Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature

Using the guinea pig as a model host, we show that aerosol spread of influenza virus is dependent upon both ambient relative humidity and temperature. Twenty experiments performed at relative humidities from 20% to 80% and 5 degrees C, 20 degrees C, or 30 degrees C indicated that both cold and dry conditions favor transmission. The relationship between transmission via aerosols and relative humidity at 20 degrees C is similar to that previously reported for the stability of influenza viruses (except at high relative humidity, 80%), implying that the effects of humidity act largely at the level of the virus particle. For infected guinea pigs housed at 5 degrees C, the duration of peak shedding was approximately…

• EM
  Ellison Medical Foundation
• WM
  W. M. Keck Foundation
• CF
  Centers for Disease Control and Prevention