontiers in Public Health, Journal Year: 2023, Volume and Issue: 10

Published: Jan. 10, 2023

The coronavirus disease (COVID-19) outbreak has turned the world upside down bringing about a massive impact on society due to enforced measures such as curtailment of personal travel and limitations economic activities. global pandemic resulted in numerous people spending their time at home, working, learning from home hence exposing them air contaminants outdoor indoor origins. COVID-19 is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which spreads airborne transmission. viruses found indoors are linked building's ventilation system quality. flow an environment controls movement advection any aerosols, pollutants, Carbon Dioxide (CO2) created sources/occupants; quantity CO2 can be measured sensors. Indoor monitoring technique used track person's risk, but high or low levels do not necessarily mean that virus present air. monitors, short, help inform individual whether they breathing clean In terms risk mitigation strategies, intelligent systems use various sensors available marketplace. This work presents review scientific articles influence development environmental quality management system. paper underlines non-dispersive infrared (NDIR) sensor ESP8266 microcontroller support low-cost facilities.

Language: Английский

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