Mucus protects airborne flu virus at all humidities

(HealthDay)—Influenza virus aerosols remain infectious at all humidity levels, according to a study published online June 7 in the Journal of Infectious Diseases.

Karen A. Kormuth, Ph.D., from University of Pittsburgh, and colleagues used humidity-controlled chambers to study the impact of relative humidity on the stability of 2009 pandemic influenza A(H1N1) virus in suspended aerosols and stationary droplets.

The researchers found that viruses supplemented with material from human airway epithelial cells (mucus) remained equally infectious for one hour at all relative humidities tested. In both fine aerosols and stationary droplets, this infectivity was sustained.

"Our data suggest, for the first time, that influenza viruses remain highly stable and infectious in aerosols across a wide range of relative humidities," the authors write. "These results have significant implications for understanding the mechanisms of transmission of influenza and its seasonality."