University of Pittsburgh
Reducing the Spread of Influenza Virus Through the Air
Every winter about 20 million people in the U.S. will get infected with an influenza virus. A key to reducing cases of influenza infections is to block the spread of influenza viruses through the air. Influenza viruses replicate in the respiratory tract. Coughing, talking, and exhaling can promote the spread of influenza viruses, since these processes expel droplets and aerosols containing viruses. People become infected by breathing in virus-containing aerosols or touching contaminated surfaces. We will investigate how the environment alters the stability of influenza viruses in expelled aerosols and droplets, in order to engineer control measures that improve the air we breathe in confined indoor environments and reduce influenza infections.
Update: In the past year, we have made some profound discoveries about the persistence of influenza viruses within droplets. First, not all human seasonal viruses interact with environmental conditions the same. We found that seasonal H3N2 and H1N1 are more stable in droplets compared to influenza B strains at a range of humidity conditions. Second, we have observed that the longevity of human seasonal viruses in droplets varies based on strain and humidity condition. Third, influenza viruses from birds are much more sensitive to decay at mid-range relative humidity conditions than human seasonal viruses. These observations provide us with important insights into how human seasonal viruses spread. Further studies into strain variations may help predict emerging influenza strains with pandemic potential.