Influenza is thought to be communicated from person by multiple pathways. However, the relative importance of different routes influenza transmission unclear. To better understand potential for airborne spread influenza, we measured amount and size aerosol particles containing virus that were produced coughing. Subjects recruited patients presenting at a student health clinic with influenza-like symptoms. Nasopharyngeal swabs collected volunteers they asked cough three times into spirometer....

Size-fractionated aerosol particles were collected in a hospital emergency department to test for airborne influenza virus. Using real-time polymerase chain reaction, we confirmed the presence of virus and found that 53% detectable within respirable fraction. Our results provide evidence may spread through route.

The question of whether influenza is transmitted to a significant degree by aerosols remains controversial, in part, because little known about the quantity and size potentially infectious airborne particles produced people with influenza. In this study, amount aerosol nine subjects during coughing were measured while they had after recovered, using laser particle spectrometer range 0.35 10 μm. Individuals produce significantly greater volume when ill compared afterward (p = 0.0143). When...

AbstractHealth care workers are exposed to potentially infectious airborne particles while providing routine coughing patients. However, much is not understood about the behavior of these aerosols and risks they pose. We used a patient simulator breathing worker investigate exposure health cough aerosol droplets, examine efficacy face shields in reducing this exposure. Our results showed that 0.9% initial burst from can be inhaled by 46 cm (18 inches) patient. During testing an...

Universal masking is one of the prevention strategies recommended by CDC to slow spread SARS-CoV-2, virus that causes coronavirus disease 2019 (COVID-19) (1). As February 1, 2021, 38 states and District Columbia had universal mandates. Mask wearing has also been mandated executive order for federal property* as well on domestic international transportation conveyances.

Face masks are recommended to reduce community transmission of SARS-CoV-2. One the primary benefits face and other coverings is as source control devices expulsion respiratory aerosols during coughing, breathing, speaking. shields neck gaiters have been proposed an alternative masks, but information about limited. We used a cough aerosol simulator with pliable skin headform propel small particles (0 7 μm) into different coverings. An N95 respirator blocked 99% (standard deviation (SD) 0.3%)...

SARS-CoV-2, the virus that causes COVID-19, can be spread by exposure to droplets and aerosols of respiratory fluids are released infected persons when they cough, sing, talk, or exhale. To reduce indoor transmission SARS-CoV-2 between persons, CDC recommends measures including physical distancing, universal masking (the use face masks in public places everyone who is not fully vaccinated), increased room ventilation (1). Ventilation systems supplemented with portable high efficiency...

Abstract Background . Considerable controversy exists with regard to whether influenza virus and respiratory syncytial (RSV) are spread by the inhalation of infectious airborne particles about importance this route, compared droplet or contact transmission. Methods Airborne were collected in an urgent care clinic use stationary personal aerosol samplers. The amounts A, B, RSV RNA determined using real-time quantitative polymerase chain reaction. Health workers patients participating study...

Background The role of relative humidity in the aerosol transmission influenza was examined a simulated examination room containing coughing and breathing manikins. Methods Nebulized coughed into Bioaerosol samplers collected size-fractionated aerosols (<1 µM, 1–4 >4 µM aerodynamic diameters) adjacent to manikin's mouth also at other locations within room. At constant temperature, RH varied from 7–73% infectivity assessed by viral plaque assay. Results Total virus for 60 minutes retained...

Background. The potential for aerosol transmission of infectious influenza virus (ie, in healthcare facilities) is controversial. We constructed a simulated patient examination room that contained coughing and breathing manikins to determine whether coughed was assessed the effectiveness an N95 respirator surgical mask blocking transmission. Methods. National Institute Occupational Safety Health samplers collected size-fractionated aerosols 60 minutes at mouth manikin, beside mouth, 3 other...

Background To prepare for a possible influenza pandemic, better understanding of the potential airborne transmission from person to is needed. Objectives The objective this study was directly compare generation aerosol particles containing viable virus during coughs and exhalations. Methods Sixty‐one adult volunteer outpatients with influenza‐like symptoms were asked cough exhale three times into spirometer. Aerosol produced coughing exhalation collected liquid media using samplers. samples...

Patients with influenza release aerosol particles containing the virus into their environment. However, importance of airborne transmission in spread is unclear, part because a lack information about infectivity virus. The purpose this study was to determine amount viable A that expelled by patients while coughing. Sixty-four symptomatic adult volunteer outpatients were asked cough 6 times collection system. Seventeen these participants tested positive for viral plaque assay (VPA)...

The biological control bacterium Pseudomonas aureofaciens 30-84 utilizes an N-acyl-homoserine lactone (AHL) signal molecule to phenazine antibiotic production in the wheat rhizosphere (D. W. Wood and L. S. Pierson III, Gene 168:49-53, 1996). In this study, we demonstrate that naturally co-existing, non-isogenic bacterial populations interact with strain at level of gene expression via exchange diffusible signals on roots. Wheat plants from three geographic locations were used generate a...

Universal mask wearing is recommended to help control the spread of COVID-19. Masks reduce expulsion aerosols respiratory fluids into environment (called source control) and offer some protection wearer. are often characterized using filtration efficiency, airflow resistance, manikin or human fit factors, which standard metrics used for personal protective devices. However, none these direct measurements how effectively a blocks coughed exhaled aerosols. We studied performance 15 cloth masks...

Abstract Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) was used to generate highly reproducible spectral ‘fingerprints’ for twelve Penicillium species. Prior MALDI‐TOF MS analysis, eight replicate cultures of each species were subjected three one‐minute bead‐beating cycles in an acetonitrile/trifluoroacetic acid solvent. The spectra contained abundant peaks the range m/z 5000–20 000, and allowed unambiguous discrimination between In addition, a...

A unique two-stage cyclone bioaerosol sampler has been developed at NIOSH that can separate aerosols into three size fractions. The ability of this to collect infectious airborne viruses from a calm-air chamber loaded with influenza virus was tested. sampler's efficiency collecting aerosolized viral particles is essentially the same as high performance SKC BioSampler collects un-fractionated directly liquid media (2.4 × 104 total per liter sampled air (TVP/L) versus 2.6 104TVP/L,...

During the COVID-19 pandemic, face masks are used as source control devices to reduce expulsion of respiratory aerosols from infected people. Modifications such mask braces, earloop straps, knotting and tucking, double masking have been proposed improve fit however data on limited.

There is strong evidence associating the indoor environment with transmission of SARS-CoV-2, virus that causes COVID-19. SARS-CoV-2 can spread by exposure to droplets and very fine aerosol particles from respiratory fluids are released infected persons. Layered mitigation strategies, including but not limited maintaining physical distancing, adequate ventilation, universal masking, avoiding overcrowding, vaccination, have shown be effective in reducing within environment. Here, we examine...

Background Influenza virus was used to characterize the efficacy of a cyclone‐based, two‐stage personal bioaerosol sampler for collection and size fractionation aerosolized viral particles. Methods A Collison single‐jet nebulizer aerosolize attenuated FluMist® vaccine into calm‐air settling chamber. Viral particles were captured with samplers that utilize 2 microcentrifuge tubes collect airborne particulates. The first tube (T1) collects greater than 1.8 μ m in diameter, while second (T2)...

Facemasks are part of the hierarchy interventions used to reduce transmission respiratory pathogens by providing a barrier. Two types facemasks healthcare workers N95 filtering facepiece respirators (FFRs) and surgical masks (SMs). These can become contaminated with during use, thus serving as potential sources for transmission. However, because lack field studies, hazard associated pathogen‐exposed is unknown. A mathematical model was calculate influenza contamination from aerosol in...

Abstract Face masks are recommended to reduce community transmission of SARS-CoV-2. One the primary benefits face and other coverings is as source control devices expulsion respiratory aerosols during coughing, breathing, speaking. shields neck gaiters have been proposed an alternative masks, but information about limited. We used a cough aerosol simulator with pliable skin headform propel small particles (0 7 µm) into different coverings. An N95 respirator blocked 99% aerosol, medical grade...

Face masks reduce the expulsion of respiratory aerosols produced during coughs and exhalations ("source control"). Factors such as directions in which people are facing (orientation) separation distance also affect aerosol dispersion. However, it is not clear how combined effects masking, orientation, exposure individuals to indoor spaces. We placed a simulator ("source") breathing ("recipient") 3 m × chamber measured concentrations for different combinations distance. When simulators were...