In a two-year study, researchers in Canada took nasal swabs from over 500 university students during their peak cold and flu season.

They found as many as 60 percent of students were infected with rhinovirus - the virus that causes the common cold - even though they didn't have any symptoms. These students can still spread the virus to people around them.

The researchers say students who reported cold symptoms had higher levels of rhinovirus in their system. Experts say frequent handwashing is the best way to prevent a cold.

WASHINGTON - Turns out the common cold may be more common than we thought.