No abstract

The global burden of lower respiratory tract infections is substantial, leading to many hospital admissions and deaths, especially among young children and older adults. 1 Respiratory viruses are responsible for almost half of such infections in adults that require in-hospital management; previous studies estimate that 28%−62% are caused by noninfluenza respiratory viruses (NIRVs). [2][3][4] With some geographical and seasonal variations, respiratory syncytial virus (RSV), human rhinovirus (hRV) and human coronavirus (hCoV) are among the most frequently identified NIRV infections. [1][2][3][4][5][6][7] Most infected adults develop mild, self-limiting illnesses, but increasing evidence suggest that NIRVs, either alone or with coinfecting bacteria, can result in severe pneumonia and death. 8,9 For instance, RSV has been shown to cause severe respiratory failure, with fatality rates comparable to or exceeding those observed among adults admitted to hospital with influenza. [10][11][12] Data on hRV, hCoV and other NIRVs are more limited, owing to the lack of accurate diagnostics and systematic case-finding approaches. 7-9 However, with the increasing availability of multiplex polymerase chain reaction (PCR) assays that can simultaneously detect influenza

Background: Bioaerosol sampling devices are necessary for the characterization of infectious bioaerosols emitted by naturally-infected hosts with acute respiratory virus infections. Assessment of these devices under multiple experimental conditions will provide insight for device use. Objectives:The primary objective of this study was to assess and compare bioaerosol sampling devices using a) an in vitro, environmentally-controlled artificial bioaerosol system at a range of different RH conditions and b) an in vivo bioaerosol system of influenza virus-infected ferrets under controlled environmental conditions. Secondarily, we also sought to examine the impact of NSAIDs on bioaerosol emission in influenza virus-infected ferrets to address its potential as a determinant of bioaerosol emission. Methods:We examined the performance of low and moderate volume bioaerosol samplers for the collection of viral RNA and infectious influenza virus in vitro and in vivo using artificial bioaerosols and the ferret model of influenza virus infection. The following samplers were tested: the polytetrafluoroethylene filter (PTFE filter), the 2stage National Institute of Occupational Safety and Health cyclone sampler (NIOSH cyclone sampler) and the 6-stage viable Andersen impactor (Andersen impactor). Results:The PTFE filter and NIOSH cyclone sampler collected similar amounts of viral RNA and infectious virus from artificially-generated aerosols under a range of relative humidities (RH). Using the ferret model, the PTFE filter, NIOSH cyclone sampler and the Andersen impactor collected up to 3.66 log 10 copies of RNA/L air, 3.84 log 10 copies of RNA/L air and 6.09 log 10 copies of RNA/L air respectively at peak recovery. Infectious virus was recovered from the PTFE filter and NIOSH cyclone samplers on the peak day of viral RNA recovery. Conclusion: The PTFE filter and NIOSH cyclone sampler are useful for influenza virus RNA and infectious virus collection and may be considered for clinical and environmental settings. K E Y W O R D S bioaerosol samplers, bioaerosols, ferret model, influenza virus | 565 BEKKING Et al.