Evaluating Modes of Influenza Transmission (EMIT)
The ways in which influenza is transmitted between people are uncertain; for example, we do not know if large droplets or fine particles (aerosols) matter most; both are produced by coughing and sneezing. This means we cannot say what precautions work best in real life. Improving our understanding is vital to allow the development of guidelines and policies to help reduce the transmission of both pandemic and seasonal flu.
The aim of this study is to explore how influenza is spread, specifically by looking at the importance of spread via small particles (aerosols/droplet nuclei) that are carried in respiratory sprays e.g. produced by coughing and sneezing.
The primary objective of this study is:
To estimate the contribution of aerosols/droplet nuclei to influenza transmission by determining the secondary attack rate (SAR) of influenza in Recipients randomised to a control arm (no intervention - allowing all modes of transmission) compared to Recipients randomised to an intervention arm (face shield and hand hygiene - allowing only transmission by aerosols/droplet nuclei) when both groups of Recipients are exposed to Donor volunteers infected with influenza via intranasal drops.
The hypothesis is that:
The SAR will be lower in Recipients exposed only to aerosols/droplet nuclei (intervention arm) compared to those exposed to all modes of transmission (the control arm): aerosols/droplet nuclei, droplet spray (larger respiratory droplets) and transmission through contact.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
|Official Title:||Evaluating Modes of Influenza Transmission Using a Human Challenge Model|
- Difference in Secondary Attack Rate (SAR) [ Time Frame: Day -2 to day 28(±3) ]The primary endpoint is the difference in SAR of influenza in Recipients randomised to an intervention arm (face shield and hand hygiene -droplet nuclei transmission only) compared to Recipients randomised to a control arm (no intervention - all modes of transmission).
- Viral parameters of infection and association with infection transmission. [ Time Frame: Day 1 to day 10 ]
To evaluate and compare the incidence, duration and quantity of human virus shedding.
To explore and compare the association of the incidence (infection rate as well as daily incidence), duration and quantity of virus shedding in Donors, with transmission to Recipients.
- Clinical parameters of infection and association with infection transmission. [ Time Frame: Day 1 to day 10 ]
To explore the association and severity of self-reported influenza symptoms and pyrexia between Recipient groups (intervention vs. no intervention), both cumulatively and by individual symptom type.
To explore the association of self-reported influenza symptoms in Donors, with transmission to Recipients, both cumulatively and by individual symptom type.
- Environmental disposition of virus during infection. [ Time Frame: Day 1 to day 10 ]
To determine the environmental dispersion and deposition of the virus (fomites and air) in Exposure rooms and the relationship between (a) virological findings and environmental deposition, (b) symptom scores and environmental deposition, and (c) environmental deposition and SAR in Recipients.
To characterize the exhaled breath particle sizes and aerosolized virus copy numbers expelled by influenza inoculated and influenza exposed volunteers.
- Safety of experimental infection in both challenged and exposed volunteers. [ Time Frame: Day 1 to day 28(±3) ]
- Incidence, severity, and relationship of adverse events to challenge virus and/or study procedures.
- Changes in safety laboratory tests, vital signs and clinical tests (electrocardiogram [ECG], spirometry) from baseline
|Study Start Date:||January 2013|
|Study Completion Date:||July 2013|
|Primary Completion Date:||July 2013 (Final data collection date for primary outcome measure)|
Experimental: Intervention Recipients Face Shield
Face shield and repeat hand hygiene measures
Device: Intervention Recipients Face Shield
Face shield and repeat hand hygiene measures
No Intervention: Control Recipients
No face shield and no repeat hand hygiene measures
The study will take place in a quarantine facility. Some volunteers (Donors) will be infected with the influenza virus via droplets into the nose. Other volunteers (Recipients) will then be exposed to them by occupying the same room (in the day time) and taking part in certain activities e.g. playing card games. Some of the Recipients will wear face shields and clean their hands regularly during the times they are with the Donors. The wearing of face shields together with good hand hygiene should reduce the spread of infection through large respiratory droplets and contact with contaminated surfaces but will not prevent infection that occurs through aerosols in the air. Use of symptom diaries and diagnostic tests for influenza will allow the presence of subsequent illness to be identified. Volunteers will be required to participate in the quarantine facility for up to approximately 13 days (typically 9 for Donors and 13 days for Recipients), plus study screening clinics and followup.
Additionally, during the study, environmental sampling will be performed looking for the presence of influenza virus. Air sampling and swabbing of surfaces and objects may provide information enabling us to better understand the routes of transmission.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01710111
|Retroscreen Virology Ltd|
|London, United Kingdom, E1 2AX|
|Principal Investigator:||Jonathan S Nguyen-Van-Tam, BM, BS, DM||University of Nottingham|