PLoS Pathogens (2020-07-01)

Minimal transmission in an influenza A (H3N2) human challenge-transmission model within a controlled exposure environment.

  • Jonathan S Nguyen-Van-Tam,
  • Ben Killingley,
  • Joanne Enstone,
  • Michael Hewitt,
  • Jovan Pantelic,
  • Michael L Grantham,
  • P Jacob Bueno de Mesquita,
  • Robert Lambkin-Williams,
  • Anthony Gilbert,
  • Alexander Mann,
  • John Forni,
  • Catherine J Noakes,
  • Min Z Levine,
  • LaShondra Berman,
  • Stephen Lindstrom,
  • Simon Cauchemez,
  • Werner Bischoff,
  • Raymond Tellier,
  • Donald K Milton,
  • EMIT Consortium

DOI
https://doi.org/10.1371/journal.ppat.1008704
Journal volume & issue
Vol. 16, no. 7
p. e1008704

Abstract

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Uncertainty about the importance of influenza transmission by airborne droplet nuclei generates controversy for infection control. Human challenge-transmission studies have been supported as the most promising approach to fill this knowledge gap. Healthy, seronegative volunteer 'Donors' (n = 52) were randomly selected for intranasal challenge with influenza A/Wisconsin/67/2005 (H3N2). 'Recipients' randomized to Intervention (IR, n = 40) or Control (CR, n = 35) groups were exposed to Donors for four days. IRs wore face shields and hand sanitized frequently to limit large droplet and contact transmission. One transmitted infection was confirmed by serology in a CR, yielding a secondary attack rate of 2.9% among CR, 0% in IR (p = 0.47 for group difference), and 1.3% overall, significantly less than 16% (p<0.001) expected based on a proof-of-concept study secondary attack rate and considering that there were twice as many Donors and days of exposure. The main difference between these studies was mechanical building ventilation in the follow-on study, suggesting a possible role for aerosols.