Viable Influenza A Virus in Airborne Particles Expelled During Coughs Versus Exhalations

Background To prepare for a possible influenza pandemic, a better understanding of the potential for the airborne transmission of influenza from person to person is needed. Objectives The objective of this study was to directly compare the generation of aerosol particles containing viable influenza virus during coughs and exhalations. Methods Sixty-one adult volunteer outpatients with influenza-like symptoms were asked to cough and exhale three times into a spirometer. Aerosol particles produced during coughing and exhalation were collected into liquid media using aerosol samplers.The samples were tested for the presence of viable influenza virus using a viral replication assay (VRA). Results Fifty-three test subjects tested positive for influenza A virus. Of these, 28 (53%) produced aerosol particles containing viable influenza A virus during coughing, and 22 (42%) produced aerosols with viable virus during exhalation. Thirteen subjects had both cough aerosol and exhalation aerosol samples that contained viable virus, 15 had positive cough aerosol samples but negative exhalation samples, and 9 had positive exhalation samples but negative cough samples. Conclusions Viable influenza A virus was detected more often in cough aerosol particles than in exhalation aerosol particles, but the difference was not large. Because individuals breathe much more often than they cough, these results suggest that breathing may generate more airborne infectious material than coughing over time. However, both respiratory activities could be important in airborne influenza transmission. Our results are also consistent with the theory that much of the aerosol containing viable influenza originates deep in the lung

Pharmacological Characterization of Sigma-2 Preferring Compounds: Implications in Cocaine-induced Behaviors

Cocaine is a powerful psychostimulant that is highly abused by 1.9 million people in the United States. It accounts for more emergency department visits than any other illicit drug. Even with the high rate of cocaine abuse, no FDA approved pharmacological treatments exist. Many attempts at finding a pharmacotherapy for cocaine abuse and addiction have been made, but proven unsuccessful. Cocaine is known to bind sigma receptors at physiologically relevant concentrations, deeming them potential targets for cocaine pharmacotherapies and helping to elucidate the actions of cocaine. Two subtypes of sigma receptors have been described, sigma-1 and sigma-2. Minimal information is known about the function of sigma-2 receptors in relationship to cocaine-induced effects. This is attributed to the inability to clone the subtype and the absence of highly selective ligands. In the present study four novel compounds (CM699, CM398, CM777 and CM775) were found through radioligand binding assays, in rat brain homogenates and liver P2 membrane (with the exception of opioid receptors in CHO cells), to possess substantially high affinities for sigma-2 receptors versus sigma-1 and non-sigma receptor sites. Behavioral studies, performed in male, Swiss-Webster mice, showed that pretreatment of CM398, CM777 and CM775 to a convulsive or stimulatory locomotor dose of cocaine led to significant attenuation of cocaine-induced convulsions and hyperactivity. Additionally, administration of pretreatment doses of CM699 to non-convulsive doses of cocaine led to the occurrence or exacerbation of cocaine-induced convulsions. The availability of these sigma-2 receptor preferring compounds provide pharmacological tools to elucidate the relationship between sigma-2 receptors and cocaine effects. Furthermore, these ligands present promising putative pharmacological treatments for cocaine abuse and addiction

Healthcare personnel exposure in an emergency department during influenza season.

INTRODUCTION:Healthcare personnel are at high risk for exposure to influenza by direct and indirect contact, droplets and aerosols, and by aerosol generating procedures. Information on air and surface influenza contamination is needed to assist in developing guidance for proper prevention and control strategies. To understand the vulnerabilities of healthcare personnel, we measured influenza in the breathing zone of healthcare personnel, in air and on surfaces within a healthcare setting, and on filtering facepiece respirators worn by healthcare personnel when conducting patient care. METHODS:Thirty participants were recruited from an adult emergency department during the 2015 influenza season. Participants wore personal bioaerosol samplers for six hours of their work shift, submitted used filtering facepiece respirators and medical masks and completed questionnaires to assess frequency and types of interactions with potentially infected patients. Room air samples were collected using bioaerosol samplers, and surface swabs were collected from high-contact surfaces within the adult emergency department. Personal and room bioaerosol samples, surface swabs, and filtering facepiece respirators were analyzed for influenza A by polymerase chain reaction. RESULTS:Influenza was identified in 42% (53/125) of personal bioaerosol samples, 43% (28/ 96) of room bioaerosol samples, 76% (23/30) of pooled surface samples, and 25% (3/12) of the filtering facepiece respirators analyzed. Influenza copy numbers were greater in personal bioaerosol samples (17 to 631 copies) compared to room bioaerosol samples (16 to 323 copies). Regression analysis suggested that the amount of influenza in personal samples was approximately 2.3 times the amount in room samples (Wald χ2 = 16.21, p<0.001). CONCLUSIONS:Healthcare personnel may encounter increased concentrations of influenza virus when in close proximity to patients. Occupations that require contact with patients are at an increased risk for influenza exposure, which may occur throughout the influenza season. Filtering facepiece respirators may become contaminated with influenza when used during patient care

Viable Influenza A Virus in Airborne Particles from Human Coughs

<div><p>Patients with influenza release aerosol particles containing the virus into their environment. However, the importance of airborne transmission in the spread of influenza is unclear, in part because of a lack of information about the infectivity of the airborne virus. The purpose of this study was to determine the amount of viable influenza A virus that was expelled by patients in aerosol particles while coughing. Sixty-four symptomatic adult volunteer outpatients were asked to cough 6 times into a cough aerosol collection system. Seventeen of these participants tested positive for influenza A virus by viral plaque assay (VPA) with confirmation by viral replication assay (VRA). Viable influenza A virus was detected in the cough aerosol particles from 7 of these 17 test subjects (41%). Viable influenza A virus was found in the smallest particle size fraction (0.3 μm to 8 μm), with a mean of 142 plaque-forming units (SD 215) expelled during the 6 coughs in particles of this size. These results suggest that a significant proportion of patients with influenza A release small airborne particles containing viable virus into the environment. Although the amounts of influenza A detected in cough aerosol particles during our experiments were relatively low, larger quantities could be expelled by influenza patients during a pandemic when illnesses would be more severe. Our findings support the idea that airborne infectious particles could play an important role in the spread of influenza.</p></div