The Conversation A group of volunteers spent days locked in a small hotel room with people actively infected with flu. They played games, shared objects and exercised together in conditions designed to help the virus spread. Yet not a single person caught influenza.
The unexpected finding comes from a well-designed study that set out to answer a basic question: how does flu really spread?
Influenza, the virus responsible for flu, is known to spread through aerosols (microscopic droplets) released when an infected person coughs, sneezes or even breathes normally. It can also pass from person to person via contaminated surfaces such as door handles or phones, known as fomite transmission.
How efficiently the virus spreads depends on several factors, including how much virus an infected person sheds, the temperature and humidity of a room and how close people are to one another.
To tease apart which of these factors matter most, researchers at the University of Maryland in the US ran a real-world transmission experiment using people who had caught flu naturally.