bird

No matter how well a mask works, however, health care workers stress that the most important protection against infection is personal vigilance.

"Masks may offer people a security blanket," said Michael Zimring, director of the Wilderness and Travel Medicine Center at Mercy Medical Center in Baltimore and co-author of the book "Healthy Travel." "But just putting on a mask isn't going to do it. You have to do everything else, too. Keep your hands clean, stay hydrated and get enough rest."