The low humidity for Roanoke Thursday is 27 percent, which is a prime condition for the flu virus to thrive according to researchers at Virginia Tech.
Virginia Tech Research Engineer Dr. Linsey Marr says, "It is very well established that the flu virus survives well at low humidity."
The numbers for December show that our area had a low humidity during the majority of December.
Marr, along with Virginia Tech-Maryland Regional College of Veterinary Medicine Virologist Dr. Elankumaran Subbiah, recently finished up two years of research that confirms the flu virus thrives in those conditions.
In order to get the facts about how the flu virus develops under different levels of humidity, they placed it in a humidity-controlled box inside a bio-safety cabinet for about 3 hours. After 3 hours the flu virus was cultured and placed in an incubator. Then, they could figure out how well the virus survived under different levels of humidity.
Our saliva is made up of protein and salt. The salt in our saliva is really the key. At humidity levels below 50 percent, salt crystallizes and doesn't hurt the virus. Once the virus is exposed to humidity between 50 and 90 percent, the conditions are toxic for flu.
"The salts become more concentrated and are more harmful to the virus," Marr says.
"The mid-range humidity is the one in which the virus cannot survive," Subbiah says.
So does that mean we should all try to keep our humidity between 50 and 60 percent because it's hard for flu to survive? It may help, but it is no guarantee.
"There are a lot of other factors that influence flu outbreaks," Marr says, "so this may be just one of them. "
"Depending on whether there are more people in the room or a change in school schedules, all of this will contribute to an extent," Subbiah says.
As we continue to deal with changing weather, that is actually the next step in the research. Scientists at Virginia Tech will be looking at how temperature affects the virus and its ability to spread.