Pitt Research Challenges Theories About Why The Flu Thrives In The Winter

Jun 11, 2018

For a long time, scientists thought that the flu virus degraded in humid conditions and that was the reason most people don’t catch it in the summer.

University of Pittsburgh microbiologist Seema Lakdawala and collaborators devised an experiment to determine how mucus enables the airborne transmission of H1N1, which caused the 2009 swine flu pandemic, and found that it survived in several types of environments. Dry, moist – it didn’t matter.

“I was really blown away by the result, because I expected there to be some loss,” she said. “I thought after an hour we would have definitely lost the majority of the virus. We didn’t lose any.”

Lakdawala specializes in influenza virus transmission, and came to Pitt because of the mucus collection housed within the university's Airway Cells and Tissues Core lab. She worked on the project with collaborators Karen KormuthLinsey MarrAJ Prussin and Kaisen Lin of Virginia Tech.

They found the virus will use mucus as a protective layer, allowing it to remain viable regardless of an environment’s humidity.

“What that really means for a person is that when someone sneezes in your office or your house, you know like your kid sneezes or is sick ... the virus is there for an hour at least, if not longer if that air is not circulating,” said Lakdawala.

She suggested opening a window or putting on a fan to reduce the amount of virus in the air. The information might help develop treatments for the flu and other viruses, she said, and could lead to understanding of why the flu is seasonal if humidity isn't a factor.

The study was published last week in the Journal of Infectious Diseases.

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