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Evaluating Modes of Influenza Transmission Observational Study of Community Acquired Influenza

NCT01769430 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 178

Last updated 2025-04-25

Study results available
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Summary

The recent swine origin influenza pandemic (2009), new emergence of swine origin H3N2v, and delayed availability of vaccine for these agents highlight the need to test and optimize public health intervention strategies to reduce transmission of influenza. We will use a new technology for biological particle collection (U.S. Provisional Patent Application No. 61/162,395, McDevitt et al., Aerosol Sci Technol 2013) to make fundamental observations on infectious respiratory droplets in a study of up to 200 naturally occurring seasonal influenza cases. We will collect respiratory droplets shed by participants while breathing normally, talking, and spontaneously coughing. We will characterize the size distribution of droplets containing infectious virus. We will use these basic data to examine the roles of large and small respiratory droplets and examine how the interaction of host factors and virus type impact the shedding of infectious respiratory droplets. Subjects will be recruited through a web based respiratory illness surveillance system, health clinics and advertisement in the campus community. Sitting in the collection booth will not create additional discomfort or risk for volunteers already suffering from influenza infection. We will recruit up to 1000 persons with symptoms of acute respiratory illness for screening with collection of nasopharyngeal swabs and questionnaire. From among those screened, we will recruit 250 to give exhaled breath samples, and ask 50 people with influenza to return for follow up exhaled breath samples on up to two subsequent days. We hypothesize that (1) fine aerosols (\<5 microns in aerodynamic diameter) will contain more viral copies than coarse aerosol particles (\>= 5 microns) (2) fine aerosols will contain culturable virus indicating that the fine aerosols are infectious, (3) aerosol shedding will correlate with virus load measured by swabs, (4) presence of active cough during sampling will be associated with increased aerosol shedding, (5) clinical symptoms and signs, including fever can be used to predict viral aerosol shedding.

Conditions

  • Influenza Virus Infection Transmission in Humans

Interventions

OTHER

Observational Study of influenza aerosol shedding -- No Intervention

No intervention -- observational study only

Sponsors & Collaborators

Principal Investigators

  • Donald K Milton, MD, DrPH · University of Maryland

Eligibility

Min Age
10 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2012-12-31
Primary Completion
2013-03-31
Completion
2013-03-31

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01769430 on ClinicalTrials.gov