Modeling the airborne survival of influenza virus in a residential setting: the impacts of home humidification

BackgroundLaboratory research studies indicate that aerosolized influenza viruses survive for longer periods at low relative humidity (RH) conditions. Further analysis has shown that absolute humidity (AH) may be an improved predictor of virus survival in the environment. Maintaining airborne moisture levels that reduce survival of the virus in the air and on surfaces could be another tool for managing public health risks of influenza.MethodsA multi-zone indoor air quality model was used to evaluate the ability of portable humidifiers to control moisture content of the air and the potential related benefit of decreasing survival of influenza viruses in single-family residences. We modeled indoor AH and influenza virus concentrations during winter months (Northeast US) using the CONTAM multi-zone indoor air quality model. A two-story residential template was used under two different ventilation conditions - forced hot air and radiant heating. Humidity was evaluated on a room-specific and whole house basis. Estimates of emission rates for influenza virus were particle-size specific and derived from published studies and included emissions during both tidal breathing and coughing events. The survival of the influenza virus was determined based on the established relationship between AH and virus survival.ResultsThe presence of a portable humidifier with an output of 0.16 kg water per hour in the bedroom resulted in an increase in median sleeping hours AH/RH levels of 11 to 19% compared to periods without a humidifier present. The associated percent decrease in influenza virus survival was 17.5 - 31.6%. Distribution of water vapor through a residence was estimated to yield 3 to 12% increases in AH/RH and 7.8-13.9% reductions in influenza virus survival.ConclusionThis modeling analysis demonstrates the potential benefit of portable residential humidifiers in reducing the survival of aerosolized influenza virus by controlling humidity indoors.

[1]  W. Thompson,et al.  Epidemiology of seasonal influenza: use of surveillance data and statistical models to estimate the burden of disease. , 2006, The Journal of infectious diseases.

[2]  Robert G. Loudon,et al.  Cough Frequency in Patients with Respiratory Disease1, 2 , 1967 .

[3]  R Akselsson,et al.  Effect of air humidification on the sick building syndrome and perceived indoor air quality in hospitals: a four month longitudinal study. , 1994, Occupational and environmental medicine.

[4]  Richard Vaille Lee,et al.  Transmission of influenza A in human beings. , 2007, The Lancet. Infectious diseases.

[5]  Steven J. Nabinger,et al.  Measurement and Simulation of the IAQ Impact of Particle Cleaners in a Single-Zone Building | NIST , 2000 .

[6]  Jeffrey Shaman,et al.  Absolute humidity modulates influenza survival, transmission, and seasonality , 2009, Proceedings of the National Academy of Sciences.

[7]  Raymond Tellier,et al.  Transmission of influenza A in human beings. , 2007, The Lancet. Infectious diseases.

[8]  A. TenWolde,et al.  3746 VENTILATION , HUMIDITY , AND CONDENSATION IN MANUFACTURED HOUSES DURING WINTER , 2007 .

[10]  Dennis D. Leber,et al.  A Collection of Homes to Represent the U.S. Housing Stock | NIST , 2006 .

[11]  Wai-ming Lee,et al.  An optimized method to detect influenza virus and human rhinovirus from exhaled breath and the airborne environment. , 2009, Journal of environmental monitoring : JEM.

[12]  M. First,et al.  Role of Absolute Humidity in the Inactivation of Influenza Viruses on Stainless Steel Surfaces at Elevated Temperatures , 2010, Applied and Environmental Microbiology.

[13]  C. S. Sale.  Humidification during the cold weather to assist perennial allergic rhinitis patients. , 1971, Annals of allergy.

[14]  Andrew K. Persily,et al.  Modeling Moisture in Residential Buildings with a Multizone IAQ Program | NIST , 2002 .

[15]  Irwin Streiff,et al.  Environmental Health service , 1974 .

[16]  Cécile Viboud,et al.  Correction: Absolute Humidity and the Seasonal Onset of Influenza in the Continental United States , 2010, PLoS Biology.

[17]  J. H. Hemmes,et al.  Virus Survival as a Seasonal Factor in Influenza and Poliomyelitis , 1960, Nature.

[18]  Michael Gardam,et al.  Transmission of influenza A in human beings. , 2007, The Lancet. Infectious diseases.

[19]  I. L. Shechmeister.  Studies on the experimental epidemiology of respiratory infections. III. Certain aspects of the behavior of type A influenza virus as an air-borne cloud. , 1950, The Journal of infectious diseases.

[20]  Raymond Tellier,et al.  Review of Aerosol Transmission of Influenza A Virus , 2006, Emerging infectious diseases.

[21]  Disease Prevention,et al.  Damp Indoor Spaces and Health , 2004 .

[22]  P. Laidlaw,et al.  Studies on air-borne virus infections: I. Experimental technique and preliminary observations on influenza and infectious ectromelia , 1943, Journal of Hygiene.

[23]  Brian J. Polidoro,et al.  Database tools for modeling emissions and control of air pollutants from consumer products, cooking, and combustion , 2006 .

[24]  D. Edward,et al.  STUDIES ON AIR-BORNE VIRUS INFECTIONS , 1943 .

[25]  Azzedine Lansari,et al.  Dispersion of Automotive Alternative Fuel Vapors within a Residence and Its Attached Garage , 1996 .

[26]  Cécile Viboud,et al.  Influenza seasonality: Lifting the fog , 2009, Proceedings of the National Academy of Sciences.

[27]  Cécile Viboud,et al.  Absolute Humidity and the Seasonal Onset of Influenza in the Continental United States , 2010, PLoS biology.

[28]  D. Tyrrell,et al.  Loss of Infectivity on Drying Various Viruses , 1962, Nature.

[29]  Steven J. Emmerich,et al.  Measurement and Simulation of the IAQ Impact of Particle Air Cleaners in a Single-Zone Building , 2000 .

[30]  J. Jaakkola,et al.  The effect of air humidification on symptoms and perception of indoor air quality in office workers: a six-period cross-over trial. , 1992, Archives of environmental health.

[31]  David L MacIntosh,et al.  Control of asthma triggers in indoor air with air cleaners: a modeling analysis , 2008, Environmental health : a global access science source.

[32]  J. E. Janssen,et al.  Ventilation for acceptable indoor air quality , 1989 .

[33]  S. Weichenthal,et al.  Indoor ultrafine particle exposures and home heating systems: A cross-sectional survey of Canadian homes during the winter months , 2007, Journal of Exposure Science and Environmental Epidemiology.

[34]  C. G. Loosli,et al.  Experimental Air-Borne Influenza Infection. I. Influence of Humidity on Survival of Virus in Air.∗ , 1943 .

[35]  Rachael M. Jones,et al.  Relative Contributions of Four Exposure Pathways to Influenza Infection Risk , 2009, Risk analysis : an official publication of the Society for Risk Analysis.

[36]  A M HOOD,et al.  Infectivity of influenza virus aerosols , 1963, Journal of Hygiene.

[37]  F. L. Schaffer,et al.  Survival of airborne influenza virus: Effects of propagating host, relative humidity, and composition of spray fluids , 2005, Archives of Virology.

[38]  George Walton,et al.  CONTAM 2.1 supplemental user guide and program documentation , 2003 .

[39]  D. Edward.  RESISTANCE OF INFLUENZA VIRUS TO DRYING AND ITS DEMONSTRATION ON DUST , 1941 .

[40]  John Steel,et al.  Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature , 2007, PLoS pathogens.

[41]  J. Kurnitski,et al.  The effects of ventilation systems and building fabric on the stability of indoor temperature and humidity in Finnish detached houses , 2009 .

[42]  C. Vionnet.  [Environmental health]. , 1983, Krankenpflege. Soins infirmiers.

[43]  Benjamin J. Cowling,et al.  Influenza Virus in Human Exhaled Breath: An Observational Study , 2008, PloS one.

[44]  W. Lester.  THE INFLUENCE OF RELATIVE HUMIDITY ON THE INFECTIVITY OF AIR-BORNE INFLUENZA A VIRUS (PR8 STRAIN) , 1948, The Journal of experimental medicine.

[45]  G. Harper,et al.  Airborne micro-organisms: survival tests with four viruses , 1961, Epidemiology and Infection.

[46]  R. Loudon,et al.  Cough frequency in patients with respiratory disease. , 1967, The American review of respiratory disease.