Evaluating Modes of Influenza Transmission Observational Study of Community Acquired Influenza (EMIT)
Influenza Virus Infection Transmission in Humans
|Study Design:||Observational Model: Case-Only
Time Perspective: Cross-Sectional
|Official Title:||Evaluating Modes of Influenza Transmission Work Package 1: Observational Study of Community Acquired Influenza|
- Viral copy number in exhaled breath aerosol coarse and fine particle fractions [ Time Frame: At enrollment and over 2 days follow-up ]Participants will sit for 30 minutes with their face inside the cone/funnel of the Gesundheit-II (G-II)human bioaerosol collector (McDevitt JJ et al. Aerosol Sci Technol 2013, in press). Subjects are free to tidal breathe, cough, and talking. A conventional slit impactor collects particles > 5.0 μm. Condensation of water vapor is used to grow remaining particles for efficient collection by a 1.0 μm slit impactor and be deposited into a buffer-containing collector. Samples are assayed by RT-PCR and viral culture. The method was previously used to assess effectiveness of surgical masks for containing influenza virus aerosols (Milton DK, et al. PLoS Pathogens 2013, in press).
- Correlation of exhaled particle counts and viral copy numbers [ Time Frame: At enrollment and over 2 days follow-up ]Hypothesis: exhaled particle numbers counted with an optical particle counter (Exhalair, Pulmatrix, Inc, Lexington, MA) during tidal breathing will correlate with exhaled viral copy numbers, especially in the fine particle fraction
- Impact of multiple infection [ Time Frame: At enrollment and over 2 days of follow-up ]Hypothesis: co-infection with other respiratory agents will increase aerosol production
- Correlation of exhaled virus in community acquired and experimental infection [ Time Frame: At enrollment and up to 2 days of follow-up ]These data will be used to compare subjects with community acquired influenza with donor subjects artificially infected with influenza in EMIT-Work Package 3 and with recipient subjects exposed the the donors. We will test the hypothesis that the donor subjects in EMIT-WP3 produce similar amounts of viral aerosol as do community acquired infection cases. We will also examine whether recipients exposed only to aerosols differ from those exposed by contact and large droplet as well as aerosol routes with respect to exhaled aerosol virus.
- RSV and other respiratory infections [ Time Frame: At enrollment ]Hypothesis: RSV and cases with other respiratory infections who are not infected with influenza will have the infecting agent present in exhaled breath aerosols
Biospecimen Retention: Samples With DNA
|Study Start Date:||December 2012|
|Study Completion Date:||March 2013|
|Primary Completion Date:||March 2013 (Final data collection date for primary outcome measure)|
Community acquired respiratory infection
Measurement of exhaled breath aerosol
This study is a follow-on to earlier projects funded by the US Centers for Disease Control and Prevention (CDC) and the National Institute for Allergy and Infectious Diseases (NIAID) that developed the sampler and studied the impact of surgical masks on reducing viral aerosol release by persons infected with influenza virus. The funding organizations have no direct control over the study design, execution, or reporting and no access to identifiable human data. The CDC IRB has determined that the CDC is not engaged in human subjects research in this cooperative agreement.
- Fine particle aerosols will contain greater numbers of viral copies than will coarse aerosol particles.
- Clinical symptoms and signs, including fever can be used to predict viral aerosol shedding
- Fine aerosols will contain culturable virus indicating that the fine aerosols are infectious
- Aerosol shedding will correlate with virus load measured by nasopharyngeal and throat swabs
- Presence of active cough during sampling will be associated with increased aerosol shedding with a stronger correlation to be found with coarse than fine particle virus aerosols
Please refer to this study by its ClinicalTrials.gov identifier: NCT01769430
|United States, Maryland|
|University of Maryland School of Public Health|
|College Park, Maryland, United States, 20742|
|Principal Investigator:||Donald K Milton, MD, DrPH||University of Maryland|