Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments.

PubMed

Gopalakrishnan, V; Subramanian, V; Baskaran, R; Venkatraman, B

2015-07-01

Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in a preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.

Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopalakrishnan, V.; Subramanian, V.; Baskaran, R.

2015-07-15

Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in amore » preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.« less

Antibacterial Loaded Spray Dried Chitosan Polyelectrolyte Complexes as Dry Powder Aerosol for the Treatment of Lung Infections

PubMed Central

Mishra, Brahmeshwar; Mishra, Madhusmita; Yadav, Sarita Kumari

2017-01-01

Inhalation delivery of aerosolized antibacterials is preferred over conventional methods of delivery for targeting lung infection. The present study is concerned with the development and characterization of a novel, spray dried, aerosolized, chitosan polyelectrolyte complex (PEC) based microparticles containing antibacterials for the treatment of lung infections. Chitosan polyelectrolyte complex microparticles were formulated by spray drying process. Prepared spray dried chitosan PEC microparticles were studied for surface morphology, drug encapsulation efficiency, moisture content, Carr’s index, solid state interaction by XRD, aerosolization behaviour and in-vitro drug release. In-vitro cytotoxicity studies of microparticles were carried out on H1299 alveolar cell lines. Antibacterial efficacy of microparticles was assessed on the basis of determination of pharmacokinetic parameters in bronchial alveolar lavage (BAL) of rats using PK/PD analysis. The PEC microparticles were mostly spherical and exhibited high drug encapsulation efficiency. Release profiles showed an initial burst phase followed by a secondary sustained release phase. Good aerosolization behaviour as dry powder inhaler was demonstrated by microparticles with high values of recovered dose, emitted dose, and fine particle fraction. No overt cytotoxicity of microparticles was detected against H1299 alveolar cell line. More than 8 to 9 folds higher Cmax values were obtained in BAL fluid with microparticles as compared to intravenously administered antibacterial solution. The findings of the study suggest that chitosan polyelectrolyte complex based microparticles as dry powder inhaler can be an efficient antibacterial delivery system for sustained and effective management of lung infection. PMID:28496463

Computational fluid dynamics study on the influence of an alternate ventilation configuration on the possible flow path of infectious cough aerosols in a mock airborne infection isolation room.

PubMed

Thatiparti, Deepthi Sharan; Ghia, Urmila; Mead, Kenneth R

2016-01-01

the cough aerosols were pulled by the exhaust vent without encountering the health care worker by 0.93 s after patient coughs and the particles were controlled as the aerosols' flow path was uninterrupted by an air particle streamline from patient to the ceiling exhaust venting out cough aerosols. However, not all the aerosols were vented out of the room. The remaining cough aerosols entered the health care worker's breathing zone by 0.98 s. This resulted in one of the critical stages in terms of the health care worker's exposure to airborne virus and presented the opportunity for the health care worker to suffer adverse health effects from the inhalation of cough aerosols. Within 2 s, the cough aerosols reentered and recirculated within the patient and health care worker's surroundings resulting in pockets of old contaminated air. By this time, coalescence losses decreased as the aerosol were no longer in very close proximity and their movement was primarily influenced by the airborne infection isolation room airflow patterns. In the patient and health care worker's area away from the supply, the fresh air supply failed to reach this part of the room to quickly dilute the cough aerosol concentration. The exhaust was also found to have minimal effect upon cough aerosol removal, except for those areas with high exhaust velocities, very close to the exhaust grill. Within 5-20 s after a patient's cough, the aerosols tended to break up to form smaller sized aerosols of less than one micron diameter. They remained airborne and entrained back into the supply air stream, spreading into the entire room. The suspended aerosols resulted in the floating time of more than 21 s in the room due to one cough cycle. The duration of airborne contagion in the room and its prolonged exposure to the health care worker is likely to happen due to successive coughing cycles. Hence, the evaluated alternate airborne infection isolation room is not effective in removing at least 38% particles

Computational fluid dynamics study on the influence of an alternate ventilation configuration on the possible flow path of infectious cough aerosols in a mock airborne infection isolation room

PubMed Central

THATIPARTI, DEEPTHI SHARAN; GHIA, URMILA; MEAD, KENNETH R.

2017-01-01

that the cough aerosols were pulled by the exhaust vent without encountering the health care worker by 0.93 s after patient coughs and the particles were controlled as the aerosols’ flow path was uninterrupted by an air particle streamline from patient to the ceiling exhaust venting out cough aerosols. However, not all the aerosols were vented out of the room. The remaining cough aerosols entered the health care worker’s breathing zone by 0.98 s. This resulted in one of the critical stages in terms of the health care worker’s exposure to airborne virus and presented the opportunity for the health care worker to suffer adverse health effects from the inhalation of cough aerosols. Within 2 s, the cough aerosols reentered and recirculated within the patient and health care worker’s surroundings resulting in pockets of old contaminated air. By this time, coalescence losses decreased as the aerosol were no longer in very close proximity and their movement was primarily influenced by the airborne infection isolation room airflow patterns. In the patient and health care worker’s area away from the supply, the fresh air supply failed to reach this part of the room to quickly dilute the cough aerosol concentration. The exhaust was also found to have minimal effect upon cough aerosol removal, except for those areas with high exhaust velocities, very close to the exhaust grill. Within 5–20 s after a patient’s cough, the aerosols tended to break up to form smaller sized aerosols of less than one micron diameter. They remained airborne and entrained back into the supply air stream, spreading into the entire room. The suspended aerosols resulted in the floating time of more than 21 s in the room due to one cough cycle. The duration of airborne contagion in the room and its prolonged exposure to the health care worker is likely to happen due to successive coughing cycles. Hence, the evaluated alternate airborne infection isolation room is not effective in removing at

“A significant source of isoprene aerosol controlled by acidity”

EPA Science Inventory

“A significant source of isoprene aerosol controlled by acidity” by Pye et al.Abstract: Isoprene is a significant contributor to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, CMAQ provides explicit p...

Environmental exposure of primary care personnel to ribavirin aerosol when supervising treatment of infants with respiratory syncytial virus infections.

PubMed Central

Rodriguez, W J; Bui, R H; Connor, J D; Kim, H W; Brandt, C D; Parrott, R H; Burch, B; Mace, J

1987-01-01

The potential exposure to ribavirin aerosol in the environment was assessed in nurses caring for infants and children with severe lower respiratory tract infections due to respiratory syncytial virus. Ribavirin aerosol was administered via a ventilator, oxygen tent, or oxygen hood. Participants worked directly with infants receiving ribavirin for 20.0 to 35.0 h over a 3-day period. No toxic or adverse effects of ribavirin aerosol were observed in any of the 19 nurses studied, and ribavirin was not detected in erythrocytes, plasma, or urine collected after the potential exposure period. PMID:3662474

Development of an Aerosol Model of Cryptococcus Reveals Humidity as an Important Factor Affecting the Viability of Cryptococcus during Aerosolization

PubMed Central

Springer, Deborah J.; Saini, Divey; Byrnes, Edmond J.; Heitman, Joseph; Frothingham, Richard

2013-01-01

Cryptococcus is an emerging global health threat that is annually responsible for over 1,000,000 infections and one third of all AIDS patient deaths. There is an ongoing outbreak of cryptococcosis in the western United States and Canada. Cryptococcosis is a disease resulting from the inhalation of the infectious propagules from the environment. The current and most frequently used animal infection models initiate infection via liquid suspension through intranasal instillation or intravenous injection. These models do not replicate the typically dry nature of aerosol exposure and may hinder our ability to decipher the initial events that lead to clearance or the establishment of infection. We have established a standardized aerosol model of murine infection for the human fungal pathogen Cryptococcus. Aerosolized cells were generated utilizing a Collison nebulizer in a whole-body Madison Chamber at different humidity conditions. The aerosols inside the chamber were sampled using a BioSampler to determine viable aerosol concentration and spray factor (ratio of viable aerosol concentration to total inoculum concentration). We have effectively delivered yeast and yeast-spore mixtures to the lungs of mice and observed the establishment of disease. We observed that growth conditions prior to exposure and humidity within the Madison Chamber during exposure can alter Cryptococcus survival and dose retained in mice. PMID:23894542

Characteristics of an aerosol photometer while automatically controlling chamber dilution-air flow rate.

PubMed

O'Shaughnessy, P T; Hemenway, D R

2000-10-01

Trials were conducted to determine those factors that affect the accuracy of a direct-reading aerosol photometer when automatically controlling airflow rate within an exposure chamber to regulate airborne dust concentrations. Photometer response was affected by a shift in the aerosol size distribution caused by changes in chamber flow rate. In addition to a dilution effect, flow rate also determined the relative amount of aerosol lost to sedimentation within the chamber. Additional calculations were added to a computer control algorithm to compensate for these effects when attempting to automatically regulate flow based on a proportional-integral-derivative (PID) feedback control algorithm. A comparison between PID-controlled trials and those performed with a constant generator output rate and dilution-air flow rate demonstrated that there was no significant decrease in photometer accuracy despite the many changes in flow rate produced when using PID control. Likewise, the PID-controlled trials produced chamber aerosol concentrations within 1% of a desired level.

Methicillin-resistant Staphylococcus aureus and infection control for restorative dental treatment in nursing homes.

PubMed

Hall, David L

2003-01-01

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in nursing home residents now averages 20-35%. This includes both numerous asymptomatic mostly unidentified carriers, and the occasional patient with an active infection. Among the most common sites for positive MRSA colonization are the nares and mouth (saliva). Ohio State University (OSU) dental students perform routine restorative dental care onsite in local nursing homes using portable equipment including handpieces that can generate aerosols. Using a series of cultured test swabs and plates, this pilot study suggests that protection for both dental health care personnel and patients are provided by the following: 1. universal barrier precautions (for example, gloves, gowns, masks, hats, facial shields, glasses), 2. surface disinfectants, 3. pre-op 0.12% chlorhexidene mouth rinses, 4. high volume evacuation, 5. perioral skin scrubs. Additional infection control methods, techniques and equipment were evaluated and compared including rubber dam isolation, hand excavation and bond technique, high-speed air turbine and electric "high" speed handpiece. There was no indication of a special tendency or heightened ability of MRSA to aerosolize.

[Effect of lead microparticles introduced into the respiratory system of the sensitivity of mice to Pasteurella multocida infection via aerosol].

PubMed

Bouley, G; Dubreuil, A; Arsac, F; Boudène, C

1977-12-19

Lead microparticles, resulting from the pyrolysis of organic lead used as an anti-knock agent in gasoline, were introduced into the lungs of Mice, during a short single exposure. When 6 microgram of lead were retained in the lungs (mean value per Mouse), the phagocytic ability of the pulmonary alveolar macrophages harvested 6 and 18 hrs. later, was significantly reduced. It was observed, in the same conditions, that the resistance of Mice to experimental infection by aerosolized Pasteurella multocida, was significantly reduced. When 3 microgram of lead were retained in the lungs, there was no significant difference between control and intoxicated Mice.

Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management

PubMed Central

2012-01-01

Background The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control. Method 45 healthy non-smokers participated in the open bench study by giving their best effort cough. A laser diffraction system was used to obtain accurate, time-dependent, quantitative measurements of the size and number of droplets expelled by the cough aerosol. Results Voluntary coughs generated droplets ranging from 0.1 - 900 microns in size. Droplets of less than one-micron size represent 97% of the total number of measured droplets contained in the cough aerosol. Age, sex, weight, height and corporal mass have no statistically significant effect on the aerosol composition in terms of size and number of droplets. Conclusions We have developed a standard human cough aerosol model. We have quantitatively characterized the pattern, size, and number of droplets present in the most important mode of person-to-person transmission of IRD: the cough bioaerosol. Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing. The cough aerosol is the single source of direct, indirect and/or airborne transmission of respiratory infections like the Influenza A H1N1 virus. Study design Open bench, Observational, Cough, Aerosol study PMID:22436202

Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management.

PubMed

Zayas, Gustavo; Chiang, Ming C; Wong, Eric; MacDonald, Fred; Lange, Carlos F; Senthilselvan, Ambikaipakan; King, Malcolm

2012-03-21

The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control. 45 healthy non-smokers participated in the open bench study by giving their best effort cough. A laser diffraction system was used to obtain accurate, time-dependent, quantitative measurements of the size and number of droplets expelled by the cough aerosol. Voluntary coughs generated droplets ranging from 0.1 - 900 microns in size. Droplets of less than one-micron size represent 97% of the total number of measured droplets contained in the cough aerosol. Age, sex, weight, height and corporal mass have no statistically significant effect on the aerosol composition in terms of size and number of droplets. We have developed a standard human cough aerosol model. We have quantitatively characterized the pattern, size, and number of droplets present in the most important mode of person-to-person transmission of IRD: the cough bioaerosol. Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing. The cough aerosol is the single source of direct, indirect and/or airborne transmission of respiratory infections like the Influenza A H1N1 virus. Open bench, Observational, Cough, Aerosol study. © 2012 Zayas et al; licensee BioMed Central Ltd.

Combination Chemotherapeutic Dry Powder Aerosols via Controlled Nanoparticle Agglomeration

PubMed Central

El-Gendy, Nashwa; Berkland, Cory

2014-01-01

Purpose To develop an aerosol system for efficient local lung delivery of chemotherapeutics where nanotechnology holds tremendous potential for developing more valuable cancer therapies. Concurrently, aerosolized chemotherapy is generating interest as a means to treat certain types of lung cancer more effectively with less systemic exposure to the compound. Methods Nanoparticles of the potent anticancer drug, paclitaxel, were controllably assembled to form low density microparticles directly after preparation of the nanoparticle suspension. The amino acid, L-leucine, was used as a colloid destabilizer to drive the assembly of paclitaxel nanoparticles. A combination chemotherapy aerosol was formed by assembling the paclitaxel nanoparticles in the presence of cisplatin in solution. Results Freeze-dried powders of the combination chemotherapy possessed desirable aerodynamic properties for inhalation. In addition, the dissolution rates of dried nanoparticle agglomerate formulations (~60% to 66% after 8 h) were significantly faster than that of micronized paclitaxel powder as received (~18% after 8 h). Interestingly, the presence of the water soluble cisplatin accelerated the dissolution of paclitaxel. Conclusions Nanoparticle agglomerates of paclitaxel alone or in combination with cisplatin may serve as effective chemotherapeutic dry powder aerosols to enable regional treatment of certain lung cancers. PMID:19415471

Enhanced hydrophobicity and volatility of submicron aerosols under severe emission control conditions in Beijing

NASA Astrophysics Data System (ADS)

Wang, Yuying; Zhang, Fang; Li, Zhanqing; Tan, Haobo; Xu, Hanbing; Ren, Jingye; Zhao, Jian; Du, Wei; Sun, Yele

2017-04-01

A series of strict emission control measures was implemented in Beijing and the surrounding seven provinces to ensure good air quality during the 2015 China Victory Day parade, rendering a unique opportunity to investigate the anthropogenic impact of aerosol properties. Submicron aerosol hygroscopicity and volatility were measured during and after the control period using a hygroscopic and volatile tandem differential mobility analyzer (H/V-TDMA) system. Three periods, namely the control clean period (Clean1), the non-control clean period (Clean2), and the non-control pollution period (Pollution), were selected to study the effect of the emission control measures on aerosol hygroscopicity and volatility. Aerosol particles became more hydrophobic and volatile due to the emission control measures. The hygroscopicity parameter (κ) of 40-200 nm particles decreased by 32.0-8.5 % during the Clean1 period relative to the Clean2 period, while the volatile shrink factor (SF) of 40-300 nm particles decreased by 7.5-10.5 %. The emission controls also changed the diurnal variation patterns of both the probability density function of κ (κ-PDF) and the probability density function of SF (SF-PDF). During Clean1 the κ-PDF showed one nearly hydrophobic (NH) mode for particles in the nucleation mode, which was likely due to the dramatic reduction in industrial emissions of inorganic trace gases. Compared to the Pollution period, particles observed during the Clean1 and Clean2 periods exhibited a more significant nonvolatile (NV) mode throughout the day, suggesting a more externally mixed state particularly for the 150 nm particles. Aerosol hygroscopicities increased as particle sizes increased, with the greatest increases seen during the Pollution period. Accordingly, the aerosol volatility became weaker (i.e., SF increased) as particle sizes increased during the Clean1 and Clean2 periods, but no apparent trend was observed during the Pollution period. Based on a correlation

Enhanced hydrophobicity and volatility of submicron aerosols under severe emission control conditions in Beijing

NASA Astrophysics Data System (ADS)

Wang, Yuying; Zhang, Fang; Li, Zhanqing

2017-04-01

A series of strict emission control measures were implemented in Beijing and the surrounding seven provinces to ensure good air quality during the 2015 China Victory Day parade, rendering a unique opportunity to investigate anthropogenic impact of aerosol properties. Submicron aerosol hygroscopicity and volatility were measured during and after the control period using a hygroscopic and volatile tandem differential mobility analyzer (H/V-TDMA) system. Three periods, namely, the control clean period (Clean1), the non-control clean period (Clean2), and the non-control pollution period (Pollution), were selected to study the effect of the emission control measures on aerosol hygroscopicity and volatility. Aerosol particles became more hydrophobic and volatile due to the emission control measures. The hygroscopicity parameter (κ) of 40-200 nm particles decreased by 32.0%-8.5% during the Clean1 period relative to the Clean2 period, while the volatile shrink factor (SF) of 40-300 nm particles decreased by 7.5%-10.5%. The emission controls also changed the diurnal variation patterns of both the probability density function of κ (κ-PDF) and the probability density function of SF (SF-PDF). During Clean1 the κ-PDF showed one nearly-hydrophobic (NH) mode for particles in the nucleation mode, which was likely due to the dramatic reduction in industrial emissions of inorganic trace gases. Compared to the Pollution period, particles observed during the Clean1 and Clean2 periods exhibited a more significant non-volatile (NV) mode throughout the day, suggesting a more externally-mixed state particularly for the 150 nm particles. Aerosol hygroscopicities increased as particle sizes increased, with the greatest increases seen during the Pollution period. Accordingly, the aerosol volatility became weaker (i.e., SF increased) during the Clean1 and Clean2 periods, but no apparent trend was observed during the Pollution period. Based on a correlation analysis of the number fractions

Confinement of surface waves at the air-water interface to control aerosol size and dispersity

NASA Astrophysics Data System (ADS)

Nazarzadeh, Elijah; Wilson, Rab; King, Xi; Reboud, Julien; Tassieri, Manlio; Cooper, Jonathan M.

2017-11-01

The precise control over the size and dispersity of droplets, produced within aerosols, is of great interest across many manufacturing, food, cosmetic, and medical industries. Amongst these applications, the delivery of new classes of high value drugs to the lungs has recently attracted significant attention from pharmaceutical companies. This is commonly achieved through the mechanical excitation of surface waves at the air liquid interface of a parent liquid volume. Previous studies have established a correlation between the wavelength on the surface of liquid and the final aerosol size. In this work, we show that the droplet size distribution of aerosols can be controlled by constraining the liquid inside micron-sized cavities and coupling surface acoustic waves into different volumes of liquid inside micro-grids. In particular, we show that by reducing the characteristic physical confinement size (i.e., either the initial liquid volume or the cavities' diameters), higher harmonics of capillary waves are revealed with a consequent reduction of both aerosol mean size and dispersity. In doing so, we provide a new method for the generation and fine control of aerosols' sizes distribution.

Establishing an infection control structure.

PubMed

Hambraeus, A

1995-06-01

In studies from the USA it has been shown that infection control can lower infection rates by 30%. To achieve this an infection control programme has to be given a firm structure. Judging from the opinions presented by an educational workshop within the International Federation of Infection Control (IFIC) and from the literature there is an international consensus on the basic components of hospital infection control. An infection control team, with the task of identifying areas of concern, providing or initiating work on written policies, educating and advising not only medical staff but also hospital administrators, constructors etc., constitutes the backbone of infection control. However, in most countries the infection control team, should it exist, is usually understaffed. This is false economy, a qualified medical input is a proven investment.

Emission Controls Versus Meteorological Conditions in Determining Aerosol Concentrations in Beijing during the 2008 Olympic Games

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Yi; Liu, Xiaohong; Zhao, Chun

A series of emission control measures were undertaken in Beijing and the adjacent provinces in China during the 2008 Beijing Olympic Games on August 8th-24th, 2008. This provides a unique opportunity for investigating the effectiveness of emission controls on air pollution in Beijing. We conducted a series of numerical experiments over East Asia for the period of July to September 2008 using a coupled meteorology-chemistry model (WRF-Chem). Model can generally reproduce the observed variation of aerosol concentrations. Consistent with observations, modeled concentrations of aerosol species (sulfate, nitrate, ammonium, black carbon, organic carbon, total particulate matter) in Beijing were decreased bymore » 30-50% during the Olympic period compared to the other periods in July and August in 2008 and the same period in 2007. Model results indicate that emission controls were effective in reducing the aerosol concentrations by comparing simulations with and without emission controls. However, our analysis suggests that meteorological conditions (e.g., wind direction and precipitation) are at least as important as emission controls in producing the low aerosol concentrations appearing during the Olympic period. Transport from the regions surrounding Beijing determines the temporal variation of aerosol concentrations in Beijing. Based on the budget analysis, we suggest that emission control strategy should focus on the regional scale instead of the local scale to improve the air quality over Beijing.« less

The Fluorocycline TP-271 Is Efficacious in Models of Aerosolized Francisella tularensis SCHU S4 Infection in BALB/c Mice and Cynomolgus Macaques

PubMed Central

Anderson, Michael S.; Christ, David; Gooldy, Melanie; Henning, Lisa N.; Heine, Henry S.; Kindt, M. Victoria; Lin, Winston; Siefkas-Patterson, Kaylyn; Radcliff, Anne K.; Tam, Vincent H.; Sutcliffe, Joyce A.

2017-01-01

ABSTRACT TP-271 is a novel, fully synthetic fluorocycline in development for complicated bacterial respiratory infections. TP-271 was active in vitro against a panel of 29 Francisella tularensis isolates, showing MICs against 50% and 90% of isolates of 0.25 and 0.5 μg/ml, respectively. In a mouse model of inhalational tularemia, animals were exposed by aerosol to 91 to 283 50% lethal doses (LD50)/mouse of F. tularensis SCHU S4. Following 21 days of once-daily intraperitoneal dosing with TP-271 at 3, 6, 12, and 18 mg/kg of body weight/day, initiating at 24 h postchallenge, survival was 80%, 100%, 100%, and 100%, respectively. When treatment was initiated at 72 h postchallenge, survival was 89%, 100%, 100%, and 100% in the 3-, 6-, 12-, and 18-mg/kg/day TP-271 groups, respectively. No mice treated with the vehicle control survived. Surviving mice treated with TP-271 showed little to no relapse during 14 days posttreatment. In a nonhuman primate model of inhalational tularemia, cynomolgus macaques received an average aerosol exposure of 1,144 CFU of F. tularensis SCHU S4. Once-daily intravenous infusion with 1 or 3 mg/kg TP-271, or vehicle control, for 21 days was initiated within 6 h of confirmed fever. All animals treated with TP-271 survived to the end of the study, with no relapse during 14 days after the last treatment, whereas no vehicle control-treated animals survived. The protection and low relapse afforded by TP-271 treatment in these studies support continued investigation of TP-271 for use in the event of aerosolized exposure to F. tularensis. PMID:28559261

Characterization of aerosols produced by surgical procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.

1994-07-01

In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured themore » size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.« less

Characterization of aerosols containing Legionella generated upon nebulization

NASA Astrophysics Data System (ADS)

Allegra, Séverine; Leclerc, Lara; Massard, Pierre André; Girardot, Françoise; Riffard, Serge; Pourchez, Jérémie

2016-09-01

Legionella pneumophila is, by far, the species most frequently associated with Legionnaires’ disease (LD). Human infection occurs almost exclusively by aerosol inhalation which places the bacteria in juxtaposition with alveolar macrophages. LD risk management is based on controlling water quality by applying standardized procedures. However, to gain a better understanding of the real risk of exposure, there is a need (i) to investigate under which conditions Legionella may be aerosolized and (ii) to quantify bacterial deposition into the respiratory tract upon nebulization. In this study, we used an original experimental set-up that enables the generation of aerosol particles containing L. pneumophila under various conditions. Using flow cytometry in combination with qPCR and culture, we determined (i) the size of the aerosols and (ii) the concentration of viable Legionella forms that may reach the thoracic region. We determined that the 0.26-2.5 μm aerosol size range represents 7% of initial bacterial suspension. Among the viable forms, 0.7% of initial viable bacterial suspension may reach the pulmonary alveoli. In conclusion, these deposition profiles can be used to standardize the size of inoculum injected in any type of respiratory tract model to obtain new insights into the dose response for LD.

To achieve an earlier IFN-γ response is not sufficient to control Mycobacterium tuberculosis infection in mice.

PubMed

Vilaplana, Cristina; Prats, Clara; Marzo, Elena; Barril, Carles; Vegué, Marina; Diaz, Jorge; Valls, Joaquim; López, Daniel; Cardona, Pere-Joan

2014-01-01

The temporo-spatial relationship between the three organs (lung, spleen and lymph node) involved during the initial stages of Mycobacterium tuberculosis infection has been poorly studied. As such, we performed an experimental study to evaluate the bacillary load in each organ after aerosol or intravenous infection and developed a mathematical approach using the data obtained in order to extract conclusions. The results showed that higher bacillary doses result in an earlier IFN-γ response, that a certain bacillary load (BL) needs to be reached to trigger the IFN-γ response, and that control of the BL is not immediate after onset of the IFN-γ response, which might be a consequence of the spatial dimension. This study may have an important impact when it comes to designing new vaccine candidates as it suggests that triggering an earlier IFN-γ response might not guarantee good infection control, and therefore that additional properties should be considered for these candidates.

To Achieve an Earlier IFN-γ Response Is Not Sufficient to Control Mycobacterium tuberculosis Infection in Mice

PubMed Central

Marzo, Elena; Barril, Carles; Vegué, Marina; Diaz, Jorge; Valls, Joaquim; López, Daniel; Cardona, Pere-Joan

2014-01-01

The temporo-spatial relationship between the three organs (lung, spleen and lymph node) involved during the initial stages of Mycobacterium tuberculosis infection has been poorly studied. As such, we performed an experimental study to evaluate the bacillary load in each organ after aerosol or intravenous infection and developed a mathematical approach using the data obtained in order to extract conclusions. The results showed that higher bacillary doses result in an earlier IFN-γ response, that a certain bacillary load (BL) needs to be reached to trigger the IFN-γ response, and that control of the BL is not immediate after onset of the IFN-γ response, which might be a consequence of the spatial dimension. This study may have an important impact when it comes to designing new vaccine candidates as it suggests that triggering an earlier IFN-γ response might not guarantee good infection control, and therefore that additional properties should be considered for these candidates. PMID:24959669

Tuberculosis and infection control.

PubMed

Karim, Kelvin

Against a background of rising tuberculosis (TB) rates, increasing incidence of TB and human immunodeficiency virus (HIV) co-infection, coupled with the emergence of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB), the need for effective TB infection control has never been more vital (World Health Organization (WHO), 2009). TB infection control has been defined as 'a combination of measures aimed at minimizing the risk of TB transmission within populations' (WHO, 2009: p.ix). Health professionals are frequently confused about appropriate infection control measures when caring for patients affected by infectious respiratory tuberculosis (Mohandas and Cunniffe, 2009). This article aims to address the key infection control measures required to optimize patient care and reduce the risk of TB transmission within hospital and community settings.

Growth conditions and environmental factors impact aerosolization but not virulence of Francisella tularensis infection in mice

PubMed Central

Faith, Seth A.; Smith, Le'Kneitah P.; Swatland, Angela S.; Reed, Douglas S.

2012-01-01

In refining methodology to develop a mouse model for inhalation of Francisella tularensis, it was noted that both relative humidity and growth media impacted the aerosol concentration of the live vaccine strain (LVS) of F. tularensis. A relative humidity of less than 55% had a negative impact on the spray factor, the ratio between the concentration of LVS in the aerosol and the nebulizer. The spray factor was significantly higher for LVS grown in brain heart infusion (BHI) broth than LVS grown in Mueller–Hinton broth (MHb) or Chamberlain's chemically defined medium (CCDM). The variability between aerosol exposures was also considerably less with BHI. LVS grown in BHI survived desiccation far longer than MHb-grown or CCDM-grown LVS (~70% at 20 min for BHI compared to <50% for MHb and CCDM). Removal of the capsule by hypertonic treatment impacted the spray factor for CCDM-grown LVS or MHb-grown LVS but not BHI-grown LVS, suggesting the choice of culture media altered the adherence of the capsule to the cell membrane. The choice of growth media did not impact the LD50 of LVS but the LD99 of BHI-grown LVS was 1 log lower than that for MHb-grown LVS or CCDM-grown LVS. Splenomegaly was prominent in mice that succumbed to MHb- and BHI-grown LVS but not CCDM-grown LVS. Environmental factors and growth conditions should be evaluated when developing new animal models for aerosol infection, particularly for vegetative bacterial pathogens. PMID:23087911

Control of particle size by coagulation of novel condensation aerosols in reservoir chambers.

PubMed

Hong, John N; Hindle, Michael; Byron, Peter R

2002-01-01

The coagulation growth behavior of capillary aerosol generator (CAG) condensation aerosols was investigated in a series of reservoir chambers. Aerosols consisted of a condensed system of 0.7% w/w benzil (model drug) in propylene glycol (vehicle). These were generated into 250-, 500-, 1,000-, and 2,000-mL reservoirs in both flowing air-stream and static air experiments. Changes in drug and total aerosol particle size were measured by a MOUDI cascade impactor. In both series of experiments the CAG aerosols grew in size. Growth in flowing air-stream experiments was attributed to the amount of accumulation aerosols experienced in reservoirs during sampling and increased with increasing reservoir volume. Mean (SD) MMAD's for the total mass distribution measured for the 250- and 2,000-mL reservoirs were 0.70 (0.02) and 0.87 (0.03) microm, respectively. For the benzil mass distribution, they were 0.64 (0.02) and 0.87 (0.06) microm, respectively. Growth in static air experiments was dependent on the volume aerosol boluses were restricted to and increased with decreasing reservoir volume. Mean (SD) initial MMAD's for the benzil mass distribution for the 250- and 2,000-mL reservoirs were 1.44 (0.03) and 1.24 (0.08) microm, respectively. Holding aerosols for up to 60 sec further increased their size. Mean (SD) MMAD's for benzil after holding for 60 sec in these reservoirs were 2.28 (0.04) and 1.67 (0.09) microm, respectively. The coagulation behavior and therefore particle size of CAG aerosols may be modified and controlled by reservoir chambers for drug targeting within the respiratory tract.

The Fluorocycline TP-271 Is Efficacious in Models of Aerosolized Francisella tularensis SCHU S4 Infection in BALB/c Mice and Cynomolgus Macaques.

PubMed

Grossman, Trudy H; Anderson, Michael S; Christ, David; Gooldy, Melanie; Henning, Lisa N; Heine, Henry S; Kindt, M Victoria; Lin, Winston; Siefkas-Patterson, Kaylyn; Radcliff, Anne K; Tam, Vincent H; Sutcliffe, Joyce A

2017-08-01

TP-271 is a novel, fully synthetic fluorocycline in development for complicated bacterial respiratory infections. TP-271 was active in vitro against a panel of 29 Francisella tularensis isolates, showing MICs against 50% and 90% of isolates of 0.25 and 0.5 μg/ml, respectively. In a mouse model of inhalational tularemia, animals were exposed by aerosol to 91 to 283 50% lethal doses (LD 50 )/mouse of F. tularensis SCHU S4. Following 21 days of once-daily intraperitoneal dosing with TP-271 at 3, 6, 12, and 18 mg/kg of body weight/day, initiating at 24 h postchallenge, survival was 80%, 100%, 100%, and 100%, respectively. When treatment was initiated at 72 h postchallenge, survival was 89%, 100%, 100%, and 100% in the 3-, 6-, 12-, and 18-mg/kg/day TP-271 groups, respectively. No mice treated with the vehicle control survived. Surviving mice treated with TP-271 showed little to no relapse during 14 days posttreatment. In a nonhuman primate model of inhalational tularemia, cynomolgus macaques received an average aerosol exposure of 1,144 CFU of F. tularensis SCHU S4. Once-daily intravenous infusion with 1 or 3 mg/kg TP-271, or vehicle control, for 21 days was initiated within 6 h of confirmed fever. All animals treated with TP-271 survived to the end of the study, with no relapse during 14 days after the last treatment, whereas no vehicle control-treated animals survived. The protection and low relapse afforded by TP-271 treatment in these studies support continued investigation of TP-271 for use in the event of aerosolized exposure to F. tularensis . Copyright © 2017 American Society for Microbiology.

Certification in infection control matters: Impact of infection control department characteristics and policies on rates of multidrug-resistant infections

PubMed Central

Pogorzelska, Monika; Stone, PatriciaW.; Larson, Elaine L.

2012-01-01

Background The study objective is to describe infection control policies aimed at multidrug-resistant organisms (MDRO) in California hospitals and assess the relationship among these policies, structural characteristics, and rates of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) bloodstream infections and Clostridium difficile infections. Methods Data on infection control policies, structural characteristics, and MDRO rates were collected through a 2010 survey of California infection control departments. Bivariate and multivariable Poisson and negative binomial regressions were conducted. Results One hundred eighty hospitals provided data (response rate, 54%). Targeted MRSA screening upon admission was reported by the majority of hospitals (87%). The majority of hospitals implemented contact precautions for confirmed MDRO and C difficile patients; presumptive isolation/contact precautions for patients with pending screens were less frequently implemented. Few infection control policies were associated with lower MDRO rates. Hospitals with a certified infection control director had significantly lower rates of MRSA bloodstream infections (P < .05). Conclusion Although most California hospitals are involved in activities to decrease MDRO, there is variation in specific activities utilized with the most focus placed on MRSA. This study highlights the importance of certification and its significant impact on infection rates. Additional research is needed to confirm these findings. PMID:22381222

Evaluation of aerosol spray and intramuscular injection of bacteriophage to treat an Escherichia coli respiratory infection.

PubMed

Huff, W E; Huff, G R; Rath, N C; Balog, J M; Donoghue, A M

2003-07-01

Two studies were conducted to determine the efficacy of either aerosol or i.m. injection of bacteriophage to treat an Escherichia coli respiratory infection in broiler chickens. An additional two studies were conducted to enumerate the bacteriophage in the blood of birds at 1, 2, 3, 4, 5, 6, 24, and 48 h after being sprayed or injected i.m. with bacteriophage. Five birds were bled at each period. In study 1, there were 10 treatments with three replicate pens of 10 birds. The treatments consisted of an untreated control, heat-killed bacteriophage spray, active bacteriophage spray, E. coli challenge at 7 d of age, and E. coli challenge followed by spraying the birds with heat-killed bacteriophage or active bacteriophage at 2, 24, or 48 h after challenge. In study 2 there were 11 treatments with three replicate pens of 10 birds per pen. The treatments were untreated controls, birds injected i.m. in the thigh with heat-killed or active bacteriophage, E. coli challenge at 7 d of age, PBS challenge, E. coli challenge followed by injection of heat-killed or active bacteriophage immediately after challenge or at 24 or 48 h after challenge. In both studies the E. coli challenge consisted of injecting 10(4) cfu into the thoracic air sac. Treatment of this severe E. coli infection with the bacteriophage aerosol spray significantly reduced mortality from 50 to 20% when given immediately after the challenge but had little treatment efficacy when administered 24 or 48 h after challenge. The i.m. injection of bacteriophage significantly reduced mortality from 53 to 17%, 46 to 10%, and 44 to 20% when given immediately, 24, or 48 h after challenge, respectively. Only a few birds sprayed with bacteriophage had detectable bacteriophage in their blood with an average of 96 pfu/mL 1 h after bacteriophage administration, and no bacteriophage was detected 24 and 48 h after bacteriophage administration. All birds injected i.m. with bacteriophage had detectable levels of bacteriophage in

Infection control: beyond the horizon.

PubMed

Gray, J

2015-04-01

This article will consider possible future directions for innovation and research in infection prevention and control, and will make the case for the importance of including clinical and cost-effectiveness evaluation in such research. Opportunities for studies in a number of broad subject areas will be considered, including prevention and control of existing and emerging infection hazards, the challenges posed by changes in the way that medical care is being delivered, technological developments that could be harnessed for infection prevention and control, how new laboratory diagnostic technologies might benefit infection prevention and control, cleaning and decontamination, and the infection control aspects of hospital design. The need for robust economic data to support the wide and timely implementation of evidence-based practice is emphasized. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Australian Infection Control Association members' use of skills and resources that promote evidence-based infection control.

PubMed

Murphy, C L; McLaws, M

2000-04-01

To adopt an evidence-based approach, professionals must be able to access, identify, interpret, and critically appraise best evidence. Critical appraisal requires essential skills, such as computer literacy and an understanding of research principles. These skills also are required for professionals to contribute to evidence. In 1996, members of the Australian Infection Control Association were surveyed to establish a profile including the extent to which they were reading infection control publications, using specific documents for policy and guideline development, developing and undertaking research, publishing research, and using computers. The relationships between demographics, computer use, and research activity were examined. The response rate was 63. 4% (630/993). The study group comprised mostly women (96.1%), and most (66.4%) were older than 40 years of age. Median infection control experience was 4 years (mean, 5.4 years; range, <12 months to 35 years). When developing guidelines and policies (92.7%; 584/630), infection control professionals reviewed State Health Department Infection Control Guidelines and Regulations. Research relating to infection control was undertaken by 21.5% (135/628) of the sample, and 27.6% (37/134) of this group published their research findings. Of the respondents (51.1%; 318/622) who used a computer to undertake infection control tasks, the majority (89.0%) used a personal computer for word processing. Regardless of infection control experience, Australian infection control professionals must be adequately prepared to contribute to, access, appraise, and where appropriate, apply best evidence to their practice. We suggest that computer literacy, an understanding of research principles, and familiarity with infection control literature are three essential skills that infection control professionals must possess and regularly exercise.

Geometrical Optics of Dense Aerosols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

2013-04-24

Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, amore » critical result for controlled focusing. __________________________________________________« less

Highly-controlled, reproducible measurements of aerosol emissions from African biomass combustion

NASA Astrophysics Data System (ADS)

Haslett, Sophie; Thomas, J. Chris; Morgan, William; Hadden, Rory; Liu, Dantong; Allan, James; Williams, Paul; Sekou, Keïta; Liousse, Catherine; Coe, Hugh

2017-04-01

Particulate emissions from biomass burning can alter the atmosphere's radiative balance and cause significant harm to human health. However, the relationship between these emissions and fundamental combustion processes is, to date, poorly characterised. In atmospheric models, aerosol emissions are represented by emission factors based on mass loss, which are averaged over an entire combustion event for each particulate species. This approach, however, masks huge variability in emissions during different phases of the combustion period. Laboratory tests have shown that even small changes to the burning environment can lead to huge variation in observed aerosol emission factors (Akagi et al., 2011). In order to address this gap in understanding, in this study, small wood samples sourced from Côte D'Ivoire were burned in a highly-controlled laboratory environment. The shape and mass of samples, available airflow and surrounding heat were carefully regulated. Organic aerosol and refractory black carbon emissions were measured in real-time using an Aerosol Mass Spectrometer and a Single Particle Soot Photometer, respectively. Both of these instruments are used regularly to measure aerosol concentrations in the field. This methodology produced remarkably repeatable results, allowing three different phases of combustion to be identified by their emissions. Black carbon was emitted predominantly during flaming combustion; organic aerosols were emitted during pyrolysis before ignition and from smouldering-dominated behaviour near the end of combustion. During the flaming period, there was a strong correlation between the emission of black carbon and the rate of mass loss, which suggests there is value in employing a mass-based emission factor for this species. However, very little correlation was seen between organic aerosol and mass loss throughout the tests. As such, results here suggest that emission factors averaged over an entire combustion event are unlikely to be

Infection prevention and control during prolonged human space travel.

PubMed

Mermel, Leonard A

2013-01-01

Prolonged human spaceflight to another planet or an asteroid will introduce unique challenges of mitigating the risk of infection. During space travel, exposure to microgravity, radiation, and stress alter human immunoregulatory responses, which can in turn impact an astronaut's ability to prevent acquisition of infectious agents or reactivation of latent infection. In addition, microgravity affects virulence, growth kinetics, and biofilm formation of potential microbial pathogens. These interactions occur in a confined space in microgravity, providing ample opportunity for heavy microbial contamination of the environment. In addition, there is the persistence of aerosolized, microbe-containing particles. Any mission involving prolonged human spaceflight must be carefully planned to minimize vulnerabilities and maximize the likelihood of success.

Economic evaluation of infection control activities.

PubMed

Seko, T; Tachi, T; Kawashima, N; Maeda, T; Yasuda, M; Noguchi, Y; Teramachi, H

2017-08-01

Healthcare-associated infections by drug-resistant bacteria affect a patient's prognosis. Infection control activities at medical institutions in Japan are increasingly focused on the threat from these bacteria. To undertake a full cost analysis that included the costs of consumables and labour required for infection control activities. The cost of infection control activities undertaken by the infection control team (ICT) at Nishimino Kosei Hospital in Japan was surveyed from January 2013 to December 2015. The evaluation index of infection control activities used the meticillin-resistant Staphylococcus aureus detection rate. The cost:effectiveness ratio (CER) of each intervention was calculated. Consumables and labour costs increased over time, as did the ratio of labour cost to total cost over time. However, the CER of interventions was found to have decreased, from ¥164,177 in 2014 to ¥57,989 in 2015. There were increases not only in the amount of consumables, but also in ICT time, suggesting the possibility of improvements in the economic efficiency of infection control. Increasing the amount of consumables and the time input of the ICT could help improve the economic efficiency of infection control. Our research suggests the possibility for improvements in the economic efficiency of infection control. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Infection control for norovirus

PubMed Central

Barclay, L.; Park, G. W.; Vega, E.; Hall, A.; Parashar, U.; Vinjé, J.; Lopman, B.

2015-01-01

Norovirus infections are notoriously difficult to prevent and control, owing to their low infectious dose, high shedding titre, and environmental stability. The virus can spread through multiple transmission routes, of which person-to-person and foodborne are the most important. Recent advances in molecular diagnostics have helped to establish norovirus as the most common cause of sporadic gastroenteritis and the most common cause of outbreaks of acute gastroenteritis across all ages. In this article, we review the epidemiology and virology of noroviruses, and prevention and control guidelines, with a focus on the principles of disinfection and decontamination. Outbreak management relies on sound infection control principles, including hand hygiene, limiting exposure to infectious individuals, and thorough environmental decontamination. Ideally, all infection control recommendations would rely on empirical evidence, but a number of challenges, including the inability to culture noroviruses in the laboratory and the challenges of outbreak management in complex environments, has made it difficult to garner clear evidence of efficacy in certain areas of infection control. New experimental data on cultivable surrogates for human norovirus and on environmental survivability and relative resistance to commonly used disinfectants are providing new insights for further refinining disinfection practices. Finally, clinical trials are underway to evaluate the efficacy of vaccines, which may shift the current infection control principles to more targeted interventions. PMID:24813073

Highly controlled, reproducible measurements of aerosol emissions from combustion of a common African biofuel source

NASA Astrophysics Data System (ADS)

Haslett, Sophie L.; Thomas, J. Chris; Morgan, William T.; Hadden, Rory; Liu, Dantong; Allan, James D.; Williams, Paul I.; Keita, Sekou; Liousse, Cathy; Coe, Hugh

2018-01-01

Particulate emissions from biomass burning can both alter the atmosphere's radiative balance and cause significant harm to human health. However, due to the large effect on emissions caused by even small alterations to the way in which a fuel burns, it is difficult to study particulate production of biomass combustion mechanistically and in a repeatable manner. In order to address this gap, in this study, small wood samples sourced from Côte D'Ivoire in West Africa were burned in a highly controlled laboratory environment. The shape and mass of samples, available airflow and surrounding thermal environment were carefully regulated. Organic aerosol and refractory black carbon emissions were measured in real time using an Aerosol Mass Spectrometer and a Single Particle Soot Photometer, respectively. This methodology produced remarkably repeatable results, allowing aerosol emissions to be mapped directly onto different phases of combustion. Emissions from pyrolysis were visible as a distinct phase before flaming was established. After flaming combustion was initiated, a black-carbon-dominant flame was observed during which very little organic aerosol was produced, followed by a period that was dominated by organic-carbon-producing smouldering combustion, despite the presence of residual flaming. During pyrolysis and smouldering, the two phases producing organic aerosol, distinct mass spectral signatures that correspond to previously reported variations in biofuel emissions measured in the atmosphere are found. Organic aerosol emission factors averaged over an entire combustion event were found to be representative of the time spent in the pyrolysis and smouldering phases, rather than reflecting a coupling between emissions and the mass loss of the sample. Further exploration of aerosol yields from similarly carefully controlled fires and a careful comparison with data from macroscopic fires and real-world emissions will help to deliver greater constraints on the

Air quality and ventilation fan control based on aerosol measurement in the bi-directional undersea Bømlafjord tunnel.

PubMed

Indrehus, Oddny; Aralt, Tor Tybring

2005-04-01

Aerosol, NO and CO concentration, temperature, air humidity, air flow and number of running ventilation fans were measured by continuous analysers every minute for a whole week for six different one-week periods spread over ten months in 2001 and 2002 at measuring stations in the 7860 m long tunnel. The ventilation control system was mainly based on aerosol measurements taken by optical scatter sensors. The ventilation turned out to be satisfactory according to Norwegian air quality standards for road tunnels; however, there was some uncertainty concerning the NO2 levels. The air humidity and temperature inside the tunnel were highly influenced by the outside metrological conditions. Statistical models for NO concentration were developed and tested; correlations between predicted and measured NO were 0.81 for a partial least squares regression (PLS1) model based on CO and aerosol, and 0.77 for a linear regression model based only on aerosol. Hence, the ventilation control system should not solely be based on aerosol measurements. Since NO2 is the hazardous polluter, modelling NO2 concentration rather than NO should be preferred in any further optimising of the ventilation control.

Ultra-low-volume ground aerosols of technical malathion for the control of Aedes aegypti L

PubMed Central

Pant, C. P.; Mount, G. A.; Jatanasen, Sujarti; Mathis, H. L.

1971-01-01

The efficacy of malathion aerosols applied from the ground was evaluated for the control of Ae. aegypti. Several techniques for applying the aerosols to an inhabited locality were investigated, and it was found that excellent control of adult mosquitos could be obtained with a dosage of 438 ml/ha. Two treatments carried out 3 days apart enabled the adult mosquito population to be reduced by 99%, and it took about 2 weeks to regain its pretreatment level. Schedules of treatment and strategies to be applied during an epidemic are discussed. PMID:5317014

Propagation of Respiratory Aerosols by the Vuvuzela

PubMed Central

Lai, Ka-Man; Bottomley, Christian; McNerney, Ruth

2011-01-01

Vuvuzelas, the plastic blowing horns used by sports fans, recently achieved international recognition during the FIFA World Cup soccer tournament in South Africa. We hypothesised that vuvuzelas might facilitate the generation and dissemination of respiratory aerosols. To investigate the quantity and size of aerosols emitted when the instrument is played, eight healthy volunteers were asked to blow a vuvuzela. For each individual the concentration of particles in expelled air was measured using a six channel laser particle counter and the duration of blowing and velocity of air leaving the vuvuzela were recorded. To allow comparison with other activities undertaken at sports events each individual was also asked to shout and the measurements were repeated while using a paper cone to confine the exhaled air. Triplicate measurements were taken for each individual. The mean peak particle counts were 658×103 per litre for the vuvuzela and 3.7×103 per litre for shouting, representing a mean log10 difference of 2.20 (95% CI: 2.03,2.36; p<0.001). The majority (>97%) of particles captured from either the vuvuzela or shouting were between 0.5 and 5 microns in diameter. Mean peak airflows recorded for the vuvuzela and shouting were 6.1 and 1.8 litres per second respectively. We conclude that plastic blowing horns (vuvuzelas) have the capacity to propel extremely large numbers of aerosols into the atmosphere of a size able to penetrate the lower lung. Some respiratory pathogens are spread via contaminated aerosols emitted by infected persons. Further investigation is required to assess the potential of the vuvuzela to contribute to the transmission of aerosol borne diseases. We recommend, as a precautionary measure, that people with respiratory infections should be advised not to blow their vuvuzela in enclosed spaces and where there is a risk of infecting others. PMID:21629778

42 CFR 460.74 - Infection control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... at least the standard precautions developed by the Centers for Disease Control and Prevention. (b...) Prevents and controls the transmission of disease and infection. (c) Contents of infection control plan... identify, investigate, control, and prevent infections in every Pace center and in each participant's place...

Infection prevention and control.

PubMed

Pegram, Anne; Bloomfield, Jacqueline

2015-03-18

All newly registered graduate nurses are required to have the appropriate knowledge and understanding to perform the skills required for patient care, specifically the competencies identified in the Nursing and Midwifery Council's essential skills clusters. This article focuses on the third essential skills cluster - infection prevention and control. It provides an overview and discussion of the key skills and behaviours that must be demonstrated to meet the standards set by the Nursing and Midwifery Council. In doing so, it considers the key principles of infection prevention and control, including local and national policies, standard infection control precautions, risk assessment, standard isolation measures and asepsis.

Significance of aerosol radiative effect in energy balance control on global precipitation change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Kentaroh; Stephens, Graeme L.; Golaz, Jean-Christophe

Historical changes of global precipitation in the 20th century simulated by a climate model are investigated. The results simulated with alternate configurations of cloud microphysics are analyzed in the context of energy balance controls on global precipitation, where the latent heat changes associated with the precipitation change is nearly balanced with changes to atmospheric radiative cooling. The atmospheric radiative cooling is dominated by its clear-sky component, which is found to correlate with changes to both column water vapor and aerosol optical depth (AOD). The water vapor-dependent component of the clear-sky radiative cooling is then found to scale with global temperaturemore » change through the Clausius–Clapeyron relationship. This component results in a tendency of global precipitation increase with increasing temperature at a rate of approximately 2%K -1. Another component of the clear-sky radiative cooling, which is well correlated with changes to AOD, is also found to vary in magnitude among different scenarios with alternate configurations of cloud microphysics that controls the precipitation efficiency, a major factor influencing the aerosol scavenging process that can lead to different aerosol loadings. These results propose how different characteristics of cloud microphysics can cause different aerosol loadings that in turn perturb global energy balance to significantly change global precipitation. This implies a possible coupling of aerosol–cloud interaction with aerosol–radiation interaction in the context of global energy balance.« less

Significance of aerosol radiative effect in energy balance control on global precipitation change

DOE PAGES

Suzuki, Kentaroh; Stephens, Graeme L.; Golaz, Jean-Christophe

2017-10-17

Historical changes of global precipitation in the 20th century simulated by a climate model are investigated. The results simulated with alternate configurations of cloud microphysics are analyzed in the context of energy balance controls on global precipitation, where the latent heat changes associated with the precipitation change is nearly balanced with changes to atmospheric radiative cooling. The atmospheric radiative cooling is dominated by its clear-sky component, which is found to correlate with changes to both column water vapor and aerosol optical depth (AOD). The water vapor-dependent component of the clear-sky radiative cooling is then found to scale with global temperaturemore » change through the Clausius–Clapeyron relationship. This component results in a tendency of global precipitation increase with increasing temperature at a rate of approximately 2%K -1. Another component of the clear-sky radiative cooling, which is well correlated with changes to AOD, is also found to vary in magnitude among different scenarios with alternate configurations of cloud microphysics that controls the precipitation efficiency, a major factor influencing the aerosol scavenging process that can lead to different aerosol loadings. These results propose how different characteristics of cloud microphysics can cause different aerosol loadings that in turn perturb global energy balance to significantly change global precipitation. This implies a possible coupling of aerosol–cloud interaction with aerosol–radiation interaction in the context of global energy balance.« less

The aerosol rabbit model of TB latency, reactivation and immune reconstitution inflammatory syndrome

PubMed Central

Manabe, Yukari C.; Kesavan, Anup K.; Lopez-Molina, Javier; Hatem, Christine L.; Brooks, Megan; Fujiwara, Ricardo; Hochstein, Karl; Pitt, M. Louise M.; Tufariello, JoAnn; Chan, John; McMurray, David N.; Bishai, William R.; Dannenberg, Arthur M.; Mendez, Susana

2015-01-01

The large reservoir of human latent tuberculosis (TB) contributes to the global success of the pathogen, Mycobacterium tuberculosis (Mtb). We sought to test whether aerosol infection of rabbits with Mtb H37Rv could model paucibacillary human latent TB. The lung burden of infection peaked at 5 weeks after aerosol infection followed by host containment of infection that was achieved in all rabbits. One-third of rabbits had at least one caseous granuloma with culturable bacilli at 36 weeks after infection suggesting persistent paucibacillary infection. Corticosteroid-induced immunosuppression initiated after disease containment resulted in reactivation of disease. Seventy-two percent of rabbits had culturable bacilli in the right upper lung lobe homogenates compared to none of the untreated controls. Discontinuation of dexamethasone led to predictable lymphoid recovery, with a proportion of rabbits developing multicentric large caseous granuloma. The development and severity of the immune reconstitution inflammatory syndrome (IRIS) was dependent on the antigen load at the time of immunosuppression and subsequent bacillary replication during corticosteroid-induced immunosuppression. Clinically, many aspects were similar to IRIS in severely immunosuppressed HIV-infected patients who have functional restoration of T cells in response to effective (highly active) antiretroviral therapy. This corticosteroid model is the only animal model of the IRIS. Further study of the rabbit model of TB latency, reactivation and IRIS may be important in understanding the immunopathogenesis of these poorly modeled states as well as for improved diagnostics for specific stages of disease. PMID:18068491

Low dose aerosol fitness at the innate phase of murine infection better predicts virulence amongst clinical strains of Mycobacterium tuberculosis.

PubMed

Caceres, Neus; Llopis, Isaac; Marzo, Elena; Prats, Clara; Vilaplana, Cristina; de Viedma, Dario Garcia; Samper, Sofía; Lopez, Daniel; Cardona, Pere-Joan

2012-01-01

Evaluation of a quick and easy model to determine the intrinsic ability of clinical strains to generate active TB has been set by assuming that this is linked to the fitness of Mycobacterium tuberculosis strain at the innate phase of the infection. Thus, the higher the bacillary load, the greater the possibility of inducting liquefaction, and thus active TB, once the adaptive response is set. The virulence of seven clinical Mycobacterium tuberculosis strains isolated in Spain was tested by determining the bacillary concentration in the spleen and lung of mice at weeks 0, 1 and 2 after intravenous (IV) inoculation of 10⁴ CFU, and by determining the growth in vitro until the stationary phase had been reached. Cord distribution automated analysis showed two clear patterns related to the high and low fitness in the lung after IV infection. This pattern was not seen in the in vitro fitness tests, which clearly favored the reference strain (H37Rv). Subsequent determination using a more physiological low-dose aerosol (AER) inoculation with 10² CFU showed a third pattern in which the three best values coincided with the highest dissemination capacity according to epidemiological data. The fitness obtained after low dose aerosol administration in the presence of the innate immune response is the most predictive factor for determining the virulence of clinical strains. This gives support to a mechanism of the induction of active TB derived from the dynamic hypothesis of latent tuberculosis infection.

Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei.

PubMed

Zimmerman, Shawn M; Dyke, Jeremy S; Jelesijevic, Tomislav P; Michel, Frank; Lafontaine, Eric R; Hogan, Robert J

2017-08-01

Burkholderia mallei , a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo , elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei , including antigen discovery. Copyright © 2017 American Society for Microbiology.

Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei

PubMed Central

Zimmerman, Shawn M.; Dyke, Jeremy S.; Jelesijevic, Tomislav P.; Michel, Frank; Lafontaine, Eric R.

2017-01-01

ABSTRACT Burkholderia mallei, a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo, elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei. Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo. Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei, including antigen discovery. PMID:28507073

Veterinary infection control in Australia: is there control?

PubMed

Attard, K; Burrows, E; Kotiranta-Harris, K; Hedlefs, R; Ketheesan, N; Govan, B

2012-11-01

There is little information relating to infection control procedures in Australian veterinary practices. This review summarises the findings of international studies in the area of zoonoses and infection control, and discusses potential reasons for the apparent complacency about these issues in veterinary practice. It is the authors' opinion that legislative changes governing veterinary practice in Australia should be implemented. The curricula in veterinary schools should also emphasise infection control. These measures would significantly improve safety issues associated with the control of zoonoses in veterinary practice. © 2012 The Authors. Australian Veterinary Journal © 2012 Australian Veterinary Association.

42 CFR 460.74 - Infection control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Infection control. 460.74 Section 460.74 Public...) PACE Administrative Requirements § 460.74 Infection control. (a) Standard procedures. The PACE organization must follow accepted policies and standard procedures with respect to infection control, including...

42 CFR 460.74 - Infection control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 4 2014-10-01 2014-10-01 false Infection control. 460.74 Section 460.74 Public...) PACE Administrative Requirements § 460.74 Infection control. (a) Standard procedures. The PACE organization must follow accepted policies and standard procedures with respect to infection control, including...

42 CFR 460.74 - Infection control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 4 2012-10-01 2012-10-01 false Infection control. 460.74 Section 460.74 Public...) PACE Administrative Requirements § 460.74 Infection control. (a) Standard procedures. The PACE organization must follow accepted policies and standard procedures with respect to infection control, including...

Fact or Infection: Do Surgical Trainees Know Enough About Infection Control?

PubMed Central

Brady, RRW; McDermott, C; Gibb, AP; Paterson-Brown, S

2008-01-01

INTRODUCTION There exists a high level of non-compliance with basic infection control measures by medical staff. One explanation may be a lack of familiarity with contemporary infection control guidelines. As surgical trainees represent a key group of stakeholders responsible for the delivery of recommended infection control practice, we assessed knowledge of infection control guidelines amongst current UK surgical trainees. MATERIALS AND METHODS Without warning, during the annual meeting of the UK Association of Surgeons in Training (ASiT), participating surgical trainees were asked to complete a questionnaire examining their basic knowledge of infection control and methicillin-resistant Staphylococcus aureus (MRSA) based on recently published guidelines. RESULTS A total of 52 trainees (13 higher surgical trainees [HSTs]; 39 basic surgical trainees [BSTs]) returned completed questionnaires in the study. BSTs demonstrated a higher level of knowledge of infection control, outperforming the HSTs in 7 out of 11 questions. Of surgical trainees, 61.5% were misinformed regarding the prevalence of MRSA blood-stream infections and 69% were unaware of policies for transfer of MRSA-positive patients. Analysis revealed areas of concern in regards to an adequate general level of knowledge of infection control in surgical trainees, particularly in some key areas. CONCLUSIONS To ensure patient safety and reduce hospital-acquired infections, it is vital that focused, co-ordinated programmes of education, in this rapidly changing field, are prioritised and formalised into surgical training, selection and assessment. PMID:18990279

Susceptibility of Monkeypox virus aerosol suspensions in a rotating chamber

PubMed Central

Verreault, Daniel; Killeen, Stephanie Z.; Redmann, Rachel K.; Roy, Chad. J.

2012-01-01

Summary Viral aerosols can have a major impact on public health and on the dynamics of infection. Once aerosolized, viruses are subjected to various stress factors and their integrity and potential of infectivity can be altered. Empirical characterization is needed in order to predict more accurately the fate of these bioaerosols both for short term and long term suspension in the air. Here the susceptibility to aerosolization of the monkeypox virus (MPXV), associated with emerging zoonotic diseases, was studied using a 10.7 liter rotating chamber. This chamber was built to fit inside a Class three biological safety cabinet, specifically for studying airborne biosafety level three (BSL3) microorganisms. Airborne viruses were detected by culture and quantitative polymerase chain reaction (qPCR) after up to 90 hours of aging. Viral concentrations detected dropped by two logs for culture analysis and by one log for qPCR analysis within the first 18 hours of aging; viral concentrations were stable between 18 and 90 hours, suggesting a potential for the MPXV to retain infectivity in aerosols for more than 90 hours. The rotating chamber used in this study maintained viral particles airborne successfully for prolonged periods and could be used to study the susceptibility of other BSL3 microorganisms. PMID:23142251

DETECTION OF AEROSOLIZED BACTERIA IN EXPIRED AIR SAMPLES FROM ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

PubMed

Burke, Sophie M; Vogelnest, Larry; Thompson, Paul; Tovey, Euan R; Williamson, Peter

2017-06-01

Elephant-mediated transmission of tuberculosis is assumed to be similar to human models, which state close and prolonged contact with an infected individual is required for transmission. Although considered a risk factor for infection, several case studies have reported that close contact with an elephant is not always necessary for transmission, and the role of aerosolized bacteria remains unclear. To investigate aerosol-mediated transmission of pathogenic bacteria from elephants, a method for the detection of aerosols using an adapted sampling system was developed. A commensal bacterium was isolated from the upper respiratory tract of elephants ( Elephas maximus ) and was used as a proxy organism to detect aerosolized droplets in the sampling system. It was found that elephants are capable of producing aerosolized bacterial particles of a size small enough to remain airborne for prolonged periods and penetrate the lower regions of the human respiratory tract.

38 CFR 51.190 - Infection control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Infection control. 51.190... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.190 Infection control. The facility management must establish and maintain an infection control program designed to provide a safe, sanitary, and...

38 CFR 51.190 - Infection control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Infection control. 51.190... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.190 Infection control. The facility management must establish and maintain an infection control program designed to provide a safe, sanitary, and...

38 CFR 51.190 - Infection control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Infection control. 51.190... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.190 Infection control. The facility management must establish and maintain an infection control program designed to provide a safe, sanitary, and...

42 CFR 483.65 - Infection control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 5 2013-10-01 2013-10-01 false Infection control. 483.65 Section 483.65 Public... Care Facilities § 483.65 Infection control. The facility must establish and maintain an infection control program designed to provide a safe, sanitary, and comfortable environment and to help prevent the...

38 CFR 51.190 - Infection control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Infection control. 51.190... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.190 Infection control. The facility management must establish and maintain an infection control program designed to provide a safe, sanitary, and...

38 CFR 52.190 - Infection control.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Infection control. 52.190... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.190 Infection control. The program management must establish and maintain an infection control program designed to prevent the development and...

42 CFR 483.65 - Infection control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Infection control. 483.65 Section 483.65 Public... Care Facilities § 483.65 Infection control. The facility must establish and maintain an infection control program designed to provide a safe, sanitary, and comfortable environment and to help prevent the...

38 CFR 52.190 - Infection control.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Infection control. 52.190... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.190 Infection control. The program management must establish and maintain an infection control program designed to prevent the development and...

42 CFR 483.65 - Infection control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 5 2014-10-01 2014-10-01 false Infection control. 483.65 Section 483.65 Public... Care Facilities § 483.65 Infection control. The facility must establish and maintain an infection control program designed to provide a safe, sanitary, and comfortable environment and to help prevent the...

38 CFR 52.190 - Infection control.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Infection control. 52.190... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.190 Infection control. The program management must establish and maintain an infection control program designed to prevent the development and...

38 CFR 51.190 - Infection control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Infection control. 51.190... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.190 Infection control. The facility management must establish and maintain an infection control program designed to provide a safe, sanitary, and...

38 CFR 52.190 - Infection control.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Infection control. 52.190... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.190 Infection control. The program management must establish and maintain an infection control program designed to prevent the development and...

38 CFR 52.190 - Infection control.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Infection control. 52.190... FOR ADULT DAY HEALTH CARE OF VETERANS IN STATE HOMES Standards § 52.190 Infection control. The program management must establish and maintain an infection control program designed to prevent the development and...

Treatment based on the type of infected TKA improves infection control.

PubMed

Kim, Young-Hoo; Choi, Yoowang; Kim, Jun-Shik

2011-04-01

A classification system with four types of infected TKAs has been commonly used to determine treatment, especially with regard to whether the prosthesis should be removed or retained. We asked whether (1) the classification-dictated treatment of the four types of infection after TKA would control infection and maintain functional TKA; (2) repeated débridement and two-stage TKA would further improve the infection control rate after initial treatment; and (3) fixation of TKA prosthesis to the host bone was achieved. We retrospectively reviewed 114 patients with 116 infected TKAs. We determined the infection control rate after initial treatment, repeated débridement and two-stage TKA. We evaluated the functional and radiographic results using the Knee Society and Hospital for Special Surgery knee scoring systems. The minimum followup was 2 years (mean, 5.6 years; range, 2-8 years). The overall infection control rate was 100% in all patients. All patients with early superficial postoperative infection, 94% of patients with early deep postoperative infection, 96% of patients with late chronic infection, and 86% of patients with acute hematogenous infection maintained functioning knee prosthesis at the final followup. One hundred nine of the 114 patients could walk with no or only slight pain and maintained functioning knee prostheses. These 109 patients had stable fixation of the TKA prosthesis to host bone. The techniques proposed by the classification effectively controlled infection and maintained functional TKA with firm fixation of the TKA prosthesis in most patients. Repeated débridement and two-stage TKA further improved the control of infection and functional TKA after initial treatment. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Tropospheric Aerosols

NASA Astrophysics Data System (ADS)

Buseck, P. R.; Schwartz, S. E.

2003-12-01

anthropogenic aerosols are thought to be of comparable magnitude to the positive forcings resulting from incremental concentrations of greenhouse gases.The magnitudes and estimated uncertainties of the several forcings over the industrial period are summarized in Figure 2, which was prepared as part of the recent assessment of climate change by the Intergovernmental Panel on Climate Change (IPCC, 2001). This figure shows for each forcing a best estimate of its magnitude and of the associated uncertainty. The uncertainty associated with forcing by the long-lived greenhouse gases is relatively small, reflective of the rather high level of understanding of both the magnitude of the incremental concentrations of these species and of the radiative perturbation per incremental concentration. In marked contrast, the uncertainties associated with the several aerosol forcings are much greater, indicative of a much lesser understanding of the controlling quantities. For direct forcing by dust aerosols, which may be positive or negative, and for indirect radiative forcing by anthropogenic aerosols the IPCC working groups ( Penner et al., 2001; Ramaswamy et al., 2001) declined to present best estimates but indicated only possible ranges. This situation is unsatisfying but unavoidable, given the current state of knowledge. Other reviews of aerosol forcings are provided by Ramanathan et al. (2001a), Haywood and Boucher (2000), Shine and Forster (1999), Schwartz (1996), and Schwartz and Slingo (1996). Hobbs (1993) provides an introduction to aerosol-cloud interactions. (9K)Figure 2. The effects of various anthropogenic constituents of the atmosphere on the global climate system for the year 2000 relative to 1750 as estimated by the Intergovernmental Panel on Climate Change (IPCC, 2001). The effects are expressed as forcings, which in this case are changes in global mean radiative flux components arising from the indicated perturbing influence. Best estimates are indicated by the bars and

Should Aerosolized Antibiotics Be Used to Treat Ventilator-Associated Pneumonia?

PubMed

Zhang, Changsheng; Berra, Lorenzo; Klompas, Michael

2016-06-01

In patients with ventilator-associated pneumonia, systemic use of antibiotics is the cornerstone of medical management. Supplemental use of aerosolized antibiotics with intravenous antibiotics in both experimental and clinical studies has been shown to have the following pharmacologic benefits: (1) aerosolized antibiotics reach the infected lung parenchyma without crossing the pulmonary alveolar capillary barrier; (2) aerosolized antibiotics increase anti-bacterial efficacy through increased local antibiotic concentration; and (3) aerosolized antibiotics decrease systemic toxicity. These benefits may be particularly beneficial to treat pneumonia caused by multidrug-resistant pathogens. Clinical data on the benefits of aerosolized antibiotics are more limited. Studies to date have not clearly shown improvements in time to extubation, mortality, or other patient-centered outcomes. At present, amikacin, colistin, and ceftazidime are the most frequently used and studied aerosolized antibiotics. This review summarizes the characteristics of aerosolized antibiotics, reviews the advantages and disadvantages of using aerosolized antibiotics, and calls for future investigations based on animal study data. Copyright © 2016 by Daedalus Enterprises.

Sequence of pathogenic events in cynomolgus macaques infected with aerosolized monkeypox virus.

PubMed

Tree, J A; Hall, G; Pearson, G; Rayner, E; Graham, V A; Steeds, K; Bewley, K R; Hatch, G J; Dennis, M; Taylor, I; Roberts, A D; Funnell, S G P; Vipond, J

2015-04-01

To evaluate new vaccines when human efficacy studies are not possible, the FDA's "Animal Rule" requires well-characterized models of infection. Thus, in the present study, the early pathogenic events of monkeypox infection in nonhuman primates, a surrogate for variola virus infection, were characterized. Cynomolgus macaques were exposed to aerosolized monkeypox virus (10(5) PFU). Clinical observations, viral loads, immune responses, and pathological changes were examined on days 2, 4, 6, 8, 10, and 12 postchallenge. Viral DNA (vDNA) was detected in the lungs on day 2 postchallenge, and viral antigen was detected, by immunostaining, in the epithelium of bronchi, bronchioles, and alveolar walls. Lesions comprised rare foci of dysplastic and sloughed cells in respiratory bronchioles. By day 4, vDNA was detected in the throat, tonsil, and spleen, and monkeypox antigen was detected in the lung, hilar and submandibular lymph nodes, spleen, and colon. Lung lesions comprised focal epithelial necrosis and inflammation. Body temperature peaked on day 6, pox lesions appeared on the skin, and lesions, with positive immunostaining, were present in the lung, tonsil, spleen, lymph nodes, and colon. By day 8, vDNA was present in 9/13 tissues. Blood concentrations of interleukin 1ra (IL-1ra), IL-6, and gamma interferon (IFN-γ) increased markedly. By day 10, circulating IgG antibody concentrations increased, and on day 12, animals showed early signs of recovery. These results define early events occurring in an inhalational macaque monkeypox infection model, supporting its use as a surrogate model for human smallpox. Bioterrorism poses a major threat to public health, as the deliberate release of infectious agents, such smallpox or a related virus, monkeypox, would have catastrophic consequences. The development and testing of new medical countermeasures, e.g., vaccines, are thus priorities; however, tests for efficacy in humans cannot be performed because it would be unethical and

Sequence of Pathogenic Events in Cynomolgus Macaques Infected with Aerosolized Monkeypox Virus

PubMed Central

Hall, G.; Pearson, G.; Rayner, E.; Graham, V. A.; Steeds, K.; Bewley, K. R.; Hatch, G. J.; Dennis, M.; Taylor, I.; Roberts, A. D.; Funnell, S. G. P.; Vipond, J.

2015-01-01

ABSTRACT To evaluate new vaccines when human efficacy studies are not possible, the FDA's “Animal Rule” requires well-characterized models of infection. Thus, in the present study, the early pathogenic events of monkeypox infection in nonhuman primates, a surrogate for variola virus infection, were characterized. Cynomolgus macaques were exposed to aerosolized monkeypox virus (105 PFU). Clinical observations, viral loads, immune responses, and pathological changes were examined on days 2, 4, 6, 8, 10, and 12 postchallenge. Viral DNA (vDNA) was detected in the lungs on day 2 postchallenge, and viral antigen was detected, by immunostaining, in the epithelium of bronchi, bronchioles, and alveolar walls. Lesions comprised rare foci of dysplastic and sloughed cells in respiratory bronchioles. By day 4, vDNA was detected in the throat, tonsil, and spleen, and monkeypox antigen was detected in the lung, hilar and submandibular lymph nodes, spleen, and colon. Lung lesions comprised focal epithelial necrosis and inflammation. Body temperature peaked on day 6, pox lesions appeared on the skin, and lesions, with positive immunostaining, were present in the lung, tonsil, spleen, lymph nodes, and colon. By day 8, vDNA was present in 9/13 tissues. Blood concentrations of interleukin 1ra (IL-1ra), IL-6, and gamma interferon (IFN-γ) increased markedly. By day 10, circulating IgG antibody concentrations increased, and on day 12, animals showed early signs of recovery. These results define early events occurring in an inhalational macaque monkeypox infection model, supporting its use as a surrogate model for human smallpox. IMPORTANCE Bioterrorism poses a major threat to public health, as the deliberate release of infectious agents, such smallpox or a related virus, monkeypox, would have catastrophic consequences. The development and testing of new medical countermeasures, e.g., vaccines, are thus priorities; however, tests for efficacy in humans cannot be performed because it

Preventing infections in nursing homes: A survey of infection control practices in southeast Michigan

PubMed Central

Mody, Lona; Langa, Kenneth M.; Saint, Sanjay; Bradley, Suzanne F.

2012-01-01

Background Studies on adherence to infection control policies in nursing homes (NHs) are limited. This pilot study explores the use of various infection control practices and the role of infection control practitioners in southeast Michigan NHs. Methods A 43-item self-administered questionnaire and explanatory cover letter were mailed to 105 licensed NHs in southeast Michigan. A second mailing was sent to the nonresponders 4 weeks later. Results Significant variability existed in adoption of various infection control measures with respect to time spent in infection control activities (50% of facilities having a full-time infection control practitioner), definitions used in monitoring infections, and immunization rates (influenza: range, 0%–100%; mean, 73.2%; pneumococcal: range, 0%–100%; mean, 38.5%). Conclusion Although strides have been made in infection control research in NHs, significant variations exist in implementation of infection control methods and guidelines. Future research should focus on identifying barriers to infection control in NHs. PMID:16216667

Aerosol Properties under Air Quality Control Measures of APEC 2014 in Beijing

NASA Astrophysics Data System (ADS)

Chen, X.; Xu, H.; Lv, Y.; Xie, Y.; Li, K.; Li, Z.; Li, D.; Ma, Y.; Mei, X.

2015-12-01

Because the economic and society were developing fast in the middle of last century, Los Angeles and London both were polluted by photochemical smog, which massacred thousands of people. Now, many regions are often covered by heavy haze in those large developing countries, especially in China and India. The Asia-Pacific Economic Cooperation (APEC) was held in Beijing during 5-11 November 2014. Beijing, Hebei, Tianjin, Shandong, Shanxi, Inner Mongolia reduced air pollution emissions for the APEC 2014 meeting held in Beijing. Only in Hebei province, there were 1028 factories stopped or restricted and 881 construction sites stopped. Half of the cars were prohibited driving even in the Zibo city which is 400 km far from Beijing. For scientific aims, these control measures were indeed a huge and uncommon atmospheric experiment led by the government. During the experiment, what did the "APEC Blue" mean? We analyzed aerosol properties with the data of an AERONET site in Beijing which is located 500m far from the main reception hall of APEC 2014. The Cimel solar photometers can give a series parameters of aerosol and water vapor. In this paper, we used CE318 solar photometer which is the main instrument of NASA AERONET. The CE318 of RADI belongs to the Chinese SONET (Sun-sky radiometer Observation NETwork) too. We analyzed the total, coarse and fine Aerosol Optical Depth (AOD), Fine-Mode Fraction (FMF) and Ångström exponent, Size Distribution and Real Refractive Index. In conclusion, the aerosol properties were analysed with the measurements of a sun photometer. During the APEC 2014, AOD decreased obviously with a 0.27 mean value compared with the annual mean 0.7. Around Beijing, the southern is polluted emission area including the cross part of Shandong, Shanxi, Hebei, Henan four provinces, and the northern is clean for less fine mode particles emission in the large Inner Mongolia province. In fact, during the APEC 2014, the weather condition was not good for the

Infection control in design and construction work.

PubMed

Collinge, William H

2015-01-01

To clarify how infection control requirements are represented, communicated, and understood in work interactions through the medical facility construction project life cycle. To assist project participants with effective infection control management by highlighting the nature of such requirements and presenting recommendations to aid practice. A 4-year study regarding client requirement representation and use on National Health Service construction projects in the United Kingdom provided empirical evidence of infection control requirement communication and understanding through design and construction work interactions. An analysis of construction project resources (e.g., infection control regulations and room data sheets) was combined with semi-structured interviews with hospital client employees and design and construction professionals to provide valuable insights into the management of infection control issues. Infection control requirements are representationally indistinct but also omnipresent through all phases of the construction project life cycle: Failure to recognize their nature, relevance, and significance can result in delays, stoppages, and redesign work. Construction project resources (e.g., regulatory guidance and room data sheets) can mask or obscure the meaning of infection control issues. A preemptive identification of issues combined with knowledge sharing activities among project stakeholders can enable infection control requirements to be properly understood and addressed. Such initiatives should also reference existing infection control regulatory guidance and advice. © The Author(s) 2015.

Low Dose Aerosol Fitness at the Innate Phase of Murine Infection Better Predicts Virulence amongst Clinical Strains of Mycobacterium tuberculosis

PubMed Central

Caceres, Neus; Llopis, Isaac; Marzo, Elena; Prats, Clara; Vilaplana, Cristina; de Viedma, Dario Garcia; Samper, Sofía; Lopez, Daniel; Cardona, Pere-Joan

2012-01-01

Background Evaluation of a quick and easy model to determine the intrinsic ability of clinical strains to generate active TB has been set by assuming that this is linked to the fitness of Mycobacterium tuberculosis strain at the innate phase of the infection. Thus, the higher the bacillary load, the greater the possibility of inducting liquefaction, and thus active TB, once the adaptive response is set. Methodology/Principal Findings The virulence of seven clinical Mycobacterium tuberculosis strains isolated in Spain was tested by determining the bacillary concentration in the spleen and lung of mice at weeks 0, 1 and 2 after intravenous (IV) inoculation of 104 CFU, and by determining the growth in vitro until the stationary phase had been reached. Cord distribution automated analysis showed two clear patterns related to the high and low fitness in the lung after IV infection. This pattern was not seen in the in vitro fitness tests, which clearly favored the reference strain (H37Rv). Subsequent determination using a more physiological low-dose aerosol (AER) inoculation with 102 CFU showed a third pattern in which the three best values coincided with the highest dissemination capacity according to epidemiological data. Conclusions/Significance The fitness obtained after low dose aerosol administration in the presence of the innate immune response is the most predictive factor for determining the virulence of clinical strains. This gives support to a mechanism of the induction of active TB derived from the dynamic hypothesis of latent tuberculosis infection. PMID:22235258

Experimental aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs.

PubMed

Twenhafel, N A; Shaia, C I; Bunton, T E; Shamblin, J D; Wollen, S E; Pitt, L M; Sizemore, D R; Ogg, M M; Johnston, S C

2015-01-01

Eight guinea pigs were aerosolized with guinea pig-adapted Zaire ebolavirus (variant: Mayinga) and developed lethal interstitial pneumonia that was distinct from lesions described in guinea pigs challenged subcutaneously, nonhuman primates challenged by the aerosol route, and natural infection in humans. Guinea pigs succumbed with significant pathologic changes primarily restricted to the lungs. Intracytoplasmic inclusion bodies were observed in many alveolar macrophages. Perivasculitis was noted within the lungs. These changes are unlike those of documented subcutaneously challenged guinea pigs and aerosolized filoviral infections in nonhuman primates and human cases. Similar to findings in subcutaneously challenged guinea pigs, there were only mild lesions in the liver and spleen. To our knowledge, this is the first report of aerosol challenge of guinea pigs with guinea pig-adapted Zaire ebolavirus (variant: Mayinga). Before choosing this model for use in aerosolized ebolavirus studies, scientists and pathologists should be aware that aerosolized guinea pig-adapted Zaire ebolavirus (variant: Mayinga) causes lethal pneumonia in guinea pigs. © The Author(s) 2014.

42 CFR 483.65 - Infection control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... development and transmission of disease and infection. (a) Infection control program. The facility must... 42 Public Health 5 2011-10-01 2011-10-01 false Infection control. 483.65 Section 483.65 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

42 CFR 483.65 - Infection control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... development and transmission of disease and infection. (a) Infection control program. The facility must... 42 Public Health 5 2012-10-01 2012-10-01 false Infection control. 483.65 Section 483.65 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

Management of infection control in dental practice.

PubMed

Smith, A; Creanor, S; Hurrell, D; Bagg, J; McCowan, M

2009-04-01

This was an observational study in which the management policies and procedures associated with infection control and instrument decontamination were examined in 179 dental surgeries by a team of trained surveyors. Information relating to the management of a wide range of infection control procedures, in particular the decontamination of dental instruments, was collected by interview and by examination of practice documentation. This study found that although the majority of surgeries (70%) claimed to have a management policy on infection control, only 50% of these were documented. For infection control policies, 79% of surgeries had access to the British Dental Association Advice Sheet A12. Infection control policies were claimed to be present in 89% of surgeries, of which 62% were documented. Seventy-seven per cent of staff claimed to have received specific infection control training, but for instrument decontamination this was provided mainly by demonstration (97%) or observed practice (88%). Many dental nurses (74%) and dental practitioners (57%) did not recognise the symbol used to designate a single-use device. Audit of infection control or decontamination activities was undertaken in 11% of surgeries. The majority of surgeries have policies and procedures for the management of infection control in dental practice, but in many instances these are not documented. The training of staff in infection control and its documentation is poorly managed and consideration should be given to development of quality management systems for use in dental practice.

Climate forcing by anthropogenic aerosols

NASA Technical Reports Server (NTRS)

Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

1992-01-01

Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol, in particular, has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

Climate forcing by anthropogenic aerosols.

PubMed

Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J

1992-01-24

Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

Stratospheric aerosols and climatic change

NASA Technical Reports Server (NTRS)

Toon, O. B.; Pollack, J. B.

1978-01-01

Stratospht1ic sulfuric acid particles scatter and absorb sunlight and they scatter, absorb and emit terrestrial thermal radiation. These interactions play a role in the earth's radiation balance and therefore affect climate. The stratospheric aerosols are perturbed by volcanic injection of SO2 and ash, by aircraft injection of SO2, by rocket exhaust of Al2O3 and by tropospheric mixing of particles and pollutant SO2 and COS. In order to assess the effects of these perturbations on climate, the effects of the aerosols on the radiation balance must be understood and in order to understand the radiation effects the properties of the aerosols must be known. The discussion covers the aerosols' effect on the radiation balance. It is shown that the aerosol size distribution controls whether the aerosols will tend to warm or cool the earth's surface. Calculations of aerosol properties, including size distribution, for various perturbation sources are carried out on the basis of an aerosol model. Calculations are also presented of the climatic impact of perturbed aerosols due to volcanic eruptions and Space Shuttle flights.

INFECTION CONTROL IN ALTERNATIVE HEALTHCARE SETTINGS

PubMed Central

Flanagan, Elaine; Chopra, Teena; Mody, Lona

2011-01-01

SYNOPSIS With the changing healthcare delivery, patients receive care at various settings including acute care hospitals, skilled nursing facilities, outpatient primary care and specialty clinics, as well as at home, exposing them to pathogens in various settings. Various healthcare settings face unique challenges requiring individualized infection control programs. Infection control programs in skilled nursing facilities should address: surveillance for infections and antimicrobial resistance, outbreak investigation and control plan for epidemics, isolation precautions, hand hygiene, staff education, and employee and resident health programs. Infection control programs in ambulatory clinics should address: Triage and standard – transmission based precautions, cleaning, disinfection and sterilization principles, surveillance in surgical clinics, safe injection practices, and bioterrorism and disaster planning for ambulatory clinics. PMID:21316005

Improving infection control in general practice.

PubMed

Farrow, S C; Zeuner, D; Hall, C

1999-03-01

Infection control measures in the health care setting should protect patients and staff from cross-infection. The prevention of harm is an essential part of good medical practice and failure might result in professional misconduct proceedings by the General Medical Council (GMC) and prosecution under the Health and Safety at Work legislation, as well as civil liability. For a health authority, overall responsibility for public health includes arrangements for the control of communicable diseases and infection in hospital and the community (NHS Management Executive, 1993), a function usually led by the Consultant in Communicable Disease Control (CCDC). This paper describes one district's collaborative approach between public health and GPs to assess and improve local infection control standards.

Distinguishing the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks in ;APEC Blue;

NASA Astrophysics Data System (ADS)

Gao, Meng; Liu, Zirui; Wang, Yuesi; Lu, Xiao; Ji, Dongsheng; Wang, Lili; Li, Meng; Wang, Zifa; Zhang, Qiang; Carmichael, Gregory R.

2017-10-01

Air quality are strongly influenced by both emissions and meteorological conditions. During the Asia Pacific Economic Cooperation (APEC) week (November 5-11, 2014), the Chinese government implemented unprecedented strict emission control measures in Beijing and surrounding provinces, and then a phenomenon referred to as ;APEC Blue; (rare blue sky) occurred. It is challenging to quantify the effectiveness of the implemented strict control measures solely based on observations. In this study, we use the WRF-Chem model to distinguish the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks during APEC week. In general, meteorological variables, PM2.5 concentrations and PM2.5 chemical compositions are well reproduced in Beijing. Positive weather conditions (lower temperature, lower relative humidity, higher wind speeds and enhanced boundary layer heights) play important roles in ;APEC Blue;. Applying strict emission control measures in Beijing and five surrounding provinces can only explain an average decrease of 17.7 μg/m3 (-21.8%) decreases in PM2.5 concentrations, roughly more than half of which is caused by emission controls that implemented in the five surrounding provinces (12.5 μg/m3). During the APEC week, non-local emissions contributed to 41.3% to PM2.5 concentrations in Beijing, and the effectiveness of implementing emission control measures hinges on dominant pathways and transport speeds. Besides, we also quantified the contribution of reduced aerosol feedbacks due to strict emission control measures in this study. During daytime, co-benefits of reduced aerosol feedbacks account for about 10.9% of the total decreases in PM2.5 concentrations in urban Beijing. The separation of contributions from aerosol absorption and scattering restates the importance of controlling BC to accelerate the effectiveness of aerosol pollution control.

Consensus summary of aerosolized antimicrobial agents: application of guideline criteria. Insights from the Society of Infectious Diseases Pharmacists.

PubMed

Le, Jennifer; Ashley, Elizabeth Dodds; Neuhauser, Melinda M; Brown, Jack; Gentry, Chris; Klepser, Michael E; Marr, Ann Marie; Schiller, Daryl; Schwiesow, Joshua N; Tice, Sally; VandenBussche, Heather L; Wood, G Christopher

2010-06-01

Aerosolized delivery of antimicrobial agents is an attractive option for management of pulmonary infections, as this is an ideal method of providing high local drug concentrations while minimizing systemic exposure. With the paucity of consensus regarding the safety, efficacy, and means with which to use aerosolized antimicrobials, a task force was created by the Society of Infectious Diseases Pharmacists to critically review and evaluate the literature on the use of aerosolized antiinfective agents. This article summarizes key findings and statements for preventing or treating a variety of infectious diseases, including cystic fibrosis, bronchiecstasis, hospital-acquired pneumonia, fungal infections, nontuberculosis mycobacterial infection, and Pneumocystis jiroveci pneumonia. Our intention was to provide guidance for clinicians on the use of aerosolized antibiotics through evidence-based pharmacotherapy. Further research with well-designed clinical trials is necessary to elucidate the optimal dosage and duration of therapy and, of equal importance, to appreciate the true risks associated with the use of aerosolized delivery systems.

Delivery of aerosolized drugs encapsulated in liposomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Yung-Sung; Lyons, C.R.; Schmid, M.H.

1995-12-01

Mycobacterium tuberculosis (Mtb) is an infectious disease that resides in the human lung. Due to the difficulty in completely killing off the disease in infected individuals, Mtb has developed drug-resistant forms and is on the rise in the human population. Therefore, ITRI and the University of New Mexico are collaborating to explore the treatment of Mtb by an aerosolized drug delivered directly to the lungs. In conclusion, it is feasible to obtain an appropriate size and concentration of the liposomes before and after aerosolization.

Generating monodisperse pharmacological aerosols using the spinning-top aerosol generator.

PubMed

Biddiscombe, Martyn F; Barnes, Peter J; Usmani, Omar S

2006-01-01

Pharmacological aerosols of precisely controlled particle size and narrow dispersity can be generated using the spinning-top aerosol generator (STAG). The ability of the STAG to generate monodisperse aerosols from solutions of raw drug compounds makes it a valuable research instrument. In this paper, the versatility of this instrument has been further demonstrated by aerosolizing a range of commercially available nebulized pulmonary therapy preparations. Nebules of Flixotide (fluticasone propionate), Pulmicort (budesonide), Combivent (salbutamol sulphate and ipratropium bromide), Bricanyl (terbutaline sulphate), Atrovent(ipratropium bromide), and Salamol (salbutamol sulphate) were each mixed with ethanol and delivered to the STAG. Monodisperse drug aerosol distributions were generated with MMADs of 0.95-6.7 microm. To achieve larger particle sizes from the nebulizer drug suspensions, the STAG formed compound particle agglomerates derived from the smaller insoluble drug particles. These compound agglomerates behaved aerodynamically as a single particle, and this was verified using an aerodynamic particle sizer and an Andersen Cascade Impactor. Scanning electron microscope images demonstrated their physical structure. On the other hand using the nebulizer drug solutions, spherical particles proportional to the original droplet diameter were generated. The aerosols generated by the STAG can allow investigators to study the scientific principles of inhaled drug deposition and lung physiology for a range of therapeutic agents.

An aerosol climatology for a rapidly growing arid region (southern Arizona): Major aerosol species and remotely sensed aerosol properties

NASA Astrophysics Data System (ADS)

Sorooshian, Armin; Wonaschütz, Anna; Jarjour, Elias G.; Hashimoto, Bryce I.; Schichtel, Bret A.; Betterton, Eric A.

2011-10-01

This study reports a comprehensive characterization of atmospheric aerosol particle properties in relation to meteorological and back trajectory data in the southern Arizona region, which includes two of the fastest growing metropolitan areas in the United States (Phoenix and Tucson). Multiple data sets (MODIS, AERONET, OMI/TOMS, MISR, GOCART, ground-based aerosol measurements) are used to examine monthly trends in aerosol composition, aerosol optical depth (AOD), and aerosol size. Fine soil, sulfate, and organics dominate PM2.5 mass in the region. Dust strongly influences the region between March and July owing to the dry and hot meteorological conditions and back trajectory patterns. Because monsoon precipitation begins typically in July, dust levels decrease, while AOD, sulfate, and organic aerosol reach their maximum levels because of summertime photochemistry and monsoon moisture. Evidence points to biogenic volatile organic compounds being a significant source of secondary organic aerosol in this region. Biomass burning also is shown to be a major contributor to the carbonaceous aerosol budget in the region, leading to enhanced organic and elemental carbon levels aloft at a sky-island site north of Tucson (Mt. Lemmon). Phoenix exhibits different monthly trends for aerosol components in comparison with the other sites owing to the strong influence of fossil carbon and anthropogenic dust. Trend analyses between 1988 and 2009 indicate that the strongest statistically significant trends are reductions in sulfate, elemental carbon, and organic carbon, and increases in fine soil during the spring (March-May) at select sites. These results can be explained by population growth, land-use changes, and improved source controls.

Evaluation of vaccines in the EU TB Vaccine Cluster using a guinea pig aerosol infection model of tuberculosis.

PubMed

Williams, Ann; Hatch, Graham J; Clark, Simon O; Gooch, Karen E; Hatch, Kim A; Hall, Graham A; Huygen, Kris; Ottenhoff, Tom H M; Franken, Kees L M C; Andersen, Peter; Doherty, T Mark; Kaufmann, Stefan H E; Grode, Leander; Seiler, Peter; Martin, Carlos; Gicquel, Brigitte; Cole, Stewart T; Brodin, Priscille; Pym, Alexander S; Dalemans, Wilfried; Cohen, Joe; Lobet, Yves; Goonetilleke, Nilu; McShane, Helen; Hill, Adrian; Parish, Tanya; Smith, Debbie; Stoker, Neil G; Lowrie, Douglas B; Källenius, Gunilla; Svenson, Stefan; Pawlowski, Andrzej; Blake, Karen; Marsh, Philip D

2005-01-01

The TB Vaccine Cluster project funded by the EU Fifth Framework programme aims to provide novel vaccines against tuberculosis that are suitable for evaluation in humans. This paper describes the studies of the protective efficacy of vaccines in a guinea pig aerosol-infection model of primary tuberculosis. The objective was to conduct comparative evaluations of vaccines that had previously demonstrated efficacy in other animal models. Groups of 6 guinea pigs were immunized with vaccines provided by the relevant EU Vaccine Cluster partners. Survival over 17 or 26 weeks was used as the principal measure of vaccine efficacy following aerosol challenge with H37Rv. Counts of mycobacteria in lungs and spleens, and histopathological changes in the lungs, were also used to provide evidence of protection. A total of 24 vaccines were evaluated in 4 experiments each of a different design. A heterologous prime-boost strategy of DNA and MVA, each expressing Ag85A and a fusion protein of ESAT-6 and Ag85B in adjuvant, protected the guinea pigs to the same extent as BCG. Genetically modified BCG vaccines and boosted BCG strategies also protected guinea pigs to the same extent as BCG but not statistically significantly better. A relatively high aerosol-challenge dose and evaluation over a protracted time post-challenge allowed superior protection over BCG to be demonstrated by BCG boosted with MVA and fowl pox vectors expressing Ag85A.

EVALUATION OF COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY APPLIED TO AN AMBIENT URBAN AEROSOL SAMPLE

EPA Science Inventory

Concerns about the environmental and public health effects of particulate matter (PM) have stimulated interest in analytical techniques capable of measuring the size and chemical composition of individual aerosol particles. Computer-controlled scanning electron microscopy (CCSE...

Distinct immune responses and virus shedding in pigs following aerosol, intra-nasal and contact infection with pandemic swine influenza A virus, A(H1N1)09.

PubMed

Hemmink, Johanneke D; Morgan, Sophie B; Aramouni, Mario; Everett, Helen; Salguero, Francisco J; Canini, Laetitia; Porter, Emily; Chase-Topping, Margo; Beck, Katy; Loughlin, Ronan Mac; Carr, B Veronica; Brown, Ian H; Bailey, Mick; Woolhouse, Mark; Brookes, Sharon M; Charleston, Bryan; Tchilian, Elma

2016-10-20

Influenza virus infection in pigs is a major farming problem, causing considerable economic loss and posing a zoonotic threat. In addition the pig is an excellent model for understanding immunity to influenza viruses as this is a natural host pathogen system. Experimentally, influenza virus is delivered to pigs intra-nasally, by intra-tracheal instillation or by aerosol, but there is little data comparing the outcome of different methods. We evaluated the shedding pattern, cytokine responses in nasal swabs and immune responses following delivery of low or high dose swine influenza pdmH1N1 virus to the respiratory tract of pigs intra-nasally or by aerosol and compared them to those induced in naturally infected contact pigs. Our data shows that natural infection by contact induces remarkably high innate and adaptive immune response, although the animals were exposed to a very low virus dose. In contacts, the kinetics of virus shedding were slow and prolonged and more similar to the low dose directly infected animals. In contrast the cytokine profile in nasal swabs, antibody and cellular immune responses of contacts more closely resemble immune responses in high dose directly inoculated animals. Consideration of these differences is important for studies of disease pathogenesis and assessment of vaccine protective efficacy.

Mosquito Infectivity and Parasitemia after Controlled Human Malaria Infection.

PubMed

Walk, Jona; van Gemert, Geert-Jan; Graumans, Wouter; Sauerwein, Robert; Bijker, Else M

2018-04-30

Controlled Human Malaria Infection (CHMI) has become an increasingly important tool for the evaluation of drugs and vaccines. Controlled Human Malaria Infection has been demonstrated to be a reproducible model; however, there is some variability in time to onset of parasitemia between volunteers and studies. At our center, mosquitoes infected with Plasmodium falciparum by membrane feeding have variable and high salivary gland sporozoite load (mean 78,415; range 26,500-160,500). To determine whether this load influences parasitemia after CHMI, we analyzed data from 13 studies. We found no correlation between the sporozoite load of a mosquito batch and time to parasitemia or parasite density of first-wave parasitemia. These findings support the use of infected mosquito bite as a reproducible means of inducing P. falciparum infection and suggest that within this range, salivary gland sporozoite load does not influence the stringency of a CHMI.

Spatial and temporal variations of aerosols around Beijing in summer 2006: 2. Local and column aerosol optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsui, Hitoshi; Koike, Makoto; Kondo, Yutaka

Weather Research and Forecasting (WRF)-chem model calculations were conducted to study aerosol optical properties around Beijing, China, during the Campaign of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing-2006) period. In this paper, we interpret aerosol optical properties in terms of aerosol mass concentrations and their chemical compositions by linking model calculations with measurements. In general, model calculations reproduced observed features of spatial and temporal variations of various surface and column aerosol optical parameters in and around Beijing. Spatial and temporal variations of aerosol absorption, scattering, and extinction coefficient corresponded well to those of elemental carbon (primary aerosol),more » sulfate (secondary aerosol), and the total aerosol mass concentration, respectively. These results show that spatial and temporal variations of the absorption coefficient are controlled by local emissions (within 100 km around Beijing during the preceding 24 h), while those of the scattering coefficient are controlled by regional-scale emissions (within 500 km around Beijing during the preceding 3 days) under synoptic-scale meteorological conditions, as discussed in our previous study of aerosol mass concentration. Vertical profiles of aerosol extinction revealed that the contribution of secondary aerosols and their water uptake increased with altitude within the planetary boundary layer, leading to a considerable increase in column aerosol optical depth (AOD) around Beijing. These effects are the main factors causing differences in regional and temporal variations between particulate matter (PM) mass concentration at the surface and column AOD over a wide region in the northern part of the Great North China Plain.« less

A randomized, controlled trial of an aerosolized vaccine against measles.

PubMed

Low, Nicola; Bavdekar, Ashish; Jeyaseelan, Lakshmanan; Hirve, Siddhivinayak; Ramanathan, Kavitha; Andrews, Nicholas J; Shaikh, Naseem; Jadi, Ramesh S; Rajagopal, Arunachalam; Brown, Kevin E; Brown, David; Fink, James B; John, Oommen; Scott, Pippa; Riveros-Balta, A Ximena; Greco, Michel; Dhere, Rajeev; Kulkarni, Prasad S; Henao Restrepo, Ana Maria

2015-04-16

Aerosolized vaccine can be used as a needle-free method of immunization against measles, a disease that remains a major cause of illness and death. Data on the immunogenicity of aerosolized vaccine against measles in children are inconsistent. We conducted an open-label noninferiority trial involving children 9.0 to 11.9 months of age in India who were eligible to receive a first dose of measles vaccine. Children were randomly assigned to receive a single dose of vaccine by means of either aerosol inhalation or a subcutaneous injection. The primary end points were seropositivity for antibodies against measles and adverse events 91 days after vaccination. The noninferiority margin was 5 percentage points. A total of 1001 children were assigned to receive aerosolized vaccine, and 1003 children were assigned to receive subcutaneous vaccine; 1956 of all the children (97.6%) were followed to day 91, but outcome data were missing for 331 children because of thawed specimens. In the per-protocol population, data on 1560 of 2004 children (77.8%) could be evaluated. At day 91, a total of 662 of 775 children (85.4%; 95% confidence interval [CI], 82.5 to 88.0) in the aerosol group, as compared with 743 of 785 children (94.6%; 95% CI, 92.7 to 96.1) in the subcutaneous group, were seropositive, a difference of -9.2 percentage points (95% CI, -12.2 to -6.3). Findings were similar in the full-analysis set (673 of 788 children in the aerosol group [85.4%] and 754 of 796 children in the subcutaneous group [94.7%] were seropositive at day 91, a difference of -9.3 percentage points [95% CI, -12.3 to -6.4]) and after multiple imputation of missing results. No serious adverse events were attributable to measles vaccination. Adverse-event profiles were similar in the two groups. Aerosolized vaccine against measles was immunogenic, but, at the prespecified margin, the aerosolized vaccine was inferior to the subcutaneous vaccine with respect to the rate of seropositivity. (Funded by the

Demolition and removal of radioactively contaminated concrete soil: Aerosol control and monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newton, G.J.; Hoover, M.D.; Grace, A.C. III

1995-12-01

From 1963 to 1985, two concrete-lined ponds were used to reduce the volume of radioactive liquids from the Institute`s research programs. Following withdrawal of the {open_quotes}hot ponds{close_quotes} from active use, the residual sludges and plastic liners of the ponds were removed and shipped to a radioactive waste disposal site. From 1987 to 1994, the concrete structures remained undisturbed pending environmental restoration on the site. Restoration began in 1994 and was completed in 1995. Restoration involved mechanical breakup and removal of the concrete structures and removal of areas of contaminated soils from the site. This report describes the design and resultsmore » of the aerosol control and monitoring program that was conducted to ensure protection of workers and the environment during the restoration process. The aerosol control and monitoring strategy developed for remediation of the ITRI hot ponds was successful both in preventing dispersion of radioactive dusts and in demonstrating that exposures of workers and offsite releases were within statutory limits.« less

Identification and validation of nebulized aerosol devices for sputum induction

PubMed Central

Davidson, Warren J; Dennis, John; The, Stephanie; Litoski, Belinda; Pieron, Cora; Leigh, Richard

2014-01-01

Induced sputum cell count measurement has proven reliability for evaluating airway inflammation in patients with asthma and other airway diseases. Although the use of nebulizer devices for sputum induction is commonplace, they are generally labelled as single-patient devices by the manufacturer and, therefore, cannot be used for multiple patients in large clinical sputum induction programs due to infect ion-control requirements. Accordingly, this study investigated the aerosol characteristics of alternative devices that could be used in such programs. BACKGROUND: Induced sputum cell counts are a noninvasive and reliable method for evaluating the presence, type and degree of airway inflammation in patients with asthma. Currently, standard nebulizer devices used for sputum induction in multiple patients are labelled as single-patient devices by the manufacturer, which conflicts with infection prevention and control requirements. As such, these devices cannot feasibly be used in a clinical sputum induction program. Therefore, there is a need to identify alternative nebulizer devices that are either disposable or labelled for multi-patient use. OBJECTIVE: To apply validated rigorous, scientific testing methods to identify and validate commercially available nebulizer devices appropriate for use in a clinical sputum induction program. METHODS: Measurement of nebulized aerosol output and size for the selected nebulizer designs followed robust International Organization for Standardization methods. Sputum induction using two of these nebulizers was successfully performed on 10 healthy adult subjects. The cytotechnologist performing sputum cell counts was blinded to the type of nebulizer used. RESULTS: The studied nebulizers had variable aerosol outputs. The AeroNeb Solo (Aerogen, Ireland), Omron NE-U17 (Omron, Japan) and EASYneb II (Flaem Nuova, Italy) systems were found to have similar measurements of aerosol size. There was no significant difference in induced sputum

Aerosol Data Assimilation at GMAO

NASA Technical Reports Server (NTRS)

da Silva, Arlindo M.; Buchard, Virginie

2017-01-01

This presentation presents an overview of the aerosol data assimilation work performed at GMAO. The GMAO Forward Processing system and the biomass burning emissions from QFED are first presented. Then, the current assimilation of Aerosol Optical Depth (AOD), performed by means of the analysis splitting method is briefly described, followed by some results on the quality control of observations using a Neural Network trained using AERONET AOD. Some applications are shown such as the Mount Pinatubo eruption in 1991 using the MERRA-2 aerosol dataset. Finally preliminary results on the EnKF implementation for aerosol assimilation are presented.

Post-treatment control of HIV infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conway, Jessica M.; Perelson, Alan S.

Antiretroviral therapy (ART) for HIV is not a cure. However, recent studies suggest that ART, initiated early during primary infection, may induce post-treatment control (PTC) of HIV infection with HIV RNA maintained at <50 copies per mL. We investigate the hypothesis that ART initiated early during primary infection permits PTC by limiting the size of the latent reservoir, which, if small enough at treatment termination, may allow the adaptive immune response to prevent viral rebound (VR) and control infection. We use a mathematical model of within host HIV dynamics to capture interactions among target cells, productively infected cells, latently infectedmore » cells, virus, and cytotoxic T lymphocytes (CTLs). Analysis of our model reveals a range in CTL response strengths where a patient may show either VR or PTC, depending on the size of the latent reservoir at treatment termination. Below this range, patients will always rebound, whereas above this range, patients are predicted to behave like elite controllers. As a result, using data on latent reservoir sizes in patients treated during primary infection, we also predict population-level VR times for non-controllers consistent with observations.« less

Post-treatment control of HIV infection

DOE PAGES

Conway, Jessica M.; Perelson, Alan S.

2015-04-13

Antiretroviral therapy (ART) for HIV is not a cure. However, recent studies suggest that ART, initiated early during primary infection, may induce post-treatment control (PTC) of HIV infection with HIV RNA maintained at <50 copies per mL. We investigate the hypothesis that ART initiated early during primary infection permits PTC by limiting the size of the latent reservoir, which, if small enough at treatment termination, may allow the adaptive immune response to prevent viral rebound (VR) and control infection. We use a mathematical model of within host HIV dynamics to capture interactions among target cells, productively infected cells, latently infectedmore » cells, virus, and cytotoxic T lymphocytes (CTLs). Analysis of our model reveals a range in CTL response strengths where a patient may show either VR or PTC, depending on the size of the latent reservoir at treatment termination. Below this range, patients will always rebound, whereas above this range, patients are predicted to behave like elite controllers. As a result, using data on latent reservoir sizes in patients treated during primary infection, we also predict population-level VR times for non-controllers consistent with observations.« less

Oral vaccination of guinea pigs with a Mycobacterium bovis bacillus Calmette-Guerin vaccine in a lipid matrix protects against aerosol infection with virulent M. bovis.

PubMed

Clark, Simon; Cross, Martin L; Nadian, Allan; Vipond, Julia; Court, Pinar; Williams, Ann; Hewinson, R Glyn; Aldwell, Frank E; Chambers, Mark A

2008-08-01

Increased incidence of bovine tuberculosis (TB) in the United Kingdom caused by infection with Mycobacterium bovis is a cause of considerable economic loss to farmers and the government. The Eurasian badger (Meles meles) represents a wildlife source of recurrent M. bovis infections of cattle in the United Kingdom, and its vaccination against TB with M. bovis bacillus Calmette-Guérin (BCG) is an attractive disease control option. Delivery of BCG in oral bait holds the best prospect for vaccinating badgers over a wide geographical area. Using a guinea pig pulmonary challenge model, we evaluated the protective efficacy of candidate badger oral vaccines, based on broth-grown or ball-milled BCG, delivered either as aqueous suspensions or formulated in two lipids with differing fatty acid profiles (one being animal derived and the other being vegetable derived). Protection was determined in terms of increasing body weight after aerosol challenge with virulent M. bovis, reduced dissemination of M. bovis to the spleen, and, in the case of one oral formulation, restricted growth of M. bovis in the lungs. Only oral BCG formulated in lipid gave significant protection. These data point to the potential of the BCG-lipid formulation for further development as a tool for controlling tuberculosis in badgers.

Chemical characteristics of size-resolved atmospheric aerosols in Iasi, north-eastern Romania: nitrogen-containing inorganic compounds control aerosol chemistry in the area

NASA Astrophysics Data System (ADS)

Giorgiana Galon-Negru, Alina; Iulian Olariu, Romeo; Arsene, Cecilia

2018-04-01

This study assesses the effects of particle size and season on the content of the major inorganic and organic aerosol ionic components in the Iasi urban area, north-eastern Romania. Continuous measurements were carried out over 2016 using a cascade Dekati low-pressure impactor (DLPI) performing aerosol size classification in 13 specific fractions over the 0.0276-9.94 µm size range. Fine-particulate Cl-, NO3-, NH4+, and K+ exhibited clear minima during the warm season and clear maxima over the cold season, mainly due to trends in emission sources, changes in the mixing layer depth and specific meteorological conditions. Fine-particulate SO42- did not show much variation with respect to seasons. Particulate NH4+ and NO3- ions were identified as critical parameters controlling aerosol chemistry in the area, and their measured concentrations in fine-mode (PM2.5) aerosols were found to be in reasonable good agreement with modelled values for winter but not for summer. The likely reason is that NH4NO3 aerosols are lost due to volatility over the warm season. We found that NH4+ in PM2.5 is primarily associated with SO42- and NO3- but not with Cl-. Actually, indirect ISORROPIA-II estimations showed that the atmosphere in the Iasi area might be ammonia rich during both the cold and warm seasons, enabling enough NH3 to be present to neutralize H2SO4, HNO3, and HCl acidic components and to generate fine-particulate ammonium salts, in the form of (NH4)2SO4, NH4NO3, and NH4Cl. ISORROPIA-II runs allowed us to estimate that over the warm season ˜ 35 % of the total analysed samples had very strongly acidic pH (0-3), a fraction that rose to ˜ 43 % over the cold season. Moreover, while in the cold season the acidity is mainly accounted for by inorganic acids, in the warm ones there is an important contribution by other compounds, possibly organic. Indeed, changes in aerosol acidity would most likely impact the gas-particle partitioning of semi-volatile organic acids. Overall, we

Comparison of five bacteriophages as models for viral aerosol studies.

PubMed

Turgeon, Nathalie; Toulouse, Marie-Josée; Martel, Bruno; Moineau, Sylvain; Duchaine, Caroline

2014-07-01

Bacteriophages are perceived to be good models for the study of airborne viruses because they are safe to use, some of them display structural features similar to those of human and animal viruses, and they are relatively easy to produce in large quantities. Yet, only a few studies have investigated them as models. It has previously been demonstrated that aerosolization, environmental conditions, and sampling conditions affect viral infectivity, but viral infectivity is virus dependent. Thus, several virus models are likely needed to study their general behavior in aerosols. The aim of this study was to compare the effects of aerosolization and sampling on the infectivity of five tail-less bacteriophages and two pathogenic viruses: MS2 (a single-stranded RNA [ssRNA] phage of the Leviviridae family), Φ6 (a segmented double-stranded RNA [dsRNA] phage of the Cystoviridae family), ΦX174 (a single-stranded DNA [ssDNA] phage of the Microviridae family), PM2 (a double-stranded DNA [dsDNA] phage of the Corticoviridae family), PR772 (a dsDNA phage of the Tectiviridae family), human influenza A virus H1N1 (an ssRNA virus of the Orthomyxoviridae family), and the poultry virus Newcastle disease virus (NDV; an ssRNA virus of the Paramyxoviridae family). Three nebulizers and two nebulization salt buffers (with or without organic fluid) were tested, as were two aerosol sampling devices, a liquid cyclone (SKC BioSampler) and a dry cyclone (National Institute for Occupational Safety and Health two-stage cyclone bioaerosol sampler). The presence of viruses in collected air samples was detected by culture and quantitative PCR (qPCR). Our results showed that these selected five phages behave differently when aerosolized and sampled. RNA phage MS2 and ssDNA phage ΦX174 were the most resistant to aerosolization and sampling. The presence of organic fluid in the nebulization buffer protected phages PR772 and Φ6 throughout the aerosolization and sampling with dry cyclones. In this

Comparison of Five Bacteriophages as Models for Viral Aerosol Studies

PubMed Central

Turgeon, Nathalie; Toulouse, Marie-Josée; Martel, Bruno; Moineau, Sylvain

2014-01-01

Bacteriophages are perceived to be good models for the study of airborne viruses because they are safe to use, some of them display structural features similar to those of human and animal viruses, and they are relatively easy to produce in large quantities. Yet, only a few studies have investigated them as models. It has previously been demonstrated that aerosolization, environmental conditions, and sampling conditions affect viral infectivity, but viral infectivity is virus dependent. Thus, several virus models are likely needed to study their general behavior in aerosols. The aim of this study was to compare the effects of aerosolization and sampling on the infectivity of five tail-less bacteriophages and two pathogenic viruses: MS2 (a single-stranded RNA [ssRNA] phage of the Leviviridae family), Φ6 (a segmented double-stranded RNA [dsRNA] phage of the Cystoviridae family), ΦX174 (a single-stranded DNA [ssDNA] phage of the Microviridae family), PM2 (a double-stranded DNA [dsDNA] phage of the Corticoviridae family), PR772 (a dsDNA phage of the Tectiviridae family), human influenza A virus H1N1 (an ssRNA virus of the Orthomyxoviridae family), and the poultry virus Newcastle disease virus (NDV; an ssRNA virus of the Paramyxoviridae family). Three nebulizers and two nebulization salt buffers (with or without organic fluid) were tested, as were two aerosol sampling devices, a liquid cyclone (SKC BioSampler) and a dry cyclone (National Institute for Occupational Safety and Health two-stage cyclone bioaerosol sampler). The presence of viruses in collected air samples was detected by culture and quantitative PCR (qPCR). Our results showed that these selected five phages behave differently when aerosolized and sampled. RNA phage MS2 and ssDNA phage ΦX174 were the most resistant to aerosolization and sampling. The presence of organic fluid in the nebulization buffer protected phages PR772 and Φ6 throughout the aerosolization and sampling with dry cyclones. In this

Widespread bronchogenic dissemination makes DBA/2 mice more susceptible than C57BL/6 mice to experimental aerosol infection with Mycobacterium tuberculosis.

PubMed

Cardona, Pere-Joan; Gordillo, Sergi; Díaz, Jorge; Tapia, Gustavo; Amat, Isabel; Pallarés, Angeles; Vilaplana, Cristina; Ariza, Aurelio; Ausina, Vicenç

2003-10-01

We have used the murine model of aerosol-induced experimental tuberculosis to assess the effects of four clinical isolates and a reference strain of Mycobacterium tuberculosis on resistant C57BL/6 mice and susceptible DBA/2 mice. Histological studies and detection of 25 cytokines potentially involved in the infection were carried out. DBA/2 mice showed higher concentrations of bacilli in bronchoalveolar lavage fluid and lung tissue. Furthermore, these mice evidenced a larger granulomatous infiltration in the parenchyma due to an increased rate of emigration of infected foamy macrophages from the granulomas to the neighboring pulmonary alveolar spaces. The better control of bacillary concentrations and pulmonary infiltration observed in C57BL/6 mice from week 3 postinfection could result from their higher RANTES, ICAM-1, and gamma interferon (IFN-gamma) mRNA levels. On the other hand, the higher MIP-2 and MCP-3 mRNA levels seen in DBA/2 mice would result in stronger lung recruitment of macrophages and neutrophils. Additionally, DBA/2 mice showed increased inducible nitric oxide synthase expression, induced by the larger number of foamy macrophages, at weeks 18 and 22. This increment was a consequence of phagocytosed bacillary debris, was independent of IFN-gamma expression, and could exert only a bacteriostatic effect. The results of the study suggest that DBA/2 mice are more susceptible than C57BL/6 mice to M. tuberculosis infection due to a higher bronchial dissemination of bacilli inside poorly activated foamy macrophages.

A humidity controlled Nephelometer system to study the hygroscopic properties of aerosols in the marine environment

NASA Astrophysics Data System (ADS)

Vaishya, Aditya; O'Dowd, Colin; Jennings, S. Gerard

2010-05-01

A Humidograph system has been designed to study the hygroscopic properties of aerosols for different air-masses and for different seasons in the marine environment. Since ambient marine aerosols are likely to be found in a metastable state, and in accordance with recommendations of WMO/GAW to sample dry aerosol, a drying unit (Nafion based) is placed just after the inlet to dry the aerosols to a relative humidity (RH) < 40% so as not to misinterpret the optical properties of hygroscopic aerosols if they are on the descending branch of the hysteresis curve. The flow after the dryer is split into two, one going to a 3-wavelength TSI-3563 Integrating Nephelometer, and the other to a Gore-Tex based humidifier followed by a single-wavelength TSI-3561 Integrating Nephelometer. The humidifier is used to vary the RH from 40% to 90%. While the TSI-3563 Integrating Nephelometer will operate at RH < 40%, the TSI-3561 Integrating Nephelometer will operate under varying RH conditions. Software developed in LabVIEW is used to control the hardware components and to log the data in a predefined format. Results of the performance of the Humidograph system in the laboratory and at the Mace Head Atmospheric Research Station are presented.

Aerosol typing - key information from aerosol studies

NASA Astrophysics Data System (ADS)

Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

2016-04-01

Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

Systemic Foot-and-Mouth Disease Vaccination in Cattle Promotes Specific Antibody-Secreting Cells at the Respiratory Tract and Triggers Local Anamnestic Responses upon Aerosol Infection.

PubMed

Pega, J; Di Giacomo, S; Bucafusco, D; Schammas, J M; Malacari, D; Barrionuevo, F; Capozzo, A V; Rodríguez, L L; Borca, M V; Pérez-Filgueira, M

2015-09-01

Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting biungulate species. Commercial vaccines, formulated with inactivated FMD virus (FMDV), are regularly used worldwide to control the disease. Here, we studied the generation of antibody responses in local lymphoid tissues along the respiratory system in vaccinated and further aerosol-infected cattle. Animals immunized with a high-payload monovalent FMD vaccine developed high titers of neutralizing antibodies at 7 days postvaccination (dpv), reaching a plateau at 29 dpv. FMDV-specific antibody-secreting cells (ASC), predominantly IgM, were evident at 7 dpv in the prescapular lymph node (LN) draining the vaccination site and in distal LN draining the respiratory mucosa, although in lower numbers. At 29 dpv, a significant switch to IgG1 was clear in prescapular LN, while FMDV-specific ASC were detected in all lymphoid tissues draining the respiratory tract, mostly as IgM-secreting cells. None of the animals (n = 10) exhibited FMD symptoms after oronasal challenge at 30 dpv. Three days postinfection, a large increase in ASC numbers and rapid isotype switches to IgG1 were observed, particularly in LN-draining virus replication sites already described. These results indicate for the first time that systemic FMD vaccination in cattle effectively promotes the presence of anti-FMDV ASC in lymphoid tissues associated with the respiratory system. Oronasal infection triggered an immune reaction compatible with a local anamnestic response upon contact with the replicating FMDV, suggesting that FMD vaccination induces the circulation of virus-specific B lymphocytes, including memory B cells that differentiate into ASC soon after contact with the infective virus. Over recent decades, world animal health organizations as well as national sanitary authorities have supported the use of vaccination as an essential component of the official FMD control programs in both endemic and disease-free settings. Very few

Impact of aerosol emission controls on future Arctic sea ice cover

NASA Astrophysics Data System (ADS)

Gagné, M.-Ã..; Gillett, N. P.; Fyfe, J. C.

2015-10-01

We examine the response of Arctic sea ice to projected aerosol and aerosol precursor emission changes under the Representative Concentration Pathway (RCP) scenarios in simulations of the Canadian Earth System Model. The overall decrease in aerosol loading causes a warming, largest over the Arctic, which leads to an annual mean reduction in sea ice extent of approximately 1 million km2 over the 21st century in all RCP scenarios. This accounts for approximately 25% of the simulated reduction in sea ice extent in RCP 4.5, and 40% of the reduction in RCP 2.5. In RCP 4.5, the Arctic ocean is projected to become ice-free during summertime in 2045, but it does not become ice-free until 2057 in simulations with aerosol precursor emissions held fixed at 2000 values. Thus, while reductions in aerosol emissions have significant health and environmental benefits, their substantial contribution to projected Arctic climate change should not be overlooked.

Vancomycin-Resistant Enterococci: Epidemiology, Infection Prevention, and Control.

PubMed

Reyes, Katherine; Bardossy, Ana Cecilia; Zervos, Marcus

2016-12-01

Vancomycin-resistant enterococci (VRE) infections have acquired prominence as a leading cause of health care-associated infections. Understanding VRE epidemiology, transmission modes in health care settings, risk factors for colonization, and infection is essential to prevention and control of VRE infections. Infection control strategies are pivotal in management of VRE infections and should be based on patient characteristics, hospital needs, and available resources. Hand hygiene is basic to decrease acquisition of VRE. The effectiveness of surveillance and contact precautions is variable and controversial in endemic settings, but important during VRE outbreak investigations and control. Environmental cleaning, chlorhexidine bathing, and antimicrobial stewardship are vital in VRE prevention and control. Copyright © 2016 Elsevier Inc. All rights reserved.

Controlling droplet-transmitted respiratory infections

PubMed Central

Hogg, William; Huston, Patricia

2006-01-01

OBJECTIVE To promote incorporation of new guidelines on control of respiratory infections into family physicians’ practices. SOURCES OF INFORMATION The World Health Organization website on pandemic influenza, the Canadian Pandemic Influenza Plan, the Ontario guidelines on respiratory infection control, and research on implementing guidelines into family practice were reviewed. We also researched and calculated what the costs of implementing the guidelines would be. MAIN MESSAGE Effective control of respiratory infections in physicians’ offices can be achieved by displaying signs in the waiting room, having reception staff give masks to patients with cough and fever, instructing these patients to clean their hands with alcohol gel and to sit at least 1 m from others, inquiring about patients’ or their close contacts’ recent travel, using disinfectant wipes to clean possibly contaminated surfaces in waiting rooms and examining areas, and having staff and care providers wear masks and wash hands or use alcohol gel. The approximate annual cost of incorporating the guidelines is about $800 per physician. CONCLUSION Because the outbreak of an influenza pandemic is likely imminent, implementing standard guidelines for control of respiratory infections in primary care offices seems wise. Following these guidelines would help prevent patients and staff from contracting serious respiratory illnesses. PMID:17279182

Geometrical optics of dense aerosols: forming dense plasma slabs.

PubMed

Hay, Michael J; Valeo, Ernest J; Fisch, Nathaniel J

2013-11-01

Assembling a freestanding, sharp-edged slab of homogeneous material that is much denser than gas, but much more rarefied than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed field, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the finite particle density reduces the effective Stokes number of the flow, a critical result for controlled focusing.

Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning

NASA Astrophysics Data System (ADS)

Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas

2014-05-01

Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in

Influence of staff infection control training on infection-related quality measures in US nursing homes.

PubMed

Kaur, Jasjit; Stone, Patricia W; Travers, Jasmine L; Cohen, Catherine C; Herzig, Carolyn T A

2017-09-01

Health care-associated infections are a leading cause of morbidity and mortality in US nursing home residents. Ongoing training of nursing home staff is vital to the implementation of infection prevention and control processes. Our aim was to describe associations between methods, frequency, and timing of staff infection prevention and control training and infection-related quality measures. In this national survey of nursing homes, timing of staff infection prevention and control training was associated with reduced indwelling urinary catheter use. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Processes Controlling the Seasonal Cycle of Arctic Aerosol Number and Size Distributions

NASA Astrophysics Data System (ADS)

Wentworth, G.; Croft, B.; Martin, R.; Leaitch, W. R.; Tunved, P.; Breider, T. J.; D'Andrea, S.; Pierce, J. R.; Murphy, J. G.; Kodros, J.; Abbatt, J.

2015-12-01

Measurements at high-Arctic sites show a strong seasonal cycle in aerosol number and size. The number of aerosols with diameters larger than 20 nm exhibits a maximum in late spring associated with a dominant accumulation mode, and a second maximum in the summer associated with a dominant Aitken mode. Seasonal-mean aerosol effective diameter ranges from about 160 nm in summer to 250 nm in winter. This study interprets these seasonal cycles with the GEOS-Chem-TOMAS global aerosol microphysics model. We find improved agreement with in situ measurements (SMPS) of aerosol size at both Alert, Nunavut, and Mt. Zeppelin, Svalbard following model developments: 1) increase the efficiency of wet scavenging in the Arctic summer and 2) represent coagulation between interstitial aerosols and aerosols activated to form cloud droplets. Our simulations indicate that the dominant summer-time Aitken mode is associated with increased efficiency of wet removal, which limits the number of larger aerosols and promotes local new-aerosol formation. We also find an important role of interstitial coagulation in clouds in the Arctic, which limits the number of Aitken-mode aerosols in the non-summer seasons when direct wet removal of these aerosols is inefficient. The summertime Arctic atmosphere is particularly pristine and strongly influenced by natural regional emissions which have poorly understood climate impacts. Especially influenced are the climatic roles of atmospheric particles and clouds. Here we present evidence that ammonia (NH3) emissions from migratory-seabird guano (dung) are the primary contributor to summertime free ammonia levels recently measured in the Canadian Arctic atmosphere. These findings suggest that ammonia from seabird guano is a key factor contributing to bursts of new-particle formation, which are observed every summer in the near-surface atmosphere at Alert, Canada. Chemical transport model simulations show that these newly formed particles can grow by vapour

Multi-sensor cloud and aerosol retrieval simulator and remote sensing from model parameters - Part 2: Aerosols

NASA Astrophysics Data System (ADS)

Wind, Galina; da Silva, Arlindo M.; Norris, Peter M.; Platnick, Steven; Mattoo, Shana; Levy, Robert C.

2016-07-01

The Multi-sensor Cloud Retrieval Simulator (MCRS) produces a "simulated radiance" product from any high-resolution general circulation model with interactive aerosol as if a specific sensor such as the Moderate Resolution Imaging Spectroradiometer (MODIS) were viewing a combination of the atmospheric column and land-ocean surface at a specific location. Previously the MCRS code only included contributions from atmosphere and clouds in its radiance calculations and did not incorporate properties of aerosols. In this paper we added a new aerosol properties module to the MCRS code that allows users to insert a mixture of up to 15 different aerosol species in any of 36 vertical layers.This new MCRS code is now known as MCARS (Multi-sensor Cloud and Aerosol Retrieval Simulator). Inclusion of an aerosol module into MCARS not only allows for extensive, tightly controlled testing of various aspects of satellite operational cloud and aerosol properties retrieval algorithms, but also provides a platform for comparing cloud and aerosol models against satellite measurements. This kind of two-way platform can improve the efficacy of model parameterizations of measured satellite radiances, allowing the assessment of model skill consistently with the retrieval algorithm. The MCARS code provides dynamic controls for appearance of cloud and aerosol layers. Thereby detailed quantitative studies of the impacts of various atmospheric components can be controlled.In this paper we illustrate the operation of MCARS by deriving simulated radiances from various data field output by the Goddard Earth Observing System version 5 (GEOS-5) model. The model aerosol fields are prepared for translation to simulated radiance using the same model subgrid variability parameterizations as are used for cloud and atmospheric properties profiles, namely the ICA technique. After MCARS computes modeled sensor radiances equivalent to their observed counterparts, these radiances are presented as input to

Multi-Sensor Cloud and Aerosol Retrieval Simulator and Remote Sensing from Model Parameters . Part 2; Aerosols

NASA Technical Reports Server (NTRS)

Wind, Galina; Da Silva, Arlindo M.; Norris, Peter M.; Platnick, Steven; Mattoo, Shana; Levy, Robert C.

2016-01-01

The Multi-sensor Cloud Retrieval Simulator (MCRS) produces a simulated radiance product from any high-resolution general circulation model with interactive aerosol as if a specific sensor such as the Moderate Resolution Imaging Spectroradiometer (MODIS) were viewing a combination of the atmospheric column and land ocean surface at a specific location. Previously the MCRS code only included contributions from atmosphere and clouds in its radiance calculations and did not incorporate properties of aerosols. In this paper we added a new aerosol properties module to the MCRS code that allows users to insert a mixture of up to 15 different aerosol species in any of 36 vertical layers. This new MCRS code is now known as MCARS (Multi-sensor Cloud and Aerosol Retrieval Simulator). Inclusion of an aerosol module into MCARS not only allows for extensive, tightly controlled testing of various aspects of satellite operational cloud and aerosol properties retrieval algorithms, but also provides a platform for comparing cloud and aerosol models against satellite measurements. This kind of two-way platform can improve the efficacy of model parameterizations of measured satellite radiances, allowing the assessment of model skill consistently with the retrieval algorithm. The MCARS code provides dynamic controls for appearance of cloud and aerosol layers. Thereby detailed quantitative studies of the impacts of various atmospheric components can be controlled. In this paper we illustrate the operation of MCARS by deriving simulated radiances from various data field output by the Goddard Earth Observing System version 5 (GEOS-5) model. The model aerosol fields are prepared for translation to simulated radiance using the same model sub grid variability parameterizations as are used for cloud and atmospheric properties profiles, namely the ICA technique. After MCARS computes modeled sensor radiances equivalent to their observed counterparts, these radiances are presented as input to

Current standards for infection control: audit assures compliance.

PubMed

Flanagan, Pauline

Having robust policies and procedures in place for infection control is fundamentally important. However, each organization has to go a step beyond this; evidence has to be provided that these policies and procedures are followed. As of 1 April 2009, with the introduction of the Care Quality Commission and The Health and Social Care Act 2008 Code of Practice for the NHS on the Prevention and Control of Healthcare-Associated Infections and Related Guidance, the assurance of robust infection control measures within any UK provider of health care became an even higher priority. Also, the commissioning of any service by the NHS must provide evidence that the provider has in place robust procedures for infection control. This article demonstrates how the clinical audit team at the Douglas Macmillan Hospice in North Staffordshire, UK, have used audit to assure high rates of compliance with the current national standards for infection control. Prior to the audit, hospice staff had assumed that the rates of compliance for infection control approached 100%. This article shows that a good quality audit tool can be used to identify areas of shortfall in infection control and the effectiveness of putting in place an action plan followed by re-audit.

Aqueous aerosol SOA formation: impact on aerosol physical properties.

PubMed

Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

2013-01-01

Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions.

Aerosol algorithm evaluation within aerosol-CCI

NASA Astrophysics Data System (ADS)

Kinne, Stefan; Schulz, Michael; Griesfeller, Jan

Properties of aerosol retrievals from space are difficult. Even data from dedicated satellite sensors face contaminations which limit the accuracy of aerosol retrieval products. Issues are the identification of complete cloud-free scenes, the need to assume aerosol compositional features in an underdetermined solution space and the requirement to characterize the background at high accuracy. Usually the development of aerosol is a slow process, requiring continuous feedback from evaluations. To demonstrate maturity, these evaluations need to cover different regions and seasons and many different aerosol properties, because aerosol composition is quite diverse and highly variable in space and time, as atmospheric aerosol lifetimes are only a few days. Three years ago the ESA Climate Change Initiative started to support aerosol retrieval efforts in order to develop aerosol retrieval products for the climate community from underutilized ESA satellite sensors. The initial focus was on retrievals of AOD (a measure for the atmospheric column amount) and of Angstrom (a proxy for aerosol size) from the ATSR and MERIS sensors on ENVISAT. The goal was to offer retrieval products that are comparable or better in accuracy than commonly used NASA products of MODIS or MISR. Fortunately, accurate reference data of ground based sun-/sky-photometry networks exist. Thus, retrieval assessments could and were conducted independently by different evaluation groups. Here, results of these evaluations for the year 2008 are summarized. The capability of these newly developed retrievals is analyzed and quantified in scores. These scores allowed a ranking of competing efforts and also allow skill comparisons of these new retrievals against existing and commonly used retrievals.

INTEGRATED PROTECTIVE FABRIC SYSTEM (IPFS) PHASE III PROGRAM: AEROSOL PROTECTION REPORT

DTIC Science & Technology

2017-08-16

one layer control. It was observed that aerosol swatch measurements showed no correlation to aerosol system test performance for the materials and...the BRHA model employed. It was observed that aerosol swatch measurements showed no correlation to aerosol system test performance for the...Testing” (McVeety et al., 2015). This report includes a description of the materials and material controls, a description of the IPFS configurations

GCM Simulations of the Aerosol Indirect Effect: Sensitivity to Cloud Parameterization and Aerosol Burden

NASA Technical Reports Server (NTRS)

Menon, Surabi; DelGenio, Anthony D.; Koch, Dorothy; Tselioudis, George; Hansen, James E. (Technical Monitor)

2001-01-01

We describe the coupling of the Goddard Institute for Space Studies (GISS) general circulation model (GCM) to an online sulfur chemistry model and source models for organic matter and sea-salt that is used to estimate the aerosol indirect effect. The cloud droplet number concentration is diagnosed empirically from field experiment datasets over land and ocean that observe droplet number and all three aerosol types simultaneously; corrections are made for implied variations in cloud turbulence levels. The resulting cloud droplet number is used to calculate variations in droplet effective radius, which in turn allows us to predict aerosol effects on cloud optical thickness and microphysical process rates. We calculate the aerosol indirect effect by differencing the top-of-the-atmosphere net cloud radiative forcing for simulations with present-day vs. pre-industrial emissions. Both the first (radiative) and second (microphysical) indirect effects are explored. We test the sensitivity of our results to cloud parameterization assumptions that control the vertical distribution of cloud occurrence, the autoconversion rate, and the aerosol scavenging rate, each of which feeds back significantly on the model aerosol burden. The global mean aerosol indirect effect for all three aerosol types ranges from -1.55 to -4.36 W m(exp -2) in our simulations. The results are quite sensitive to the pre-industrial background aerosol burden, with low pre-industrial burdens giving strong indirect effects, and to a lesser extent to the anthropogenic aerosol burden, with large burdens giving somewhat larger indirect effects. Because of this dependence on the background aerosol, model diagnostics such as albedo-particle size correlations and column cloud susceptibility, for which satellite validation products are available, are not good predictors of the resulting indirect effect.

GCM Simulations of the Aerosol Indirect Effect: Sensitivity to Cloud Parameterization and Aerosol Burden

NASA Technical Reports Server (NTRS)

Menon, Surabi; DelGenio, Anthony D.; Koch, Dorothy; Tselioudis, George; Hansen, James E. (Technical Monitor)

2001-01-01

We describe the coupling of the Goddard Institute for Space Studies (GISS) general circulation model (GCM) to an online sulfur chemistry model and source models for organic matter and sea-salt that is used to estimate the aerosol indirect effect. The cloud droplet number concentration is diagnosed empirically from field experiment datasets over land and ocean that observe droplet number and all three aerosol types simultaneously; corrections are made for implied variations in cloud turbulence levels. The resulting cloud droplet number is used to calculate variations in droplet effective radius, which in turn allows us to predict aerosol effects on cloud optical thickness and microphysical process rates. We calculate the aerosol indirect effect by differencing the top-of-the-atmosphere net cloud radiative forcing for simulations with present-day vs. pre-industrial emissions. Both the first (radiative) and second (microphysical) indirect effects are explored. We test the sensitivity of our results to cloud parameterization assumptions that control the vertical distribution of cloud occurrence, the autoconversion rate, and the aerosol scavenging rate, each of which feeds back significantly on the model aerosol burden. The global mean aerosol indirect effect for all three aerosol types ranges from -1.55 to -4.36 W/sq m in our simulations. The results are quite sensitive to the pre-industrial background aerosol burden, with low pre-industrial burdens giving strong indirect effects, and to a lesser extent to the anthropogenic aerosol burden, with large burdens giving somewhat larger indirect effects. Because of this dependence on the background aerosol, model diagnostics such as albedo-particle size correlations and column cloud susceptibility, for which satellite validation products are available, are not good predictors of the resulting indirect effect.

Infection and diabetes: the case for glucose control.

PubMed

Rayfield, E J; Ault, M J; Keusch, G T; Brothers, M J; Nechemias, C; Smith, H

1982-03-01

This review summarizes data concerning the host resistance to infection in diabetes and the influence of an acute infection upon the endocrinologic-metabolite status of the diabetic patient. While it is well known that acute infections lead to difficulty in controlling blood sugar levels and the infection is the most frequently documented cause of ketoacidosis, controversy persists as to whether or not patients with diabetes mellitus are more susceptible to infection than age- and sex-matched nondiabetic control subjects. Our data obtained from the charts of 241 diabetic patients who were being followed as outpatients show a striking direct correlation between the overall prevalence of infection (p less than 0.001) and the mean plasma glucose levels (representing three or more fasting glucose determinations taken at times when no evidence of infection existed). There is a significant diminution in intracellular bactericidal activity of leukocytes with Staphylococcus aureus and Escherichia coli in subjects with poorly controlled diabetes in comparison with the control group. Serum opsonic activity for both Staph. Aureus and E. coli were significantly lower than in the control subjects. Taken together, the results from published reports as well as our data suggest to us that good control of blood sugar in diabetic patients is a desirable goal in the prevention of certain infections (Candida vaginitis, for example) and to ensure maintenance of normal host defense mechanisms that determine resistance and response to infection.

Production of Highly Charged Pharmaceutical Aerosols Using a New Aerosol Induction Charger

PubMed Central

Golshahi, Laleh; Longest, P. Worth; Holbrook, Landon; Snead, Jessica; Hindle, Michael

2015-01-01

Purpose Properly charged particles can be used for effective lung targeting of pharmaceutical aerosols. The objective of this study was to characterize the performance of a new induction charger that operates with a mesh nebulizer for the production of highly charged submicrometer aerosols to bypass the mouth-throat and deliver clinically relevant doses of medications to the lungs. Methods Variables of interest included combinations of model drug (i.e. albuterol sulfate) and charging excipient (NaCl) as well as strength of the charging field (1–5 kV/cm). Aerosol charge and size were measured using a modified electrical low pressure impactor system combined with high performance liquid chromatography. Results At the approximate mass median aerodynamic diameter (MMAD) of the aerosol (~ 0.4 μm), the induction charge on the particles was an order of magnitude above the field and diffusion charge limit. The nebulization rate was 439.3 ± 42.9 μl/min, which with a 0.1 % w/v solution delivered 419.5 ± 34.2 μg of medication per minute. A new correlation was developed to predict particle charge produced by the induction charger. Conclusions The combination of the aerosol induction charger and predictive correlations will allow for the practical generation and control of charged submicrometer aerosols for targeting deposition within the lungs. PMID:25823649

Contrasting Secondary Organic Aerosol Formation in Aerosol Liquid Water During Summer and Winter

NASA Astrophysics Data System (ADS)

El-Sayed, M.; Hennigan, C. J.

2017-12-01

In this study, we characterize the formation of aqueous secondary organic aerosols (aqSOA) in the eastern United States during summer and winter. The aim was to identify the main factors affecting the reversible and irreversible uptake of water-soluble organic gases to aerosol liquid water under variable influence from biogenic and anthropogenic sources. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was measured in Baltimore, MD using a recently developed on-line method. The formation of aqSOA was observed during the summer and the winter; however, the amount of aqSOA varied significantly between the two seasons, as did the reversible and irreversible nature of the uptake. While the availability of aerosol liquid water (ALW) predominantly controlled aqSOA formation in the summer, wintertime aqSOA formation was limited by precursor VOCs as well. During the summer, aqSOA formation was tightly linked with isoprene oxidation, while the aqSOA formed in the winter was associated with biomass burning. Irreversible aqSOA was formed in both seasons; however, reversible aqSOA was only observed in the summer. Overall, these results demonstrate the importance of multi-phase chemistry in aerosol formation and underscore the significance of soluble organic gases partitioning to aerosol water both reversibly and irreversibly.

[Medical technologist as a member of infection control team].

PubMed

Okuzumi, Katsuko; Ieiri, Tamio

2005-11-01

For the prevention of infection at institutions, an Anti-nosocomial Infection Committee or an Infection Control Team (ICT) is organized at each institution according to its scale. We report the present status of the ICT managed mainly by medical technologists engaged in microbiological examination (certified medical microbiological technologists) at Dokkyo University School of Medicine. Since this hospital is an educational hospital, the department of clinical laboratory medicine cooperates with the microbiological laboratory of the clinical laboratory in infection control education of medical workers (such as medical students, nursing students, physicians and nurses) in infection diagnosis, infection control/infection management. Since infection control is achieved by improvement in hygiene knowledge and its practice in all citizens, we also attached importance to publicity activities associated with microbiology for patients, their families, and all medical workers.

The role of 'no-touch' automated room disinfection systems in infection prevention and control.

PubMed

Otter, J A; Yezli, S; Perl, T M; Barbut, F; French, G L

2013-01-01

Surface contamination in hospitals is involved in the transmission of pathogens in a proportion of healthcare-associated infections. Admission to a room previously occupied by a patient colonized or infected with certain nosocomial pathogens increases the risk of acquisition by subsequent occupants; thus, there is a need to improve terminal disinfection of these patient rooms. Conventional disinfection methods may be limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. These problems can be reduced by the use of 'no-touch' automated room disinfection (NTD) systems. To summarize published data related to NTD systems. Pubmed searches for relevant articles. A number of NTD systems have emerged, which remove or reduce reliance on the operator to ensure distribution, contact time and process repeatability, and aim to improve the level of disinfection and thus mitigate the increased risk from the prior room occupant. Available NTD systems include hydrogen peroxide (H(2)O(2)) vapour systems, aerosolized hydrogen peroxide (aHP) and ultraviolet radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. Typically, there is a trade-off between time and effectiveness among NTD systems. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints. NTD systems are gaining acceptance as a useful tool for infection prevention and control. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Background aerosol over the Himalayas and Tibetan Plateau: observed characteristics of aerosol mass loading

NASA Astrophysics Data System (ADS)

Liu, B.; Cong, Z.; Wang, Y.; Xin, J.; Wan, X.; Pan, Y.; Liu, Z.; Wang, Y.; Zhang, G.; Kang, S.

2016-12-01

To investigate the atmospheric aerosols of the Himalayas and Tibetan Plateau (HTP), an observation network was established within the region's various ecosystems, including at Ngari, Qomolangma (QOMS), Nam Co, and SouthEastern Tibetan (SET) stations. In this paper we illustrate aerosol mass loadings by integrating in situ measurements with satellite and ground-based remote sensing datasets for the 2011-2013 period, on both local and large scales. Mass concentrations of these surface atmospheric aerosols were relatively low and varied with land cover, showing a general tendency of Ngari and QOMS (barren sites) > Nam Co (grassland site) > SET (forest site). Bimodal mass distributions of size-segregated particles were found at all sites, with a relatively small peak in accumulation mode and a more notable peak in coarse mode. Diurnal variations in fine aerosol masses generally displayed a bi-peak pattern at the QOMS, Nam Co and SET stations and a single-peak pattern at the Ngari station, controlled by the effects of local geomorphology, mountain-valley breeze circulation and aerosol emissions. Combining surface aerosols data and atmospheric-column aerosol optical properties, the TSP mass and aerosol optical depth (AOD) of the Multi-angle Imaging Spectroradiometer (MISR) generally decreased as land cover changed from barren to forest, in inverse relation to the PM2.5 ratios. The seasonality of aerosol mass parameters was land-cover dependent. Over forest and grassland areas, TSP mass, PM2.5 mass, MISR-AOD and fine-mode AOD were higher in spring and summer, followed by relatively lower values in autumn and winter. At the barren site (the QOMS station), there were inconsistent seasonal variations between surface TSP mass (PM2.5 mass) and atmospheric column AOD (fine-mode AOD). Our findings implicate that, HTP aerosol masses (especially their reginal characteristics and fine particle emissions) need to be treated sensitively in relation to assessments of their climatic

Infrared sensor-based aerosol sanitization system for controlling Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on fresh produce.

PubMed

Kim, Sang-Oh; Ha, Jae-Won; Park, Ki-Hwan; Chung, Myung-Sub; Kang, Dong-Hyun

2014-06-01

An economical aerosol sanitization system was developed based on sensor technology for minimizing sanitizer usage, while maintaining bactericidal efficacy. Aerosol intensity in a system chamber was controlled by a position-sensitive device and its infrared value range. The effectiveness of the infrared sensor-based aerosolization (ISA) system to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on spinach leaf surfaces was compared with conventional aerosolization (full-time aerosol treated), and the amount of sanitizer consumed was determined after operation. Three pathogens artificially inoculated onto spinach leaf surfaces were treated with aerosolized peracetic acid (400 ppm) for 15, 30, 45, and 60 min at room temperature (22 ± 2°C). Using the ISA system, inactivation levels of the three pathogens were equal or better than treatment with conventional full-time aerosolization. However, the amount of sanitizer consumed was reduced by ca. 40% using the ISA system. The results of this study suggest that an aerosol sanitization system combined with infrared sensor technology could be used for transportation and storage of fresh produce efficiently and economically as a practical commercial intervention.

Perceptions of Clostridium difficile infections among infection control professionals in Taiwan.

PubMed

Hung, Yuan-Pin; Lee, Jen-Chieh; Lin, Hsiao-Ju; Chiu, Chun-Wei; Wu, Jia-Ling; Liu, Hsiao-Chieh; Huang, I-Hsiu; Tsai, Pei-Jane; Ko, Wen-Chien

2017-08-01

High Clostridium difficile colonization and infection rates among hospitalized patients had been noted in Taiwan. Nevertheless, the cognition about clinical diagnosis and management of CDI among infection control professionals in Taiwan is not clear. A 24-item survey questionnaire about the diagnosis, therapy, or infection control policies toward CDI was distributed in the annual meeting of the Infectious Disease Society of Taiwan (IDST) in October 2015 and Infectious Control Society of Taiwan (ICST) in April 2016. Totally 441 individuals responded to the survey, and 280 (63.5%) participants would routinely monitor the prevalence of CDI and 347 (78.7%) reported the formulation of infection control policies of CDI in their hospital, including contact precaution (75.7%), wearing gloves (88.9%) or dressing (80.0%) at patient care, single room isolation (49.7%), preference of soap or disinfectant-based sanitizer (83.2%) and avoidance of alcohol-based sanitizer (63.3%), and environmental disinfection with 1000 ppm bleach (87.1%). For the timing of contact precaution discontinuation isolation for CDI patients, most (39.9%) participants suggested the time point of the absence of C. difficile toxin in feces. To treat mild CDI, most (61.9%) participants preferred oral metronidazole, and for severe CDI 26.1% would prescribe oral vancomycin as the drug of choice. There were substantial gaps in infection control polices and therapeutic choices for CDI between international guidelines and the perceptions of medical professionals in Taiwan. Professional education program and the setup of guideline for CDI should be considered in Taiwan. Copyright © 2017. Published by Elsevier B.V.

Advancing infection control in dental care settings

PubMed Central

Cleveland, Jennifer L.; Bonito, Arthur J.; Corley, Tammy J.; Foster, Misty; Barker, Laurie; Brown, G. Gordon; Lenfestey, Nancy; Lux, Linda

2015-01-01

Background and Overview The authors set out to identify factors associated with implementation by U.S. dentists of four practices first recommended in the Centers for Disease Control and Prevention’s Guidelines for Infection Control in Dental Health-Care Settings—2003. Methods In 2008, the authors surveyed a stratified random sample of 6,825 U.S. dentists. The response rate was 49 percent. The authors gathered data regarding dentists’ demographic and practice characteristics, attitudes toward infection control, sources of instruction regarding the guidelines and knowledge about the need to use sterile water for surgical procedures. Then they assessed the impact of those factors on the implementation of four recommendations: having an infection control coordinator, maintaining dental unit water quality, documenting percutaneous injuries and using safer medical devices, such as safer syringes and scalpels. The authors conducted bivariate analyses and proportional odds modeling. Results Responding dentists in 34 percent of practices had implemented none or one of the four recommendations, 40 percent had implemented two of the recommendations and 26 percent had implemented three or four of the recommendations. The likelihood of implementation was higher among dentists who acknowledged the importance of infection control, had practiced dentistry for less than 30 years, had received more continuing dental education credits in infection control, correctly identified more surgical procedures that require the use of sterile water, worked in larger practices and had at least three sources of instruction regarding the guidelines. Dentists with practices in the South Atlantic, Middle Atlantic or East South Central U.S. Census divisions were less likely to have complied. Conclusions Implementation of the four recommendations varied among U.S. dentists. Strategies targeted at raising awareness of the importance of infection control, increasing continuing education

New Satellite Project Aerosol-UA: Remote Sensing of Aerosols in the Terrestrial Atmosphere

NASA Technical Reports Server (NTRS)

Milinevsky, G.; Yatskiv, Ya.; Degtyaryov, O.; Syniavskyi, I.; Mishchenko, Michael I.; Rosenbush, V.; Ivanov, Yu.; Makarov, A.; Bovchaliuk, A.; Danylevsky, V.;

Intervention for medical students: effective infection control.

PubMed

Calabro, K; Weltge, A; Parnell, S; Kouzekanani, K; Ramirez, E

1998-08-01

Needlestick injuries, which lead to the transmission of hepatitis B, hepatitis C, and the AIDS virus, are a potentially serious threat to students during their clinical experiences. Exposure to infectious diseases, blood, and hazardous body fluids is one of the most frequently reported injury events by medical students at a health science center in the southwestern region of the United States. This study was conducted to determine the effectiveness of a customized intervention about infection control for second-year medical students (N = 200). Preparation for the intervention included a needs assessment, which included both qualitative and quantitative research methods that incorporated input from fourth-year medical students, medical staff members, and local hospital infection control specialists. The intervention included a pretest, a lecture, a demonstration of standard precautions and infection control procedure with 2 clinical scenarios, an exercise on proper handwashing, and a posttest. The evaluation of the intervention demonstrated a significant increase in posttest knowledge scores about infection control (from 12.6 +/- 2.1 pretest to 16.5 +/- 1.8 posttest, P < .001). Medical students showed a significant knowledge increase about infection control after participating in the intervention . Thus we recommend that all medical colleges and universities develop and evaluate a similar customized intervention for their medical students.

Loss in lung volume and changes in the immune response demonstrate disease progression in African green monkeys infected by small-particle aerosol and intratracheal exposure to Nipah virus.

PubMed

Cong, Yu; Lentz, Margaret R; Lara, Abigail; Alexander, Isis; Bartos, Christopher; Bohannon, J Kyle; Hammoud, Dima; Huzella, Louis; Jahrling, Peter B; Janosko, Krisztina; Jett, Catherine; Kollins, Erin; Lackemeyer, Matthew; Mollura, Daniel; Ragland, Dan; Rojas, Oscar; Solomon, Jeffrey; Xu, Ziyue; Munster, Vincent; Holbrook, Michael R

2017-04-01

Nipah virus (NiV) is a paramyxovirus (genus Henipavirus) that emerged in the late 1990s in Malaysia and has since been identified as the cause of sporadic outbreaks of severe febrile disease in Bangladesh and India. NiV infection is frequently associated with severe respiratory or neurological disease in infected humans with transmission to humans through inhalation, contact or consumption of NiV contaminated foods. In the work presented here, the development of disease was investigated in the African Green Monkey (AGM) model following intratracheal (IT) and, for the first time, small-particle aerosol administration of NiV. This study utilized computed tomography (CT) and magnetic resonance imaging (MRI) to temporally assess disease progression. The host immune response and changes in immune cell populations over the course of disease were also evaluated. This study found that IT and small-particle administration of NiV caused similar disease progression, but that IT inoculation induced significant congestion in the lungs while disease following small-particle aerosol inoculation was largely confined to the lower respiratory tract. Quantitative assessment of changes in lung volume found up to a 45% loss in IT inoculated animals. None of the subjects in this study developed overt neurological disease, a finding that was supported by MRI analysis. The development of neutralizing antibodies was not apparent over the 8-10 day course of disease, but changes in cytokine response in all animals and activated CD8+ T cell numbers suggest the onset of cell-mediated immunity. These studies demonstrate that IT and small-particle aerosol infection with NiV in the AGM model leads to a severe respiratory disease devoid of neurological indications. This work also suggests that extending the disease course or minimizing the impact of the respiratory component is critical to developing a model that has a neurological component and more accurately reflects the human condition.

Factors controlling the solubility of trace metals in atmospheric aerosols over the Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Nikolaou, Panagiota; Mihalopoulos, Nikolaos; Kanakidou, Maria

2015-04-01

Atmospheric input of aerosols is recognized, as an important source of nutrients, for the oceans. The chemical interactions between aerosols and varying composition of air masses lead to different coating of their surfaces with sulfate, nitrate and organic compounds, increasing their solubility and their role as a carrier of nutrients and pollutants in ecosystems. Recent works have highlighted that atmospheric inputs of nutrients and trace metals can considerably influence the marine ecosystem functioning at semi-enclosed or enclosed water bodies such as the eastern Mediterranean. The current work aims to determine the sources and the factors controlling the variability of nutrients in the eastern Mediterranean. Special focus has been given on trace elements solubility, considered either as key nutrients for phytoplankton growth such as iron (Fe), phosphorus (P) or inhibitors such as copper (Cu). This has been accomplished by analyzing size segregated aerosol samples collected at the background site of Finokalia in Crete for an entire year. Phosphorus concentrations indicate important increases in air masses influenced both by anthropogenic activities in the northeast European countries and by dust outbreaks. The last is confirmed by the correlation observed between total P and dust concentrations and by the air mass backward trajectories computed by running the NOAA Hysplit Model (Hybrid Single - Particle Langrangian Integrated Trajectory (http://www.arl.noaa.gov/ready/hysplit4.html). Overall 73% of total P has been found to be associated with anthropogenic sources. The solubility of P and Fe has been found to be closely related to the acidity (pH) and dust amount in aerosols. The aerosol pH was predicted using thermodynamic modeling (ISORROPIA-II), meteorological observations (RH, T), and gas/particle observations. More specifically P and Fe solubility appears to be inversely related to the crustal elements levels, while it increases in acidic environment. The

Aerosol Properties and Radiative Forcing over Kanpur during Severe Aerosol Loading Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaskaoutis, D. G.; Sinha, P. R.; Vinoj, V.

2013-11-01

Atmospheric aerosols over India exhibit large spatio-temporal fluctuation driven by the local monsoon system, emission rates and seasonally-changed air masses. The northern part of India is well-known for its high aerosol loading throughout the year due to anthropogenic emissions, dust influence and biomass burning. On certain circumstances and, under favorable weather conditions, the aerosol load can be severe, causing significant health concerns and climate implications. The present work analyzes the aerosol episode (AE) days and examines the modification in aerosol properties and radiative forcing during the period 2001-2010 based on Kanpur-AERONET sun photometer data. As AEs are considered the daysmore » having daily-mean aerosol optical depth (AOD) above the decadal mean + 1 STD (standard deviation); the threshold value is defined at 0.928. The results identify 277 out of 2095 days (13.2%) of AEs over Kanpur, which are most frequently observed during post-monsoon (78 cases, 18.6%) and monsoon (76, 14.7%) seasons due to biomass-burning episodes and dust influence, respectively. On the other hand, the AEs in winter and pre-monsoon are lower in both absolute and percentage values (65, 12.5% and 58, 9.1%, respectively). The modification in aerosol properties on the AE days is strongly related to season. Thus, in post-monsoon and winter the AEs are associated with enhanced presence of fine-mode aerosols and Black Carbon from anthropogenic pollution and any kind of burning, while in pre-monsoon and monsoon seasons they are mostly associated with transported dust. Aerosol radiative forcing (ARF) calculated using SBDART shows much more surface (~-69 to -97 Wm-2) and Top of Atmosphere cooling (-20 to -30 Wm-2) as well as atmospheric heating (~43 to 71 Wm-2) during the AE days compared to seasonal means. These forcing values are mainly controlled by the higher AODs and the modified aerosol characteristics (Angstrom α, SSA) during the AE days in each season and may

42 CFR 494.30 - Condition: Infection control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (with the exception of screening for hepatitis C), found in “Recommendations for Preventing Transmission of Infections Among Chronic Hemodialysis Patients,” developed by the Centers for Disease Control and... Patient Safety § 494.30 Condition: Infection control. The dialysis facility must provide and monitor a...

42 CFR 494.30 - Condition: Infection control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of Infections Among Chronic Hemodialysis Patients,” developed by the Centers for Disease Control and... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Infection control. 494.30 Section 494.30 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

42 CFR 494.30 - Condition: Infection control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of Infections Among Chronic Hemodialysis Patients,” developed by the Centers for Disease Control and... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Infection control. 494.30 Section 494.30 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

42 CFR 494.30 - Condition: Infection control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of Infections Among Chronic Hemodialysis Patients,” developed by the Centers for Disease Control and... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: Infection control. 494.30 Section 494.30 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

Induction of abnormal respiratory sounds by capsaicin in rats previously infected with Bordetella pertussis.

PubMed

Parton, R; Hall, E; Wardlaw, A C

1998-02-01

Sprague Dawley rats, previously infected with Phase-I Bordetella pertussis, developed more severe abnormal respiratory sounds than normal animals, but not coughing, when exposed to aerosolized capsaicin, one of several cough-inducing agents tested. Stethoscope examination suggested that greater production of pulmonary mucus might be occurring after capsaicin challenge of the infected animals, compared to the uninfected controls. Rats of three other strains gave characteristically different responses from the Sprague Dawleys. The administration of capsaicin to B. pertussis-infected rats may provide useful insights into the pathophysiology of excess mucus secretion in human pertussis.

Exploration of the link between Emiliania huxleyi bloom dynamics and aerosol fluxes to the lower Atmosphere

NASA Astrophysics Data System (ADS)

Trainic, M.

2013-12-01

Phytoplankton blooms are responsible for about 50% of the global photosynthesis, thus are a key component of the major nutrient cycles in the ocean. These blooms can be a significant source for flux of volatiles and aerosols, affecting physical chemical processes in the atmosphere. One of the most widely distributed and abundant phytoplankton species in the oceans is the coccolithophore Emiliania huxleyi. In this research, we explore the influence of the different stages of E. huxleyi bloom on the emission of primary aerosols. For this purpose, we conducted a series of controlled lab experiments to measure aerosol emissions during the growth of E. huxleyi. The cultures were grown in a specially designed growth chamber, and the aerosols were generated in a bubbling system. We collected the emitted aerosol particles on filters, and conducted a series of analysis. Scanning electron microscopy (SEM) analysis of the aerosols emitted from E.huxleyi 1216 cultures demonstrate emission of CaCO3 platelets from their exoskeleton into the air, while coccolithophores cells were absent. The results suggest that while healthy coccolithophore cells are too heavy to aerosolize, during cell lysis the coccoliths shed from the coccolithophore cells are emitted into the atmosphere. Therefore, aerosol production during bloom demise may be greater than from healthy E.huxleyi populations. We also investigated the size distribution of the aerosols at various stages of E. huxleyi growth. The presence of calcified cells greatly effects the size distribution of the emitted aerosol population. This work motivated us to explore aerosols emitted during E. huxleyi spring bloom, in a laboratory we constructed onboard the R/V Knorr research vessel, as part of the North Atlantic Virus Infection of Coccolithophore Expedition (June-July 2012). These results have far-reaching implications on the effect of E. huxleyi bloom dynamics on aerosol properties. We not only show that the E. huxleyi calcite

Clinically Significant Pocket Hematoma Increases Long-Term Risk of Device Infection: BRUISE CONTROL INFECTION Study.

PubMed

Essebag, Vidal; Verma, Atul; Healey, Jeff S; Krahn, Andrew D; Kalfon, Eli; Coutu, Benoit; Ayala-Paredes, Felix; Tang, Anthony S; Sapp, John; Sturmer, Marcio; Keren, Arieh; Wells, George A; Birnie, David H

2016-03-22

The BRUISE CONTROL trial (Bridge or Continue Coumadin for Device Surgery Randomized Controlled Trial) demonstrated that a strategy of continued warfarin during cardiac implantable electronic device surgery was safe and reduced the incidence of clinically significant pocket hematoma (CSH). CSH was defined as a post-procedure hematoma requiring further surgery and/or resulting in prolongation of hospitalization of at least 24 h, and/or requiring interruption of anticoagulation. Previous studies have inconsistently associated hematoma with the subsequent development of device infection; reasons include the retrospective nature of many studies, lack of endpoint adjudication, and differing subjective definitions of hematoma. The BRUISE CONTROL INFECTION (Bridge or Continue Coumadin for Device Surgery Randomized Controlled Trial Extended Follow-Up for Infection) prospectively examined the association between CSH and subsequent device infection. The study included 659 patients with a primary outcome of device-related infection requiring hospitalization, defined as 1 or more of the following: pocket infection; endocarditis; and bloodstream infection. Outcomes were verified by a blinded adjudication committee. Multivariable analysis was performed to identify predictors of infection. The overall 1-year device-related infection rate was 2.4% (16 of 659). Infection occurred in 11% of patients (7 of 66) with previous CSH and in 1.5% (9 of 593) without CSH. CSH was the only independent predictor and was associated with a >7-fold increased risk of infection (hazard ratio: 7.7; 95% confidence interval: 2.9 to 20.5; p < 0.0001). Empiric antibiotics upon development of hematoma did not reduce long-term infection risk. CSH is associated with a significantly increased risk of infection requiring hospitalization within 1 year following cardiac implantable electronic device surgery. Strategies aimed at reducing hematomas may decrease the long-term risk of infection. (Bridge or Continue

Day Care Infection Control Protocol.

ERIC Educational Resources Information Center

Seattle-King County Dept. of Public Health, Seattle, WA.

This day care infection control manual was assembled to provide technical guidance for the prevention and control of communicable diseases to child day care facilities in Seattle and King County, Washington. For each disease, the manual provides background information, public health control recommendations, and letters that can be used to…

Classifying aerosol type using in situ surface spectral aerosol optical properties

NASA Astrophysics Data System (ADS)

Schmeisser, Lauren; Andrews, Elisabeth; Ogren, John A.; Sheridan, Patrick; Jefferson, Anne; Sharma, Sangeeta; Kim, Jeong Eun; Sherman, James P.; Sorribas, Mar; Kalapov, Ivo; Arsov, Todor; Angelov, Christo; Mayol-Bracero, Olga L.; Labuschagne, Casper; Kim, Sang-Woo; Hoffer, András; Lin, Neng-Huei; Chia, Hao-Ping; Bergin, Michael; Sun, Junying; Liu, Peng; Wu, Hao

2017-10-01

Knowledge of aerosol size and composition is important for determining radiative forcing effects of aerosols, identifying aerosol sources and improving aerosol satellite retrieval algorithms. The ability to extrapolate aerosol size and composition, or type, from intensive aerosol optical properties can help expand the current knowledge of spatiotemporal variability in aerosol type globally, particularly where chemical composition measurements do not exist concurrently with optical property measurements. This study uses medians of the scattering Ångström exponent (SAE), absorption Ångström exponent (AAE) and single scattering albedo (SSA) from 24 stations within the NOAA/ESRL Federated Aerosol Monitoring Network to infer aerosol type using previously published aerosol classification schemes.Three methods are implemented to obtain a best estimate of dominant aerosol type at each station using aerosol optical properties. The first method plots station medians into an AAE vs. SAE plot space, so that a unique combination of intensive properties corresponds with an aerosol type. The second typing method expands on the first by introducing a multivariate cluster analysis, which aims to group stations with similar optical characteristics and thus similar dominant aerosol type. The third and final classification method pairs 3-day backward air mass trajectories with median aerosol optical properties to explore the relationship between trajectory origin (proxy for likely aerosol type) and aerosol intensive parameters, while allowing for multiple dominant aerosol types at each station.The three aerosol classification methods have some common, and thus robust, results. In general, estimating dominant aerosol type using optical properties is best suited for site locations with a stable and homogenous aerosol population, particularly continental polluted (carbonaceous aerosol), marine polluted (carbonaceous aerosol mixed with sea salt) and continental dust/biomass sites

Building new hospitals: a UK infection control perspective.

PubMed

Stockley, J M; Constantine, C E; Orr, K E

2006-03-01

Infection control input is vital throughout the planning, design and building stages of a new hospital project, and must continue through the commissioning (and decommissioning) process, evaluation and putting the facility into full clinical service. Many hospitals continue to experience problems months or years after occupying the new premises; some of these could have been avoided by infection control involvement earlier in the project. The importance of infection control must be recognized by the chief executive of the hospital trust and project teams overseeing the development. Clinical user groups and contractors must also be made aware of infection control issues. It is vital that good working relationships are built up between the infection control team (ICT) and all these parties. ICTs need the authority to influence the process. This may require their specific recognition by the Private Finance Initiative National Unit, the Department of Health or other relevant authorities. ICTs need training in how to read design plans, how to write effective specifications, and in other areas with which they may be unfamiliar. The importance of documentation and record keeping is paramount. External or independent validation of processes should be available, particularly in commissioning processes. Building design in relation to infection control needs stricter national regulations, allowing ICTs to focus on more local usage issues. Further research is needed to provide evidence regarding the relationship between building design and the prevalence of infection.

Infection control professionals' information-seeking preferences.

PubMed

Mortensen, Heidi J; Alexander, Jeffrey L; Nehrenz, Guy M; Porter, Cynthia

2013-03-01

The aims of this study were to: 1) establish whether infection control professionals (ICPs) who had access to and utilised medical librarian services for evidence-based medicine (EBM) research perceived this assistance to be useful and 2) to establish whether ICPs who used electronic or hard copy resources for EBM research perceived that those resources had a significant impact on their work. Convenience sampling was used to collect quantitative data via a questionnaire. Study participants were members of South-west and Western chapters of the Association for Professionals in Infection Control and Epidemiology. There were 264 questionnaires distributed in this study; 179 participants completed the questionnaire. The response rate for eligible respondents was 59.5% (157). Results indicated 56.7% (51) of the ICPs with librarian access reported requesting assistance from their work facility librarian. In reference to locating infection control information, 77.9% (95), 87.3% (124) and 93.3% (138) of ICPs found textbooks, journals and the Internet 'very useful' or 'useful', respectively. Study results indicated ICPs who used the assistance of medical librarians and/or hard copy or electronic resources for EBM research perceived such sources to be valuable for obtaining infection control information. © 2012 The authors. Health Information and Libraries Journal © 2012 Health Libraries Group.

Aerosol feed direct methanol fuel cell

NASA Technical Reports Server (NTRS)

Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

2002-01-01

Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.

Concentration Effects and Ion Properties Controlling the Fractionation of Halides during Aerosol Formation

NASA Technical Reports Server (NTRS)

Guzman, Marcelo I.; Athalye, Richa R.; Rodriguez, Jose M.

2012-01-01

During the aerosolization process at the sea surface, halides are incorporated into aerosol droplets, where they may play an important role in tropospheric ozone chemistry. Although this process may significantly contribute to the formation of reactive gas phase molecular halogens, little is known about the environmental factors that control how halides selectively accumulate at the air-water interface. In this study, the production of sea spray aerosol is simulated using electrospray ionization (ESI) of 100 nM equimolar solutions of NaCl, NaBr, NaI, NaNO2, NaNO3, NaClO4, and NaIO4. The microdroplets generated are analyzed by mass spectrometry to study the comparative enrichment of anions (f (Isub x-)) and their correlation with ion properties. Although no correlation exists between f (sub x-) and the limiting equivalent ionic conductivity, the correlation coefficient of the linear fit with the size of the anions R(sub x-), dehydration free-energy ?Gdehyd, and polarizability alpha, follows the order: (R(sub x-)(exp -2)) > (R(sub x-)(exp -1)) >(R(sub x-) > delta G(sub dehyd) > alpha. The same pure physical process is observed in H2O and D2O. The factor f (sub x-) does not change with pH (6.8-8.6), counterion (Li+, Na+, K+, and Cs+) substitution effects, or solvent polarity changes in methanol - and ethanol-water mixtures (0 <= xH2O <= 1). Sodium polysorbate 20 surfactant is used to modify the structure of the interface. Despite the observed enrichment of I- on the air-water interface of equimolar solutions, our results of seawater mimic samples agree with a model in which the interfacial composition is increasingly enriched in I- < Br- < Cl- over the oceanic boundary layer due to concentration effects in sea spray aerosol formation.

Method for detecting viruses in aerosols.

PubMed Central

Wallis, C; Melnick, J L; Rao, V C; Sox, T E

1985-01-01

A simple method with poliovirus as the model was developed for recovering human enteric viruses from aerosols. Filterite filters (pore size, 0.45 micron; Filterite Corp., Timonium, Md.) moistened with glycine buffer (pH 3.5) were used for adsorbing the aerosolized virus. No virus passed the filter, even with air flow rates of 100 liters/min. Virus recovery from the filter was achieved by rapid elution with 800 ml of glycine buffer, pH 10. The virus in the primary eluate was reconcentrated by adjusting the pH to 3.5, adding AlCl3 to 0.0005 M, collecting the virus on a 0.25-micron-pore Filerite disk (diameter, 25 mm) and and eluting with 6 ml of buffer, pH 10. With this method, virus could be detected regularly in aerosols produced by flushing when 3 X 10(8) PFU of poliovirus were present in the toilet bowl. Poliovirus-containing fecal material from two of four infants who had recently received oral polio vaccine also yielded virus in the aerosols when feces containing 2.4 X 10(7) to 4.5 X 10(7) PFU of virus had been added to the toilet bowl. Persons infected with a variety of natural enteric viruses are known to excrete this amount of virus in their daily stools. Images PMID:3004329

Evaluation of liquid aerosol transport through porous media

NASA Astrophysics Data System (ADS)

Hall, R.; Murdoch, L.; Falta, R.; Looney, B.; Riha, B.

2016-07-01

Application of remediation methods in contaminated vadose zones has been hindered by an inability to effectively distribute liquid- or solid-phase amendments. Injection as aerosols in a carrier gas could be a viable method for achieving useful distributions of amendments in unsaturated materials. The objectives of this work were to characterize radial transport of aerosols in unsaturated porous media, and to develop capabilities for predicting results of aerosol injection scenarios at the field-scale. Transport processes were investigated by conducting lab-scale injection experiments with radial flow geometry, and predictive capabilities were obtained by developing and validating a numerical model for simulating coupled aerosol transport, deposition, and multi-phase flow in porous media. Soybean oil was transported more than 2 m through sand by injecting it as micron-scale aerosol droplets. Oil saturation in the sand increased with time to a maximum of 0.25, and decreased with radial distance in the experiments. The numerical analysis predicted the distribution of oil saturation with only minor calibration. The results indicated that evolution of oil saturation was controlled by aerosol deposition and subsequent flow of the liquid oil, and simulation requires including these two coupled processes. The calibrated model was used to evaluate field applications. The results suggest that amendments can be delivered to the vadose zone as aerosols, and that gas injection rate and aerosol particle size will be important controls on the process.

Factors controlling the evaporation of secondary organic aerosol from α‐pinene ozonolysis

PubMed Central

Pajunoja, Aki; Tikkanen, Olli‐Pekka; Buchholz, Angela; Faiola, Celia; Väisänen, Olli; Hao, Liqing; Kari, Eetu; Peräkylä, Otso; Garmash, Olga; Shiraiwa, Manabu; Ehn, Mikael; Lehtinen, Kari; Virtanen, Annele

2017-01-01

Abstract Secondary organic aerosols (SOA) forms a major fraction of organic aerosols in the atmosphere. Knowledge of SOA properties that affect their dynamics in the atmosphere is needed for improving climate models. By combining experimental and modeling techniques, we investigated the factors controlling SOA evaporation under different humidity conditions. Our experiments support the conclusion of particle phase diffusivity limiting the evaporation under dry conditions. Viscosity of particles at dry conditions was estimated to increase several orders of magnitude during evaporation, up to 109 Pa s. However, at atmospherically relevant relative humidity and time scales, our results show that diffusion limitations may have a minor effect on evaporation of the studied α‐pinene SOA particles. Based on previous studies and our model simulations, we suggest that, in warm environments dominated by biogenic emissions, the major uncertainty in models describing the SOA particle evaporation is related to the volatility of SOA constituents. PMID:28503004

Challenge of N95 Filtering Facepiece Respirators with Viable H1N1 Influenza Aerosols (Postprint)

DTIC Science & Technology

2013-05-01

Response, US Department of Health and Human Services. references 1. Tellier R. Aerosol transmission of influenza A virus: a review of new studies. J R...5. Tellier R. Review of aerosol transmission of influenza A virus. Emerg Infect Dis 2006;12:1657–1662. 6. Bridges CB, Kuehnert MJ, Hall CB

Intragranulomatous necrosis in pulmonary granulomas is not related to resistance against Mycobacterium tuberculosis infection in experimental murine models induced by aerosol.

PubMed

Guirado, Evelyn; Gordillo, Sergi; Gil, Olga; Díaz, Jorge; Tapia, Gustavo; Vilaplana, Cristina; Ausina, Vicenç; Cardona, Pere-Joan

2006-04-01

Intragranulomatous necrosis is a primary feature in the natural history of human tuberculosis (TB). Unfortunately, this phenomenon is not usually seen in the experimental TB murine model. Artificial induction of this necrosis in pulmonary granulomas (INPG) may be achieved through aerosol inoculation of lipopolysaccharide (LPS) 3 weeks after Mycobacterium tuberculosis infection. At week 9 post-infection, the centre of primary granulomas became larger, showing eosinophilic necrosis. Interestingly, INPG induction was related to mice strains C57BL/6 and 129/Sv, but not to BALB/c and DBA/2. Furthermore, the same pattern was obtained with the induction of infection using a clinical M. tuberculosis strain (UTE 0335R) that naturally induces INPG. In all the mice strains tested, the study of pulmonary mRNA expression revealed a tendency to increase or to maintain the expression of RANTES, interferon-gamma, tumour necrosis factor and iNOS, in both LPS- and UTE 0335R-induced INPG, thus suggesting that this response must be necessary but not sufficient for inducing INPG. Our work supports that INPG induction is a local phenomenon unrelated to the resistant (C57BL/6 and BALB/c) or susceptible (129/Sv and DBA/2) background of mice strains against M. tuberculosis infection.

Stratospheric Aerosol Measurements

NASA Technical Reports Server (NTRS)

Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

1998-01-01

Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses

Ferrets develop fatal influenza after inhaling small particle aerosols of highly pathogenic avian influenza virus A/Vietnam/1203/2004 (H5N1)

PubMed Central

2010-01-01

Background There is limited knowledge about the potential routes for H5N1 influenza virus transmission to and between humans, and it is not clear whether humans can be infected through inhalation of aerosolized H5N1 virus particles. Ferrets are often used as a animal model for humans in influenza pathogenicity and transmissibility studies. In this manuscript, a nose-only bioaerosol inhalation exposure system that was recently developed and validated was used in an inhalation exposure study of aerosolized A/Vietnam/1203/2004 (H5N1) virus in ferrets. The clinical spectrum of influenza resulting from exposure to A/Vietnam/1203/2004 (H5N1) through intranasal verses inhalation routes was analyzed. Results Ferrets were successfully infected through intranasal instillation or through inhalation of small particle aerosols with four different doses of Influenza virus A/Vietnam/1203/2004 (H5N1). The animals developed severe influenza encephalomyelitis following intranasal or inhalation exposure to 101, 102, 103, or 104 infectious virus particles per ferret. Conclusions Aerosolized Influenza virus A/Vietnam/1203/2004 (H5N1) is highly infectious and lethal in ferrets. Clinical signs appeared earlier in animals infected through inhalation of aerosolized virus compared to those infected through intranasal instillation. PMID:20843329

Infection Control: MedlinePlus Health Topic

MedlinePlus

... Control and Prevention) VISA/VRSA (Vancomycin-Intermediate/Resistant Staphylococcus aureus) in Healthcare Settings (Centers for Disease Control and ... Whenever Possible. Article: Risk factors for methicillin-resistant Staphylococcus aureus colonization in the neonatal... Infection Control -- see more ...

Whole-body nanoparticle aerosol inhalation exposures.

PubMed

Yi, Jinghai; Chen, Bean T; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L; Stapleton, Phoebe A; Minarchick, Valerie C; Nurkiewicz, Timothy R

2013-05-07

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter < 200 nm and a geometric standard deviation σg < 2.5 (5). The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size (6), which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria (5). A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m(3) whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm(3)) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m(3)). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M

Whole-Body Nanoparticle Aerosol Inhalation Exposures

PubMed Central

Yi, Jinghai; Chen, Bean T.; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L.; Stapleton, Phoebe A.; Minarchick, Valerie C.; Nurkiewicz, Timothy R.

2013-01-01

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter < 200 nm and a geometric standard deviation σg < 2.5 5. The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size 6, which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria 5. A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m3 whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm3) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m3). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpreand Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is

A brief history of infection control - past and present.

PubMed

Forder, A A

2007-11-01

The scientific study of hospital or nosocomial cross-infection began during the first half of the 18th century, and from that time until the start of the 'Bacteriological Era' many of the most notable contributions originated in Scotland. However it was only 100 years later in 1858 that Florence Nightingale promoted the case for hospital reform. The real understanding of hospital infection followed upon the discoveries of Pasteur, Koch and Lister and the beginning of the 'Bacteriological Era'. The close of the 19th century saw the triumphs of hospital reform and asepsis and seemed to herald the final victory over hospital cross-infection. However, the victory was short-lived. It was soon realised that infections occurred not only in obstetric and surgical patients, but in medical patients as well, and that air could also be a source of infection. Streptococcal, staphylococcal and then Gram-negative bacilli as a cause of hospital infection became a focus of attention, as did antibiotic-resistant organisms. This paper looks briefly at the establishment of the control of infection doctor, infection control committee and infection control nurse as well as summarising the changes, problems and advances in infection control up to the present time.

Impacts of controlling biomass burning emissions on wintertime carbonaceous aerosol in Europe

NASA Astrophysics Data System (ADS)

Fountoukis, C.; Butler, T.; Lawrence, M. G.; Denier van der Gon, H. A. C.; Visschedijk, A. J. H.; Charalampidis, P.; Pilinis, C.; Pandis, S. N.

2014-04-01

We use a 3-D regional chemical transport model, with the latest advancements in the organic aerosol (OA) treatment, and an updated emission inventory for wood combustion to study the organic aerosol change in response to the replacement of current residential wood combustion technologies with pellet stoves. Simulations show a large decrease of fine organic aerosol (more than 60%) in urban and suburban areas during winter and decreases of 30-50% in elemental carbon levels in large parts of Europe. There is also a considerable decrease (around 40%) of oxidized OA, mostly in rural and remote regions. Total PM2.5 mass is predicted to decrease by 15-40% on average during the winter in continental Europe. Accurate representation of the intermediate volatility precursors of organic aerosol in the emission inventory is crucial in assessing the efficiency of such abatement strategies.

Preliminary investigation tests of novel antifungal topical aerosol

PubMed Central

Kapadia, Monali M.; Solanki, S. T.; Parmar, V.; Thosar, M. M.; Pancholi, S. S.

2012-01-01

Spray formulation can minimize pain and irritation experience during the application of conventional dosage forms. Econazole Nitrate is an active ingredient of the aerosol concentrate to be used for twice-daily application because of its long durability in the superficial layers of the fungal infected skin. The aim of this study is preliminary investigation of Econazole Nitrate spray by varying the concentrations of different constituents of the spray. The ratios of Propylene glycol (PG) and isopropyl myristate (IPM) were selected as independent variables in 22 full factorial designs, keeping the concentration of solvent, co-solvent and propellant LPG constant. Aerosol also contained Ethanol as solvent and Isopropyl alcohol as co-solvent. All ingredients of the aerosol were packaged in an aluminum container fitted with continuous-spray valves. Physical properties evaluated for the Econazole Nitrate spray included delivery rate, delivery amount, pressure, minimum fill, leakage, flammability, spray patterns, particle image and plume angle. Glass containers were used to study incompatibility between concentrate and propellant due to the ease of visible inspection. Isopropyl myristate at lower concentrate showed turbidity, while at high concentration it met the requirements for aerosol and produced Econazole Nitrate spray with expected characteristics. PMID:23066214

Spatial and temporal variations of aerosols around Beijing in summer 2006: 2. Local and column aerosol optical properties

NASA Astrophysics Data System (ADS)

Matsui, H.; Koike, M.; Kondo, Y.; Takegawa, N.; Fast, J. D.; PöSchl, U.; Garland, R. M.; Andreae, M. O.; Wiedensohler, A.; Sugimoto, N.; Zhu, T.

2010-11-01

Model calculations were conducted using the Weather Research and Forecasting model coupled with chemistry (WRF-chem) for the region around Beijing, China, in the summer of 2006, when the CAREBeijing-2006 intensive campaign was conducted. In this paper, we interpret aerosol optical properties in terms of aerosol mass concentrations and their chemical compositions by linking model calculations with measurements. The model calculations generally captured the observed variability of various surface and column aerosol optical parameters in and around Beijing. At the surface, the spatial and temporal variations of aerosol absorption and scattering coefficients corresponded well to those of elemental carbon and sulfate mass concentrations, respectively, and were controlled by local-scale (<100 km and <24 hours) and regional-scale (<500 km and <3 days) emissions, respectively. The contribution of secondary aerosols and their water uptake increased with altitude within the planetary boundary layer. This variation led to a considerable increase in column aerosol optical depth and was responsible for the differences in regional and temporal variations between surface and column aerosol optical properties around Beijing. These processes are expected to be common in other megacity regions as well. Model calculations, however, underestimated or overestimated the absolute levels of aerosol optical properties in and around Beijing by up to 60%. Sensitivity studies showed that these discrepancies were mostly due to the uncertainties in aerosol mixing state and aerosol density (affecting mass extinction efficiency) in the model calculations. Good agreement with measurements is achieved when these aerosol properties are accurately predicted or assumed; however, significant bias can result when these properties are inadequately treated, even if total aerosol mass concentrations are reproduced well in the model calculations.

Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to evaluate the NASA MERRA Aerosol Reanalysis

NASA Astrophysics Data System (ADS)

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2014-12-01

A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and Aerosol Absorption Optical Depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the South African and South American biomass burning regions indicates that revising the spectrally-dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons

Using the OMI aerosol index and absorption aerosol optical depth to evaluate the NASA MERRA Aerosol Reanalysis

NASA Astrophysics Data System (ADS)

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2015-05-01

A radiative transfer interface has been developed to simulate the UV aerosol index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and aerosol absorption optical depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the AErosol RObotic NETwork (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model-produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the southern African and South American biomass burning regions indicates that revising the spectrally dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons

Evaluation of Nosocomial Infection Control Programs in health services 1

PubMed Central

Menegueti, Mayra Gonçalves; Canini, Silvia Rita Marin da Silva; Bellissimo-Rodrigues, Fernando; Laus, Ana Maria

2015-01-01

OBJECTIVES: to evaluate the Nosocomial Infection Control Programs in hospital institutions regarding structure and process indicators. METHOD: this is a descriptive, exploratory and quantitative study conducted in 2013. The study population comprised 13 Nosocomial Infection Control Programs of health services in a Brazilian city of the state of São Paulo. Public domain instruments available in the Manual of Evaluation Indicators of Nosocomial Infection Control Practices were used. RESULTS: The indicators with the highest average compliance were "Evaluation of the Structure of the Nosocomial Infection Control Programs" (75%) and "Evaluation of the Epidemiological Surveillance System of Nosocomial Infection" (82%) and those with the lowest mean compliance scores were "Evaluation of Operational Guidelines" (58.97%) and "Evaluation of Activities of Control and Prevention of Nosocomial Infection" (60.29%). CONCLUSION: The use of indicators identified that, despite having produced knowledge about prevention and control of nosocomial infections, there is still a large gap between the practice and the recommendations. PMID:25806637

Association for Professionals in Infection Control and Epidemiology

MedlinePlus

... Prevention Strategist . View Issue American Journal of Infection Control—October 2017 10/26/2017 Highlights: International Infection ... info@apic.org Association for Professionals in Infection Control and Epidemiology, Inc.

[Critical role of clinical laboratories in hospital infection control].

PubMed

Yagi, Tetsuya

2010-11-01

The hospital infection control and prevention is recognized to be more and more important according to the advances in modern medical treatment and care. Clinical microbiology laboratory play critical roles in the hospital infection control as a member of infection control team (ICT). They are the first in a hospital to identify outbreak of MRSA in NICU and molecular epidemiological analysis of the isolates lead proper intervention of ICT to the concerned ward. From a viewpoint of infectious disease specialist, rapid and precise microbiological information is essential for the appropriate diagnosis and treatment of infectious diseases. Each medical technologist need to make efforts to understand the characteristics of the examinations for infectious diseases and send out information useful for clinical practices. In our hospital, with the participation of all members of medical technologists, rapid reporting system was developed for blood culture examinations, which greatly contribute to the appropriate treatment of bloodstream infections. Collaborations of clinical microbiology laboratory with other members of ICT realize high quality hospital infection control. They also need to be aware of themselves as good practitioners of infection control measures to prevent hospital infections.

Landscape fires dominate terrestrial natural aerosol - climate feedbacks

NASA Astrophysics Data System (ADS)

Scott, C.; Arnold, S.; Monks, S. A.; Asmi, A.; Paasonen, P.; Spracklen, D. V.

2017-12-01

The terrestrial biosphere is an important source of natural aerosol including landscape fire emissions and secondary organic aerosol (SOA) formed from biogenic volatile organic compounds (BVOCs). Atmospheric aerosol alters the Earth's climate by absorbing and scattering radiation (direct radiative effect; DRE) and by perturbing the properties of clouds (aerosol indirect effect; AIE). Natural aerosol sources are strongly controlled by, and can influence, climate; giving rise to potential natural aerosol-climate feedbacks. Earth System Models (ESMs) include a description of some of these natural aerosol-climate feedbacks, predicting substantial changes in natural aerosol over the coming century with associated radiative perturbations. Despite this, the sensitivity of natural aerosols simulated by ESMs to changes in climate or emissions has not been robustly tested against observations. Here we combine long-term observations of aerosol number and a global aerosol microphysics model to assess terrestrial natural aerosol-climate feedbacks. We find a strong positive relationship between the summertime anomaly in observed concentration of particles greater than 100 nm diameter and the anomaly in local air temperature. This relationship is reproduced by the model and driven by variability in dynamics and meteorology, as well as natural sources of aerosol. We use an offline radiative transfer model to determine radiative effects due to changes in two natural aerosol sources: landscape fire and biogenic SOA. We find that interannual variability in the simulated global natural aerosol radiative effect (RE) is negatively related to the global temperature anomaly. The magnitude of global aerosol-climate feedback (sum of DRE and AIE) is estimated to be -0.15 Wm-2 K-1 for landscape fire aerosol and -0.06 Wm-2 K-1 for biogenic SOA. These feedbacks are comparable in magnitude, but opposite in sign to the snow albedo feedback, highlighting the need for natural aerosol feedbacks to

Discourse of 'transformational leadership' in infection control.

PubMed

Koteyko, Nelya; Carter, Ronald

2008-10-01

The article explores the impact of the ;transformational leadership' style in the role of modern matron with regards to infection control practices. Policy and guidance on the modern matron role suggest that it is distinctive in its combination of management and clinical components, and in its reliance on transformational leadership. Senior nurses are therefore expected to motivate staff by creating high expectations, modelling appropriate behaviour, and providing personal attention to followers by giving respect and responsibility. In this article, we draw on policy documents and interview data to explore the potential impact of this new management style on infection control practices. Combining the techniques of discourse analysis and corpus linguistics, we identify examples where matrons appear to disassociate themselves from the role of ;an empowered manager' who has control over human and financial resources to resolve problems in infection control efficiently.

Modeling the Relationships Between Aerosol Properties and the Direct and Indirect Effects of Aerosols on Climate

NASA Technical Reports Server (NTRS)

Toon, Owen B.

1994-01-01

Aerosols may affect climate directly by scattering and absorbing visible and infrared energy, They may also affect climate indirectly by modifying the properties of clouds through microphysical processes, and by altering abundances of radiatively important gases through heterogeneous chemistry. Researchers understand which aerosol properties control the direct effect of aerosols on the radiation budget. Unfortunately, despite an abundance of data on certain types of aerosols, much work remains to be done to determine the values of these properties. For instance we have little idea about the global distribution, seasonal variation, or interannual variability of the aerosol optical depth. Also we do not know the visible light absorption properties of tropical aerosols which may contain much debris from slash and burn agriculture. A positive correlation between aerosol concentrations and albedos of marine stratus clouds is observed, and the causative microphysics is understood. However, models suggest that it is difficult to produce new particles in the marine boundary layer. Some modelers have suggested that the particles in the marine boundary layer may originate in the free troposphere and be transported into the boundary layer. Others argue that the aerosols are created in the marine boundary layer. There are no data linking aerosol concentration and cirrus cloud albedo, and models suggest cirrus properties may not be very sensitive to aerosol abundance. There is clear evidence of a radiatively significant change in the global lower stratospheric ozone abundance during the past few decades. These changes are caused by heterogeneous chemical reactions occurring on the surfaces of particles. The rates of these reactions depend upon the chemical composition of the particles. Although rapid advances in understanding heterogeneous chemistry have been made, much remains to be done.

A Global Data Assimilation System for Atmospheric Aerosol

NASA Technical Reports Server (NTRS)

daSilva, Arlindo

1999-01-01

We will give an overview of an aerosol data assimilation system which combines advances in remote sensing of atmospheric aerosols, aerosol modeling and data assimilation methodology to produce high spatial and temporal resolution 3D aerosol fields. Initially, the Goddard Aerosol Assimilation System (GAAS) will assimilate TOMS, AVHRR and AERONET observations; later we will include MODIS and MISR. This data assimilation capability will allows us to integrate complementing aerosol observations from these platforms, enabling the development of an assimilated aerosol climatology as well as a global aerosol forecasting system in support of field campaigns. Furthermore, this system provides an interactive retrieval framework for each aerosol observing satellites, in particular TOMS and AVHRR. The Goddard Aerosol Assimilation System (GAAS) takes advantage of recent advances in constituent data assimilation at DAO, including flow dependent parameterizations of error covariances and the proper consideration of model bias. For its prognostic transport model, GAAS will utilize the Goddard Ozone, Chemistry, Aerosol, Radiation and Transport (GOCART) model developed at NASA/GSFC Codes 916 and 910.3. GOCART includes the Lin-Rood flux-form, semi-Langrangian transport model with parameterized aerosol chemistry and physical processes for absorbing (dust and black carbon) and non-absorbing aerosols (sulfate and organic carbon). Observations and model fields are combined using a constituent version of DAO's Physical-space Statistical Analysis System (PSAS), including its adaptive quality control system. In this talk we describe the main components of this assimilation system and present preliminary results obtained by assimilating TOMS data.

CMAQ AEROSOL MODULE DEVELOPMENT RECENT ENHANCEMENTS & FUTURE PLANS

EPA Science Inventory

Recent enhancements to the CMAQ aerosol module will be reviewed briefly. These include revision of the secondary organic aerosol subroutine to improve numerical efficiency and control the growth of the accumulation mode standard deviation, revision of the nucleation subroutine t...

Skin penetration operators' knowledge and attitudes towards infection control.

PubMed

Oberdorfer, Aurmporn; Wiggers, John H; Considine, Robyn J; Bowman, Jenny; Cockburn, Jill

2003-01-01

To assess the knowledge and attitudes of owners/managers of commercial skin-penetration premises regarding infection control. A telephone survey was conducted with a randomly selected sample of 874 owners/managers. Participants appeared to lack knowledge of essential infection-control practices. Less than 39% correctly identified recommended disinfection procedures, and between 12% to 67% were not aware of inappropriate sterlization procedures. Almost all participants accepted the need for guidelines. Half acknowledged a need to improve their infection-control compliance, and most accepted having their premises regularly checked by the councils. There is a considerable opportunity to increase infection-control compliance among skin-penetration operators.

Substantial large-scale feedbacks between natural aerosols and climate

NASA Astrophysics Data System (ADS)

Scott, C. E.; Arnold, S. R.; Monks, S. A.; Asmi, A.; Paasonen, P.; Spracklen, D. V.

2018-01-01

The terrestrial biosphere is an important source of natural aerosol. Natural aerosol sources alter climate, but are also strongly controlled by climate, leading to the potential for natural aerosol-climate feedbacks. Here we use a global aerosol model to make an assessment of terrestrial natural aerosol-climate feedbacks, constrained by observations of aerosol number. We find that warmer-than-average temperatures are associated with higher-than-average number concentrations of large (>100 nm diameter) particles, particularly during the summer. This relationship is well reproduced by the model and is driven by both meteorological variability and variability in natural aerosol from biogenic and landscape fire sources. We find that the calculated extratropical annual mean aerosol radiative effect (both direct and indirect) is negatively related to the observed global temperature anomaly, and is driven by a positive relationship between temperature and the emission of natural aerosol. The extratropical aerosol-climate feedback is estimated to be -0.14 W m-2 K-1 for landscape fire aerosol, greater than the -0.03 W m-2 K-1 estimated for biogenic secondary organic aerosol. These feedbacks are comparable in magnitude to other biogeochemical feedbacks, highlighting the need for natural aerosol feedbacks to be included in climate simulations.

Effectiveness of short-term, enhanced, infection control support in improving compliance with infection control guidelines and practice in nursing homes: a cluster randomized trial.

PubMed

Gopal Rao, G; Jeanes, A; Russell, H; Wilson, D; Atere-Roberts, E; O'Sullivan, D; Donaldson, N

2009-10-01

In this prospective cluster randomized controlled trial we evaluated the impact of short-term provision of enhanced infection control support on infection control practice in nursing homes in South London. Twelve nursing homes were recruited, six each in intervention (300 residents) and control (265 residents) groups. Baseline observations of hand hygiene facilities, environmental cleanliness and safe disposal of clinical waste showed poor compliance in both groups. Post-intervention observations showed improvement in both groups. There was no statistical difference between the two groups in the compliance for hand hygiene facilities (P=0.69); environmental cleanliness (P=0.43) and safe disposal of clinical waste (P=0.96). In both groups, greatest improvement was in compliance with safe disposal of clinical waste and the least improvement was in hand hygiene facilities. Since infection control practice improved in intervention and control groups, we could not demonstrate that provision of short-term, enhanced, infection control support in nursing homes had a significant impact in infection control practice.

Experimental Characterization of Radiation Forcing due to Atmospheric Aerosols

NASA Astrophysics Data System (ADS)

Sreenivas, K. R.; Singh, D. K.; Ponnulakshmi, V. K.; Subramanian, G.

2011-11-01

Micro-meteorological processes in the nocturnal atmospheric boundary layer (NBL) including the formation of radiation-fog and the development of inversion layers are controlled by heat transfer and the vertical temperature distribution close to the ground. In a recent study, it has been shown that the temperature profile close to the ground in stably-stratified, NBL is controlled by the radiative forcing due to suspended aerosols. Estimating aerosol forcing is also important in geo-engineering applications to evaluate the use of aerosols to mitigate greenhouse effects. Modeling capability in the above scenarios is limited by our knowledge of this forcing. Here, the design of an experimental setup is presented which can be used for evaluating the IR-radiation forcing on aerosols under either Rayleigh-Benard condition or under conditions corresponding to the NBL. We present results indicating the effect of surface emissivities of the top and bottom boundaries and the aerosol concentration on the temperature profiles. In order to understand the observed enhancement of the convection-threshold, we have determined the conduction-radiation time constant of an aerosol laden air layer. Our results help to explain observed temperature profiles in the NBL, the apparent stability of such profiles and indicate the need to account for the effect of aerosols in climatic/weather models.

Computer-automated silica aerosol generator and animal inhalation exposure system

PubMed Central

McKinney, Walter; Chen, Bean; Schwegler-Berry, Diane; Frazer, Dave G.

2015-01-01

Inhalation exposure systems are necessary tools for determining the dose response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this study was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. An acoustical aerosol generator was developed which was capable of re-suspending particles from bulk powder. The aerosolized silica output from the generator was introduced into the throat of a venturi tube. The turbulent high-velocity air stream within the venturi tube increased the dispersion of the re-suspended powder. That aerosol was then used to expose small laboratory animals to constant aerosol concentrations, up to 20mg/m3, for durations lasting up to 8h. Particle distribution and morphology of the silica aerosol delivered to the exposure chamber were characterized to verify that a fully dispersed and respirable aerosol was being produced. The inhalation exposure system utilized a combination of airflow controllers, particle monitors, data acquisition devices and custom software with automatic feedback control to achieve constant and repeatable exposure environments. The automatic control algorithm was capable of maintaining median aerosol concentrations to within ±0.2 mg/m3 of a user selected target concentration during exposures lasting from 2 to 8 h. The system was able to reach 95% of the desired target value in <10min during the beginning phase of an exposure. This exposure system provided a highly automated tool for conducting inhalation toxicology studies involving silica particles. PMID:23796015

Informing Aerosol Transport Models With Satellite Multi-Angle Aerosol Measurements

NASA Technical Reports Server (NTRS)

Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.

2011-01-01

As the aerosol products from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the aerosol amount and type data products, and aerosol plume heights, to constrain aerosol transport models. We have demonstrated the ability to map aerosol air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the aerosol type information content, that varies depending upon retrieval conditions. We have shown that MISR aerosol type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution aerosol components in urban settings. We demonstrated the use of stereo imaging to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS aerosol optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining aerosol transport models, planet-wide.

Sources and Removal of Springtime Arctic Aerosol

NASA Astrophysics Data System (ADS)

Willis, M. D.; Burkart, J.; Bozem, H.; Kunkel, D.; Schulz, H.; Hanna, S.; Aliabadi, A. A.; Bertram, A. K.; Hoor, P. M.; Herber, A. B.; Leaitch, R.; Abbatt, J.

2017-12-01

The sources and removal mechanisms of pollution transported to Arctic regions are key factors in controlling the impact of short-lived climate forcing agents on Arctic climate. We lack a predictive understanding of pollution transport to Arctic regions largely due to poor understanding of removal mechanisms and aerosol chemical and physical processing both within the Arctic and during transport. We present vertically resolved observations of aerosol physical and chemical properties in High Arctic springtime. While much previous work has focused on characterizing episodic events of high pollutant concentrations transported to Arctic regions, here we focus on measurements made under conditions consistent with chronic Arctic Haze, which is more representative of the pollution seasonal maximum observed at long term monitoring stations. On six flights based at Alert and Eureka, Nunavut, Canada, we observe evidence for vertical variations in both aerosol sources and removal mechanisms. With support from model calculations, we show evidence for sources of partially neutralized aerosol with higher organic aerosol (OA) and black carbon content in the middle troposphere, compared to lower tropospheric aerosol with higher amounts of acidic sulfate. Further, we show evidence for aerosol depletion relative to carbon monoxide, both in the mid-to-upper troposphere and within the Arctic Boundary Layer (ABL). Dry deposition, with relatively low removal efficiency, was responsible for aerosol removal in the ABL while ice or liquid-phase scavenging was responsible for aerosol removal at higher altitudes during transport. Overall, we find that vertical variations in both regional and remote aerosol sources, and removal mechanisms, combine with long aerosol residence times to drive the properties of springtime Arctic aerosol.

What is the impact of natural variability and aerosol-cloud interaction on the effective radiative forcing of anthropogenic aerosol?

NASA Astrophysics Data System (ADS)

Fiedler, S.; Stevens, B.; Mauritsen, T.

2017-12-01

State-of-the-art climate models have persistently shown a spread in estimates of the effective radiative forcing (ERF) associated with anthropogenic aerosol. Different reasons for the spread are known, but their relative importance is poorly understood. In this presentation we investigate the role of natural atmospheric variability, global patterns of aerosol radiative effects, and magnitudes of aerosol-cloud interaction in controlling the ERF of anthropogenic aerosol (Fiedler et al., 2017). We use the Earth system model MPI-ESM1.2 for conducting ensembles of atmosphere-only simulations and calculate the shortwave ERF of anthropogenic aerosol at the top of the atmosphere. The radiative effects are induced with the new parameterisation MACv2-SP (Stevens et al., 2017) that prescribes observationally constrained anthropogenic aerosol optical properties and an associated Twomey effect. Firstly, we compare the ERF of global patterns of anthropogenic aerosol from the mid-1970s and today. Our results suggest that such a substantial pattern difference has a negligible impact on the global mean ERF, when the natural variability of the atmosphere is considered. The clouds herein efficiently mask the clear-sky contributions to the forcing and reduce the detectability of significant anthropogenic aerosol radiative effects in all-sky conditions. Secondly, we strengthen the forcing magnitude through increasing the effect of aerosol-cloud interaction by prescribing an enhanced Twomey effect. In that case, the different spatial pattern of aerosol radiative effects from the mid-1970s and today causes a moderate change (15%) in the ERF of anthropogenic aerosol in our model. This finding lets us speculate that models with strong aerosol-cloud interactions would show a stronger ERF change with anthropogenic aerosol patterns. Testing whether the anthropogenic aerosol radiative forcing is model-dependent under prescribed aerosol conditions is currently ongoing work using MACv2-SP in

Biology of the Coarse Aerosol Mode: Insights Into Urban Aerosol Ecology

NASA Astrophysics Data System (ADS)

Dueker, E.; O'Mullan, G. D.; Montero, A.

2015-12-01

Microbial aerosols have been understudied, despite implications for climate studies, public health, and biogeochemical cycling. Because viable bacterial aerosols are often associated with coarse aerosol particles, our limited understanding of the coarse aerosol mode further impedes our ability to develop models of viable bacterial aerosol production, transport, and fate in the outdoor environment, particularly in crowded urban centers. To address this knowledge gap, we studied aerosol particle biology and size distributions in a broad range of urban and rural settings. Our previously published findings suggest a link between microbial viability and local production of coarse aerosols from waterways, waste treatment facilities, and terrestrial systems in urban and rural environments. Both in coastal Maine and in New York Harbor, coarse aerosols and viable bacterial aerosols increased with increasing wind speeds above 4 m s-1, a dynamic that was observed over time scales ranging from minutes to hours. At a New York City superfund-designated waterway regularly contaminated with raw sewage, aeration remediation efforts resulted in significant increases of coarse aerosols and bacterial aerosols above that waterway. Our current research indicates that bacterial communities in aerosols at this superfund site have a greater similarity to bacterial communities in the contaminated waterway with wind speeds above 4 m s-1. Size-fractionated sampling of viable microbial aerosols along the urban waterfront has also revealed significant shifts in bacterial aerosols, and specifically bacteria associated with coarse aerosols, when wind direction changes from onshore to offshore. This research highlights the key connections between bacterial aerosol viability and the coarse aerosol fraction, which is important in assessments of production, transport, and fate of bacterial contamination in the urban environment.

Measurements of Semi-volatile Aerosol and Its Effect on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

NASA Astrophysics Data System (ADS)

Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

2013-12-01

Semi-volatile compounds, including particle-bound water, comprise a large part of aerosol mass and have a significant influence on aerosol lifecycle and its optical properties. Understanding the properties of semi-volatile compounds, especially those pertaining to gas/aerosol partitioning, is of critical importance for our ability to predict concentrations and properties of ambient aerosol. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of temperature and relative humidity on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). In parallel to these measurements, a long residence time temperature-stepping thermodenuder and a variable residence time constant temperature thermodenuder in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. It was found that both temperature and relative humidity have a strong effect on aerosol optical properties. The variable residence time thermodenuder data suggest that aerosol equilibrated fairly quickly, within 2 s, in contrast to other ambient observations. Preliminary analysis show that approximately 50% and 90% of total aerosol mass evaporated at temperatures of 100 C and 180C, respectively. Evaporation varied substantially with ambient aerosol loading and composition and meteorology. During course of this study, T50 (temperatures at which 50% aerosol mass evaporates) varied from 60 C to more than 120 C.

Today's minimal requirements for a practical dental office infection control and exposure control program.

PubMed

Terezhalmy, G T; Gitto, C A

1998-10-01

The current climate in society regarding infectious diseases in general, and herpes, hepatitis, and HIV infections in particular, dictates that today's dental practices must use effective infection control techniques. The Occupational Safety and Health Administration continues to inspect, cite, and fine health care facilities. More states are implementing regulations concerning the operation of health care facilities. Patients are becoming more sophisticated in their scrutinizing of the dental and medical professions' approach to asepsis. Media coverage of exposure incidents is becoming more intense. All these factors leave dentists no choice; they must implement appropriate infection control techniques. The life-time cost of effective infection control is far less than one malpractice settlement. Implementation of an effective infection control program to promote dental asepsis can be cost-effective. In addition, it can be a practice builder.

Improving implementation of infection control guidelines to reduce nosocomial infection rates: pioneering the report card.

PubMed

Yinnon, A M; Wiener-Well, Y; Jerassy, Z; Dor, M; Freund, R; Mazouz, B; Lupyan, T; Shapira, S; Attias, D; Assous, M V; Kopuit, P; Block, C; Raveh, D; Freier-Dror, Y; Moses, A E; Benenson, S

2012-07-01

Two detailed checklists were developed, based on published infection control guidelines, for daily use by infection control practitioners in departments and operating rooms. To assess the impact of the checklists on nosocomial infection rates in three hospitals over the course of one year. The checklists included 20 subheadings (± 150 items). Project nurses conducted rounds in the study (but not control) departments; during each round, the nurses selected 15-20 items for observation, marked the checklists according to appropriateness of observed behaviour and provided on-the-spot corrective education. Rates of adherence to the checklist, antibiotic use, number of obtained and positive cultures, and positive staff hand and patient environment cultures were reported monthly as a report card to relevant personnel and administrators. The rate of nosocomial infections was determined in the first and last months. The baseline nosocomial infection rate was similar in the study and control departments: 37/345 (11%) and 26/270 (10%) respectively. In the last month, the rate in the study department decreased to 16/383 (4%) (P<0.01); in the control it decreased insignificantly to 21/248 (8%) (not significant). No significant trends were detected in the number of obtained cultures, positive cultures, or antibiotic use. Adherence to guidelines ranged from 75% to 94% between the hospitals (P<0.001): the overall rate increased from 80% to 91% (P<0.01). The use of checklists during the conduct of infection control rounds, combined with monthly reports, was associated with a significant decrease in nosocomial infections in study departments. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

HIV and measures to control infection in general practice.

PubMed Central

Foy, C; Gallagher, M; Rhodes, T; Setters, J; Philips, P; Donaldson, C; Bond, J; Moore, M; Naji, S

1990-01-01

OBJECTIVE--To assess the impact of HIV on procedures to control infection in general practices. DESIGN--A postal questionnaire survey. SETTING--General practices throughout Britain. SUBJECTS--5359 General practitioners, 3429 (63.9%) of whom returned the questionnaire. MAIN OUTCOME MEASURE--Response to questionnaire on knowledge about HIV and policies for controlling infection. RESULTS--Most doctors (2018) had started to wear gloves when taking blood. Almost half (1510) had not resheathed needles previously but a further 776 had adopted this policy because of HIV. Over half of the doctors did not know or were unsure about the risk of infection from needlestick injuries, and 1759 had no practice policy for controlling infection. CONCLUSIONS--Many doctors are uncertain about measures to control infection in general practice. More information and advice are needed to help doctors develop policies to protect patients and staff. PMID:2344517

Particle Size Distribution of Serratia marcescens Aerosols Created During Common Laboratory Procedures and Simulated Laboratory Accidents

PubMed Central

Kenny, Michael T.; Sabel, Fred L.

1968-01-01

Andersen air samplers were used to determine the particle size distribution of Serratia marcescens aerosols created during several common laboratory procedures and simulated laboratory accidents. Over 1,600 viable particles per cubic foot of air sampled were aerosolized during blending operations. More than 98% of these particles were less than 5 μ in size. In contrast, 80% of the viable particles aerosolized by handling lyophilized cultures were larger than 5 μ. Harvesting infected eggs, sonic treatment, centrifugation, mixing cultures, and dropping infectious material produced aerosols composed primarily of particles in the 1.0- to 7.5-μ size range. Images Fig. 1 PMID:4877498

Variability in Nose-to-Lung Aerosol Delivery

PubMed Central

Walenga, Ross L; Tian, Geng; Hindle, Michael; Yelverton, Joshua; Dodson, Kelley; Longest, P. Worth

2014-01-01

Nasal delivery of lung targeted pharmaceutical aerosols is ideal for drugs that need to be administered during high flow nasal cannula (HFNC) gas delivery, but based on previous studies losses and variability through both the delivery system and nasal cavity are expected to be high. The objective of this study was to assess the variability in aerosol delivery through the nose to the lungs with a nasal cannula interface for conventional and excipient enhanced growth (EEG) delivery techniques. A database of nasal cavity computed tomography (CT) scans was collected and analyzed, from which four models were selected to represent a wide range of adult anatomies, quantified based on the nasal surface area-to-volume ratio (SA/V). Computational fluid dynamics (CFD) methods were validated with existing in vitro data and used to predict aerosol delivery through a streamlined nasal cannula and the four nasal models at a steady state flow rate of 30 L/min. Aerosols considered were solid particles for EEG delivery (initial 0.9 μm and 1.5 μm aerodynamic diameters) and conventional droplets (5 μm) for a control case. Use of the EEG approach was found to reduce depositional losses in the nasal cavity by an order of magnitude and substantially reduce variability. Specifically, for aerosol deposition efficiency in the four geometries, the 95% confidence intervals (CI) for 0.9 and 5 μm aerosols were 2.3-3.1 and 15.5-66.3%, respectively. Simulations showed that the use of EEG as opposed to conventional methods improved delivered dose of aerosols through the nasopharynx, expressed as penetration fraction (PF), by approximately a factor of four. Variability of PF, expressed by the coefficient of variation (CV), was reduced by a factor of four with EEG delivery compared with the control case. Penetration fraction correlated well with SA/V for larger aerosols, but smaller aerosols showed some dependence on nasopharyngeal exit hydraulic diameter. In conclusion, results indicated that

[Infection control and hand hygiene in nursing homes in Oslo].

PubMed

Sie, Ingrid; Thorstad, Margrete; Andersen, Bjørg Marit

2008-06-26

Nosocomial infections and transmission can be substantially reduced by good infection control. The laws and regulations for infection control in heath care institutions emphasize establishment of infection control programs and improved hand hygiene. Our study reviews some factors that are important for practicing adequate hand hygiene (knowledge about infection control and hand-washing facilities). Health care workers (HCW) in nursing homes in Oslo participated in this study in 2006-2007. A questionnaire was made and SPSS was used to analyse the data . 70.7% of 324 HCW (in 42 nursing homes) answered the questionnaires. Nearly all of the respondents (95.6%) knew about the written procedures for hygiene and infection control; 88.5% knew that an infection control program was in place and about 50% had received information through internal education. Three of four had read the National guidelines for hand hygiene, 77.5% thought that hand disinfection was more effective than hand washing, and 97% reported hand hygiene after contact with a patient having an infection. Dispensers for hand disinfection were situated at central work places. At the same time, 17.9% informed that they worked in more than one place at the same time. This study confirms that most nursing homes in Oslo have an infection control program and training that improves the knowledge and awareness of hand hygiene among HCWs. However, the fact that nursing homes in Oslo have the resources, knowledge and education, is not the same as compliance.

Ovine progressive pneumonia virus is transmitted more effectively via aerosol nebulization than oral administration

USDA-ARS?s Scientific Manuscript database

A new method of experimental infection of ovine progressive pneumonia virus (OPPV), aerosol nebulization (Nb), was compared to intravenous (IV) and oral (PO) methods of experimental infection. Seven month old lambs were given 3.5 × 107 TCID50 of Dubois OPPV LMH19 isolate using IV, PO, or Nb methods ...

Cough Aerosols of Mycobacterium tuberculosis in the Prediction of Incident Tuberculosis Disease in Household Contacts

PubMed Central

Jones-López, Edward C.; Acuña-Villaorduña, Carlos; Ssebidandi, Martin; Gaeddert, Mary; Kubiak, Rachel W.; Ayakaka, Irene; White, Laura F.; Joloba, Moses; Okwera, Alphonse; Fennelly, Kevin P.

2016-01-01

Background. Tuberculosis disease develops in only 5%–10% of humans infected with Mycobacterium tuberculosis . The mechanisms underlying this variability remain poorly understood. We recently demonstrated that colony-forming units of M. tuberculosis in cough-generated aerosols are a better predictor of infection than the standard sputum acid-fast bacilli smear. We hypothesized that cough aerosol cultures may also predict progression to tuberculosis disease in contacts. Methods. We conducted a retrospective cohort study of 85 patients with smear-positive tuberculosis and their 369 household contacts in Kampala, Uganda. Index case patients underwent a standard evaluation, and we cultured M. tuberculosis from cough aerosols. Contacts underwent a standard evaluation at enrollment, and they were later traced to determine their tuberculosis status. Results. During a median follow-up of 3.9 years, 8 (2%) of the contacts developed tuberculosis disease. In unadjusted and adjusted analyses, incident tuberculosis disease in contacts was associated with sputum Mycobacterial Growth Indicator Tube culture (odds ratio, 8.2; 95% confidence interval, 1.1–59.2; P = .04), exposure to a high-aerosol tuberculosis case patient (6.0, 1.4–25.2; P = .01), and marginally, human immunodeficiency virus in the contact (6.11; 0.89–41.7; P = .07). We present data demonstrating that sputum and aerosol specimens measure 2 related but different phenomena. Conclusions. We found an increased risk of tuberculosis progression among contacts of high-aerosol case patients. The hypothesis that a larger infectious inoculum, represented by high aerosol production, determines the risk of disease progression deserves evaluation in future prospective studies. PMID:27025837

Cough Aerosols of Mycobacterium tuberculosis in the Prediction of Incident Tuberculosis Disease in Household Contacts.

PubMed

Jones-López, Edward C; Acuña-Villaorduña, Carlos; Ssebidandi, Martin; Gaeddert, Mary; Kubiak, Rachel W; Ayakaka, Irene; White, Laura F; Joloba, Moses; Okwera, Alphonse; Fennelly, Kevin P

2016-07-01

Tuberculosis disease develops in only 5%-10% of humans infected with Mycobacterium tuberculosis The mechanisms underlying this variability remain poorly understood. We recently demonstrated that colony-forming units of M. tuberculosis in cough-generated aerosols are a better predictor of infection than the standard sputum acid-fast bacilli smear. We hypothesized that cough aerosol cultures may also predict progression to tuberculosis disease in contacts. We conducted a retrospective cohort study of 85 patients with smear-positive tuberculosis and their 369 household contacts in Kampala, Uganda. Index case patients underwent a standard evaluation, and we cultured M. tuberculosis from cough aerosols. Contacts underwent a standard evaluation at enrollment, and they were later traced to determine their tuberculosis status. During a median follow-up of 3.9 years, 8 (2%) of the contacts developed tuberculosis disease. In unadjusted and adjusted analyses, incident tuberculosis disease in contacts was associated with sputum Mycobacterial Growth Indicator Tube culture (odds ratio, 8.2; 95% confidence interval, 1.1-59.2; P = .04), exposure to a high-aerosol tuberculosis case patient (6.0, 1.4-25.2; P = .01), and marginally, human immunodeficiency virus in the contact (6.11; 0.89-41.7; P = .07). We present data demonstrating that sputum and aerosol specimens measure 2 related but different phenomena. We found an increased risk of tuberculosis progression among contacts of high-aerosol case patients. The hypothesis that a larger infectious inoculum, represented by high aerosol production, determines the risk of disease progression deserves evaluation in future prospective studies. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

A clinical data repository enhances hospital infection control.

PubMed Central

Samore, M.; Lichtenberg, D.; Saubermann, L.; Kawachi, C.; Carmeli, Y.

1997-01-01

We describe the benefits of a relational database of hospital clinical data (Clinical Data Repository; CDR) for an infection control program. The CDR consists of > 40 Sybase tables, and is directly accessible for ad hoc queries by members of the infection control unit who have been granted privileges for access by the Information Systems Department. The data elements and functional requirements most useful for surveillance of nosocomial infections, antibiotic use, and resistant organisms are characterized. Specific applications of the CDR are presented, including the use of automated definitions of nosocomial infection, graphical monitoring of resistant organisms with quality control limits, and prospective detection of inappropriate antibiotic use. Hospital surveillance and quality improvement activities are significantly benefited by the availability of a querable set of tables containing diverse clinical data. PMID:9357588

The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

NASA Astrophysics Data System (ADS)

Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

2014-12-01

Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.

Guidelines for environmental infection control in health-care facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC).

PubMed

Sehulster, Lynne; Chinn, Raymond Y W

2003-06-06

The health-care facility environment is rarely implicated in disease transmission, except among patients who are immunocompromised. Nonetheless, inadvertent exposures to environmental pathogens (e.g., Aspergillus spp. and Legionella spp.) or airborne pathogens (e.g., Mycobacterium tuberculosis and varicella-zoster virus) can result in adverse patient outcomes and cause illness among health-care workers. Environmental infection-control strategies and engineering controls can effectively prevent these infections. The incidence of health-care--associated infections and pseudo-outbreaks can be minimized by 1) appropriate use of cleaners and disinfectants; 2) appropriate maintenance of medical equipment (e.g., automated endoscope reprocessors or hydrotherapy equipment); 3) adherence to water-quality standards for hemodialysis, and to ventilation standards for specialized care environments (e.g., airborne infection isolation rooms, protective environments, or operating rooms); and 4) prompt management of water intrusion into the facility. Routine environmental sampling is not usually advised, except for water quality determinations in hemodialysis settings and other situations where sampling is directed by epidemiologic principles, and results can be applied directly to infection-control decisions. This report reviews previous guidelines and strategies for preventing environment-associated infections in health-care facilities and offers recommendations. These include 1) evidence-based recommendations supported by studies; 2) requirements of federal agencies (e.g., Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Department of Labor, Occupational Safety and Health Administration, and U.S. Department of Justice); 3) guidelines and standards from building and equipment professional organizations (e.g., American Institute of Architects, Association for the Advancement of Medical Instrumentation, and American Society of Heating, Refrigeration, and Air

[Preliminary result on the nosocomial infection of severe acute respiratory syndrome in one hospital of Beijing].

PubMed

He, Yao; Jiang, Yong; Xing, Yu-bin; Zhong, Guang-lin; Wang, Lei; Sun, Zheng-ji; Jia, Hong; Chang, Qing; Wang, Yong; Ni, Bin; Chen, Shi-ping

2003-07-01

To study the transmission route of severe acute respiratory syndrome (SARS) nosocomial infection. Ten identified SARS patients were selected from a general hospital in March. Survey was carried out through a standardized questionnaire provided by Chinese Center for Disease Control and Prevention. Contents of the questionnaire would include: history of contact with SARS patient, route of infection, methods used for protection and so on. (1) Distribution os SARS patients were confined to 3 wards: 4, 5, and 6 on the 7, 8, 12, 13 and 14 floors in the west unit of the inpatient building. Most of the inpatients were elderly and having severe original diseases. (2) Index patients were the first generation source of transmission and they infected inpatients and medical staff, making them the second generation. People with latent infection who had close contact with SARS patients might also serve as the possible source of transmission. (3) The major transmission routes were: near distant droplet infection and close contact infection. There was also a clue to the probability of aerosol or droplet nuclei infection through air-conditioning and ventilation system. Nosocomial infection appeared to be the main characteristic of the SARS epidemic in the early stage of this hospital. Other than close contact and near space airborne transmission of SARS virus, the possibility of long-distance aerosol transmission called for further epidemiological and experimental studies in the future.

Loss in lung volume and changes in the immune response demonstrate disease progression in African green monkeys infected by small-particle aerosol and intratracheal exposure to Nipah virus

PubMed Central

Cong, Yu; Lentz, Margaret R.; Lara, Abigail; Alexander, Isis; Bartos, Christopher; Bohannon, J. Kyle; Hammoud, Dima; Huzella, Louis; Jahrling, Peter B.; Janosko, Krisztina; Jett, Catherine; Kollins, Erin; Lackemeyer, Matthew; Mollura, Daniel; Ragland, Dan; Rojas, Oscar; Solomon, Jeffrey; Xu, Ziyue; Munster, Vincent

2017-01-01

Nipah virus (NiV) is a paramyxovirus (genus Henipavirus) that emerged in the late 1990s in Malaysia and has since been identified as the cause of sporadic outbreaks of severe febrile disease in Bangladesh and India. NiV infection is frequently associated with severe respiratory or neurological disease in infected humans with transmission to humans through inhalation, contact or consumption of NiV contaminated foods. In the work presented here, the development of disease was investigated in the African Green Monkey (AGM) model following intratracheal (IT) and, for the first time, small-particle aerosol administration of NiV. This study utilized computed tomography (CT) and magnetic resonance imaging (MRI) to temporally assess disease progression. The host immune response and changes in immune cell populations over the course of disease were also evaluated. This study found that IT and small-particle administration of NiV caused similar disease progression, but that IT inoculation induced significant congestion in the lungs while disease following small-particle aerosol inoculation was largely confined to the lower respiratory tract. Quantitative assessment of changes in lung volume found up to a 45% loss in IT inoculated animals. None of the subjects in this study developed overt neurological disease, a finding that was supported by MRI analysis. The development of neutralizing antibodies was not apparent over the 8–10 day course of disease, but changes in cytokine response in all animals and activated CD8+ T cell numbers suggest the onset of cell-mediated immunity. These studies demonstrate that IT and small-particle aerosol infection with NiV in the AGM model leads to a severe respiratory disease devoid of neurological indications. This work also suggests that extending the disease course or minimizing the impact of the respiratory component is critical to developing a model that has a neurological component and more accurately reflects the human condition. PMID

The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

PubMed Central

Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.; Ryder, Olivia S.; Stokes, M. Dale; Beall, Charlotte M.; Santander, Mitchell V.; Burrows, Susannah M.; Sultana, Camille M.; Prather, Kimberly A.

2017-01-01

The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate. PMID:28630346

The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles

NASA Astrophysics Data System (ADS)

Wang, Xiaofei; Deane, Grant B.; Moore, Kathryn A.; Ryder, Olivia S.; Stokes, M. Dale; Beall, Charlotte M.; Collins, Douglas B.; Santander, Mitchell V.; Burrows, Susannah M.; Sultana, Camille M.; Prather, Kimberly A.

2017-07-01

The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate.

Complex Coupling of Air Quality and Climate-Relevant Aerosols in a Chemistry-Aerosol Microphysics Model

NASA Astrophysics Data System (ADS)

Yoshioka, M.; Carslaw, K. S.; Reddington, C.; Mann, G.

2013-12-01

Controlling emissions of aerosols and their precursors to improve air quality will impact the climate through direct and indirect radiative forcing. We have investigated the impacts of changes in a range of aerosol and gas-phase emission fluxes and changes in temperature on air quality and climate change metrics using a global aerosol microphysics and chemistry model, GLOMAP. We investigate how the responses of PM2.5 and cloud condensation nuclei (CCN) are coupled, and how attempts to improve air quality could have inadvertent effects on CCN, clouds and climate. The parameter perturbations considered are a 5°C increase in global temperature, increased or decreased precursor emissions of anthropogenic SO2, NH3, and NOx, and biogenic monoterpenes, and increased or decreased primary emissions of organic and black carbon aerosols from wildfire, fossil fuel, and biofuel. To quantify the interactions, we define a new sensitivity metric in terms of the response of CCN divided by the response of PM in different regions. .Our results show that the coupled chemistry and aerosol processes cause complex responses that will make any co-benefit policy decision problematic. In particular, we show that reducing SO2 emissions effectively reduces surface-level PM2.5 over continental regions in summer when background PM2.5 is high, with a relatively small reduction in marine CCN (and hence indirect radiative cooling over ocean), which is beneficial for near-term climate. Reducing NOx emissions does not improve summertime air quality very effectively but leads to a relatively high reduction of marine CCN. Reducing NH3 emissions has moderate effects on both PM2.5 and CCN. These three species are strongly coupled chemically and microphysically and the effects of changing emissions of one species on mass and size distributions of aerosols are very complex and spatially and temporally variable. For example, reducing SO2 emissions leads to reductions in sulphate and ammonium mass

Infection Prevention and Control in Pediatric Ambulatory Settings.

PubMed

Rathore, Mobeen H; Jackson, Mary Anne

2017-11-01

Since the American Academy of Pediatrics published its statement titled "Infection Prevention and Control in Pediatric Ambulatory Settings" in 2007, there have been significant changes that prompted this updated statement. Infection prevention and control is an integral part of pediatric practice in ambulatory medical settings as well as in hospitals. Infection prevention and control practices should begin at the time the ambulatory visit is scheduled. All health care personnel should be educated regarding the routes of transmission and techniques used to prevent the transmission of infectious agents. Policies for infection prevention and control should be written, readily available, updated every 2 years, and enforced. Many of the recommendations for infection control and prevention from the Centers for Disease Control and Prevention for hospitalized patients are also applicable in the ambulatory setting. These recommendations include requirements for pediatricians to take precautions to identify and protect employees likely to be exposed to blood or other potentially infectious materials while on the job. In addition to emphasizing the key principles of infection prevention and control in this policy, we update those that are relevant to the ambulatory care patient. These guidelines emphasize the role of hand hygiene and the implementation of diagnosis- and syndrome-specific isolation precautions, with the exemption of the use of gloves for routine diaper changes and wiping a well child's nose or tears for most patient encounters. Additional topics include respiratory hygiene and cough etiquette strategies for patients with a respiratory tract infection, including those relevant for special populations like patients with cystic fibrosis or those in short-term residential facilities; separation of infected, contagious children from uninfected children when feasible; safe handling and disposal of needles and other sharp medical devices; appropriate use of personal

Constructing An Event Based Aerosol Product Under High Aerosol Loading Conditions

NASA Astrophysics Data System (ADS)

Levy, R. C.; Shi, Y.; Mattoo, S.; Remer, L. A.; Zhang, J.

2016-12-01

High aerosol loading events, such as the Indonesia's forest fire in Fall 2015 or the persistent wintertime haze near Beijing, gain tremendous interests due to their large impact on regional visibility and air quality. Understanding the optical properties of these events and further being able to simulate and predict these events are beneficial. However, it is a great challenge to consistently identify and then retrieve aerosol optical depth (AOD) from passive sensors during heavy aerosol events. Some reasons include:1). large differences between optical properties of high-loading aerosols and those under normal conditions, 2) spectral signals of optically thick aerosols can be mistaken with surface depending on aerosol types, and 3) Extremely optically thick aerosol plumes can also be misidentified as clouds due to its high optical thickness. Thus, even under clear-sky conditions, the global distribution of extreme aerosol events is not well captured in datasets such as the MODIS Dark-Target (DT) aerosol product. In this study, with the synthetic use of OMI Aerosol Index, MODIS cloud product, and operational DT product, the heavy smoke events over the seven sea region are identified and retrieved over the dry season. An event based aerosol product that would compensate the standard "global" aerosol retrieval will be created and evaluated. The impact of missing high AOD retrievals on the regional aerosol climatology will be studied using this newly developed research product.

Controlled human malaria infection trials: How tandems of trust and control construct scientific knowledge.

PubMed

Bijker, Else M; Sauerwein, Robert W; Bijker, Wiebe E

2016-02-01

Controlled human malaria infections are clinical trials in which healthy volunteers are deliberately infected with malaria under controlled conditions. Controlled human malaria infections are complex clinical trials: many different groups and institutions are involved, and several complex technologies are required to function together. This functioning together of technologies, people, and institutions is under special pressure because of potential risks to the volunteers. In this article, the authors use controlled human malaria infections as a strategic research site to study the use of control, the role of trust, and the interactions between trust and control in the construction of scientific knowledge. The authors argue that tandems of trust and control play a central role in the successful execution of clinical trials and the construction of scientific knowledge. More specifically, two aspects of tandems of trust and control will be highlighted: tandems are sites where trust and control coproduce each other, and tandems link the personal, the technical, and the institutional domains. Understanding tandems of trust and control results in setting some agendas for both clinical trial research and science and technology studies.

Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol

NASA Astrophysics Data System (ADS)

Ye, Jianhuai

Secondary organic aerosol (SOA) formed from oxidation of volatile organic compounds (VOCs), comprises a major fraction of atmospheric submicron particulate matter, which is crucial for global climate change and human health. While biogenic VOCs are naturally emitted and cannot be directly controlled, field measurements and satellite observations have shown that biogenic SOA (BSOA) formation correlates well with anthropogenic pollutants and may be anthropogenically controlled. In this work, the formation of the "anthropogenically controllable BSOA" was examined. BSOA from alpha-pinene ozonolysis was investigated in the presence of laboratory-generated or ambient organic aerosol such as Toronto ambient particles. It is shown that SOA was not equally miscible with all organic species. Aerosol mixing thermodynamics in the atmosphere is composition dependent. Based on laboratory observations, an empirical framework using bulk elemental ratios was developed to predict atmospheric organic miscibility and SOA yield enhancements. Besides organic aerosol, interactions between BSOA formation and SO2 was also examined. Synergistic effects were observed between BSOA formation and SO2 oxidation through Criegee and peroxide chemistry under atmospherically relevant RH conditions. In addition to the physicochemical properties of SOA, health impacts of SOA were examined. An atmospheric simulation reactor (ASR) was developed to investigate the health effects of air pollutants by permitting controlled chronic in vivo exposure of mice to combine particulate and gaseous pollutants at 'real-life' concentrations. Results show that daily exposure to SOA from naphthalene photooxidation led to increased airway hyperresponsiveness (AHR) to methacholine in a dose-dependent manner. Multi-pollutant exposures with ozone and/or NO2 in conjunction with a sub-toxic concentration of SOA resulted in additive effects on AHR to methacholine. Inflammatory cell recruitment to the airways was not observed

[Ethyl chloride aerosol spray for local anesthesia before arterial puncture: randomized placebo-controlled trial].

PubMed

Ballesteros-Peña, Sendoa; Fernández-Aedo, Irrintzi; Vallejo-De la Hoz, Gorka

2017-06-01

To compare the efficacy of an ethyl chloride aerosol spray to a placebo spray applied in the emergency department to the skin to reduce pain from arterial puncture for blood gas analysis. Single-blind, randomized placebo-controlled trial in an emergency department of Hospital de Basurto in Bilbao, Spain. We included 126 patients for whom arterial blood gas analysis had been ordered. They were randomly assigned to receive application of the experimental ethyl chloride spray (n=66) or a placebo aerosol spray of a solution of alcohol in water (n=60). The assigned spray was applied just before arterial puncture. The main outcome variable was pain intensity reported on an 11-point numeric rating scale. The median (interquartile range) pain level was 2 (1-5) in the experimental arm and 2 (1-4.5) in the placebo arm (P=.72). Topical application of an ethyl chloride spray did not reduce pain caused by arterial puncture.

Involving patients in understanding hospital infection control using visual methods.

PubMed

Wyer, Mary; Jackson, Debra; Iedema, Rick; Hor, Su-Yin; Gilbert, Gwendolyn L; Jorm, Christine; Hooker, Claire; O'Sullivan, Matthew Vincent Neil; Carroll, Katherine

2015-06-01

This paper explores patients' perspectives on infection prevention and control. Healthcare-associated infections are the most frequent adverse event experienced by patients. Reduction strategies have predominantly addressed front-line clinicians' practices; patients' roles have been less explored. Video-reflexive ethnography. Fieldwork undertaken at a large metropolitan hospital in Australia involved 300 hours of ethnographic observations, including 11 hours of video footage. This paper focuses on eight occasions, where video footage was shown back to patients in one-on-one reflexive sessions. Viewing and discussing video footage of clinical care enabled patients to become articulate about infection risks, and to identify their own roles in reducing transmission. Barriers to detailed understandings of preventative practices and their roles included lack of conversation between patients and clinicians about infection prevention and control, and being ignored or contradicted when challenging perceived suboptimal practice. It became evident that to compensate for clinicians' lack of engagement around infection control, participants had developed a range of strategies, of variable effectiveness, to protect themselves and others. Finally, the reflexive process engendered closer scrutiny and a more critical attitude to infection control that increased patients' sense of agency. This study found that patients actively contribute to their own safety. Their success, however, depends on the quality of patient-provider relationships and conversations. Rather than treating patients as passive recipients of infection control practices, clinicians can support and engage with patients' contributions towards achieving safer care. This study suggests that if clinicians seek to reduce infection rates, they must start to consider patients as active contributors to infection control. Clinicians can engage patients in conversations about practices and pay attention to patient feedback

Aerosol Optical Properties Measured Onboard the Ronald H. Brown During ACE Asia as a Function of Aerosol Chemical Composition and Source Region

NASA Technical Reports Server (NTRS)

Quinn, P. K.; Coffman, D. J.; Bates, T. S.; Welton, E. J.; Covert, D. S.; Miller, T. L.; Johnson, J. E.; Maria, S.; Russell, L.; Arimoto, R.

2004-01-01

matter, and dust found for the ACE Asia aerosol are comparable to values estimated for ACE 1, Aerosols99, and INDOEX. Unique to the ACE Asia aerosol was the large mass fractions of dust, the dominance of dust in controlling the aerosol optical properties, and the interaction of dust with soot aerosol.

Economics of infection control surveillance technology: cost-effective or just cost?

PubMed

Furuno, Jon P; Schweizer, Marin L; McGregor, Jessina C; Perencevich, Eli N

2008-04-01

Previous studies have suggested that informatics tools, such as automated alert and decision support systems, may increase the efficiency and quality of infection control surveillance. However, little is known about the cost-effectiveness of these tools. We focus on 2 types of economic analyses that have utility in assessing infection control interventions (cost-effectiveness analysis and business-case analysis) and review the available literature on the economics of computerized infection control surveillance systems. Previous studies on the effectiveness of computerized infection control surveillance have been limited to assessments of whether these tools increase the sensitivity and specificity of surveillance over traditional methods. Furthermore, we identified only 2 studies that assessed the costs associated with computerized infection control surveillance. Thus, it remains unknown whether computerized infection control surveillance systems are cost-effective and whether use of these systems improves patient outcomes. The existing data are insufficient to allow for a summary conclusion on the cost-effectiveness of infection control surveillance technology. All future studies of computerized infection control surveillance systems should aim to collect outcomes and economic data to inform decision making and assist hospitals with completing business-cases analyses.

The effects of training inpatients and their relatives about infection control measures and subsequent rate of infection.

PubMed

Erdek, Funda Ozturkan; Gozutok, Ciler Keles; Merih, Yeliz Dogan; Aliogulları, Aysegul

2017-01-01

Healthcare-associated infections are one of the most important problems of all health institutions. This study was conducted to evaluate results of training about infection control measures provided to patients treated and hospitalized in clinics of obstetrics and gynecology, and to their relatives, as well as subsequent effect on infection rate. The study was conducted in clinics of obstetrics and gynecology of a state hospital. Study group comprised midwives and nursing staff, and inpatients and their relatives. Survey made up of 16 questions was administered to patients and relatives before and after training provided by infection nurses. Survey with 18 questions was administered to midwives/nurses to evaluate compliance of patients and relatives with infection control measures. Study data were analyzed using statistical analysis software and findings were evaluated as numbers and percentages using Student's t-test. According to survey of patients and relatives, mean knowledge level score before and after training was 20.07±46.76 and 96.36±11.85, respectively. Results indicated that training about infection control measures was effective at increasing knowledge level and compliance of patients and their relatives (p<0.05). Of the total, 87.5% of midwives/nurses stated that educating patients and relatives about infection control measures facilitated treatment and healthcare processes. In all, 95.9% of midwives/nurses thought that such education contributed to observance of infection control measures by patients and relatives. It is thought that regular education about infection control measures provided to patients and relatives would have positive effect and reduce incidence rate of healthcare-associated infection.

Collaboration with an infection control team for patients with infection after spine surgery.

PubMed

Kobayashi, Kazuyoshi; Imagama, Shiro; Kato, Daizo; Ando, Kei; Hida, Tetsuro; Ito, Kenyu; Tsushima, Mikito; Matsumoto, Akiyuki; Morozumi, Masayoshi; Tanaka, Satoshi; Yagi, Tetsuya; Nishida, Yoshihiro; Ishiguro, Naoki

2017-07-01

The risk of infection, including surgical site infection (SSI), after spine surgery has increased due to aging and more immunocompromised hosts. An infection control team (ICT) is responsible for management of health care-associated infections at our institution. The study subjects were 40 patients (18 men and 22 women with an average age of 54 years) referred to the ICT after spine surgery since 2010. Pathogenic bacteria and treatment in these cases were reviewed. Collaboration with the ICT involved guidance on use of antibiotics for infection in 30 patients (16 SSI and 14 non-SSI) and a search for the infection focus for fever of unknown origin in 10 patients (7 patients were found to have urinary tract infections and 2 patients were found to have pneumonia). The detection rate of causative bacteria in ICT consultation was 88% (35 out of 40 patients). SSI patients with instrumentation involved had a significantly higher rate of methicillin-resistant Staphylococcus aureus infection compared with those without instrumentation (42% vs 13%; P < .05). All cases of SSI with instrumentation involved were cured by ICT support without removal of instrumentation. Early assistance from the ICT was important for prevention of worsening of methicillin-resistant S aureus infection. Collaboration with the ICT was helpful for detection of pathogenic bacteria and allowed appropriate use of antibiotics at an early stage. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Imaging aerosol viscosity

NASA Astrophysics Data System (ADS)

Pope, Francis; Athanasiadis, Thanos; Botchway, Stan; Davdison, Nicholas; Fitzgerald, Clare; Gallimore, Peter; Hosny, Neveen; Kalberer, Markus; Kuimova, Marina; Vysniauskas, Aurimas; Ward, Andy

2017-04-01

Organic aerosol particles play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states; however, diffusion rates of small molecules such as water appear not to be limited by these high viscosities. We have developed a technique for measuring viscosity that allows for the imaging of aerosol viscosity in micron sized aerosols through use of fluorescence lifetime imaging of viscosity sensitive dyes which are also known as 'molecular rotors'. These rotors can be introduced into laboratory generated aerosol by adding minute quantities of the rotor to aerosol precursor prior to aerosolization. Real world aerosols can also be studied by doping them in situ with the rotors. The doping is achieved through generation of ultrafine aerosol particles that contain the rotors; the ultrafine aerosol particles deliver the rotors to the aerosol of interest via impaction and coagulation. This work has been conducted both on aerosols deposited on microscope coverslips and on particles that are levitated in their true aerosol phase through the use of a bespoke optical trap developed at the Central Laser Facility. The technique allows for the direct observation of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles. The technique is non-destructive thereby allowing for multiple experiments to be carried out on the same sample. It can dynamically quantify and track viscosity changes during atmospherically relevant processes such oxidation and hygroscopic growth (1). This presentation will focus on the oxidation of aerosol particles composed of unsaturated and saturated organic species. It will discuss how the type of oxidant, oxidation rate and the composition of the oxidized products affect the time

Controlled Human Malaria Infection: Applications, Advances, and Challenges.

PubMed

Stanisic, Danielle I; McCarthy, James S; Good, Michael F

2018-01-01

Controlled human malaria infection (CHMI) entails deliberate infection with malaria parasites either by mosquito bite or by direct injection of sporozoites or parasitized erythrocytes. When required, the resulting blood-stage infection is curtailed by the administration of antimalarial drugs. Inducing a malaria infection via inoculation with infected blood was first used as a treatment (malariotherapy) for neurosyphilis in Europe and the United States in the early 1900s. More recently, CHMI has been applied to the fields of malaria vaccine and drug development, where it is used to evaluate products in well-controlled early-phase proof-of-concept clinical studies, thus facilitating progression of only the most promising candidates for further evaluation in areas where malaria is endemic. Controlled infections have also been used to immunize against malaria infection. Historically, CHMI studies have been restricted by the need for access to insectaries housing infected mosquitoes or suitable malaria-infected individuals. Evaluation of vaccine and drug candidates has been constrained in these studies by the availability of a limited number of Plasmodium falciparum isolates. Recent advances have included cryopreservation of sporozoites, the manufacture of well-characterized and genetically distinct cultured malaria cell banks for blood-stage infection, and the availability of Plasmodium vivax -specific reagents. These advances will help to accelerate malaria vaccine and drug development by making the reagents for CHMI more widely accessible and also enabling a more rigorous evaluation with multiple parasite strains and species. Here we discuss the different applications of CHMI, recent advances in the use of CHMI, and ongoing challenges for consideration. Copyright © 2017 American Society for Microbiology.

Intragranulomatous necrosis in lungs of mice infected by aerosol with Mycobacterium tuberculosis is related to bacterial load rather than to any one cytokine or T cell type.

PubMed

Gil, Olga; Guirado, Evelyn; Gordillo, Sergi; Díaz, Jorge; Tapia, Gustavo; Vilaplana, Cristina; Ariza, Aurelio; Ausina, Vicenç; Cardona, Pere-Joan

2006-03-01

Low dose aerosol infection of C57BL/6 mice with a clinical strain of Mycobacterium tuberculosis (UTE 0335 R) induced intragranulomatous necrosis in pulmonary granulomas (INPG) at week 9 postinfection. Infection of different knockout (KO) mouse strains with UTE 0335 R induced INPG in all strains and established two histopathological patterns. The first pattern was seen in SCID mice and in mice with deleted alpha/beta T receptor, TNF R1, IL-12, IFN-gamma, or iNOS genes, and showed a massive INPG with a high granulomatous infiltration of the lung, a large and homogeneous eosinophilic necrosis full of acid-fast bacilli, with marked karyorrhexis, coarse basophilic necrosis, and surrounded by patches delimited by partially conserved alveolar septum full of PMNs. The second pattern was seen in mice with deleted IL-1 R1, IL-6, IL-10, CD4, CD8 or gamma/delta T cell receptor genes, and showed more discrete lesions with predominant homogeneous eosinophilic necrosis with few bacilli and surrounded by a well-defined lymphocyte-based ring. Local expression of IFN-gamma, iNOS, TNF and RANTES showed no significant differences between these mouse strains generating a discrete INPG. Mouse strains showing a massive INPG showed higher, lower or equal expression values compared to the control strain. In conclusion, the severity of the INPG pattern correlated with pulmonary CFU counts, irrespective of the genetic absence or the infection-induced levels of cytokine mediators.

Evaluation of an air-filtration system for preventing aerosol transmission of Porcine reproductive and respiratory syndrome virus

PubMed Central

2005-01-01

Abstract The purpose of this study was to evaluate the ability of a commercial air-filtration system to reduce aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV). The system consisted of a pre-filter and 2 filters with EU8 and EU13 ratings. In each of 4 trials, 5 PRRSV-infected donor pigs and 1 naïve recipient pig (each 25 kg) were housed in opposing chambers connected by a 1.3-m-long duct. The system filtered air entering 1 recipient-pig chamber (filtered facility) from the donor- chamber but not a 2nd recipient-pig chamber (nonfiltered facility). The donor pigs had been experimentally infected with PRRSV MN-184, an isolate previously documented to be shed at a high frequency in contagious aerosols. On days 3 to 7 after infection of the donors, the 2 groups were housed in their respective chambers for 6 h and then in separate facilities, where samples were collected for testing by polymerase chain reaction and enzyme-linked immunosorbent assay over 14 d. Aerosol transmission was observed in 6 of the 20 replicates in the nonfiltered facility, whereas all pigs remained PRRSV-negative in the filtered facility; the difference was significant at P < 0.01. Thus, under the conditions of this study, the air-filtration system evaluated appeared to be highly effective at reducing aerosol transmission of PRRSV. PMID:16479728

Climatology of Aerosol Optical Properties in Southern Africa

NASA Technical Reports Server (NTRS)

Queface, Antonio J.; Piketh, Stuart J.; Eck, Thomas F.; Tsay, Si-Chee

2011-01-01

A thorough regionally dependent understanding of optical properties of aerosols and their spatial and temporal distribution is required before we can accurately evaluate aerosol effects in the climate system. Long term measurements of aerosol optical depth, Angstrom exponent and retrieved single scattering albedo and size distribution, were analyzed and compiled into an aerosol optical properties climatology for southern Africa. Monitoring of aerosol parameters have been made by the AERONET program since the middle of the last decade in southern Africa. This valuable information provided an opportunity for understanding how aerosols of different types influence the regional radiation budget. Two long term sites, Mongu in Zambia and Skukuza in South Africa formed the core sources of data in this study. Results show that seasonal variation of aerosol optical thicknesses at 500 nm in southern Africa are characterized by low seasonal multi-month mean values (0.11 to 0.17) from December to May, medium values (0.20 to 0.27) between June and August, and high to very high values (0.30 to 0.46) during September to November. The spatial distribution of aerosol loadings shows that the north has high magnitudes than the south in the biomass burning season and the opposite in none biomass burning season. From the present aerosol data, no long term discernable trends are observable in aerosol concentrations in this region. This study also reveals that biomass burning aerosols contribute the bulk of the aerosol loading in August-October. Therefore if biomass burning could be controlled, southern Africa will experience a significant reduction in total atmospheric aerosol loading. In addition to that, aerosol volume size distribution is characterized by low concentrations in the non biomass burning period and well balanced particle size contributions of both coarse and fine modes. In contrast high concentrations are characteristic of biomass burning period, combined with

Identifying Aerosol Type/Mixture from Aerosol Absorption Properties Using AERONET

NASA Technical Reports Server (NTRS)

Giles, D. M.; Holben, B. N.; Eck, T. F.; Sinyuk, A.; Dickerson, R. R.; Thompson, A. M.; Slutsker, I.; Li, Z.; Tripathi, S. N.; Singh, R. P.;

Optimal control analysis of malaria-schistosomiasis co-infection dynamics.

PubMed

Okosun, Kazeem Oare; Smith, Robert

2017-04-01

This paper presents a mathematical model for malaria--schistosomiasis co-infection in order to investigate their synergistic relationship in the presence of treatment. We first analyse the single infection steady states, then investigate the existence and stability of equilibria and then calculate the basic reproduction numbers. Both the single-infection models and the co-infection model exhibit backward bifurcations. We carrying out a sensitivity analysis of the co-infection model and show that schistosomiasis infection may not be associated with an increased risk of malaria. Conversely, malaria infection may be associated with an increased risk of schistosomiasis. Furthermore, we found that effective treatment and prevention of schistosomiasis infection would also assist in the effective control and eradication of malaria. Finally, we apply Pontryagin's Maximum Principle to the model in order to determine optimal strategies for control of both diseases.

Infection Control and Prevention: A Review of Hospital-Acquired Infections and the Economic Implications

PubMed Central

Reed, Deoine; Kemmerly, Sandra A.

2009-01-01

The Centers for Disease Control and Prevention estimates that 2 million patients suffer from hospital-acquired infections every year and nearly 100,000 of them die. Most of these medical errors are preventable. Hospital-acquired infections result in up to $4.5 billion in additional healthcare expenses annually. The U.S. government has responded to this financial loss by focusing on healthcare quality report cards and by taking strong action to curb healthcare spending. The Medicare Program has proposed changes to the Hospital Inpatient Prospective Payment System and Fiscal Year Rates: Proposed Rule CMS 1488-P-Healthcare-associated infection. Payment will be linked to performance. Under the new rule, payment will be withheld from hospitals for care associated with treating certain catheter-associated urinary tract infections, vascular catheter-associated infections, and mediastinitis after coronary artery bypass graft surgery. Infection-prevention strategies are essential. In the healthcare setting, the infection control department is categorized as non-revenue-producing. Funds dedicated to resources such as staff, educational programs, and prevention measures are vastly limited. Hospital leaders will need to balance the upfront cost needed to prevent hospital-related infections with the non-reimbursed expense accrued secondary to potentially preventable infections. The purpose of this paper is to present case studies and cost analysis of hospital-acquired infections and present strategies that reduce infections and cost. PMID:21603406

Qualitative evaluation and economic estimates of an infection control champions program.

PubMed

Lloyd-Smith, Elisa; Curtin, Jim; Gilbart, Wayne; Romney, Marc G

2014-12-01

In many North American hospitals, conventional infection control operational models often struggle to provide sufficient support to frontline health care workers. The objective of this study was to describe a sustainable infection control champion (ICC) program based on findings from focus groups. A distributed model of infection control was established by placing infection prevention and control-trained ICCs in 3 Canadian hospitals for a period of 12 months. Subsequently, semistructured focus groups were conducted to describe overall feasibility and impeding and critical factors affecting sustainability. An economic estimate of the ICC program compared with the cost of hiring a new infection control practitioner was also calculated. Focus group participants considered the program feasible. Barriers included lack of time and staff turnover. Themes critical for the successful implementation of an ICC program included defined ICC roles and goals, adequate support and resources for the ICC, engagement with all levels of staff, flexible structure, and program evaluation. The cost per bed of the ICC program was less than the cost per bed of hiring a new infection control practitioner. A distributed model of providing infection prevention and control services may have benefit when hospital infection control teams are underresourced, as is often the case. Several key factors are needed for the successful implementation of an ICC program. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Multidrug-resistant opportunistic pathogens challenging veterinary infection control.

PubMed

Walther, Birgit; Tedin, Karsten; Lübke-Becker, Antina

2017-02-01

Although the problems associated with healthcare-associated infections (HAI) and the emergence of zoonotic and multidrug-resistant pathogens in companion animal (dogs, cats and horses) medicine have been well-known for decades, current progress with respect to practical implementation of infection control programs in veterinary clinics has been limited. Clinical outbreak events reported for methicillin-resistant Staphylooccus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), extended spectrum beta-lactamase (ESBL)-producing Escherichia coli and multidrug-resistant (MDR) Salmonella Serovars indicate the necessity of infection control strategies for protecting animal patients at risk as well as veterinary personnel. The close bond between humans and their companion animals provides opportunities for exchange of microorganisms, including MDR pathogens. This particular aspect of the "One Health" idea requires more representative surveillance efforts and infection control strategies with respect to animal-species specific characters. Copyright © 2016 Elsevier B.V. All rights reserved.

Infection control in South African oral hygiene practice.

PubMed

de Kock, K; van Wyk, C W

2001-12-01

The aim was to gain information about the practice of infection control in oral hygiene practice. A questionnaire based on OSHA and CDC guidelines was submitted to oral hygienists who attended a refresher course followed by a second posted questionnaire seeking information about hand hygiene practice. The questions were directed to observance of personal protection by oral hygienists and the application of procedures required for infection control in the surgery. 87.5% wore face masks but the proper use of facial protection, overcoats and disposable overcoats was reported by fewer than 50%. A total of 97% wore gloves and 88% changed gloves between patients. Skin reactions to gloves were reported by 26%. Only 7% had not been vaccinated against hepatitis B. The correct procedures for sterilising equipment and instruments were carried out by fewer than 50%, and 57% of participants wanted an improvement of infection control arrangements in their workplace. It is concluded that a need exists for proper practice of infection control by oral hygienists which can be remedied by interceptive and preventive education and peer pressure.

Assessment of infection control practices in teaching hospitals of Quetta.

PubMed

Anwar, Muhammad; Majeed, Abdul; Saleem, Rana Muhammad; Manzoor, Farkhanda; Sharif, Saima

2016-08-01

To identify the gaps in infection control and prevention practices in teaching hospitals. This cross-sectional study was conducted at Bolan Medical Complex and Sandeman Medical College Hospital, Quetta, from August 2012 to January 2013.The study comprised members (n=7) of infection control committee who were interviewed through a self-developed, closed-ended questionnaire and their perception regarding infection control and prevention was recorded. Data was analysed using SPSS 16. Only 3(42.9%) of the committee members believed that the administrative factors for causing hospital-acquired infections were nurse-patient ratio. On the patient care side, 1(14.3%) participants at one of the hospitals attributed infections to antibiotic use, 5(71.4%) to invasive medical device and 1(14.3%) to other factors. Poor perception held by the members of infection control committee was the basic cause of bad outcome. Capacity-building of all the stakeholders is required.

Aerosol and CCN in southwest Saudi Arabia

NASA Astrophysics Data System (ADS)

Collins, Don; Li, Runjun; Axisa, Duncan; Kucera, Paul; Burger, Roelof

2010-05-01

As part of an ongoing study of the microphysical and dynamical controls on precipitation in southwest Saudi Arabia, a number of surface and aircraft-based instruments were used in summer / fall 2009 to measure the size distribution, hygroscopic properties, and cloud droplet nucleation efficiency of the local aerosol. Submicron size distributions were measured using differential mobility analyzers both on the ground and on board the aircraft, while an aerodynamic particle sizer and a forward scattering spectrometer probe were used to measure the supermicron size distributions on the ground and from on board the aircraft, respectively. Identical continuous flow cloud condensation nuclei counters were used to measure CCN spectra at the surface and aloft and a humidified tandem differential mobility analyzer was operated on the ground to measure size-resolved hygroscopicity. The aerosol in this arid environment is characterized by a persistent accumulation mode having hygroscopic and CCN efficiency properties consistent with a sulfate-rich aged aerosol. The particles in that background aerosol are generally sufficiently large and hygroscopic to activate at those supersaturations expected in the convective clouds responsible for most of the regional precipitation, which consequently acts as a lower bound on the resulting cloud droplet concentrations. Though the concentration, size distribution, and properties of the submicron aerosol generally changed very slowly over periods of several hours, abrupt ~doubling in concentration almost always accompanied the arrival of the sea breeze front that began along the Red Sea. Interestingly, the hygroscopicity and the shape of the size distribution differed little in the pre- and post-sea breeze air masses. The dust-dominated coarse mode typically contributed significantly more to the aerosol mass concentration than did the submicron mode and likely controlled the ice nuclei concentration, though no direct measurements were made

A Comprehensive Breath Plume Model for Disease Transmission via Expiratory Aerosols

PubMed Central

Halloran, Siobhan K.; Wexler, Anthony S.; Ristenpart, William D.

2012-01-01

The peak in influenza incidence during wintertime in temperate regions represents a longstanding, unresolved scientific question. One hypothesis is that the efficacy of airborne transmission via aerosols is increased at lower humidities and temperatures, conditions that prevail in wintertime. Recent work with a guinea pig model by Lowen et al. indicated that humidity and temperature do modulate airborne influenza virus transmission, and several investigators have interpreted the observed humidity dependence in terms of airborne virus survivability. This interpretation, however, neglects two key observations: the effect of ambient temperature on the viral growth kinetics within the animals, and the strong influence of the background airflow on transmission. Here we provide a comprehensive theoretical framework for assessing the probability of disease transmission via expiratory aerosols between test animals in laboratory conditions. The spread of aerosols emitted from an infected animal is modeled using dispersion theory for a homogeneous turbulent airflow. The concentration and size distribution of the evaporating droplets in the resulting “Gaussian breath plume” are calculated as functions of position, humidity, and temperature. The overall transmission probability is modeled with a combination of the time-dependent viral concentration in the infected animal and the probability of droplet inhalation by the exposed animal downstream. We demonstrate that the breath plume model is broadly consistent with the results of Lowen et al., without invoking airborne virus survivability. The results also suggest that, at least for guinea pigs, variation in viral kinetics within the infected animals is the dominant factor explaining the increased transmission probability observed at lower temperatures. PMID:22615902

Aerosol, a health hazard during ultrasonic scaling: A clinico-microbiological study.

PubMed

Singh, Akanksha; Shiva Manjunath, R G; Singla, Deepak; Bhattacharya, Hirak S; Sarkar, Arijit; Chandra, Neeraj

2016-01-01

Ultrasonic scaling is a routinely used treatment to remove plaque and calculus from tooth surfaces. These scalers use water as a coolant which is splattered during the vibration of the tip. The splatter when mixed with saliva and plaque of the patients causes the aerosol highly infectious and acts as a major risk factor for transmission of the disease. In spite of necessary protection, sometimes, the operator might get infected because of the infectious nature of the splatter. To evaluate the aerosol contamination produced during ultrasonic scaling by the help of microbiological analysis. This clinico-microbiological study consisted of twenty patients. Two agar plates were used for each patient; the first was kept at the center of the operatory room 20 min before the treatment while the second agar plate was kept 40 cm away from the patient's chest during the treatment. Both the agar plates were sent for microbiological analysis. The statistical analysis was done with the help of STATA 11.0 (StataCorp. 2013. Stata Statistical Software, Release 13. College Station, TX: StataCorp LP, 4905 Lakeway Drive College Station, Texas, USA). Statistical software was used for data analysis and the P < 0.001 was considered to be statistically significant. The results for bacterial count were highly significant when compared before and during the treatment. The Gram staining showed the presence of Staphylococcus and Streptococcus species in high numbers. The aerosols and splatters produced during dental procedures have the potential to spread infection to dental personnel. Therefore, proper precautions should be taken to minimize the risk of infection to the operator.

The design of an aerosol test tunnel for occupational hygiene investigations

NASA Astrophysics Data System (ADS)

Blackford, D. B.; Heighington, K.

An aerosol test tunnel which provides large working sections is described and its performance evaluated. Air movement within the tunnel is achieved with a powerful D.C. motor and centrifugal fan. Test dusts are dispersed and injected into the tunnel by means of an aerosol generator. A unique divertor valve allows aerosol laden air to be either cleaned by a commercial pulse jet filtration unit or recycled around the tunnel to obtain a high aerosol concentration. The tunnel instrumentation is managed by a microcomputer which automatically controls the airspeed and aerosol concentration.

Aerosol mobility size spectrometer

DOEpatents

Wang, Jian; Kulkarni, Pramod

2007-11-20

A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

Infection control in cystic fibrosis: barriers to implementation and ideas for improvement.

PubMed

Saiman, Lisa; Garber, Elizabeth

2009-11-01

This review will focus on recent research documenting baseline adherence to infection control recommendations and barriers to their implementation as experienced by multidisciplinary cystic fibrosis (CF) care providers. In addition, controversies regarding optimal infection control will be discussed. Finally, suggestions to improve infection control in CF will be proposed. Compliance with recent guidelines was assessed for clinical microbiology laboratories and for infection control policies at CF care centers in the United States. Unlike earlier reports, the vast majority of laboratories used selective media for Burkholderia cepacia complex and identified all species of nonlactose fermenting Gram-negative bacilli. Fewer used selective media for Staphylococcus aureus or used agar-based susceptibility testing assays for Pseudomonas aeruginosa. Only 103 (65%) of 158 CF care centers provided written infection control policies for review and these were more likely to address inpatient than outpatient settings. Surveys of healthcare professionals showed that access to a copy of the CF infection control guidelines reduced barriers to adherence to selected infection control practices. These data suggest that access to national infection control guidelines and written local policies are critically important to improving infection control for CF.

Impact of an Infection Control Program in a Specialized Preschool.

ERIC Educational Resources Information Center

Krilov, Leonard R.; And Others

1996-01-01

Evaluated effects of infection control interventions--including infection control lectures and attention to environmental hygiene--on the number and types of infection illnesses occurring in a specialized preschool. Subjects were infants and preschoolers with Down Syndrome. Found that total illnesses decreased significantly, particularly for…

Health care workers' knowledge, attitudes and practices on tuberculosis infection control, Nepal.

PubMed

Shrestha, Anita; Bhattarai, Dipesh; Thapa, Barsha; Basel, Prem; Wagle, Rajendra Raj

2017-11-17

Infection control remains a key challenge for Tuberculosis (TB) control program with an increased risk of TB transmission among health care workers (HCWs), especially in settings with inadequate TB infection control measures. Poor knowledge among HCWs and inadequate infection control practices may lead to the increased risk of nosocomial TB transmission. An institution-based cross-sectional survey was conducted in 28 health facilities providing TB services in the Kathmandu Valley, Nepal. A total of 190 HCWs were assessed for the knowledge, attitudes and practices on TB infection control using a structured questionnaire. The level of knowledge on TB infection control among almost half (45.8%) of the HCWs was poor, and was much poorer among administration and lower level staff. The knowledge level was significantly associated with educational status, and TB training and/or orientation received. The majority (73.2%) of HCWs had positive attitude towards TB infection control. Sixty-five percent of HCWs were found to be concerned about being infected with TB. Use of respirators among the HCWs was limited and triage of TB suspects was also lacking. Overall knowledge and practices of HCWs on TB infection control were not satisfactory. Effective infection control measures including regular skill-based training and/or orientation for all categories of HCWs can improve infection control practices in health facilities.

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

NASA Astrophysics Data System (ADS)

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-05-01

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

Secondary sulfate is internally mixed with sea spray aerosol and organic aerosol in the winter Arctic

NASA Astrophysics Data System (ADS)

Kirpes, Rachel M.; Bondy, Amy L.; Bonanno, Daniel; Moffet, Ryan C.; Wang, Bingbing; Laskin, Alexander; Ault, Andrew P.; Pratt, Kerri A.

2018-03-01

Few measurements of aerosol chemical composition have been made during the winter-spring transition (following polar sunrise) to constrain Arctic aerosol-cloud-climate feedbacks. Herein, we report the first measurements of individual particle chemical composition near Utqiaġvik (Barrow), Alaska, in winter (seven sample days in January and February 2014). Individual particles were analyzed by computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX, 24 847 particles), Raman microspectroscopy (300 particles), and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS, 290 particles). Sea spray aerosol (SSA) was observed in all samples, with fresh and aged SSA comprising 99 %, by number, of 2.5-7.5 µm diameter particles, 65-95 % from 0.5-2.5 µm, and 50-60 % from 0.1-0.5 µm, indicating SSA is the dominant contributor to accumulation and coarse-mode aerosol during the winter. The aged SSA particles were characterized by reduced chlorine content with 94 %, by number, internally mixed with secondary sulfate (39 %, by number, internally mixed with both nitrate and sulfate), indicative of multiphase aging reactions during transport. There was a large number fraction (40 % of 1.0-4.0 µm diameter particles) of aged SSA during periods when particles were transported from near Prudhoe Bay, consistent with pollutant emissions from the oil fields participating in atmospheric processing of aerosol particles. Organic carbon and sulfate particles were observed in all samples and comprised 40-50 %, by number, of 0.1-0.4 µm diameter particles, indicative of Arctic haze influence. Soot was internally mixed with organic and sulfate components. All sulfate was mixed with organic carbon or SSA particles. Therefore, aerosol sources in the Alaskan Arctic and resulting aerosol chemical mixing states need to be considered when predicting aerosol climate effects, particularly cloud

The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics.

PubMed

Chen, Chun; Zhao, Bin; Cui, Weilin; Dong, Lei; An, Na; Ouyang, Xiangying

2010-07-06

Dental healthcare workers (DHCWs) are at high risk of occupational exposure to droplets and aerosol particles emitted from patients' mouths during treatment. We evaluated the effectiveness of an air cleaner in reducing droplet and aerosol contamination by positioning the device in four different locations in an actual dental clinic. We applied computational fluid dynamics (CFD) methods to solve the governing equations of airflow, energy and dispersion of different-sized airborne droplets/aerosol particles. In a dental clinic, we measured the supply air velocity and temperature of the ventilation system, the airflow rate and the particle removal efficiency of the air cleaner to determine the boundary conditions for the CFD simulations. Our results indicate that use of an air cleaner in a dental clinic may be an effective method for reducing DHCWs' exposure to airborne droplets and aerosol particles. Further, we found that the probability of droplet/aerosol particle removal and the direction of airflow from the cleaner are both important control measures for droplet and aerosol contamination in a dental clinic. Thus, the distance between the air cleaner and droplet/aerosol particle source as well as the relative location of the air cleaner to both the source and the DHCW are important considerations for reducing DHCWs' exposure to droplets/aerosol particles emitted from the patient's mouth during treatments.

The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics

PubMed Central

Chen, Chun; Zhao, Bin; Cui, Weilin; Dong, Lei; An, Na; Ouyang, Xiangying

2010-01-01

Dental healthcare workers (DHCWs) are at high risk of occupational exposure to droplets and aerosol particles emitted from patients' mouths during treatment. We evaluated the effectiveness of an air cleaner in reducing droplet and aerosol contamination by positioning the device in four different locations in an actual dental clinic. We applied computational fluid dynamics (CFD) methods to solve the governing equations of airflow, energy and dispersion of different-sized airborne droplets/aerosol particles. In a dental clinic, we measured the supply air velocity and temperature of the ventilation system, the airflow rate and the particle removal efficiency of the air cleaner to determine the boundary conditions for the CFD simulations. Our results indicate that use of an air cleaner in a dental clinic may be an effective method for reducing DHCWs' exposure to airborne droplets and aerosol particles. Further, we found that the probability of droplet/aerosol particle removal and the direction of airflow from the cleaner are both important control measures for droplet and aerosol contamination in a dental clinic. Thus, the distance between the air cleaner and droplet/aerosol particle source as well as the relative location of the air cleaner to both the source and the DHCW are important considerations for reducing DHCWs' exposure to droplets/aerosol particles emitted from the patient's mouth during treatments. PMID:20031985

Monitoring biological aerosols using UV fluorescence

NASA Astrophysics Data System (ADS)

Eversole, Jay D.; Roselle, Dominick; Seaver, Mark E.

1999-01-01

An apparatus has been designed and constructed to continuously monitor the number density, size, and fluorescent emission of ambient aerosol particles. The application of fluorescence to biological particles suspended in the atmosphere requires laser excitation in the UV spectral region. In this study, a Nd:YAG laser is quadrupled to provide a 266 nm wavelength to excite emission from single micrometer-sized particles in air. Fluorescent emission is used to continuously identify aerosol particles of biological origin. For calibration, biological samples of Bacillus subtilis spores and vegetative cells, Esherichia coli, Bacillus thuringiensis and Erwinia herbicola vegetative cells were prepared as suspensions in water and nebulized to produce aerosols. Detection of single aerosol particles, provides elastic scattering response as well as fluorescent emission in two spectral bands simultaneously. Our efforts have focuses on empirical characterization of the emission and scattering characteristics of various bacterial samples to determine the feasibility of optical discrimination between different cell types. Preliminary spectroscopic evidence suggest that different samples can be distinguished as separate bio-aerosol groups. In addition to controlled sample results, we will also discuss the most recent result on the effectiveness of detection outdoor releases and variations in environmental backgrounds.

A scoping review on bio-aerosols in healthcare and the dental environment.

PubMed

Zemouri, Charifa; de Soet, Hans; Crielaard, Wim; Laheij, Alexa

2017-01-01

Bio-aerosols originate from different sources and their potentially pathogenic nature may form a hazard to healthcare workers and patients. So far no extensive review on existing evidence regarding bio-aerosols is available. This study aimed to review evidence on bio-aerosols in healthcare and the dental setting. The objectives were 1) What are the sources that generate bio-aerosols?; 2) What is the microbial load and composition of bio-aerosols and how were they measured?; and 3) What is the hazard posed by pathogenic micro-organisms transported via the aerosol route of transmission? Systematic scoping review design. Searched in PubMed and EMBASE from inception to 09-03-2016. References were screened and selected based on abstract and full text according to eligibility criteria. Full text articles were assessed for inclusion and summarized. The results are presented in three separate objectives and summarized for an overview of evidence. The search yielded 5,823 studies, of which 62 were included. Dental hand pieces were found to generate aerosols in the dental settings. Another 30 sources from human activities, interventions and daily cleaning performances in the hospital also generate aerosols. Fifty-five bacterial species, 45 fungi genera and ten viruses were identified in a hospital setting and 16 bacterial and 23 fungal species in the dental environment. Patients with certain risk factors had a higher chance to acquire Legionella in hospitals. Such infections can lead to irreversible septic shock and death. Only a few studies found that bio-aerosol generating procedures resulted in transmission of infectious diseases or allergic reactions. Bio-aerosols are generated via multiple sources such as different interventions, instruments and human activity. Bio-aerosols compositions reported are heterogeneous in their microbiological composition dependent on the setting and methodology. Legionella species were found to be a bio-aerosol dependent hazard to elderly

Atmosphere aerosol satellite project Aerosol-UA

NASA Astrophysics Data System (ADS)

Milinevsky, Gennadi; Yatskiv, Yaroslav; Syniavskyi, Ivan; Bovchaliuk, Andrii; Degtyaryov, Oleksandr; Sosonkin, Mikhail; Mishchenko, Michael; Danylevsky, Vassyl; Ivanov, Yury; Oberemok, Yevgeny; Masley, Volodymyr; Rosenbush, Vera; Moskalev, Sergii

2017-04-01

The experiment Aerosol-UA is Ukrainian space mission aimed to the terrestrial atmospheric aerosol spatial distribution and microphysics investigations. The experiment concept is based on idea of Glory/APS mission of precise orbital measurements of polarization and intensity of the sunlight scattered by the atmosphere, aerosol and the surface the multichannel Scanning Polarimeter (ScanPol) with narrow field-of-view. ScanPol measurements will be accompanied by the wide-angle MultiSpectral Imager-Polarimeter (MSIP). The ScanPol is designed to measure Stokes parameters I, Q, U within the spectral range from the UV to the SWIR in a wide range of phase angles along satellite ground path. Expected ScanPol polarimetric accuracy is 0.15%. A high accuracy measurement of the degree of linear polarization is provided by on-board calibration of the ScanPol polarimeter. On-board calibration is performed for each scan of the mirror scanning system. A set of calibrators is viewed during the part of the scan range when the ScanPol polarimeter looks in the direction opposite to the Earth's surface. These reference assemblies provide calibration of the zero of the polarimetric scale (unpolarized reference assembly) and the scale factor for the polarimetric scale (polarized reference assembly). The zero of the radiometric scale is provided by the dark reference assembly.The spectral channels of the ScanPol are used to estimate the tropospheric aerosol absorption, the aerosol over the ocean and the land surface, the signals from cirrus clouds, stratospheric aerosols caused by major volcanic eruptions, and the contribution of the Earth's surface. The imager-polarimeter MSIP will collect 60°x60° field-of-view images on the state of the atmosphere and surface in the area, where the ScanPol polarimeter will measure, to retrieve aerosol optical depth and polarization properties of aerosol by registration of three Stokes parameters simultaneously in three spectral channels. The two more

Synthesis of nanoparticles in a flame aerosol reactor with independent and strict control of their size, crystal phase and morphology

NASA Astrophysics Data System (ADS)

Jiang, Jingkun; Chen, Da-Ren; Biswas, Pratim

2007-07-01

A flame aerosol reactor (FLAR) was developed to synthesize nanoparticles with desired properties (crystal phase and size) that could be independently controlled. The methodology was demonstrated for TiO2 nanoparticles, and this is the first time that large sets of samples with the same size but different crystal phases (six different ratios of anatase to rutile in this work) were synthesized. The degree of TiO2 nanoparticle agglomeration was determined by comparing the primary particle size distribution measured by scanning electron microscopy (SEM) to the mobility-based particle size distribution measured by online scanning mobility particle spectrometry (SMPS). By controlling the flame aerosol reactor conditions, both spherical unagglomerated particles and highly agglomerated particles were produced. To produce monodisperse nanoparticles, a high throughput multi-stage differential mobility analyser (MDMA) was used in series with the flame aerosol reactor. Nearly monodisperse nanoparticles (geometric standard deviation less than 1.05) could be collected in sufficient mass quantities (of the order of 10 mg) in reasonable time (1 h) that could be used in other studies such as determination of functionality or biological effects as a function of size.

Aerosol Lidar and MODIS Satellite Comparisons for Future Aerosol Loading Forecast

NASA Technical Reports Server (NTRS)

DeYoung, Russell; Szykman, James; Severance, Kurt; Chu, D. Allen; Rosen, Rebecca; Al-Saadi, Jassim

2006-01-01

Knowledge of the concentration and distribution of atmospheric aerosols using both airborne lidar and satellite instruments is a field of active research. An aircraft based aerosol lidar has been used to study the distribution of atmospheric aerosols in the California Central Valley and eastern US coast. Concurrently, satellite aerosol retrievals, from the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra and Aqua satellites, were take over the Central Valley. The MODIS Level 2 aerosol data product provides retrieved ambient aerosol optical properties (e.g., optical depth (AOD) and size distribution) globally over ocean and land at a spatial resolution of 10 km. The Central Valley topography was overlaid with MODIS AOD (5x5 sq km resolution) and the aerosol scattering vertical profiles from a lidar flight. Backward air parcel trajectories for the lidar data show that air from the Pacific and northern part of the Central Valley converge confining the aerosols to the lower valley region and below the mixed layer. Below an altitude of 1 km, the lidar aerosol and MODIS AOD exhibit good agreement. Both data sets indicate a high presence of aerosols near Bakersfield and the Tehachapi Mountains. These and other results to be presented indicate that the majority of the aerosols are below the mixed layer such that the MODIS AOD should correspond well with surface measurements. Lidar measurements will help interpret satellite AOD retrievals so that one day they can be used on a routine basis for prediction of boundary layer aerosol pollution events.

Infection control for SARS in a tertiary neonatal centre.

PubMed

Ng, P C; So, K W; Leung, T F; Cheng, F W T; Lyon, D J; Wong, W; Cheung, K L; Fung, K S C; Lee, C H; Li, A M; Hon, K L E; Li, C K; Fok, T F

2003-09-01

The Severe Acute Respiratory Syndrome (SARS) is a newly discovered infectious disease caused by a novel coronavirus, which can readily spread in the healthcare setting. A recent community outbreak in Hong Kong infected a significant number of pregnant women who subsequently required emergency caesarean section for deteriorating maternal condition and respiratory failure. As no neonatal clinician has any experience in looking after these high risk infants, stringent infection control measures for prevention of cross infection between patients and staff are important to safeguard the wellbeing of the work force and to avoid nosocomial spread of SARS within the neonatal unit. This article describes the infection control and patient triage policy of the neonatal unit at the Prince of Wales Hospital, Hong Kong. We hope this information is useful in helping other units to formulate their own infection control plans according to their own unit configuration and clinical needs.

Temporal Variation of Aerosol Properties at a Rural Continental Site and Study of Aerosol Evolution through Growth Law Analysis

NASA Technical Reports Server (NTRS)

Wang, Jian; Collins, Don; Covert, David; Elleman, Robert; Ferrare, Richard A.; Gasparini, Roberto; Jonsson, Haflidi; Ogren, John; Sheridan, Patrick; Tsay, Si-Chee

2006-01-01

Aerosol size distributions were measured by a Scanning Mobility Particle Sizer (SMPS) onboard the CIRPAS Twin Otter aircraft during 16 flights at the Southern Great Plains (SGP) site in northern central Oklahoma as part of the Aerosol Intensive Operation period in May, 2003. During the same period a second SMPS was deployed at a surface station and provided continuous measurements. Combined with trace gas measurements at the SGP site and back-trajectory analysis, the aerosol size distributions provided insights into the sources of aerosols observed at the SGP site. High particle concentrations, observed mostly during daytime, were well correlated with the sulfur dioxide (SO2) mixing ratios, suggesting nucleation involving sulfuric acid is likely the main source of newly formed particles at the SGP. Aerosols within plumes originating from wildfires in Central America were measured at the surface site. Vertically compact aerosol layers, which can be traced back to forest fires in East Asia, were intercepted at altitudes over 3000 meters. Analyses of size dependent particle growth rates for four periods during which high cloud coverage was observed indicate growth dominated by volume controlled reactions. Sulfate accounts for 50% to 72% of the increase in aerosol volume concentration; the rest of the volume concentration increase was likely due to secondary organic species. The growth law analyses and meteorological conditions indicate that the sulfate was produced mainly through aqueous oxidation of SO2 in clouds droplets and hydrated aerosol particles.

Mycobacterium avium Subspecies paratuberculosis: Human Exposure through Environmental and Domestic Aerosols

PubMed Central

Rhodes, Glenn; Richardson, Hollian; Hermon-Taylor, John; Weightman, Andrew; Higham, Andrew; Pickup, Roger

2014-01-01

Mycobacterium avium subspecies paratuberculosis (Map) causes Johne’s disease in animals and is significantly associated with Crohn’s disease (CD) in humans. Our previous studies have shown Map to be present in U.K. rivers due to land deposition from chronic livestock infection and runoff driven by rainfall. The epidemiology of CD in Cardiff showed a significant association with the River Taff, in which Map can be detected on a regular basis. We have previously hypothesized that aerosols from the river might influence the epidemiology of CD. In this preliminary study, we detected Map by quantitative PCR in one of five aerosol samples collected above the River Taff. In addition, we examined domestic showers from different regions in the U.K. and detected Map in three out of 30 independent samples. In detecting Map in river aerosols and those from domestic showers, this is the first study to provide evidence that aerosols are an exposure route for Map to humans and may play a role in the epidemiology of CD. PMID:25438013

The MAC aerosol climatology

NASA Astrophysics Data System (ADS)

Kinne, S.

2015-12-01

Aerosol is highly diverse in space and time. And many different aerosol optical properties are needed (consistent to each other) for the determination of radiative effects. To sidestep a complex (and uncertain) aerosol treatment (emission to mass to optics) a monthly gridded climatology for aerosol properties has been developed. This MPI Aerosol Climatology (MAC) is strongly tied to observational statistics for aerosol column optical properties by AERONET (over land) and by MAN (over oceans). To fill spatial gaps, to address decadal change and to address vertical variability, these sparsely distributed local data are extended with central data of an ensemble of output from global models with complex aerosol modules. This data merging in performed for aerosol column amount (AOD), for aerosol size (AOD,fine) and for aerosol absorption (AAOD). The resulting MAC aerosol climatology is an example for the combination of high quality local observations with spatial, temporal and vertical context from model simulations.

Telehealth infection control: a movement toward best practice.

PubMed

Suter, Paula; Yueng, Carole; Johnston, Donna; Suter, W Newton

2009-05-01

As healthcare transitions to the home environment, there is an increasing need to prevent and control infections traced to telehealth equipment. Background information about infection control is presented, and the need for a survey of agency cleaning policies is described. Findings from 31 agencies using telehealth equipment are described followed by suggested Best Practice Guidelines for the cleaning of telehealth equipment.

Aerosol-delivered programmed cell death 4 enhanced apoptosis, controlled cell cycle and suppressed AP-1 activity in the lungs of AP-1 luciferase reporter mice.

PubMed

Hwang, S-K; Jin, H; Kwon, J T; Chang, S-H; Kim, T H; Cho, C-S; Lee, K H; Young, M R; Colburn, N H; Beck, G R; Yang, H-S; Cho, M-H

2007-09-01

The long-term survival of lung cancer patients treated with conventional therapies remains poor and therefore the need for novel approaches remains high. This has led to the re-emergence of aerosol delivery as a therapeutic intervention. In this study, glucosylated polyethylenimine (GPEI) was used as carrier to investigate programmed cell death 4 (PDCD4) and PDCD4 mutant (D418A), an eIF4A-binding mutant, on PDCD4-related signaling and activator protein-1 (AP-1) activity in the lungs of AP-1 luciferase reporter mice. After confirming the efficiency of GPEI as a carrier in lungs, the effects of aerosol-delivered PDCD4 were investigated in AP-1 luciferase reporter mice. Aerosol delivery of GPEI/PDCD4 through a nose-only inhalation facilitated the apoptosis of lungs whereas aerosol PDCD4 mutant did not. Also, such aerosol delivery regulated proteins relevant to cell-cycle control and suppressed AP-1 activity. Results obtained by western blot analysis, immunohistochemistry, luciferase assay and deoxynucleotidyl-transferase-mediated nick end labeling study suggest that combined actions such as facilitating apoptosis, controlling cell cycle and suppression of AP-1 activity by PDCD4 may provide useful tool for designing lung tumor prevention and treatment by which PDCD4 functions as a transformation suppressor in the future.

Remote Sensing of Aerosol and Non-Aerosol Absorption

NASA Technical Reports Server (NTRS)

Kaufman, Y. J.; Dubovik, O.; Holben, B. N.; Remer, L. A.; Tanre, D.; Lau, William K. M. (Technical Monitor)

2001-01-01

Remote sensing of aerosol from the new satellite instruments (e.g. MODIS from Terra) and ground based radiometers (e.g. the AERONET) provides the opportunity to measure the absorption characteristics of the ambient undisturbed aerosol in the entire atmospheric column. For example Landsat and AERONET data are used to measure spectral absorption of sunlight by dust from West Africa. Both Application of the Landsat and AERONET data demonstrate that Saharan dust absorption of solar radiation is several times smaller than the current international standards. This is due to difficulties of measuring dust absorption in situ, and due to the often contamination of dust properties by the presence of air pollution or smoke. We use the remotely sensed aerosol absorption properties described by the spectral sin le scattering albedo, together with statistics of the monthly optical thickness for the fine and coarse aerosol derived from the MODIS data. The result is an estimate of the flux of solar radiation absorbed by the aerosol layer in different regions around the globe where aerosol is prevalent. If this aerosol forcing through absorption is not included in global circulation models, it may be interpreted as anomalous absorption in these regions. In a preliminary exercise we also use the absorption measurements by AERONET, to derive the non-aerosol absorption of the atmosphere in cloud free conditions. The results are obtained for the atmospheric windows: 0.44 microns, 0.66 microns, 0.86 microns and 1.05 microns. In all the locations over the land and ocean that were tested no anomalous absorption in these wavelengths, was found within absorption optical thickness of +/- 0.005.

Staffing and structure of infection prevention and control programs.

PubMed

Stone, Patricia W; Dick, Andrew; Pogorzelska, Monika; Horan, Teresa C; Furuya, E Yoko; Larson, Elaine

2009-06-01

The nature of infection prevention and control is changing; however, little is known about current staffing and structure of infection prevention and control programs. Our objectives were to provide a snapshot of the staffing and structure of hospital-based infection prevention and control programs in the United States. A Web-based survey was sent to 441 hospitals that participate in the National Healthcare Safety Network. The response rate was 66% (n = 289); data were examined on 821 professionals. Infection preventionist (IP) staffing was significantly negatively related to bed size, with higher staffing in smaller hospitals (P < .001). Median staffing was 1 IP per 167 beds. Forty-seven percent of IPs were certified, and 24 percent had less than 2 years of experience. Most directors or hospital epidemiologists were reported to have authority to close beds for outbreaks always or most of the time (n = 225, 78%). Only 32% (n = 92) reported using an electronic surveillance system to track infections. This study is the first to provide a comprehensive description of current infection prevention and control staffing, organization, and support in a select group of hospitals across the nation. Further research is needed to identify effective staffing levels for various hospital types as well as examine how the IP role is changing over time.

Factors Affecting Aerosol Radiative Forcing

NASA Astrophysics Data System (ADS)

Wang, Jingxu; Lin, Jintai; Ni, Ruijing

2016-04-01

resulting relocation of emissions would meant drastic changes in both the spatial distribution and the magnitude of RF, with consequences on regional and global climate forcing. Our findings are relevant to global aerosol control and climate mitigation.

Factors Affecting Aerosol Radiative Forcing

NASA Astrophysics Data System (ADS)

Wang, J.; Lin, J.; Ni, R.

2016-12-01

relocation of emissions would meant drastic changes in both the spatial distribution and the magnitude of RF, with consequences on regional and global climate forcing. Our findings are relevant to global aerosol control and climate mitigation.

Impact of aerosol size representation on modeling aerosol-cloud interactions

DOE PAGES

Zhang, Y.; Easter, R. C.; Ghan, S. J.; ...

2002-11-07

In this study, we use a 1-D version of a climate-aerosol-chemistry model with both modal and sectional aerosol size representations to evaluate the impact of aerosol size representation on modeling aerosol-cloud interactions in shallow stratiform clouds observed during the 2nd Aerosol Characterization Experiment. Both the modal (with prognostic aerosol number and mass or prognostic aerosol number, surface area and mass, referred to as the Modal-NM and Modal-NSM) and the sectional approaches (with 12 and 36 sections) predict total number and mass for interstitial and activated particles that are generally within several percent of references from a high resolution 108-section approach.more » The modal approach with prognostic aerosol mass but diagnostic number (referred to as the Modal-M) cannot accurately predict the total particle number and surface areas, with deviations from the references ranging from 7-161%. The particle size distributions are sensitive to size representations, with normalized absolute differences of up to 12% and 37% for the 36- and 12-section approaches, and 30%, 39%, and 179% for the Modal-NSM, Modal-NM, and Modal-M, respectively. For the Modal-NSM and Modal-NM, differences from the references are primarily due to the inherent assumptions and limitations of the modal approach. In particular, they cannot resolve the abrupt size transition between the interstitial and activated aerosol fractions. For the 12- and 36-section approaches, differences are largely due to limitations of the parameterized activation for non-log-normal size distributions, plus the coarse resolution for the 12-section case. Differences are larger both with higher aerosol (i.e., less complete activation) and higher SO2 concentrations (i.e., greater modification of the initial aerosol distribution).« less

How to Manage and Control Healthcare Associated Infections

NASA Astrophysics Data System (ADS)

Wijaya, L.

2018-03-01

Healthcare associated infections (HAI) are the major complications of modern medical therapy. The most important HAIs are related to invasive devices including central line- associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI), ventilator-associated pneumonia (VAP) and surgical-site infections (SSI). Excessive use of antibiotics has also led to the emergence and the global dissemination of antibiotic resistant bacteria over the last few decades. Reducing HAIs will involve a multi-modal approach to infection control practices as well as antibiotic stewardship program.

Infection prevention and control in pediatric ambulatory settings.

PubMed

2007-09-01

Since the American Academy of Pediatrics published a statement titled "Infection Control in Physicians' Offices" (Pediatrics. 2000;105[6]:1361-1369), there have been significant changes that prompted this updated statement. Infection prevention and control is an integral part of pediatric practice in ambulatory medical settings as well as in hospitals. Infection prevention and control practices should begin at the time the ambulatory visit is scheduled. All health care personnel should be educated regarding the routes of transmission and techniques used to prevent transmission of infectious agents. Policies for infection prevention and control should be written, readily available, updated annually, and enforced. The standard precautions for hospitalized patients from the Centers for Disease Control and Prevention, with a modification from the American Academy of Pediatrics exempting the use of gloves for routine diaper changes and wiping a well child's nose or tears, are appropriate for most patient encounters. As employers, pediatricians are required by the Occupational Safety and Health Administration to take precautions to identify and protect employees who are likely to be exposed to blood or other potentially infectious materials while on the job. Key principles of standard precautions include hand hygiene (ie, use of alcohol-based hand rub or hand-washing with soap [plain or antimicrobial] and water) before and after every patient contact; implementation of respiratory hygiene and cough-etiquette strategies for patients with suspected influenza or infection with another respiratory tract pathogen to the extent feasible; separation of infected, contagious children from uninfected children when feasible; safe handling and disposal of needles and other sharp medical devices and evaluation and implementation of needle-safety devices; appropriate use of personal protective equipment such as gloves, gowns, masks, and eye protection; and appropriate sterilization

Impact of Infection Prevention and Control Initiatives on Acute Respiratory Infections in a Pediatric Long-Term Care Facility.

PubMed

Murray, Meghan T; Jackson, Olivia; Cohen, Bevin; Hutcheon, Gordon; Saiman, Lisa; Larson, Elaine; Neu, Natalie

2016-07-01

We evaluated the collective impact of several infection prevention and control initiatives aimed at reducing acute respiratory infections (ARIs) in a pediatric long-term care facility. ARIs did not decrease overall, though the proportion of infections associated with outbreaks and average number of cases per outbreak decreased. Influenza rates decreased significantly. Infect Control Hosp Epidemiol 2016;37:859-862.

Continuous standalone controllable aerosol/cloud droplet dryer for atmospheric sampling

NASA Astrophysics Data System (ADS)

Sjogren, S.; Frank, G. P.; Berghof, M. I. A.; Martinsson, B. G.

2012-08-01

We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH) of the sample flow (lower than the atmospheric humidity) is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry highly charged cloud droplets (maximum diameter approximately 25 μm) with minimum losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2). The water vapour transfer coefficient, k, was measured to 4.6 × 10-7 kg m-2 s-1% RH-1 in the laboratory and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s-1 was achieved in the field. This corresponds to drying a 5.7 L min-1 (0.35 m3 h-1) aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min-1). The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l.) in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was > 94% during these five months.

Modern trends in infection control practices in intensive care units.

PubMed

Gandra, Sumanth; Ellison, Richard T

2014-01-01

Hospital-acquired infections (HAIs) are common in intensive care unit (ICU) patients and are associated with increased morbidity and mortality. There has been an increasing effort to prevent HAIs, and infection control practices are paramount in avoiding these complications. In the last several years, numerous developments have been seen in the infection prevention strategies in various health care settings. This article reviews the modern trends in infection control practices to prevent HAIs in ICUs with a focus on methods for monitoring hand hygiene, updates in isolation precautions, new methods for environmental cleaning, antimicrobial bathing, prevention of ventilator-associated pneumonia, central line-associated bloodstream infections, catheter-associated urinary tract infections, and Clostridium difficile infection. © The Author(s) 2013.

Aerosol Properties Observed in the Subtropical North Pacific Boundary Layer

NASA Astrophysics Data System (ADS)

Royalty, T. M.; Phillips, B. N.; Dawson, K. W.; Reed, R.; Meskhidze, N.; Petters, M. D.

2017-09-01

The impact of anthropogenic aerosol on climate forcing remains uncertain largely due to inadequate representation of natural aerosols in climate models. The marine boundary layer (MBL) might serve as a model location to study natural aerosol processes. Yet source and sink mechanisms controlling the MBL aerosol number, size distribution, chemical composition, and hygroscopic properties remain poorly constrained. Here aerosol size distribution and water uptake measurements were made aboard the R/V Hi'ialakai from 27 June to 3 July 2016 in the subtropical North Pacific Ocean. Size distributions were predominantly bimodal with an average integrated number concentration of 197 ± 98 cm-3. Hygroscopic growth factors were measured using the tandem differential mobility analyzer technique for dry 48, 96, and 144 nm particles. Mode kappa values for these were 0.57 ± 0.12, 0.51 ± 0.09, and 0.52 ± 0.08, respectively. To better understand remote MBL aerosol sources, a new algorithm was developed which decomposes hygroscopicity distributions into three classes: carbon-containing particles, sulfate-like particles, and sodium-containing particles. Results from this algorithm showed low and steady sodium-containing particle concentrations while the sulfate-like and carbon-containing particle concentrations varied during the cruise. According to the classification scheme, carbon-containing particles contributed at least 3-7%, sulfate-like particles contributed at most 77-88% and sodium-containing particles at least contributed 9-16% to the total aerosol number concentration. Size distribution and hygroscopicity data, in conjunction with air mass back trajectory analysis, suggested that the aerosol budget in the subtropical North Pacific MBL may be controlled by aerosol entrainment from the free troposphere.

What Controls the Vertical Distribution of Aerosol? Relationships Between Process Sensitivity in HadGEM3-UKCA and Inter-Model Variation from AeroCom Phase II

NASA Technical Reports Server (NTRS)

Kipling, Zak; Stier, Philip; Johnson, Colin E.; Mann, Graham W.; Bellouin, Nicolas; Bauer, Susanne E.; Bergman, Tommi; Chin, Mian; Diehl, Thomas; Ghan, Steven J.;

75 FR 63844 - Healthcare Infection Control Practices Advisory Committee (HICPAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Healthcare Infection Control Practices Advisory Committee (HICPAC) In accordance with section 10(a)(2) of the Federal...), regarding the practice of healthcare infection control and strategies for surveillance, prevention, and...

42 CFR 418.60 - Condition of participation: Infection control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 3 2011-10-01 2011-10-01 false Condition of participation: Infection control. 418.60 Section 418.60 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND....60 Condition of participation: Infection control. The hospice must maintain and document an effective...

42 CFR 482.42 - Condition of participation: Infection control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... communicable diseases. The infection control officer or officers must develop a system for identifying... 42 Public Health 5 2014-10-01 2014-10-01 false Condition of participation: Infection control. 482.42 Section 482.42 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

42 CFR 482.42 - Condition of participation: Infection control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... communicable diseases. The infection control officer or officers must develop a system for identifying... 42 Public Health 5 2012-10-01 2012-10-01 false Condition of participation: Infection control. 482.42 Section 482.42 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

42 CFR 416.51 - Conditions for coverage-Infection control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... communicable diseases. In addition, the infection control and prevention program must include documentation... 42 Public Health 3 2012-10-01 2012-10-01 false Conditions for coverage-Infection control. 416.51 Section 416.51 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...

42 CFR 416.51 - Conditions for coverage-Infection control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... communicable diseases. In addition, the infection control and prevention program must include documentation... 42 Public Health 3 2014-10-01 2014-10-01 false Conditions for coverage-Infection control. 416.51 Section 416.51 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...

42 CFR 416.51 - Conditions for coverage-Infection control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... communicable diseases. In addition, the infection control and prevention program must include documentation... 42 Public Health 3 2013-10-01 2013-10-01 false Conditions for coverage-Infection control. 416.51 Section 416.51 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...

42 CFR 416.51 - Conditions for coverage-Infection control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... an ongoing program designed to prevent, control, and investigate infections and communicable diseases... 42 Public Health 3 2011-10-01 2011-10-01 false Conditions for coverage-Infection control. 416.51 Section 416.51 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...

42 CFR 482.42 - Condition of participation: Infection control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... communicable diseases. The infection control officer or officers must develop a system for identifying... 42 Public Health 5 2013-10-01 2013-10-01 false Condition of participation: Infection control. 482.42 Section 482.42 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...

42 CFR 416.51 - Conditions for coverage-Infection control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... an ongoing program designed to prevent, control, and investigate infections and communicable diseases... 42 Public Health 3 2010-10-01 2010-10-01 false Conditions for coverage-Infection control. 416.51 Section 416.51 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN...

Middle East Respiratory Syndrome Infection Control and Prevention Guideline for Healthcare Facilities.

PubMed

Kim, Jin Yong; Song, Joon Young; Yoon, Young Kyung; Choi, Seong-Ho; Song, Young Goo; Kim, Sung-Ran; Son, Hee-Jung; Jeong, Sun-Young; Choi, Jung-Hwa; Kim, Kyung Mi; Yoon, Hee Jung; Choi, Jun Yong; Kim, Tae Hyong; Choi, Young Hwa; Kim, Hong Bin; Yoon, Ji Hyun; Lee, Jacob; Eom, Joong Sik; Lee, Sang-Oh; Oh, Won Sup; Choi, Jung-Hyun; Yoo, Jin-Hong; Kim, Woo Joo; Cheong, Hee Jin

2015-12-01

Middle East Respiratory Syndrome (MERS) is an acute viral respiratory illness with high mortality caused by a new strain of betacoronavirus (MERS-CoV). Since the report of the first patient in Saudi Arabia in 2012, large-scale outbreaks through hospital-acquired infection and inter-hospital transmission have been reported. Most of the patients reported in South Korea were also infected in hospital settings. Therefore, to eliminate the spread of MERS-CoV, infection prevention and control measures should be implemented with rigor. The present guideline has been drafted on the basis of the experiences of infection control in the South Korean hospitals involved in the recent MERS outbreak and on domestic and international infection prevention and control guidelines. To ensure efficient MERS-CoV infection prevention and control, care should be taken to provide comprehensive infection control measures including contact control, hand hygiene, personal protective equipment, disinfection, and environmental cleaning.

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

NASA Astrophysics Data System (ADS)

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-09-01

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

Prevalence of surgical site infections before and after the implementation of a multimodal infection control programme.

PubMed

Barchitta, Martina; Matranga, Domenica; Quattrocchi, Annalisa; Bellocchi, Patrizia; Ruffino, Maria; Basile, Guido; Agodi, Antonella

2012-03-01

In order to assess the prevalence of surgical site infections (SSIs) before and after the implementation of a multimodal infection control programme including the realization of a campaign to increase compliance with guidelines for antimicrobial prophylaxis, we designed and conducted the present study involving all 20 of the surgical departments of a large teaching hospital in Catania, Italy. SSI definitions of the Hospital in Europe Link for Infection Control through Surveillance (HELICS) protocol were used in four 1 day point-prevalence surveys. After the first survey, an infection control programme was implemented involving the active commitment of surgeons and infection control staff. Overall, a total of 600 surgical patients were enrolled. A significant decreasing trend in the SSI rate (from 16.4 to 8.2 per 100 surgical patients, P=0.018) was shown. After multivariate analysis, significant risk factors for SSI were identified: age >31 years, kidney insufficiency and infection at admission. Taking into account the indication and the timing of administration of antibiotic prophylaxis, in the four surveys prophylaxis was administered inappropriately in 55.3% of surgical procedures. The approach used in this study remains a feasible method of evaluating the burden of SSIs using repeated prevalence surveys. The results provide evidence of a significant decreasing trend in the SSI rate following the infection control intervention. Furthermore, our study underlines the need to develop evidence-based guidelines in collaboration with surgeons, to achieve consensus before implementation in order to improve compliance with antimicrobial prophylaxis and, finally, decrease SSI rates.

Characterization of urban aerosol in Cork city (Ireland) using aerosol mass spectrometry

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Ovadnevaite, J.; Ceburnis, D.; Martin, D.; Healy, R. M.; O'Connor, I. P.; Kourtchev, I.; Sodeau, J. R.; Wenger, J. C.; O'Dowd, C.

2013-05-01

Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles characterized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich particle types, internally mixed to different proportions with elemental carbon (EC), sulphate and nitrate, while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was characterized using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS) and was also found to comprise organic aerosol as the most abundant species (62%), followed by nitrate (15%), sulphate (9%) and ammonium (9%), and chloride (5%). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, "hydrocarbon-like" organic aerosol (HOA) comprised 20% of the mass, "low-volatility" oxygenated organic aerosol (LV-OOA) comprised 18%, "biomass burning" organic aerosol (BBOA) comprised 23%, non-wood solid-fuel combustion "peat and coal" organic aerosol (PCOA) comprised 21%, and finally a species type characterized by primary {m/z} peaks at 41 and 55, similar to previously reported "cooking" organic aerosol (COA), but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Despite wood, coal and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosol mass and non-refractory total PM1, respectively).

Estimating Marine Aerosol Particle Volume and Number from Maritime Aerosol Network Data

NASA Technical Reports Server (NTRS)

Sayer, A. M.; Smirnov, A.; Hsu, N. C.; Munchak, L. A.; Holben, B. N.

2012-01-01

As well as spectral aerosol optical depth (AOD), aerosol composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The average solution MODIS dataset agrees more closely with MAN than the best solution dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data.

Behavioral interventions to improve infection control practices.

PubMed

Kretzer, E K; Larson, E L

1998-06-01

No single intervention has been successful in improving and sustaining such infection control practices as universal precautions and handwashing by health care professionals. This paper examines several behavioral theories (Health Belief Model, Theory of Reasoned Action and Theory of Planned Behavior, self-efficacy, and the Transtheoretic Model) and relates them to individual factors, also considering interpersonal and organizational factors. Further, this article includes recommendations of individual and organizational components to be addressed when planning a theoretically based intervention for improving infection control practices. A hypothetic framework to enhance handwashing practice is proposed.

Background aerosol over the Himalayas and Tibetan Plateau: observed characteristics of aerosol mass loading

NASA Astrophysics Data System (ADS)

Liu, Bin; Cong, Zhiyuan; Wang, Yuesi; Xin, Jinyuan; Wan, Xin; Pan, Yuepeng; Liu, Zirui; Wang, Yonghong; Zhang, Guoshuai; Wang, Zhongyan; Wang, Yongjie; Kang, Shichang

2017-01-01

To investigate the atmospheric aerosols of the Himalayas and Tibetan Plateau (HTP), an observation network was established within the region's various ecosystems, including at the Ngari, Qomolangma (QOMS), Nam Co, and Southeastern Tibetan (SET) stations. In this paper we illustrate aerosol mass loadings by integrating in situ measurements with satellite and ground-based remote sensing datasets for the 2011-2013 period, on both local and large scales. Mass concentrations of these surface atmospheric aerosols were relatively low and varied with land cover, showing a general tendency of Ngari and QOMS (barren sites) > Nam Co (grassland site) > SET (forest site). Daily averages of online PM2.5 (particulates with aerodynamic diameters below 2.5 µm) at these sites were sequentially 18.2 ± 8.9, 14.5 ± 7.4, 11.9 ± 4.9 and 11.7 ± 4.7 µg m-3. Correspondingly, the ratios of PM2.5 to total suspended particles (TSP) were 27.4 ± 6.65, 22.3 ± 10.9, 37.3 ± 11.1 and 54.4 ± 6.72 %. Bimodal mass distributions of size-segregated particles were found at all sites, with a relatively small peak in accumulation mode and a more notable peak in coarse mode. Diurnal variations in fine-aerosol masses generally displayed a bi-peak pattern at the QOMS, Nam Co and SET stations and a single-peak pattern at the Ngari station, controlled by the effects of local geomorphology, mountain-valley breeze circulation and aerosol emissions. Dust aerosol content in PM2.1 samples gave fractions of 26 % at the Ngari station and 29 % at the QOMS station, or ˜ 2-3 times that of reported results at human-influenced sites. Furthermore, observed evidence confirmed the existence of the aerodynamic conditions necessary for the uplift of fine particles from a barren land surface. Combining surface aerosol data and atmospheric-column aerosol optical properties, the TSP mass and aerosol optical depth (AOD) of the Multi-angle Imaging Spectroradiometer (MISR) generally decreased as land cover changed from

Aerosol Chemistry over a High Altitude Station at Northeastern Himalayas, India

PubMed Central

Chatterjee, Abhijit; Adak, Anandamay; Singh, Ajay K.; Srivastava, Manoj K.; Ghosh, Sanjay K.; Tiwari, Suresh; Devara, Panuganti C. S.; Raha, Sibaji

2010-01-01

Background There is an urgent need for an improved understanding of the sources, distributions and properties of atmospheric aerosol in order to control the atmospheric pollution over northeastern Himalayas where rising anthropogenic interferences from rapid urbanization and development is becoming an increasing concern. Methodology/Principal Findings An extensive aerosol sampling program was conducted in Darjeeling (altitude ∼2200 meter above sea level (masl), latitude 27°01′N and longitude 88°15′E), a high altitude station in northeastern Himalayas, during January–December 2005. Samples were collected using a respirable dust sampler and a fine dust sampler simultaneously. Ion chromatograph was used to analyze the water soluble ionic species of aerosol. The average concentrations of fine and coarse mode aerosol were found to be 29.5±20.8 µg m−3 and 19.6±11.1 µg m−3 respectively. Fine mode aerosol dominated during dry seasons and coarse mode aerosol dominated during monsoon. Nitrate existed as NH4NO3 in fine mode aerosol during winter and as NaNO3 in coarse mode aerosol during monsoon. Gas phase photochemical oxidation of SO2 during premonsoon and aqueous phase oxidation during winter and postmonsoon were the major pathways for the formation of SO4 2− in the atmosphere. Long range transport of dust aerosol from arid regions of western India was observed during premonsoon. The acidity of fine mode aerosol was higher in dry seasons compared to monsoon whereas the coarse mode acidity was higher in monsoon compared to dry seasons. Biomass burning, vehicular emissions and dust particles were the major types of aerosol from local and continental regions whereas sea salt particles were the major types of aerosol from marine source regions. Conclusions/Significance The year-long data presented in this paper provide substantial improvements to the heretofore poor knowledge regarding aerosol chemistry over northeastern Himalayas, and should be useful to

Aerosol chemistry over a high altitude station at northeastern Himalayas, India.

PubMed

Chatterjee, Abhijit; Adak, Anandamay; Singh, Ajay K; Srivastava, Manoj K; Ghosh, Sanjay K; Tiwari, Suresh; Devara, Panuganti C S; Raha, Sibaji

2010-06-16

There is an urgent need for an improved understanding of the sources, distributions and properties of atmospheric aerosol in order to control the atmospheric pollution over northeastern Himalayas where rising anthropogenic interferences from rapid urbanization and development is becoming an increasing concern. An extensive aerosol sampling program was conducted in Darjeeling (altitude approximately 2200 meter above sea level (masl), latitude 27 degrees 01'N and longitude 88 degrees 15'E), a high altitude station in northeastern Himalayas, during January-December 2005. Samples were collected using a respirable dust sampler and a fine dust sampler simultaneously. Ion chromatograph was used to analyze the water soluble ionic species of aerosol. The average concentrations of fine and coarse mode aerosol were found to be 29.5+/-20.8 microg m(-3) and 19.6+/-11.1 microg m(-3) respectively. Fine mode aerosol dominated during dry seasons and coarse mode aerosol dominated during monsoon. Nitrate existed as NH(4)NO(3) in fine mode aerosol during winter and as NaNO(3) in coarse mode aerosol during monsoon. Gas phase photochemical oxidation of SO(2) during premonsoon and aqueous phase oxidation during winter and postmonsoon were the major pathways for the formation of SO(4)(2-) in the atmosphere. Long range transport of dust aerosol from arid regions of western India was observed during premonsoon. The acidity of fine mode aerosol was higher in dry seasons compared to monsoon whereas the coarse mode acidity was higher in monsoon compared to dry seasons. Biomass burning, vehicular emissions and dust particles were the major types of aerosol from local and continental regions whereas sea salt particles were the major types of aerosol from marine source regions. The year-long data presented in this paper provide substantial improvements to the heretofore poor knowledge regarding aerosol chemistry over northeastern Himalayas, and should be useful to policy makers in making control

Healthcare-associated infections: infection prevention and control within the Accreditation Canada Qmentum Program.

PubMed

Nicklin, Wendy; Greco, Paula; Mitchell, Jonathan I

2009-01-01

Gardam, Lemieux, Reason, van Dijk and Goel argue that healthcare-associated infections (HAIs) are "a pressing and imminent concern in the context of patient safety." Accreditation Canada supports the position taken by these authors. The prevention and control of two HAIs of great concern, methicillin-resistant Staphylococcus aureus and Clostridium difficile, are an integral part of the Accreditation Canada program. A coordinated approach to combating HAIs and developing a culture of infection prevention and control is necessary, one that involves front-line healthcare professionals, senior leadership, national and provincial partners and the public. Since 2005, Accreditation Canada has increasingly strengthened the accreditation program in this area through a number of new strategies, including enhanced standards, required organizational practices, performance measures and indicators and the introduction of education programs. Optimizing the value of accreditation through an integrative approach with organizations' quality improvement programs will contribute to effectively combating HAIs and developing a culture of infection prevention and control.

Presence of multiple lesion types with vastly different microenvironments in C3HeB/FeJ mice following aerosol infection with Mycobacterium tuberculosis

PubMed Central

Irwin, Scott M.; Driver, Emily; Lyon, Edward; Schrupp, Christopher; Ryan, Gavin; Gonzalez-Juarrero, Mercedes; Basaraba, Randall J.; Nuermberger, Eric L.; Lenaerts, Anne J.

2015-01-01

ABSTRACT Cost-effective animal models that accurately reflect the pathological progression of pulmonary tuberculosis are needed to screen and evaluate novel tuberculosis drugs and drug regimens. Pulmonary disease in humans is characterized by a number of heterogeneous lesion types that reflect differences in cellular composition and organization, extent of encapsulation, and degree of caseous necrosis. C3HeB/FeJ mice have been increasingly used to model tuberculosis infection because they produce hypoxic, well-defined granulomas exhibiting caseous necrosis following aerosol infection with Mycobacterium tuberculosis. A comprehensive histopathological analysis revealed that C3HeB/FeJ mice develop three morphologically distinct lesion types in the lung that differ with respect to cellular composition, degree of immunopathology and control of bacterial replication. Mice displaying predominantly the fulminant necrotizing alveolitis lesion type had significantly higher pulmonary bacterial loads and displayed rapid and severe immunopathology characterized by increased mortality, highlighting the pathological role of an uncontrolled granulocytic response in the lung. Using a highly sensitive novel fluorescent acid-fast stain, we were able to visualize the spatial distribution and location of bacteria within each lesion type. Animal models that better reflect the heterogeneity of lesion types found in humans will permit more realistic modeling of drug penetration into solid caseous necrotic lesions and drug efficacy testing against metabolically distinct bacterial subpopulations. A more thorough understanding of the pathological progression of disease in C3HeB/FeJ mice could facilitate modulation of the immune response to produce the desired pathology, increasing the utility of this animal model. PMID:26035867

Staffing and structure of infection prevention and control programs

PubMed Central

Stone, Patricia W.; Dick, Andrew; Pogorzelska, Monika; Horan, Teresa C.; Furuya, E. Yoko; Larson, Elaine

2009-01-01

Background The nature of infection prevention and control is changing; however, little is known about current staffing and structure of infection prevention and control programs. Methods Our objectives were to provide a snapshot of the staffing and structure of hospital-based infection prevention and control programs in the United States. A Web-based survey was sent to 441 hospitals that participate in the National Healthcare Safety Network. Results The response rate was 66% (n = 289); data were examined on 821 professionals. Infection preventionist (IP) staffing was significantly negatively related to bed size, with higher staffing in smaller hospitals (P < .001). Median staffing was 1 IP per 167 beds. Forty-seven percent of IPs were certified, and 24 percent had less than 2 years of experience. Most directors or hospital epidemiologists were reported to have authority to close beds for outbreaks always or most of the time (n = 225, 78%). Only 32% (n = 92) reported using an electronic surveillance system to track infections. Conclusion This study is the first to provide a comprehensive description of current infection prevention and control staffing, organization, and support in a select group of hospitals across the nation. Further research is needed to identify effective staffing levels for various hospital types as well as examine how the IP role is changing over time. PMID:19201510

[Infection control and safety culture in German hospitals].

PubMed

Hansen, Sonja; Schwab, Frank; Gropmann, Alexander; Behnke, Michael; Gastmeier, Petra

2016-07-01

Healthcare-associated infections (HAI) are the most frequent adverse events in the healthcare setting and their prevention is an important contribution to patient safety in hospitals. To analyse to what extent safety cultural aspects with relevance to infection control are implemented in German hospitals. Safety cultural aspects of infection control were surveyed with an online questionnaire; data were analysed descriptively. Data from 543 hospitals with a median of [IQR] 275 [157; 453] beds were analysed. Almost all hospitals (96.6 %) had internal guidelines for infection control (IC) in place; 82 % defined IC objectives, most often regarding hand hygiene (HH) (93 %) and multidrug resistant organisms (72 %) and less frequently for antibiotic stewardship (48 %) or prevention of specific HAI. In 94 % of hospitals, a reporting system for adverse events was in place, which was also used to report low compliance with HH, outbreaks and Clostridium difficile-associated infections. Members of the IC team were most often seen to hold daily responsibility for IC in the hospital, but rarely other hospital staff (94 versus 19 %). Safety cultural aspects are not fully implemented in German hospitals. IC should be more strongly implemented in healthcare workers' daily routine and more visibly supported by hospital management.

Chamber for Aerosol Deposition of Bioparticles

NASA Technical Reports Server (NTRS)

Kern, Roger; Kirschner, Larry

2008-01-01

Laboratory apparatus is depicted that is a chamber for aerosol deposition of bioparticles on surfaces of test coupons. It is designed for primary use in inoculating both flat and three-dimensional objects with approximately reproducible, uniform dispersions of bacterial spores of the genus Bacillus so that the objects could be used as standards for removal of the spores by quantitative surface sampling and/or cleaning processes. The apparatus is also designed for deposition of particles other than bacterial spores, including fungal spores, viruses, bacteriophages, and standard micron-sized beads. The novelty of the apparatus lies in the combination of a controllable nebulization system with a settling chamber large enough to contain a significant number of test coupons. Several companies market other nebulizer systems, but none are known to include chambers for deposition of bioparticles to mimic the natural fallout of bioparticles. The nebulization system is an expanded and improved version of commercially available aerosol generators that include nebulizers and drying columns. In comparison with a typical commercial aerosol generator, this system includes additional, higher-resolution flowmeters and an additional pressure regulator. Also, unlike a typical commercial aerosol generator, it includes stopcocks for separately controlling flows of gases to the nebulizer and drying column. To maximize the degree of uniformity of dispersion of bioaerosol, the chamber is shaped as an axisymmetrical cylinder and the aerosol generator is positioned centrally within the chamber and aimed upward like a fountain. In order to minimize electric charge associated with the aerosol particles, the drying column is made of aluminum, the drying column is in direct contact with an aluminum base plate, and three equally spaced Po-210 antistatic strips are located at the exit end of the drying column. The sides and top of the chamber are made of an acrylic polymer; to prevent

Middle East Respiratory Syndrome Infection Control and Prevention Guideline for Healthcare Facilities

PubMed Central

Kim, Jin Yong; Song, Joon Young; Yoon, Young Kyung; Choi, Seong-Ho; Song, Young Goo; Kim, Sung-Ran; Son, Hee-Jung; Jeong, Sun-Young; Choi, Jung-Hwa; Kim, Kyung Mi; Yoon, Hee Jung; Choi, Jun Yong; Kim, Tae Hyong; Choi, Young Hwa; Kim, Hong Bin; Yoon, Ji Hyun; Lee, Jacob; Eom, Joong Sik; Lee, Sang-Oh; Oh, Won Sup; Choi, Jung-Hyun; Yoo, Jin-Hong; Kim, Woo Joo

2015-01-01

Middle East Respiratory Syndrome (MERS) is an acute viral respiratory illness with high mortality caused by a new strain of betacoronavirus (MERS-CoV). Since the report of the first patient in Saudi Arabia in 2012, large-scale outbreaks through hospital-acquired infection and inter-hospital transmission have been reported. Most of the patients reported in South Korea were also infected in hospital settings. Therefore, to eliminate the spread of MERS-CoV, infection prevention and control measures should be implemented with rigor. The present guideline has been drafted on the basis of the experiences of infection control in the South Korean hospitals involved in the recent MERS outbreak and on domestic and international infection prevention and control guidelines. To ensure efficient MERS-CoV infection prevention and control, care should be taken to provide comprehensive infection control measures including contact control, hand hygiene, personal protective equipment, disinfection, and environmental cleaning. PMID:26788414

ICMR programme on Antibiotic Stewardship, Prevention of Infection & Control (ASPIC).

PubMed

Chandy, Sujith J; Michael, Joy Sarojini; Veeraraghavan, Balaji; Abraham, O C; Bachhav, Sagar S; Kshirsagar, Nilima A

2014-02-01

Antimicrobial resistance and hospital infections have increased alarmingly in India. Antibiotic stewardship and hospital infection control are two broad strategies which have been employed globally to contain the problems of resistance and infections. For this to succeed, it is important to bring on board the various stakeholders in hospitals, especially the clinical pharmacologists. The discipline of clinical pharmacology needs to be involved in themes such as antimicrobial resistance and hospital infection which truly impact patient care. Clinical pharmacologists need to collaborate with faculty in other disciplines such as microbiology to achieve good outcomes for optimal patient care in the hospital setting. The ASPIC programme was initiated by the Indian Council of Medical Research (ICMR) in response to the above need and was designed to bring together faculty from clinical pharmacology, microbiology and other disciplines to collaborate on initiating and improving antibiotic stewardship and concurrently curbing hospital infections through feasible infection control practices. This programme involves the participation of 20 centres per year throughout the country which come together for a training workshop. Topics pertaining to the above areas are discussed in addition to planning a project which helps to improve antibiotic stewardship and infection control practices in the various centres. It is hoped that this programme would empower hospitals and institutions throughout the country to improve antibiotic stewardship and infection control and ultimately contain antimicrobial resistance.

Climatic Effects of 1950-2050 Changes in US Anthropogenic Aerosols. Part 1; Aerosol Trends and Radiative Forcing

NASA Technical Reports Server (NTRS)

Leibensperger, E. M.; Mickley, L. J.; Jacob, D. J.; Chen, W.-T.; Seinfeld, J. H.; Nenes, A.; Adams, P. J.; Streets, D. G.; Kumar, N.; Rind, D.

2012-01-01

We calculate decadal aerosol direct and indirect (warm cloud) radiative forcings from US anthropogenic sources over the 1950-2050 period. Past and future aerosol distributions are constructed using GEOS-Chem and historical emission inventories and future projections from the IPCC A1B scenario. Aerosol simulations are evaluated with observed spatial distributions and 1980-2010 trends of aerosol concentrations and wet deposition in the contiguous US. Direct and indirect radiative forcing is calculated using the GISS general circulation model and monthly mean aerosol distributions from GEOS-Chem. The radiative forcing from US anthropogenic aerosols is strongly localized over the eastern US. We find that its magnitude peaked in 1970-1990, with values over the eastern US (east of 100 deg W) of -2.0Wm(exp-2 for direct forcing including contributions from sulfate (-2.0Wm-2), nitrate (-0.2Wm(exp-2), organic carbon (-0.2Wm(exp-2), and black carbon (+0.4Wm(exp-2). The uncertainties in radiative forcing due to aerosol radiative properties are estimated to be about 50 %. The aerosol indirect effect is estimated to be of comparable magnitude to the direct forcing. We find that the magnitude of the forcing declined sharply from 1990 to 2010 (by 0.8Wm(exp-2) direct and 1.0Wm(exp-2 indirect), mainly reflecting decreases in SO2 emissions, and project that it will continue declining post-2010 but at a much slower rate since US SO2 emissions have already declined by almost 60% from their peak. This suggests that much of the warming effect of reducing US anthropogenic aerosol sources has already been realized. The small positive radiative forcing from US BC emissions (+0.3Wm(exp-2 over the eastern US in 2010; 5% of the global forcing from anthropogenic BC emissions worldwide) suggests that a US emission control strategy focused on BC would have only limited climate benefit.

Artificial-intelligence-based hospital-acquired infection control.

PubMed

Adlassnig, Klaus-Peter; Blacky, Alexander; Koller, Walter

2009-01-01

Nosocomial or hospital-acquired infections (NIs) are a frequent complication in hospitalized patients. The growing availability of computerized patient records in hospitals permits automated identification and extended monitoring for signs of NIs. A fuzzy- and knowledge-based system to identify and monitor NIs at intensive care units (ICUs) according to the European Surveillance System HELICS (NI definitions derived from the Centers of Disease Control and Prevention (CDC) criteria) was developed and put into operation at the Vienna General Hospital. This system, named Moni, for monitoring of nosocomial infections contains medical knowledge packages (MKPs) to identify and monitor various infections of the bloodstream, pneumonia, urinary tract infections, and central venous catheter-associated infections. The MKPs consist of medical logic modules (MLMs) in Arden syntax, a medical knowledge representation scheme, whose definition is part of the HL7 standards. These MLM packages together with the Arden software are well suited to be incorporated in medical information systems such as hospital information or intensive-care patient data management systems, or in web-based applications. In terms of method, Moni contains an extended data-to-symbol conversion with several layers of abstraction, until the top level defining NIs according to HELICS is reached. All included medical concepts such as "normal", "increased", "decreased", or similar ones are formally modeled by fuzzy sets, and fuzzy logic is used to process the interpretations of the clinically observed and measured patient data through an inference network. The currently implemented cockpit surveillance connects 96 ICU beds with Moni and offers the hospital's infection control department a hitherto unparalleled NI infection survey.

[Infection control and hygiene management in equine hospitals].

PubMed

Walther, Birgit; Janssen, Traute; Gehlen, Heidrun; Vincze, Szilvia; Borchers, Kerstin; Wieler, Lothar H; Barton, Ann Kristin; Lübke-Becker, Antina

2014-01-01

With the rising importance of nosocomial infections in equine hospitals, increased efforts with regard to biosecurity and infection control are necessary. This even more since nosocomial infections are often associated with multi-drug resistant pathogens. Consequently, the implementation of targeted prevention programs is essential. Since nosocomial infections are usually multifactorial events, realization of only a single measure is rarely effective to overcome nosocomial spread in clinical practice. Equine patients may be colonized at admission with multi-drug resistant pathogens such as methicillin resistant Staphylococcus aureus (MRSA) and/or extended spectrum beta lactamase-producing (ESBL-) Enterobacteriaceae. Regardless of their individual resistance properties, these bacteria are common and usually unnoticed colonizers of either the nasopharynx or the intestinal tract. Also viral diseases caused by equine herpesvirus 1 (EHV-1) and EHV-4 may reach a clinic by patients which are latently infected or in the incubation period. To prevent nosocomal outbreaks, achieve an interruption in the infection chain and to eradicate infectious agents from the hospital environment, a professional hospital management is necessary. This should be adapted to both the wide range of pathogens causing nosocomial infections and the individual needs of equine patients. Amongst others, this approach includes a risk classification of equine patients at admission and information/enlightenment of the animal owners at discharge. An efficient management of inpatients, a targeted hygiene management and clear responsibilities with respect to biosecurity together with a surveillance of nosocomial infections form the cornerstone of infection control in equine hospitals.

Aerosols

Atmospheric Science Data Center

2013-04-17

... depth. A color scale is used to represent this quantity, and high aerosol amount is indicated by yellow or green pixels, and clearer skies ... out most clearly, whereas MISR's oblique cameras enhance sensitivity to even thin layers of aerosols. In the March image, the only ...

Whitecaps, sea-salt aerosols, and climate

NASA Astrophysics Data System (ADS)

Anguelova, Magdalena Dimitrova

Oceanic whitecaps are the major source of sea-salt aerosols. Because these aerosols are dominant in remote marine air, they control the radiative properties of the clean background atmosphere by scattering sunlight, changing cloud properties and lifetime, and providing media for chemical reactions. Including sea-salt effects in climate models improves predictions, but simulating their generation is first necessary. To make the sea-salt generation function currently used in climate models more relevant for aerosol investigations, this study proposes two modifications. First, the conventional relation between whitecap coverage, W, and the 10-meter wind speed, U10, used in typical generation functions is expanded to include additional factors that affect whitecaps and sea-salt aerosol formation. Second, the sea-salt generation function is extended to smaller sizes; sea-salt aerosol with initial radii from 0.4 to 20 mum can now be modeled. To achieve these goals, this thesis develops a new method for estimating whitecap coverage on a global scale using satellite measurements of the brightness temperature of the ocean surface. Whitecap coverage evaluated with this method incorporates the effects of atmospheric stability, sea-surface temperature, salinity, wind fetch, wind duration, and the amount of surface-active material. Assimilating satellite-derived values for whitecap coverage in the sea-salt generation function incorporates the effects of all environmental factors on sea-salt production and predicts realistic sea-salt aerosol loadings into the atmosphere. An extensive database of whitecap coverage and sea-salt aerosol fluxes has been compiled with the new method and is used to investigate their spatial and temporal characteristics. The composite effect of all environmental factors suggests a more uniform latitudinal distribution of whitecaps and sea-salt aerosols than that predicted from wind speed alone. The effect of sea-surface temperature, TS, is

Correlation between aerosol therapy in early childhood and Molar Incisor Hypomineralisation.

PubMed

Loli, D; Costacurta, M; Maturo, P; Docimo, R

2015-03-01

To evaluate the correlation between the use of aerosol therapy in early childhood and the presence of Molar Incisor Hypomineralisation (MIH). a retrospective case-control study in which a group (cases) consisted of children from 6 to 13 years with MIH visited at the unit of Pediatric Dentistry of the Policlinico Tor Vergata (Rome, Italy), and a group (controls) consisted of an equal number of children of the same age without MIH. Data about the aerosol therapy and the presence of MIH were obtained respectively by medical history and intraoral clinical examination. Collected data underwent statistical analysis using mainly non-parametric tests (p < 0.05). In the study were included 182 patients, of which 91 (46 males, 51%) were children with MIH (cases), and 91 (46 males, 51%) were children without MIH (controls). In the group of patients with MIH, in the early childhood, 12 (13.1%) never had aerosol therapy, 6 (6.6%) underwent aerosol therapy less than 7 days per year, 22 (24.2%) from 8 to 15 days per year, 22 (24.2%) from 16 to 45 days a year, and 29 (31.9%) more than 45 days per year. In the control group, in the early childhood, 9 (9.9%) never had aerosol therapy, 29 (31.9%) underwent aerosol therapy less than 7 days per year, 26 (28.6%) from 8 to 15 days per year, 20 (22.0%) from 16 to 45 days a year and 7 (7.6%) more than 45 days per year. the risk of developing MIH in children undergoing intensive use of aerosol therapy with respect to those receiving a less intensive use resulted in an odds ratio of 3.19 (p <0.001) in the general population, 4.83 (p < 0.001) in males and was not statistically significant in females (p = 0.132). The Spearman correlation between aerosol therapy and MIH was 0.278 (p < 0.001) in the general population, 0.372 (p < 0.001) in male, and it was not statistically significant (p = 0.08) in female subjects. Aerosol therapy carried out in early childhood appears to be a risk factor for the development of MIH, particularly in male

EFFECT OF ACIDITY ON SECONDARY ORGANIC AEROSOL FORMATION FROM ISOPRENE

EPA Science Inventory

The effect of particle-phase acidity on secondary organic aerosol (SOA) formation from isoprene is investigated in a laboratory chamber study, in which the acidity of the inorganic seed aerosol was controlled systematically. The observed enhancement in SOA mass concentration is c...

Secondary Organic Aerosol Formation in the Captive Aerosol Growth and Evolution (CAGE) Chambers during the Southern Oxidant and Aerosol Study (SOAS) in Centreville, AL

NASA Astrophysics Data System (ADS)

Leong, Y.; Karakurt Cevik, B.; Hernandez, C.; Griffin, R. J.; Taylor, N.; Matus, J.; Collins, D. R.

2013-12-01

Secondary organic aerosol (SOA) represents a large portion of sub-micron particulate matter on a global scale. The composition of SOA and its formation processes are heavily influenced by anthropogenic and biogenic activity. Volatile organic compounds (VOCs) that are emitted naturally from forests or from human activity serve as precursors to SOA formation. Biogenic SOA (BSOA) is formed from biogenic VOCs and is prevalent in forested regions like the Southeastern United States. The formation and enhancement of BSOA under anthropogenic influences such as nitrogen oxides (NOx), sulfur dioxide (SO2), and oxygen radicals are still not well understood. The lack of information on anthropogenic BSOA enhancement and the reversibility of SOA formation could explain the underprediction of SOA in current models. To address some of these gaps in knowledge, this study was conducted as part of the Southern Oxidant and Aerosol Study (SOAS) in Centreville, AL during the summer of 2013. SOA growth experiments were conducted in two Captive Aerosol Growth and Evolution (CAGE) outdoor chambers located at the SEARCH site. Ambient trace gas concentrations were maintained in these chambers using semi-permeable gas-exchange membranes, while studying the growth of injected monodisperse seed aerosol. The control chamber was operated under ambient conditions; the relative humidity and oxidant and NOx levels were perturbed in the second chamber. This design allows experiments to capture the natural BSOA formation processes in the southeastern atmosphere and to study the influence of anthropogenic activity on aerosol chemistry. Chamber experiments were periodically monitored with physical and chemical instrumentation including a scanning mobility particle sizer (SMPS), a cloud condensation nuclei counter (CCNC), a humidified tandem differential mobility analyzer (H-TDMA), and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The CAGE experiments focused on SOA

Uniform-related infection control practices of dental students

PubMed Central

Aljohani, Yazan; Almutadares, Mohammed; Alfaifi, Khalid; El Madhoun, Mona; Albahiti, Maysoon H; Al-Hazmi, Nadia

2017-01-01

Background Uniform-related infection control practices are sometimes overlooked and underemphasized. In Saudi Arabia, personal protective equipment must meet global standards for infection control, but the country’s Islamic legislature also needs to be taken into account. Aim To assess uniform-related infection control practices of a group of dental students in a dental school in Saudi Arabia and compare the results with existing literature related to cross-contamination through uniforms in the dental field. Method A questionnaire was formulated and distributed to dental students at King Abdulaziz University Faculty of Dentistry in Jeddah, Saudi Arabia, which queried the students about their uniform-related infection control practices and their methods and frequency of laundering and sanitizing their uniforms, footwear, and name tags. Results There is a significant difference between genders with regard to daily uniform habits. The frequency of uniform washing was below the standard and almost 30% of students were not aware of how their uniforms are washed. Added to this, there is no consensus on a unified uniform for male and female students. Conclusion Information on preventing cross-contamination through wearing uniforms must be supplied, reinforced, and emphasized while taking into consideration the cultural needs of the Saudi society. PMID:28490894

Aerosol-phase activity of iodine captured from a triiodide resin filter on fine particles containing an infectious virus.

PubMed

Heimbuch, B K; Harnish, D A; Balzli, C; Lumley, A; Kinney, K; Wander, J D

2015-06-01

To avoid interference by water-iodine disinfection chemistry and measure directly the effect of iodine, captured from a triiodide complex bound to a filter medium, on viability of penetrating viral particles. Aerosols of MS2 coli phage were passed through control P100 or iodinated High-Efficiency Particulate Air media, collected in plastic bags, incubated for 0-10 min, collected in an impinger containing thiosulphate to consume all unreacted iodine, plated and enumerated. Comparison of viable counts demonstrated antimicrobial activity with an apparent half-life for devitalization in tens of seconds; rate of kill decreased at low humidity and free iodine was captured by the bags. The results support the mechanism of near-contact capture earlier proposed; however, the disinfection chemistry in the aerosol phase is very slow on the time scale of inhalation. This study shows that disinfection by filter-bound iodine in the aerosol phase is too slow to be clinically significant in individual respiratory protection, but that it might be of benefit to limit airborne transmission of infections in enclosed areas. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Design, assembly, and validation of a nose-only inhalation exposure system for studies of aerosolized viable influenza H5N1 virus in ferrets

PubMed Central

2010-01-01

Background The routes by which humans acquire influenza H5N1 infections have not been fully elucidated. Based on the known biology of influenza viruses, four modes of transmission are most likely in humans: aerosol transmission, ingestion of undercooked contaminated infected poultry, transmission by large droplets and self-inoculation of the nasal mucosa by contaminated hands. In preparation of a study to resolve whether H5N1 viruses are transmissible by aerosol in an animal model that is a surrogate for humans, an inhalation exposure system for studies of aerosolized H5N1 viruses in ferrets was designed, assembled, and validated. Particular attention was paid towards system safety, efficacy of dissemination, the viability of aerosolized virus, and sampling methodology. Results An aerosol generation and delivery system, referred to as a Nose-Only Bioaerosol Exposure System (NBIES), was assembled and function tested. The NBIES passed all safety tests, met expected engineering parameters, required relatively small quantities of material to obtain the desired aerosol concentrations of influenza virus, and delivered doses with high-efficacy. Ferrets withstood a mock exposure trial without signs of stress. Conclusions The NBIES delivers doses of aerosolized influenza viruses with high efficacy, and uses less starting material than other similar designs. Influenza H5N1 and H3N2 viruses remain stable under the conditions used for aerosol generation and sample collection. The NBIES is qualified for studies of aerosolized H5N1 virus. PMID:20573226

Characterization of aerosols produced by cell sorters and evaluation of containment

PubMed Central

Holmes, Kevin L.

2011-01-01

In spite of the recognition by the flow cytometry community of potential aerosol hazards associated with cell sorting, there has been no previous study that has thoroughly characterized the aerosols that can be produced by cell sorters. In this study an Aerodynamic Particle Sizer was used to determine the concentration and aerodynamic diameter of aerosols produced by a FACS Aria II cell sorter under various conditions. Aerosol containment and evacuation was also evaluated using this novel methodology. The results showed that high concentrations of aerosols in the range of 1–3 μm can be produced in fail mode and that with decreased sheath pressure, aerosol concentration decreased and aerodynamic diameter increased. Although the engineering controls of the FACS Aria II for containment were effective, sort chamber evacuation of aerosols following a simulated nozzle obstruction was ineffective. However, simple modifications to the FACS Aria II are described that greatly improved sort chamber aerosol evacuation. The results of this study will facilitate the risk assessment of cell sorting potentially biohazardous samples by providing much needed data regarding aerosol production and containment. PMID:22052694

T-cell-dependent control of acute Giardia lamblia infections in mice.

PubMed

Singer, S M; Nash, T E

2000-01-01

We have studied immune mechanisms responsible for control of acute Giardia lamblia and Giardia muris infections in adult mice. Association of chronic G. lamblia infection with hypogammaglobulinemia and experimental infections of mice with G. muris have led to the hypothesis that antibodies are required to control these infections. We directly tested this hypothesis by infecting B-cell-deficient mice with either G. lamblia or G. muris. Both wild-type mice and B-cell-deficient mice eliminated the vast majority of parasites between 1 and 2 weeks postinfection with G. lamblia. G. muris was also eliminated in both wild-type and B-cell-deficient mice. In contrast, T-cell-deficient and scid mice failed to control G. lamblia infections, as has been shown previously for G. muris. Treatment of wild-type or B-cell-deficient mice with antibodies to CD4 also prevented elimination of G. lamblia, confirming a role for T cells in controlling infections. By infecting mice deficient in either alphabeta- or gammadelta-T-cell receptor (TCR)-expressing T cells, we show that the alphabeta-TCR-expressing T cells are required to control parasites but that the gammadelta-TCR-expressing T cells are not. Finally, infections in mice deficient in production of gamma interferon or interleukin 4 (IL-4) and mice deficient in responding to IL-4 and IL-13 revealed that neither the Th1 nor the Th2 subset is absolutely required for protection from G. lamblia. We conclude that a T-cell-dependent mechanism is essential for controlling acute Giardia infections and that this mechanism is independent of antibody and B cells.

A Yersinia pestis tat mutant is attenuated in bubonic and small-aerosol pneumonic challenge models of infection but not as attenuated by intranasal challenge.

PubMed

Bozue, Joel; Cote, Christopher K; Chance, Taylor; Kugelman, Jeffrey; Kern, Steven J; Kijek, Todd K; Jenkins, Amy; Mou, Sherry; Moody, Krishna; Fritz, David; Robinson, Camenzind G; Bell, Todd; Worsham, Patricia

2014-01-01

Bacterial proteins destined for the Tat pathway are folded before crossing the inner membrane and are typically identified by an N-terminal signal peptide containing a twin arginine motif. Translocation by the Tat pathway is dependent on the products of genes which encode proteins possessing the binding site of the signal peptide and mediating the actual translocation event. In the fully virulent CO92 strain of Yersinia pestis, the tatA gene was deleted. The mutant was assayed for loss of virulence through various in vitro and in vivo assays. Deletion of the tatA gene resulted in several consequences for the mutant as compared to wild-type. Cell morphology of the mutant bacteria was altered and demonstrated a more elongated form. In addition, while cultures of the mutant strain were able to produce a biofilm, we observed a loss of adhesion of the mutant biofilm structure compared to the biofilm produced by the wild-type strain. Immuno-electron microscopy revealed a partial disruption of the F1 antigen on the surface of the mutant. The virulence of the ΔtatA mutant was assessed in various murine models of plague. The mutant was severely attenuated in the bubonic model with full virulence restored by complementation with the native gene. After small-particle aerosol challenge in a pneumonic model of infection, the mutant was also shown to be attenuated. In contrast, when mice were challenged intranasally with the mutant, very little difference in the LD50 was observed between wild-type and mutant strains. However, an increased time-to-death and delay in bacterial dissemination was observed in mice infected with the ΔtatA mutant as compared to the parent strain. Collectively, these findings demonstrate an essential role for the Tat pathway in the virulence of Y. pestis in bubonic and small-aerosol pneumonic infection but less important role for intranasal challenge.

A Yersinia pestis tat Mutant Is Attenuated in Bubonic and Small-Aerosol Pneumonic Challenge Models of Infection but Not As Attenuated by Intranasal Challenge

PubMed Central

Bozue, Joel; Cote, Christopher K.; Chance, Taylor; Kugelman, Jeffrey; Kern, Steven J.; Kijek, Todd K.; Jenkins, Amy; Mou, Sherry; Moody, Krishna; Fritz, David; Robinson, Camenzind G.; Bell, Todd; Worsham, Patricia

2014-01-01

Bacterial proteins destined for the Tat pathway are folded before crossing the inner membrane and are typically identified by an N-terminal signal peptide containing a twin arginine motif. Translocation by the Tat pathway is dependent on the products of genes which encode proteins possessing the binding site of the signal peptide and mediating the actual translocation event. In the fully virulent CO92 strain of Yersinia pestis, the tatA gene was deleted. The mutant was assayed for loss of virulence through various in vitro and in vivo assays. Deletion of the tatA gene resulted in several consequences for the mutant as compared to wild-type. Cell morphology of the mutant bacteria was altered and demonstrated a more elongated form. In addition, while cultures of the mutant strain were able to produce a biofilm, we observed a loss of adhesion of the mutant biofilm structure compared to the biofilm produced by the wild-type strain. Immuno-electron microscopy revealed a partial disruption of the F1 antigen on the surface of the mutant. The virulence of the ΔtatA mutant was assessed in various murine models of plague. The mutant was severely attenuated in the bubonic model with full virulence restored by complementation with the native gene. After small-particle aerosol challenge in a pneumonic model of infection, the mutant was also shown to be attenuated. In contrast, when mice were challenged intranasally with the mutant, very little difference in the LD50 was observed between wild-type and mutant strains. However, an increased time-to-death and delay in bacterial dissemination was observed in mice infected with the ΔtatA mutant as compared to the parent strain. Collectively, these findings demonstrate an essential role for the Tat pathway in the virulence of Y. pestis in bubonic and small-aerosol pneumonic infection but less important role for intranasal challenge. PMID:25101850

Methoprene and synergized pyrethrins as an aerosol treatment to control Plodia interpunctella (Hubner), the Indian meal moth (Lepidoptera: Pyralidae)

USDA-ARS?s Scientific Manuscript database

Aerosol insecticides (also known as ULV or fogging treatments) delivered through an ultra-low volume application system, are available commercially to control insect pests such as Plodia interpunctella Hübner, the Indianmeal moth. However, little is known about the susceptibility of eggs of P. inter...

Sources and Variability of Aerosols and Aerosol-Cloud Interactions in the Arctic

NASA Astrophysics Data System (ADS)

Liu, H.; Zhang, B.; Taylor, P. C.; Moore, R.; Barahona, D.; Fairlie, T. D.; Chen, G.; Ham, S. H.; Kato, S.

2017-12-01

Arctic sea ice in recent decades has significantly declined. This requires understanding of the Arctic surface energy balance, of which clouds are a major driver. However, the mechanisms for the formation and evolution of clouds in the Arctic and the roles of aerosols therein are highly uncertain. Here we conduct data analysis and global model simulations to examine the sources and variability of aerosols and aerosol-cloud interactions in the Arctic. We use the MERRA-2 reanalysis data (2006-present) from the NASA Global Modeling and Assimilation Office (GMAO) to (1) quantify contributions of different aerosol types to the aerosol budget and aerosol optical depths in the Arctic, (2) ­examine aerosol distributions and variability and diagnose the major pathways for mid-latitude pollution transport to the Arctic, including their seasonal and interannual variability, and (3) characterize the distribution and variability of clouds (cloud optical depth, cloud fraction, cloud liquid and ice water path, cloud top height) in the Arctic. We compare MERRA-2 aerosol and cloud properties with those from C3M, a 3-D aerosol and cloud data product developed at NASA Langley Research Center and merged from multiple A-Train satellite (CERES, CloudSat, CALIPSO, and MODIS) observations. We also conduct perturbation experiments using the NASA GEOS-5 chemistry-climate model (with GOCART aerosol module coupled with two-moment cloud microphysics), and discuss the roles of various types of aerosols in the formation and evolution of clouds in the Arctic.

Implementing GermWatcher, an enterprise infection control application.

PubMed

Doherty, Joshua; Noirot, Laura A; Mayfield, Jennie; Ramiah, Sridhar; Huang, Christine; Dunagan, Wm Claiborne; Bailey, Thomas C

2006-01-01

Automated surveillance tools can provide significant advantages to infection control practitioners. When stored in a relational database, the data collected can also be used to support numerous research and quality improvement opportunities. A previously described electronic infection control surveillance system was remodeled to provide multi-hospital support, an XML based rule set, and interoperability with an enterprise terminology server. This paper describes the new architecture being used at hospitals across BJC HealthCare.

Aerosol Indirect Effects on Cirrus Clouds in Global Aerosol-Climate Models

NASA Astrophysics Data System (ADS)

Liu, X.; Zhang, K.; Wang, Y.; Neubauer, D.; Lohmann, U.; Ferrachat, S.; Zhou, C.; Penner, J.; Barahona, D.; Shi, X.

2015-12-01

Cirrus clouds play an important role in regulating the Earth's radiative budget and water vapor distribution in the upper troposphere. Aerosols can act as solution droplets or ice nuclei that promote ice nucleation in cirrus clouds. Anthropogenic emissions from fossil fuel and biomass burning activities have substantially perturbed and enhanced concentrations of aerosol particles in the atmosphere. Global aerosol-climate models (GCMs) have now been used to quantify the radiative forcing and effects of aerosols on cirrus clouds (IPCC AR5). However, the estimate uncertainty is very large due to the different representation of ice cloud formation and evolution processes in GCMs. In addition, large discrepancies have been found between model simulations in terms of the spatial distribution of ice-nucleating aerosols, relative humidity, and temperature fluctuations, which contribute to different estimates of the aerosol indirect effect through cirrus clouds. In this presentation, four GCMs with the start-of-the art representations of cloud microphysics and aerosol-cloud interactions are used to estimate the aerosol indirect effects on cirrus clouds and to identify the causes of the discrepancies. The estimated global and annual mean anthropogenic aerosol indirect effect through cirrus clouds ranges from 0.1 W m-2 to 0.3 W m-2 in terms of the top-of-the-atmosphere (TOA) net radiation flux, and 0.5-0.6 W m-2 for the TOA longwave flux. Despite the good agreement on global mean, large discrepancies are found at the regional scale. The physics behind the aerosol indirect effect is dramatically different. Our analysis suggests that burden of ice-nucleating aerosols in the upper troposphere, ice nucleation frequency, and relative role of ice formation processes (i.e., homogeneous versus heterogeneous nucleation) play key roles in determining the characteristics of the simulated aerosol indirect effects. In addition to the indirect effect estimate, we also use field campaign

The colors of biomass burning aerosols in the atmosphere.

PubMed

Liu, Chao; Chung, Chul Eddy; Zhang, Feng; Yin, Yan

2016-06-16

Biomass burning aerosols mainly consist of black carbon (BC) and organic aerosols (OAs), and some of OAs are brown carbon (BrC). This study simulates the colors of BrC, BC and their mixture with scattering OAs in the ambient atmosphere by using a combination of light scattering simulations, a two-stream radiative transfer model and a RGB (Red, Green, Blue) color model. We find that both BCs and tar balls (a class of BrC) appear brownish at small particle sizes and blackish at large sizes. This is because the aerosol absorption Ångström exponent (AAE) largely controls the color and larger particles give smaller AAE values. At realistic size distributions, BCs look more blackish than tar balls, but still exhibit some brown color. However, when the absorptance of aerosol layer at green wavelength becomes larger than approximately 0.8, all biomass burning aerosols look blackish. The colors for mixture of purely scattering and absorptive carbonaceous aerosol layers in the atmosphere are also investigated. We suggest that the brownishness of biomass burning aerosols indicates the amount of BC/BrC as well as the ratio of BC to BrC.

Characterization of urban aerosol in Cork City (Ireland) using aerosol mass spectrometry

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Ovadnevaite, J.; Ceburnis, D.; Martin, D.; Healy, R. M.; O'Connor, I. P.; Sodeau, J. R.; Wenger, J. C.; O'Dowd, C.

2012-11-01

Ambient wintertime background urban aerosol in Cork City, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the 1 200 000 single particles characterized by an Aerosol Time-Of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich particle types, internally-mixed to different proportions with Elemental Carbon (EC), sulphate and nitrate while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was also characterized using a High Resolution Time-Of-Flight Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS) and was also found to comprise organic matter as the most abundant species (62%), followed by nitrate (15%), sulphate (9%) and ammonium (9%), and then chloride (5%). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix and a five-factor solution was found to describe the variance in the data well. Specifically, "Hydrocarbon-like" Organic Aerosol (HOA) comprised 19% of the mass, "Oxygenated low volatility" Organic Aerosols (LV-OOA) comprised 19%, "Biomass wood Burning" Organic Aerosol (BBOA) comprised 23%, non-wood solid-fuel combustion "Peat and Coal" Organic Aerosol (PCOA) comprised 21%, and finally, a species type characterized by primary m/z peaks at 41 and 55, similar to previously-reported "Cooking" Organic Aerosol (COA) but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Despite wood, cool and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosols mass and non refractory PM1, respectively).

Aerosol Climate Time Series in ESA Aerosol_cci

NASA Astrophysics Data System (ADS)

Popp, Thomas; de Leeuw, Gerrit; Pinnock, Simon

2016-04-01

Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. Meanwhile, full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer, but also from ATSR instruments and the POLDER sensor), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which were also validated and improved in the reprocessing. For the three ATSR algorithms the use of an ensemble method was tested. The paper will summarize and discuss the status of dataset reprocessing and validation. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension

Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration.

PubMed

Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H; Henry, Mike; Baden, Daniel G

2010-05-01

Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5-10 microg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m(3). The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction. Copyright 2009 Elsevier Ltd. All rights reserved.

An examination of the effect of aerosolized permanone insecticide on zebra finch susceptibility to West Nile virus

USGS Publications Warehouse

Jankowski, Mark D.; Murray, E. Moore; Hofmeister, Erik K.

2017-01-01

West Nile virus is primarily maintained cryptically primarily in avian (Passerine) populations where it is transmitted by Culex spp. mosquitoes. Mosquito control measures currently include physical activities to reduce mosquito breeding sites, the application of mosquito larvicides, or aerosolized insecticides to kill adults (adulticides) when arboviral diseases such as West Nile virus (WNV) or Zika virus are detected in mosquito populations. Organochlorine, organohosphorus, carbamate and pyrethroid insecticides are often used. Previous work suggests an effect of pyrethroids on the immune system in a variety of vertebrates. We examined the effects of exposure to aerosolized Permanone® 30:30 insecticide (permethrin and piperonyl butoxide in soy oil vehicle) at ∼103−106x potential environmental concentrations on the response of captive zebra finches (Taeniopygia guttata) to experimental challenge with WNV. Compared to vehicle control birds, WNV outcome was unchanged (65% of birds produced a viremia) in the ‘low’ exposure (9.52 mg/m3±3.13 SD permethrin) group, but reduced in the ‘high’ exposure (mean 376.5 mg/m3±27.9 SD permethrin) group (30% were viremic) (p < 0.05). After clearing WNV infection, birds treated with Permanone regained less body mass than vehicle treated birds (p < 0.001). Our study suggests that exposure to aerosolized Permanone insecticide at levels exceeding typical application rates has the potential to not change or mildly enhance a bird's resistance to WNV.

Ten Questions Concerning the Aerosolization and Transmission of Legionella in the Built Environment.

PubMed

Prussin, Aaron J; Schwake, David Otto; Marr, Linsey C

2017-10-01

Legionella is a genus of pathogenic Gram-negative bacteria responsible for a serious disease known as legionellosis, which is transmitted via inhalation of this pathogen in aerosol form. There are two forms of legionellosis: Legionnaires' disease, which causes pneumonia-like symptoms, and Pontiac fever, which causes influenza-like symptoms. Legionella can be aerosolized from various water sources in the built environment including showers, faucets, hot tubs/swimming pools, cooling towers, and fountains. Incidence of the disease is higher in the summertime, possibly because of increased use of cooling towers for air conditioning systems and differences in water chemistry when outdoor temperatures are higher. Although there have been decades of research related to Legionella transmission, many knowledge gaps remain. While conventional wisdom suggests that showering is an important source of exposure in buildings, existing measurements do not provide strong support for this idea. There has been limited research on the potential for Legionella transmission through heating, ventilation, and air conditioning (HVAC) systems. Epidemiological data suggest a large proportion of legionellosis cases go unreported, as most people who are infected do not seek medical attention. Additionally, controlled laboratory studies examining water-to-air transfer and source tracking are still needed. Herein, we discuss ten questions that spotlight current knowledge about Legionella transmission in the built environment, engineering controls that might prevent future disease outbreaks, and future research that is needed to advance understanding of transmission and control of legionellosis.

Infection control best practices in clinical research in resource-limited settings.

PubMed

Godfrey, Catherine; Schouten, Jeffrey T

2014-01-01

Infection control activities in the international research setting include the development of meaningful and effective policies on specific topics such as hand and respiratory hygiene. Prevention of infection in health care workers and management of occupational exposure to transmissible agents are important aspects of the role of an infection control practitioner. Hand hygiene reduces health care associated infections and practices may be implemented in the research setting.

Knowledge and acceptability of patient-specific infection control measures for pulmonary tuberculosis.

PubMed

Gonzalez-Angulo, Yulieth; Geldenhuys, Hennie; Van As, Danelle; Buckerfield, Norma; Shea, Jawaya; Mahomed, Hassan; Hanekom, Willem; Hatherill, Mark

2013-08-01

Effective infection control measures are essential to reduce tuberculosis (TB) transmission in domestic, workplace, and health care settings. Acceptability of infection control measures is key to patient adherence. We used a prospective questionnaire study to determine knowledge and acceptability of potential patient-specific TB infection control measures in a rural South African community. Fifty adult TB suspects were interviewed at investigation, and 50 newly diagnosed TB patients were interviewed at the start and at the end of TB treatment. TB patients and TB suspects had similar knowledge of infection control measures at baseline. Fifty-seven percent of all participants reported knowing the cause of TB, but only 25% correctly identified microbial etiology. Basic cough hygiene was accepted by 98% of participants. Most participants (89%) accepted wearing of face masks in health facilities, but only 42% of TB suspects and 66% of TB patients (P = .016) would accept wearing face masks at home. Only 68% of participants accepted separate cohorting in health facilities and avoidance of co-sleeping with uninfected household members. At the end of treatment, TB patients demonstrated increased knowledge of TB and increased acceptability of certain household infection control measures. Acceptability of patient-specific infection control measures within households increases with acquired knowledge of TB. National control programs should maximize early TB education to improve adherence to infection control measures. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Development of a resource model for infection prevention and control programs in acute, long term, and home care settings: conference proceedings of the Infection Prevention and Control Alliance.

PubMed

Morrison, Judith

2004-02-01

There is mounting concern about the impact of health care restructuring on the provision of infection prevention services across the health care continuum. In response to this, Health Canada hosted two meetings of Canadian infection control experts to develop a model upon which the resources required to support an effective, integrated infection prevention and control program across the health care continuum could be based. The final models project the IPCP needs as three full time equivalent infection control professionals/500 beds in acute care hospitals and one full time equivalent infection control professional/150-250 beds in long term care facilities. Non human resource requirements are also described for acute, long term, community, and home care settings.

The optical properties of absorbing aerosols with fractal soot aggregates: Implications for aerosol remote sensing

NASA Astrophysics Data System (ADS)

Cheng, Tianhai; Gu, Xingfa; Wu, Yu; Chen, Hao; Yu, Tao

2013-08-01

Applying sphere aerosol models to replace the absorbing fine-sized dominated aerosols can potentially result in significant errors in the climate models and aerosol remote sensing retrieval. In this paper, the optical properties of absorbing fine-sized dominated aerosol were modeled, which are taking into account the fresh emitted soot particles (agglomerates of primary spherules), aged soot particles (semi-externally mixed with other weakly absorbing aerosols), and coarse aerosol particles (dust particles). The optical properties of the individual fresh and aged soot aggregates are calculated using the superposition T-matrix method. In order to quantify the morphology effect of absorbing aerosol models on the aerosol remote sensing retrieval, the ensemble averaged optical properties of absorbing fine-sized dominated aerosols are calculated based on the size distribution of fine aerosols (fresh and aged soot) and coarse aerosols. The corresponding optical properties of sphere absorbing aerosol models using Lorenz-Mie solutions were presented for comparison. The comparison study demonstrates that the sphere absorbing aerosol models underestimate the absorption ability of the fine-sized dominated aerosol particles. The morphology effect of absorbing fine-sized dominated aerosols on the TOA radiances and polarized radiances is also investigated. It is found that the sphere aerosol models overestimate the TOA reflectance and polarized reflectance by approximately a factor of 3 at wavelength of 0.865 μm. In other words, the fine-sized dominated aerosol models can cause large errors in the retrieved aerosol properties if satellite reflectance measurements are analyzed using the conventional Mie theory for spherical particles.

MATRIX-VBS Condensing Organic Aerosols in an Aerosol Microphysics Model

NASA Technical Reports Server (NTRS)

Gao, Chloe Y.; Tsigaridis, Konstas; Bauer, Susanne E.

2015-01-01

The condensation of organic aerosols is represented in a newly developed box-model scheme, where its effect on the growth and composition of particles are examined. We implemented the volatility-basis set (VBS) framework into the aerosol mixing state resolving microphysical scheme Multiconfiguration Aerosol TRacker of mIXing state (MATRIX). This new scheme is unique and advances the representation of organic aerosols in models in that, contrary to the traditional treatment of organic aerosols as non-volatile in most climate models and in the original version of MATRIX, this new scheme treats them as semi-volatile. Such treatment is important because low-volatility organics contribute significantly to the growth of particles. The new scheme includes several classes of semi-volatile organic compounds from the VBS framework that can partition among aerosol populations in MATRIX, thus representing the growth of particles via condensation of low volatility organic vapors. Results from test cases representing Mexico City and a Finish forrest condistions show good representation of the time evolutions of concentration for VBS species in the gas phase and in the condensed particulate phase. Emitted semi-volatile primary organic aerosols evaporate almost completely in the high volatile range, and they condense more efficiently in the low volatility range.

Inflammasome control of viral infection

PubMed Central

Lupfer, Christopher; Malik, Ankit; Kanneganti, Thirumala-Devi

2015-01-01

The inflammasome is a caspase-1 containing complex that activates the proinflammatory cytokines IL-1β and IL-18 and results in the proinflammatory cell death known as pyroptosis. Numerous recent publications have highlighted the importance of inflammasome activation in the control of virus infection. Inflammasome activation during viral infection is dependent on a variety of upstream receptors including the NOD-Like receptor, RIG-I-Like receptor and AIM2-Like receptor families. Various receptors also function in inflammasome activation in different cellular compartments, including the cytoplasm and the nucleus. The effectiveness of inflammasomes at suppressing virus replication is highlighted by the prevalence and diversity of virus encoded inflammasome inhibitors. Also, the host has a myriad of regulatory mechanisms in place to prevent unwanted inflammasome activation and overt inflammation. Finally, recent reports begin to suggest that inflammasome activation and inflammasome modulation may have important clinical applications. Herein, we highlight recent advances and discuss potential future directions toward understanding the role of inflammasomes during virus infection. PMID:25771504

Airborne measurements of multi-wavelength aerosol optical depth and cloud-transmitted radiances in the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES)

NASA Astrophysics Data System (ADS)

Shinozuka, Y.; Johnson, R. R.; LeBlanc, S. E.; Chang, C. S.; Redemann, J.

2016-12-01

We report on our recent airborne measurements of multi-wavelength aerosol optical depth and cloud-transmitted radiances over the North Atlantic. We ran the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) in November 2015 and the 14-channel Ames Airborne Tracking Sunphotometer (AATS-14) in May and June 2016, both aboard the NASA C-130 aircraft. These sunphotometers provide measurements of overlying cirrus and aerosol optical depths of up to about 0.5 and constrain ecosystem and aerosol retrievals from the accompanying nadir-viewing remote sensing instruments. In addition, 4STAR measures hyperspectral transmitted light, which enables the retrieval of cloud optical depth, effective radius, and thermodynamic phase from below cloud. Our measurements contribute to the science objectives of the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES), an interdisciplinary investigation resolving key processes controlling marine ecosystems and aerosols that are essential to our understanding of Earth system function and future change.

Relationship between fluid bed aerosol generator operation and the aerosol produced

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, R.L.; Yerkes, K.

1980-12-01

The relationships between bed operation in a fluid bed aerosol generator and aerosol output were studied. A two-inch diameter fluid bed aerosol generator (FBG) was constructed using stainless steel powder as a fluidizing medium. Fly ash from coal combustion was aerosolized and the influence of FBG operating parameters on aerosol mass median aerodynamic diameter (MMAD), geometric standard deviation (sigma/sub g/) and concentration was examined. In an effort to extend observations on large fluid beds to small beds using fine bed particles, minimum fluidizing velocities and elutriation constant were computed. Although FBG minimum fluidizing velocity agreed well with calculations, FBG elutriationmore » constant did not. The results of this study show that the properties of aerosols produced by a FBG depend on fluid bed height and air flow through the bed after the minimum fluidizing velocity is exceeded.« less

Global Atmospheric Aerosol Modeling

NASA Technical Reports Server (NTRS)

Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

2012-01-01

Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

Aerosol Climate Time Series Evaluation In ESA Aerosol_cci

NASA Astrophysics Data System (ADS)

Popp, T.; de Leeuw, G.; Pinnock, S.

2015-12-01

Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. By the end of 2015 full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which are also validated. The paper will summarize and discuss the results of major reprocessing and validation conducted in 2015. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension with successor instruments of the Sentinel family will be described and the complementarity of the different satellite aerosol products

Hospital design for better infection control

PubMed Central

Lateef, Fatimah

2009-01-01

The physical design and infrastructure of a hospital or institution is an essential component of its infection control measure. Thus is must be a prerequisite to take these into consideration from the initial conception and planning stages of the building. The balance between designing a hospital to be an open, accessible and public place and the control to reduce the spread of infections diseases is a necessity. At Singapore General Hospital, many lessons were learnt during the SARS outbreak pertaining to this. During and subsequent to the SARS outbreak, many changes evolved in the hospital to enable us to handle and face any emerging infectious situation with calm, confidence and the knowledge that staff and patients will be in good stead. This paper will share some of our experiences as well as challenges PMID:20009307

Aerogenic vaccination with a Burkholderia mallei auxotroph protects against aerosol-initiated glanders in mice.

PubMed

Ulrich, Ricky L; Amemiya, Kei; Waag, David M; Roy, Chad J; DeShazer, David

2005-03-14

Burkholderia mallei is an obligate mammalian pathogen that causes the zoonotic disease glanders. Two live attenuated B. mallei strains, a capsule mutant and a branched-chain amino acid auxotroph, were evaluated for use as vaccines against aerosol-initiated glanders in mice. Animals were aerogenically vaccinated and serum samples were obtained before aerosol challenge with a high-dose (>300 times the LD50) of B. mallei ATCC 23344. Mice vaccinated with the capsule mutant developed a Th2-like Ig subclass antibody response and none survived beyond 5 days. In comparison, the auxotrophic mutant elicited a Th1-like Ig subclass antibody response and 25% of the animals survived for 1 month postchallenge. After a low-dose (5 times the LD50) aerosol challenge, the survival rates of auxotroph-vaccinated and unvaccinated animals were 50 and 0%, respectively. Thus, live attenuated strains that promote a Th1-like Ig response may serve as promising vaccine candidates against aerosol infection with B. mallei.

An Electronic Cigarette Vaping Machine for the Characterization of Aerosol Delivery and Composition.

PubMed

Havel, Christopher M; Benowitz, Neal L; Jacob, Peyton; St Helen, Gideon

2017-10-01

Characterization of aerosols generated by electronic cigarettes (e-cigarettes) is one method used to evaluate the safety of e-cigarettes. While some researchers have modified smoking machines for e-cigarette aerosol generation, these machines are either not readily available, not automated for e-cigarette testing or have not been adequately described. The objective of this study was to build an e-cigarette vaping machine that can be used to test, under standard conditions, e-liquid aerosolization and nicotine and toxicant delivery. The vaping machine was assembled from commercially available parts, including a puff controller, vacuum pump, power supply, switch to control current flow to the atomizer, three-way value to direct air flow to the atomizer, and three gas dispersion tubes for aerosol trapping. To validate and illustrate its use, the variation in aerosol generation was assessed within and between KangerTech Mini ProTank 3 clearomizers, and the effect of voltage on aerosolization and toxic aldehyde generation were assessed. When using one ProTank 3 clearomizer and different e-liquid flavors, the coefficient of variation (CV) of aerosol generated ranged between 11.5% and 19.3%. The variation in aerosol generated between ProTank 3 clearomizers with different e-liquid flavors and voltage settings ranged between 8.3% and 16.3% CV. Aerosol generation increased linearly at 3-6V across e-liquids and clearomizer brands. Acetaldehyde, acrolein, and formaldehyde generation increased markedly at voltages at or above 5V. The vaping machine that we describe reproducibly aerosolizes e-liquids from e-cigarette atomizers under controlled conditions and is useful for testing of nicotine and toxicant delivery. This study describes an electronic cigarette vaping machine that was assembled from commercially available parts. The vaping machine can be replicated by researchers and used under standard conditions to generate e-cigarette aerosols and characterize nicotine and

Evaluating Aerosol Process Modules within the Framework of the Aerosol Modeling Testbed

NASA Astrophysics Data System (ADS)

Fast, J. D.; Velu, V.; Gustafson, W. I.; Chapman, E.; Easter, R. C.; Shrivastava, M.; Singh, B.

2012-12-01

Factors that influence predictions of aerosol direct and indirect forcing, such as aerosol mass, composition, size distribution, hygroscopicity, and optical properties, still contain large uncertainties in both regional and global models. New aerosol treatments are usually implemented into a 3-D atmospheric model and evaluated using a limited number of measurements from a specific case study. Under this modeling paradigm, the performance and computational efficiency of several treatments for a specific aerosol process cannot be adequately quantified because many other processes among various modeling studies (e.g. grid configuration, meteorology, emission rates) are different as well. The scientific community needs to know the advantages and disadvantages of specific aerosol treatments when the meteorology, chemistry, and other aerosol processes are identical in order to reduce the uncertainties associated with aerosols predictions. To address these issues, an Aerosol Modeling Testbed (AMT) has been developed that systematically and objectively evaluates new aerosol treatments for use in regional and global models. The AMT consists of the modular Weather Research and Forecasting (WRF) model, a series testbed cases for which extensive in situ and remote sensing measurements of meteorological, trace gas, and aerosol properties are available, and a suite of tools to evaluate the performance of meteorological, chemical, aerosol process modules. WRF contains various parameterizations of meteorological, chemical, and aerosol processes and includes interactive aerosol-cloud-radiation treatments similar to those employed by climate models. In addition, the physics suite from the Community Atmosphere Model version 5 (CAM5) have also been ported to WRF so that they can be tested at various spatial scales and compared directly with field campaign data and other parameterizations commonly used by the mesoscale modeling community. Data from several campaigns, including the 2006

[Healthcare-Associated Infection Control with Awareness of Patient Safety].

PubMed

Murakami, Nobuo

2016-03-01

In order to provide safe and secure medical care for patients, health care-associated infections (HAI) must not occur. HAI should be considered as incidents, and countermeasures should be viewed as a patient safety management itself. Healthcare-associated infection control (HAIC) is practiced by the infection control team (ICT), which is based on multidisciplinary cooperation. Team members have to recognize that it is the most important to make use of the expertise of each discipline. In addition, all members must try to respond quickly, to help the clinic staff. Visualized rapid information provision and sharing, environmental improvement, outbreak factor analysis, hand hygiene compliance rate improvement, proper antibiotic use (Antimicrobial Stewardship Program: ASP), and regional cooperation & leadership comprise the role of the ICT in the flagship hospital. Regarding this role, we present our hospital's efforts and the outcomes. In conclusion, for medical practice quality improvement, healthcare-associated infection control should be conducted thoroughly along with an awareness of patient safety.

Fast Adjustments of the Asian Summer Monsoon to Anthropogenic Aerosols

NASA Astrophysics Data System (ADS)

Li, Xiaoqiong; Ting, Mingfang; Lee, Dong Eun

2018-01-01

Anthropogenic aerosols are a major factor contributing to human-induced climate change, particularly over the densely populated Asian monsoon region. Understanding the physical processes controlling the aerosol-induced changes in monsoon rainfall is essential for reducing the uncertainties in the future projections of the hydrological cycle. Here we use multiple coupled and atmospheric general circulation models to explore the physical mechanisms for the aerosol-driven monsoon changes on different time scales. We show that anthropogenic aerosols induce an overall reduction in monsoon rainfall and circulation, which can be largely explained by the fast adjustments over land north of 20∘N. This fast response occurs before changes in sea surface temperature (SST), largely driven by aerosol-cloud interactions. However, aerosol-induced SST feedbacks (slow response) cause substantial changes in the monsoon meridional circulation over the oceanic regions. Both the land-ocean asymmetry and meridional temperature gradient are key factors in determining the overall monsoon circulation response.

E-learning of infection control: it's contagious.

PubMed

Bryce, Elizabeth; Yassi, Annalee; Maultsaid, Deirdre; Gamage, Bruce; Landstrom, Margaret; LoChang, Justin; Hon, Chun-Yip

2008-01-01

This article outlines the steps taken to deliver standardized infection control and occupational health training to all healthcare workers across a Canadian health authority, using an online module developed by a multidisciplinary team. The course had to meet a diverse variety of learner needs, be relevant to day-to-day practice, be accessible, as well as fulfill healthcare guidelines for both infection control and occupational health. The course was designed to be interactive and uses a wide variety of techniques to engage the learner such as video clips describing use of personal protective equipment, and drop-and-drag technology. Since implementation in 2006, the course has been endorsed by stakeholders and used in staff clinical orientations, for residents, for student placements, and for physicians as part of their hospital privileges, as well as healthcare workers across the health authority. Results of the user satisfaction survey (N=280) showed that the course was relevant and simple to navigate. Observations (N=117) of personal protective equipment donning and doffing of staff post-course showed that the module effectively transferred knowledge. Analysis of the interview results (N=50) suggested that making the course required would be seen as an incentive and visible sign of management commitment to safety. Development of the module was instructive both for the learners and the online infection control/education team. The implementation process provided insight into how best to deliver and evaluate healthcare content while ensuring that the product is user friendly. The process underscored the importance of engaging key stakeholders. With this course, learning of infection control principles has been made more efficient and enjoyable.

Electrostatics of Pharmaceutical Aerosols for Pulmonary Delivery.

PubMed

Lip Kwok, Philip Chi

2015-01-01

This paper provides a review on key research findings in the rapidly developing area of pharmaceutical aerosol electrostatics. Solids and liquids can become charged without electric fields, the former by contact or friction and the latter by flowing or spraying. Therefore, charged particles and droplets carrying net charges are produced from pharmaceutical inhalers (e.g. dry powder inhalers, metered dose inhalers, and nebulisers) due to the mechanical processes involved in aerosolisation. The charging depends on many physicochemical factors, such as formulation composition, solid state properties, inhaler material and design, and relative humidity. In silico, in vitro, and limited in vivo studies have shown that electrostatic charges may potentially influence particle deposition in the airways. However, the evidence is not yet conclusive. Furthermore, there are currently no regulatory requirements on the characterisation and control of the electrostatic properties of inhaled formulations. Besides the need for further investigations on the relationship between physicochemical factors and charging characteristics of the aerosols, controlled and detailed in vivo studies are also required to confirm whether charges can affect particle deposition in the airways. Since pharmaceutical aerosol electrostatics is a relatively new research area, much remains to be explored. Thus there is certainly potential for development. New findings in the future may contribute to the advancement of pharmaceutical aerosol formulations and respiratory drug delivery.

Patient safety and infection control: bases for curricular integration.

PubMed

Silva, Andréa Mara Bernardes da; Bim, Lucas Lazarini; Bim, Felipe Lazarini; Sousa, Alvaro Francisco Lopes; Domingues, Pedro Castania Amadio; Nicolussi, Adriana Cristina; Andrade, Denise de

2018-05-01

To analyze curricular integration between teaching of patient safety and good infection prevention and control practices. Integrative review, designed to answer the question: "How does curricular integration of content about 'patient safety teaching' and content about 'infection prevention and control practices' occur in undergraduate courses in the health field?". The following databases were searched for primary studies: CINAHL, LILACS, ScienceDirect, Web of Science, Scopus, Europe PMC and MEDLINE. The final sample consisted of 13 studies. After content analysis, primary studies were grouped into two subject categories: "Innovative teaching practices" and "Curricular evaluation. Patient safety related to infection prevention and control practices is present in the curriculum of health undergraduate courses, but is not coordinated with other themes, is taught sporadically, and focuses mainly on hand hygiene.

Infection control education: how to make an impact--tools for the job.

PubMed

Farrington, Mark

2007-06-01

Infection control education is difficult and time consuming, but there is persuasive evidence to demonstrate its effectiveness. When Infection Control practitioners are educating and influencing healthcare workers, compliance with the well-established guidance on implementation of health service research is advisable, and thus educative efforts must be repeated and administered as part of a concerted and multifaceted approach. Infection Control education must be specifically designed for and targeted at the groups of staff concerned, and medical staff pose especial problems. Recruitment of clinical champions from peer groups, and direct approaches from medical members of the Infection Control team are usually needed. Familiarity with only a limited range of published evidence is needed to answer the majority of clinicians who challenge Infection Control practices, and referral to higher medical and managerial authority is required very infrequently and as a last resort. Some recent initiatives in the NHS in England may make Infection Control education more difficult, and these are reviewed. New sanctions have been made available to hospitals and Infection control teams in the UK with the passing of the Health Act in 2006, and the effects of these allied to educative interventions on benchmarks such as hospitals' MRSA bacteraemia rates will be observed with interest.

Uncertainties of aerosol retrieval from neglecting non-sphericity of dust aerosols

NASA Astrophysics Data System (ADS)

Li, Chi; Xue, Yong; Yang, Leiku; Guang, Jie

2013-04-01

The Mie theory is conventionally applied to calculate aerosol optical properties in satellite remote sensing applications, while dust aerosols cannot be well modeled by the Mie calculation for their non-sphericity. It has been cited in Mishchenko et al. (1995; 1997) that neglecting non-sphericity can severely influence aerosol optical depth (AOD, ?) retrieval in case of dust aerosols because of large difference of phase functions under spherical and non-spherical assumptions, whereas this uncertainty has not been thoroughly studied. This paper aims at a better understanding of uncertainties on AOD retrieval caused by aerosol non-sphericity. A dust aerosol model with known refractive index and size distribution is generated from long-term AERONET observations since 1999 over China. Then aerosol optical properties, such as the extinction, phase function, single scattering albedo (SSA) are calculated respectively in the assumption of spherical and non-spherical aerosols. Mie calculation is carried out for spherical assumption, meanwhile for non-spherical aerosol modeling, we adopt the pre-calculated scattering kernels and software package presented by Dubovik et al. (2002; 2006), which describes dust as a shape mixture of randomly oriented polydisperse spheroids. Consequently we generate two lookup tables (LUTspheric and LUTspheroid) from simulated satellite received reflectance at top of atmosphere (TOA) under varieties of observing conditions and aerosol loadings using Second Simulation of a Satellite Signal in the Solar Spectrum - Vector (6SV) code. All the simulations are made at 550 nm, and for simplicity the Lambertian surface is assumed. Using the obtained LUTs we examine the differences of TOA reflectance (Δ?TOA = ?spheric - ?spheroid) under different surface reflectance and aerosol loadings. Afterwards AOD is retrieved using LUTspheric from the simulated TOA reflectance by LUTspheroid in order to detect the retrieval errors (Δ? = ?retreived -?input) induced

Infection prevention and control in the design of healthcare facilities.

PubMed

Farrow, Tye S; Black, Stephen M

2009-01-01

The lead paper, "Healthcare-Associated Infections as Patient Safety Indicators," written by Gardam, Lemieux, Reason, van Dijk and Goel, puts forward the design of healthcare facilities as one of many strategies to improve patient safety with respect to healthcare-associated infections. This commentary explores some of the issues in balancing infection prevention and control priorities with other needs and values brought to the design process. This balance is challenged not only by a lack of supporting evidence but also by the superficial nature in which infection prevention and control are often discussed within a design context. For the physical environment to support any patient safety initiative, the design of the processes must be developed in conjunction with that of the physical environment so that compliance can be natural and convenient. Finally, consideration is given to the value of documenting decision-making related to infection prevention and control in facility design and ongoing assessments of existing facilities.

The rectal microbiota of cats infected with feline immunodeficiency virus infection and uninfected controls.

PubMed

Weese, J S; Nichols, J; Jalali, M; Litster, A

2015-10-22

Rectal swabs were collected from 31 cats, 16 with FIV infection and 15 uninfected controls, to evaluate and compare the rectal bacterial microbiota in cats with feline immunodeficiency virus (FIV) infection and uninfected controls. The rectal microbiota was characterized via next generation sequencing of 16S rRNA gene (V4 region) polymerase chain reaction products. Eighteen different phyla were identified. Firmicutes dominated in both groups, followed by Proteobacteria and Actinobacteria, but there were no significant differences between groups. When predominant orders are compared, FIV-infected cats had significant higher median relative abundances of Bifidobacteriales (P=0.022), Lactobacillales (P=0.022) and Aeromonadales (P=0.043). No differences were identified in the 50 most common genera when adjusted for false discovery rate. There were significant differences in community membership (Jaccard index, unifrac P=0.008, AMOVA P<0.001) and community structure (Yue&Clayton index, unifrac P=0.03, AMOVA P=0.005) between groups. However, only one metacommunity (enterotype) was identified. The rectal microbiota differed between cats with FIV infection and uninfected controls. Some of the changes that were noted have been associated with 'dysbiosis' and proinflammatory states in other species, so it is possible that subclinical alteration in the intestinal microbiota could influence the health of FIV-infected cats. Evaluation of the reasons for microbiota alteration and the potential impact on cat health is required. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of effort-reward imbalance and burnout on infection control among Ecuadorian nurses.

PubMed

Colindres, C V; Bryce, E; Coral-Rosero, P; Ramos-Soto, R M; Bonilla, F; Yassi, A

2018-06-01

Nurses are frequently exposed to transmissible infections, yet adherence to infection control measures is suboptimal. There has been inadequate research into how the psychosocial work environment affects compliance with infection control measures, especially in low- and middle-income countries. To examine the association between effort-reward imbalance, burnout and adherence to infection control measures among nurses in Ecuador. A cross-sectional study linking psychosocial work environment indicators to infection control adherence. The study was conducted among 333 nurses in four Ecuadorian hospitals. Self-administered questionnaires assessed demographic variables, perceived infection risk, effort-reward imbalance, burnout and infection control adherence. Increased effort-reward imbalance was found to be a unique incremental predictor of exposure to burnout, and burnout was a negative unique incremental predictor of nurses' self-reported adherence with infection control measures. Results suggest an effort-reward imbalance-burnout continuum, which, at higher levels, contributes to reduce adherence to infection control. The Ecuadorean government has made large efforts to improve universal access to health care, yet this study suggests that workplace demands on nurses remain problematic. This study highlights the contribution of effort-reward-imbalance-burnout continuum to the chain of infection by decreased adherence to infection control of nurses. Health authorities should closely monitor the effect of new policies on psychosocial work environment, especially when expanding services and increasing public accessibility with limited resources. Additionally, organizational and psychosocial interventions targeting effort-reward imbalance and burnout in nurses should be considered part of a complete infection prevention and control strategy. Further study is warranted to identify interventions that best ameliorate effort-reward imbalance and burnout in low- and middle

Public perception of cross-infection control in dentistry.

PubMed

Thomson, W M; Stewart, J F; Carter, K D; Spencer, A J

1997-10-01

Since the advent of HIV/AIDS at the beginning of the 1980s, concern has generated considerable impetus for change in cross-infection control procedures in dentistry. This process has been hastened partly by media coverage which, in tending to favour sensation over rational discourse, has played a not inconsiderable role in shaping public understanding and expectations. This study aimed to investigate public perceptions of cross-infection control in dentistry in Australia using a postal follow-up to the 1995 National Dental Telephone Interview Survey. The postal survey response rate was 85.2 per cent. Concerns about the procedures used by their dentist to sterilize instruments were reported by 13.3 per cent of respondents overall, and this was greater among non-health-card-holders, individuals who mainly spoke a language other than English in the home, and those who reported a non-routine dental visiting pattern. Avoidance or delaying of dental visits due to the perceived cross-infection risk was reported by an overall 3.6 per cent of people, and this was higher among females and those who expressed concern about cross-infection control. The profession has a responsibility to ensure that information on the measures which have been taken to reduce the risk of cross-infection in dentistry is disseminated as widely and as clearly as possible so that undue public concern and avoidance of dental care are minimized.

Strategies to promote infection prevention and control in acute care hospitals with the help of infection control link nurses: A systematic literature review.

PubMed

Peter, Daniel; Meng, Michael; Kugler, Christiane; Mattner, Frauke

2018-02-01

Infection control link nurses (ICLNs) are important backup personnel for the prevention and control of infections in hospitals. To identify facilitators and barriers for the implementation of and long-term collaboration with ICLNs. We conducted a systematic literature review, following the preferred reporting items for systematic reviews and meta-analyses guidelines. Inclusion criteria were defined as description of de novo implementation of an ICLN system, strengthening of an existing ICLN system, or analysis of an ICLN system. In 10 publications, facilitators and barriers were identified for mode of selection of ICLN candidates, characteristics and responsibilities of ICLNs, composition of a training curriculum, educational strategies, and external influencing factors. Experienced nurses with an interest in infection control seemed appropriate candidates. The importance of psychological skills in addition to technical knowledge was emphasized. A clear definition of responsibilities was important. Viable tasks for ICLNs included surveillance and teaching activities and the implementation of prevention measures. Ongoing teaching was superior to a single course. Management support was pivotal for success. Research on ICLNs is scarce. The potential to decrease health care-associated infections with the help of ICLNs has been demonstrated. The training in psychological skills in addition to technical knowledge deserves more attention. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Ask, speak up, and be proactive: Empowering patient infection control to prevent health care-acquired infections.

PubMed

Seale, Holly; Chughtai, Abrar A; Kaur, Rajneesh; Crowe, Philip; Phillipson, Lyn; Novytska, Yuliya; Travaglia, Joanne

2015-05-01

Over the last decade, there has been a slow shift toward the more active engagement of patients and families in preventing health care-associated infections (HCAIs). This pilot study aimed to examine the receptiveness of hospital patients toward a new empowerment tool aimed at increasing awareness and engagement of patients in preventing HCAI. Patients from the surgical department were recruited and randomized into 2 groups: active and control. Patients in the active arm were given an empowerment tool, whereas control patients continued with normal practices. Pre- and postsurveys were administered. At the baseline survey, just over half of the participants were highly willing to assist with infection control strategies. Participants were significantly more likely to be willing to ask a doctor or nurse a factual question then a challenging question. After discharge, 23 of the 60 patients reported discussing a health concern with a staff member; however, only 3 participants asked a staff member to wash their hands. Our results suggest that patients would like to be more informed about HCAIs and are willing to engage with staff members to assist with the prevention of infections while in the hospital setting. Further work is going to need to be undertaken to ascertain the best strategies to promote engagement and participation in infection control activities. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Continuous stand-alone controllable aerosol/cloud droplet dryer for atmospheric sampling

NASA Astrophysics Data System (ADS)

Sjogren, S.; Frank, G. P.; Berghof, M. I. A.; Martinsson, B. G.

2013-02-01

We describe a general-purpose dryer designed for continuous sampling of atmospheric aerosol, where a specified relative humidity (RH) of the sample flow (lower than the atmospheric humidity) is required. It is often prescribed to measure the properties of dried aerosol, for instance for monitoring networks. The specific purpose of our dryer is to dry cloud droplets (maximum diameter approximately 25 μm, highly charged, up to 5 × 102 charges). One criterion is to minimise losses from the droplet size distribution entering the dryer as well as on the residual dry particle size distribution exiting the dryer. This is achieved by using a straight vertical downwards path from the aerosol inlet mounted above the dryer, and removing humidity to a dry, closed loop airflow on the other side of a semi-permeable GORE-TEX membrane (total area 0.134 m2). The water vapour transfer coefficient, k, was measured to be 4.6 × 10-7 kg m-2 s-1% RH-1 in the laboratory (temperature 294 K) and is used for design purposes. A net water vapour transfer rate of up to 1.2 × 10-6 kg s-1 was achieved in the field. This corresponds to drying a 5.7 L min-1 (0.35 m3 h-1) aerosol sample flow from 100% RH to 27% RH at 293 K (with a drying air total flow of 8.7 L min-1). The system was used outdoors from 9 May until 20 October 2010, on the mountain Brocken (51.80° N, 10.67° E, 1142 m a.s.l.) in the Harz region in central Germany. Sample air relative humidity of less than 30% was obtained 72% of the time period. The total availability of the measurement system was >94% during these five months.

A simple method for estimation of coagulation efficiency in mixed aerosols. [environmental pollution control

NASA Technical Reports Server (NTRS)

Dimmick, R. L.; Boyd, A.; Wolochow, H.

1975-01-01

Aerosols of KBr and AgNO3 were mixed, exposed to light in a glass tube and collected in the dark. About 15% of the collected material was reduced to silver upon development. Thus, two aerosols of particles that react to form a photo-reducible compound can be used to measure coagulation efficiency.

Aerosols and lightning activity: The effect of vertical profile and aerosol type

NASA Astrophysics Data System (ADS)

Proestakis, E.; Kazadzis, S.; Lagouvardos, K.; Kotroni, V.; Amiridis, V.; Marinou, E.; Price, C.; Kazantzidis, A.

2016-12-01

The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument on board the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite has been utilized for the first time in a study regarding lightning activity modulation due to aerosols. Lightning activity observations, obtained by the ZEUS long range Lightning Detection Network, European Centre for Medium range Weather Forecasts (ECMWF) Convective Available Potential Energy (CAPE) data and Cloud Fraction (CF) retrieved by MODIS on board Aqua satellite have been combined with CALIPSO CALIOP data over the Mediterranean basin and for the period March to November, from 2007 to 2014. The results indicate that lightning activity is enhanced during days characterized by higher Aerosol Optical Depth (AOD) values, compared to days with no lightning. This study contributes to existing studies on the link between lightning activity and aerosols, which have been based just on columnar AOD satellite retrievals, by performing a deeper analysis into the effect of aerosol profiles and aerosol types. Correlation coefficients of R = 0.73 between the CALIPSO AOD and the number of lightning strikes detected by ZEUS and of R = 0.93 between ECMWF CAPE and lightning activity are obtained. The analysis of extinction coefficient values at 532 nm indicates that at an altitudinal range exists, between 1.1 km and 2.9 km, where the values for extinction coefficient of lightning-active and non-lightning-active cases are statistically significantly different. Finally, based on the CALIPSO aerosol subtype classification, we have investigated the aerosol conditions of lightning-active and non-lightning-active cases. According to the results polluted dust aerosols are more frequently observed during non-lightning-active days, while dust and smoke aerosols are more abundant in the atmosphere during the lightning-active days.

Aerosol climatology: on the discrimination of aerosol types over four AERONET sites

NASA Astrophysics Data System (ADS)

Kaskaoutis, D. G.; Kambezidis, H. D.; Hatzianastassiou, N.; Kosmopoulos, P. G.; Badarinath, K. V. S.

2007-05-01

Aerosols have a significant regional and global effect on climate, which is about equal in magnitude but opposite in sign to that of greenhouse gases. Nevertheless, the aerosol climatic effect changes strongly with space and time because of the large variability of aerosol physical and optical properties, which is due to the variety of their sources, which are natural, and anthropogenic, and their dependence on the prevailing meteorological and atmospheric conditions. Characterization of aerosol properties is of major importance for the assessment of their role for climate. In the present study, 3-year AErosol RObotic NETwork (AERONET) data from ground-based sunphotometer measurements are used to establish climatologies of aerosol optical depth (AOD) and Ångström exponent α in several key locations of the world, characteristic of different atmospheric environments. Using daily mean values of AOD at 500 nm (AOD500) and Ångström exponent at the pair of wavelengths 440 and 870 nm (α 440-870), a discrimination of the different aerosol types occurring in each location is achieved. For this discrimination, appropriate thresholds for AOD500 and α 440-870 are applied. The discrimination of aerosol types in each location is made on an annual and seasonal basis. It is shown that a single aerosol type in a given location can exist only under specific conditions (e.g. intense forest fires or dust outbreaks), while the presence of well-mixed aerosols is the accustomed situation. Background clean aerosol conditions (AOD500<0.06) are mostly found over remote oceanic surfaces occurring on average in ~56.7% of total cases, while this situation is quite rare over land (occurrence of 3.8-13.7%). Our analysis indicates that these percentages change significantly from season to season. The spectral dependence of AOD exhibits large differences between the examined locations, while it exhibits a strong annual cycle.

Questionnaire-based survey on structural quality of hospitals and nursing homes for the elderly, their staffing with infection control personal, and implementation of infection control measures in Germany

PubMed Central

Kramer, A.; Assadian, O.; Helfrich, J.; Krüger, C.; Pfenning, I.; Ryll, S.; Perner, A.; Loczenski, B.

2013-01-01

From January to May 2012, 1,860 hospitals throughout Germany received a questionnaire encompassing 77 items. Additionally, 300 outpatient care services and 310 nursing homes for elderly in Berlin also received a 10-item questionnaire asking on their implemented infection control practices. All questionnaires were anonymous. A total of 229 completed questionnaires from hospitals, 14 questionnaires from outpatient care services, and 16 questionnaires from nursing homes were eligible for further analysis. The lack of Infection Control physicians was identified as the largest issue. In hospitals sized 400–999 beds a gap of 71%, and in hospitals sized ≥1,000 beds a gap of 17% was reported. Depending on the number of hospital beds, 13–29% of hospitals sized ≥100 beds reported not havening one infection control nurse. Since based on the number of beds in larger institutions or in facilities caring for high-risk patients several infection control nurses may be required, the deficiency in infection control nurses may even be higher, particularly in secondary and tertiary care facilities. Furthermore, the analysis revealed that the legal requirements for surveillance and reporting of notifiable infectious diseases have not yet been implemented in 11% of the facilities. The implementation of antibiotic strategies did show significant gaps. However, deficiencies in the implemented measures for the prevention of surgical site infections were less frequent. Yet 12% of the participants did not have a dedicated infection control concept for their surgical services. Eight percent of hospitals were not prepared for an outbreak management and 10% did not have established regulations for wearing surgical scrubs. Deficiencies in waste disposal and the control of air-conditioning systems were also noted. Based on the results of this survey, conclusions on the optimal resource allocation for further improvement of patient safety may be drawn. While all participating nursing homes

Characterization of Aerosols of Titanium Dioxide Nanoparticles Following Three Generation Methods Using an Optimized Aerosolization System Designed for Experimental Inhalation Studies

PubMed Central

Pujalté, Igor; Serventi, Alessandra; Noël, Alexandra; Dieme, Denis; Haddad, Sami; Bouchard, Michèle

2017-01-01

Nanoparticles (NPs) can be released in the air in work settings, but various factors influence the exposure of workers. Controlled inhalation experiments can thus be conducted in an attempt to reproduce real-life exposure conditions and assess inhalation toxicology. Methods exist to generate aerosols, but it remains difficult to obtain nano-sized and stable aerosols suitable for inhalation experiments. The goal of this work was to characterize aerosols of titanium dioxide (TiO2) NPs, generated using a novel inhalation system equipped with three types of generators—a wet collision jet nebulizer, a dry dust jet and an electrospray aerosolizer—with the aim of producing stable aerosols with a nano-diameter average (<100 nm) and monodispersed distribution for future rodent exposures and toxicological studies. Results showed the ability of the three generation systems to provide good and stable dispersions of NPs, applicable for acute (continuous up to 8 h) and repeated (21-day) exposures. In all cases, the generated aerosols were composed mainly of small aggregates/agglomerates (average diameter <100 nm) with the electrospray producing the finest (average diameter of 70–75 mm) and least concentrated aerosols (between 0.150 and 2.5 mg/m3). The dust jet was able to produce concentrations varying from 1.5 to 150 mg/m3, and hence, the most highly concentrated aerosols. The nebulizer collision jet aerosolizer was the most versatile generator, producing both low (0.5 mg/m3) and relatively high concentrations (30 mg/m3). The three optimized generators appeared suited for possible toxicological studies of inhaled NPs. PMID:29051446

Global epidemiology, ecology and control of soil-transmitted helminth infections

PubMed Central

Brooker, Simon; Clements, Archie CA; Bundy, Don AP

2007-01-01

Soil-transmitted helminth (STH) infections are among the most prevalent of chronic human infections worldwide. Based on the demonstrable impact on child development, there is a global commitment to finance and implement control strategies with a focus on school-based chemotherapy programmes. The major obstacle to the implementation of cost-effective control is the lack of accurate descriptions of the geographical distribution of infection. In recent years considerable progress has been made in the use of geographical information systems (GIS) and remote sensing (RS) to better understand helminth ecology and epidemiology, and to develop low cost ways to identify target populations for treatment. This chapter explores how this information has been used practically to guide large-scale control programmes. The use of satellite-derived environmental data has yielded new insights into the ecology of infection at a geographical scale that has proven impossible to address using more traditional approaches, and has in turn allowed spatial distributions of infection prevalence to be predicted robustly by statistical approaches. GIS/RS have increasingly been used in the context of large-scale helminth control programmes, including not only STH infections but also those focusing on schistosomiasis, filariasis and onchocerciasis. The experience indicates that GIS/RS provides a cost-effective approach to designing and monitoring programs at realistic scale. Importantly, the use of this approach has begun to transition from being a specialist approach of international vertical programs to become a routine tool in developing public sector control programs. GIS/RS is used here to describe the global distribution of STH infections and to estimate the number of infections in school age children in sub-Saharan Africa (89.9 million) and the annual cost of providing a single anthelmintic treatment using a school-based approach (US$5.0-7.6 million). These are the first estimates at a

Infection control in hemodialysis units: a quick access to essential elements.

PubMed

Karkar, Ayman; Bouhaha, Betty Mandin; Dammang, Mienalyn Lim

2014-05-01

Infection is the most common cause of hospitalization and the second most common cause of mortality among hemodialysis (HD) patients, after cardiovascular disease. HD patients as well as the dialysis staff are vulnerable to contracting health-care-associated infections (HAIs) due to frequent and prolonged exposure to many possible contaminants in the dialysis environment. The extracorporeal nature of the therapy, the associated common environmental conditions and the immune compromised status of HD patients are major predisposing factors. The evident increased potential for transmission of infections in the HD settings led to the creation and implementation of specific and stricter infection prevention and control measures in addition to the usual standard precautions. Different international organizations have generated guidelines and recommendations on infection prevention and control for implementation in the HD settings. These include the Centers for Disease Control and Prevention (CDC), the Association of Professionals in Infection Control (APIC), the Kidney Disease Outcomes Quality Initiative (K/DOQI), the European Best Practice Guidelines/European Renal Best Practice (EBPG/ERBP) and the Kidney Disease: Improving Global Outcomes (KDIGO). However, these guidelines are extensive and sometimes vary among different guideline-producing bodies. Our aim in this review is to facilitate the access, increase the awareness and encourage implementation among dialysis providers by reviewing, extracting and comparing the essential elements of guidelines and recommendations on infection prevention and control in HD units.