SBIR-STTR Award

While knowledge of the transmission modes for respiratory pathogenic viruses is critical, understandingtheir transmission mechanisms is hampered by existing sampling methods. Commonly used bioaerosolsamplers have low collection efficiencies for particles < 0.3 m (e.g., influenza virus and the recent SARS-CoV-2), and the process involved in the collection often reduces infectivity, lowering the chances to accuratelyassess the extent of the occurrence. To address these issues, we developed under a NIAID grant the VIableVirus Aerosol Sampler (VIVAS), which has been proven more efficient and reliable in collecting viable virusesthan the industry standard samplers. This system has been tested in the laboratory and the field, and it is nowcommercially available as the BioSpot Sampler (sold by our licensee Aerosol Devices Inc.). Nevertheless, none of the commercial bioaerosol samplers, including the BioSpot, has the capability tocollect size-fractionated airborne particles. Although previous efforts have tried to separate virus-containingparticles by aerodynamic size, maintaining their infectivity during sampling remains challenging. Here, we aimto develop a novel sampling system, the BioCascade that will allow the collection into liquid of four differentparticle fractions: >10 m, PM4-10, PM1-4 and PM1 (fine) while maintaining infectivity. In Phase I, we will build aBioCascade prototype that can be attached to a VIVAS unit and to a gelatin filter collection device. Theproposed approach will create a powerful tool, not available before, that can transform our current disease-control paradigm from a reactive approach (to an outbreak after its fact) to a proactive approach (informing usthe forthcoming outbreak.) Specific aims of this proposal are: 1) Achieve the desired particle size cut-offs (>10 m, PM4-10, PM1-4 andPM1) while minimizing particle losses in the impactors and efficiently delivering each fraction simultaneouslyinto a liquid collection medium. Preliminary tests to determine the effective cut-off of the BioCascade will beconducted at Aerosol Dynamics Inc. in combination with the Viable Virus Aerosol Sampler, using aerosolparticles of known sizes. (2) Demonstrate a high viability/infectivity in the delivered samples while achievingoptimal size separation. The BioCascade unit combined with the VIVAS or the gelatin filter, will be furthertested at the University of Florida using aerosolized microorganisms of different sizes. The effect of the systemon the viability of the samples will be determined. (3) Evaluate the exposure level to influenza viruses at aStudent Health Care Center (SHCC). The BioCascade with the VIVAS will be placed at the waiting room in theSHCC for collecting respiratory viruses in the four size fractions during the "flu season" to capture thecirculating strains and to determine the pathogen loading in each size fraction. This information will be of utmost importance to understanding the reach of an outbreak, establishingrecommendations for public safety, and determining the best strategies to control/stop future viral diseases. Project Narrative Viral respiratory diseases, such as common flu and the recent COVID-19, can spread from person to person by larger droplets coughed or sneezed into the air that settle quickly and/or by smaller particles (<5 um) that can remain airborne for longer periods thus prolonging the risk for acquiring an infection and increasing the likelihood of community transmission. The knowledge of the transmission modes for respiratory viruses is critical to establishing best strategies to control viral diseases, but its understanding is hampered by limitations of existing sampling tools. Developing a unique instrument capable of delivering samples containing viable/infectious viruses in different aerodynamic size modes, will help answering a vital question regarding the main transmission mode of the viral disease, and thus establish the best protocols to control and stop future outbreaks. Aerosols ; Air ; Bacteria ; Bacteriophages ; Phages ; bacterial virus ; Communities ; Coughing ; Crowding ; Cessation of life ; Death ; Disease ; Disorder ; Disease Outbreaks ; Outbreaks ; Florida ; Future ; Gelatin ; Grant ; Infection ; Influenza ; Grippe ; Laboratories ; Lung diseases ; Pulmonary Diseases ; Pulmonary Disorder ; Respiratory Disease ; Respiratory System Disease ; Respiratory System Disorder ; disease of the lung ; disorder of the lung ; lung disorder ; Methods ; Persons ; Particle Size ; Probability ; Recommendation ; Research ; Risk ; Saccharomyces ; Safety ; Seasons ; Sneezing ; Students ; Technology ; Testing ; Travel ; Universities ; Virus Diseases ; Viral Diseases ; viral infection ; virus infection ; virus-induced disease ; Virus ; Yeasts ; Micrococcus luteus ; M luteus ; M. luteus ; symposium ; conference ; convention ; summit ; symposia ; Healthcare ; health care ; Risk Assessment ; base ; Surface ; Phase ; fluid ; liquid ; Liquid substance ; Deposit ; Deposition ; tool ; instrument ; Knowledge ; programs ; Exhaling ; Respiratory Expiration ; Exhalation ; Protocol ; Protocols documentation ; microorganism ; System ; Viral ; respiratory ; interest ; experience ; particle ; Performance ; respiratory virus ; novel ; Devices ; Sampling ; response ; air sampling ; disease control ; disorder control ; Diameter ; Caliber ; Influenza Virus ; influenzavirus ; Address ; Data ; NIAID ; National Institute of Allergy and Infectious Disease ; Resolution ; Collection ; transmission process ; Transmission ; Process ; design ; designing ; pathogen ; Coupled ; flu ; Microbe ; aerosolized ; prototype ; Industry Standard ; Inhalation ; Inhaling ; pathogenic virus ; viral pathogen ; virus pathogen ; infection risk ; COVID-19 ; COVID19 ; CV-19 ; CV19 ; corona virus disease 2019 ; coronavirus disease 2019 ; 2019-nCoV ; 2019 novel corona virus ; 2019 novel coronavirus ; COVID-19 virus ; COVID19 virus ; CoV-2 ; CoV2 ; SARS corona virus 2 ; SARS-CoV-2 ; SARS-CoV2 ; SARS-associated corona virus 2 ; SARS-associated coronavirus 2 ; SARS-coronavirus-2 ; SARS-related corona virus 2 ; SARS-related coronavirus 2 ; SARSCoV2 ; Severe Acute Respiratory Distress Syndrome CoV 2 ; Severe Acute Respiratory Distress Syndrome Corona Virus 2 ; Severe Acute Respiratory Distress Syndrome Coronavirus 2 ; Severe Acute Respiratory Syndrome CoV 2 ; Severe Acute Respiratory Syndrome-associated coronavirus 2 ; Severe Acute Respiratory Syndrome-related coronavirus 2 ; Severe acute respiratory syndrome associated corona virus 2 ; Severe acute respiratory syndrome corona virus 2 ; Severe acute respiratory syndrome coronavirus 2 ; Severe acute respiratory syndrome related corona virus 2 ; Wuhan coronavirus ; coronavirus disease 2019 virus ; hCoV19 ; nCoV2 ;

Respiratory infections are the most common reason for doctor visits and the third leading causeof deaths. Viruses are the causative agents of most respiratory tract infections. Knowledge ofthe transmission modes for pathogenic respiratory viruses is critical for improving mitigationstrategies that safeguard public health, but understanding their transmission mechanisms ishampered by existing sampling methods. So far, no method has been recommended by thepublic health organizations for the collection and detection of airborne viruses. The lack ofstandard protocols results from the fact that no sampling procedure is appropriate for samplingof all bioaerosols. During sampling, it is necessary to minimize inactivation of microbes, such asincapacitating desiccation and destructive impaction upon collection onto a collection surface.When collecting samples for detection of viral genomic RNA or DNA, maintaining the viability ofthe virus is not necessary, but maintaining nucleic acid integrity is essential, especially for RNA,which is rapidly degraded upon exposure to the environment. For assessing infectivity, thepathogen needs to be viable. In both cases, gentle collection methods are required. Although previous efforts have tried to separate virus-containing particles by aerodynamicsize, maintaining their infectivity during sampling remains challenging. Here, we aim to developa novel sampling system, the BioCascade, that will allow the collection of airborne viruses withinfour different bioaerosol particle size-fractions: >10 um, PM4-10, PM1.5-4 and PM1.5 into liquidmedium, while maintaining infectivity of the viruses that are collected. In Phase I, we built aBioCascade prototype. Its particle size-range cut-off and the collection efficiency of each stagewere modeled and designed by numerical simulations followed by validation through laboratoryexperiments using National Institutes of Science and Technology (NIST)-certified standard-sized particles. Its ability to collect and maintain the infectivity of bioaerosol was then assessedusing microorganisms that were representative of the size ranges that would be encountered inbioaerosols. All Phase-I aims were successfully achieved. In Phase II, we aim to improve ourprototype by expanding its capabilities, such as a cold collection chamber for providing a betterenvironment for the collected pathogens, and a control system to maintain the liquid level thatenables increased sampling time to several hours. By providing size-fractionated air samplesthat contain infectious pathogens, the Biocascade is envisioned as a powerful tool, not availablebefore, that can transform our current disease-control paradigm from a reactive approach (to anoutbreak after its fact) to a proactive approach (inform us the forthcoming viruses).

Public Health Relevance Statement:
Project Narrative To accurately assess the risk of Airborne transmission of viral respiratory diseases, we need to not only identify the route of transmission (droplet or aerosol) for respiratory viruses but also whether the viruses are infectious ("viable, live"). This proposal presents a novel instrument for assessment of the different transmission modalities by separating airborne virus-containing particles by size and collecting them into liquid medium to conserve their viability, with the goal of determining the preferential particle sizes containing infectious viruses. Successful development of the proposed sampler will result in a powerful tool that allows better understanding of how viral respiratory diseases are spread through the air.

Project Terms:
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