High humidity leads to loss of infectious influenza virus from simulated coughs

Details

• Personal Author:
  Beezhold, Donald H. ; Blanchere, Francoise M. ; Kashon ML ; Lindsley, William G. ; McMillen DM ; Noti JD ; Slaughter DR
• Description:
  Background: The role of relative humidity in the aerosol transmission of influenza was examined in a simulated examination room containing coughing and breathing manikins. Methods: Nebulized influenza was coughed into the examination room and Bioaerosol samplers collected size-fractionated aerosols (<1 micorM, 1-4 micorM, and >4 microM aerodynamic diameters) adjacent to the breathing manikin's mouth and also at other locations within the room. At constant temperature, the RH was varied from 7-73% and infectivity was assessed by the viral plaque assay. Results: Total virus collected for 60 minutes retained 70.6-77.3% infectivity at relative humidity = / <23% but only 14.6-22.2% at relative humidity = / >43%. Analysis of the individual aerosol fractions showed a similar loss in infectivity among the fractions. Time interval analysis showed that most of the loss in infectivity within each aerosol fraction occurred 0-15 minutes after coughing. Thereafter, losses in infectivity continued up to 5 hours after coughing, however, the rate of decline at 45% relative humidity was not statistically different than that at 20% regardless of the aerosol fraction analyzed. Conclusion: At low relative humidity, influenza retains maximal infectivity and inactivation of the virus at higher relative humidity occurs rapidly after coughing. Although virus carried on aerosol particles <4 microM have the potential for remaining suspended in air currents longer and traveling further distances than those on larger particles, their rapid inactivation at high humidity tempers this concern. Maintaining indoor relative humidity >40% will significantly reduce the infectivity of aerosolized virus. [Description provided by NIOSH]
• Subjects:
  Aerosols Communicable Diseases Disease Vectors Humidity Occupational Health Safety Viral Diseases
• Keywords:
  Biological-effects Disease-vectors Diseases Infectious-diseases Statistical-analysis Viral-diseases
• ISSN:
  1932-6203
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  8
• Issue:
  2
• NIOSHTIC Number:
  nn:20042261
• Citation:
  PLoS One 2013 Feb; 8(2):e57485
• Contact Point Address:
  John D. Noti, PhD, HELD/NIOSH/CDC, 1095 Willowdale Road, M.S. 4020, Morgantown, WV 26505-2888
• Email:
  ivr2@cdc.gov
• Federal Fiscal Year:
  2013
• NORA Priority Area:
  Healthcare and Social Assistance
• Peer Reviewed:
  True
• Source Full Name:
  PLoS One
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:136a31309f22829248a8dc85480d860cb9cfdbf33a13f80cf2f84296fd7772cd1663bf9d0201b75c85eeff68ad74670e5e1704fafe1b06d9e03e8ecb63ac2cae
• Download URL:
  https://stacks.cdc.gov/view/cdc/194542/cdc_194542_DS1.pdf
• File Type:
  [PDF - 1.20 MB ]