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Little is known about the amount and infectiousness of influenza virus shed into exhaled breath. This contributes to uncertainty about the importance of airborne influenza transmission. We screened 355 symptomatic volunteers with acute respiratory illness and report 142 cases with confirmed influenza infection who provided 218 paired nasopharyngeal (NP) and 30-minute breath samples (coarse >5-µm and fine ≤5-µm fractions) on days 1-3 after symptom onset. We assessed viral RNA copy number for all samples and cultured NP swabs and fine aerosols. We recovered infectious virus from 52 (39%) of the fine aerosols and 150 (89%) of the NP swabs with valid cultures. The geometric mean RNA copy numbers were 3.8 × 104/30-minutes fine-, 1.2 × 104/30-minutes coarse-aerosol sample, and 8.2 × 108 per NP swab. Fine- and coarse-aerosol viral RNA were positively associated with body mass index and number of coughs and negatively associated with increasing days since symptom onset in adjusted models. Fine-aerosol viral RNA was also positively associated with having influenza vaccination for both the current and prior season. NP swab viral RNA was positively associated with upper respiratory symptoms and negatively associated with age but was not significantly associated with fine- or coarse-aerosol viral RNA or their predictors. Sneezing was rare, and sneezing and coughing were not necessary for infectious aerosol generation. Our observations suggest that influenza infection in the upper and lower airways are compartmentalized and independent.

Dass viele chemische Reaktionen unter Lichterscheinung verlaufen, ist jedem geläufig. Chemische Reaktionen, bei denen es leuchtet, stehen mit einer groß,en Bandbreite für Demonstrationsversuche zur Verfügung: Wollen wir Explosionen sehen? Flammen? Kaltes Licht? Wir haben uns zu Weihnachten für die ruhigeren Varianten dieser Experimente entschieden und versucht, durch chemische Leuchterscheinungen hervorgerufene Effekte zum einen zu erklären, vor allem aber assoziativ in Zusammenhänge zu stellen die auch Nicht-Chemikern eingängig sind., At christmas, experimental scientists love to demonstrate to a public auditory the special pleasures of their art. Here a physical and an inorganic chemist have put together their knowledge and their ideas to create a collection of experiments, explanations, images, music and effects, that was interwoven and subsumed under the title Chemistry and Light. A special mixture of theory and experiment was selected to meet the expectations of listeners and spectators of different ages and different backgrounds. Besides the wish to entertain, one main reason for this choice of presentation was to show that historical social and scientific aspects belong together as well as experiment and theory, and that natural sciences deliberately should be included into the approach of life of everybody. A tremendous pleasure can be gained from observing and understanding changes of matter that are caused by chemical reactions.