Understandably, the unknowns about a new strain of influenza - combined with the images of people with their mouths and noses hidden behind masks - may be fueling fear and panic.

The most-recommended precautions are modest - thorough hand-washing, good cough-and-sneeze etiquette. But some people don surgical masks. Is that necessary? Is it helpful?

On the topic of masks, the Public Health Agency of Canada (PHAC) has this to say:

"The Public Health Agency of Canada does not recommend that members of the general public wear surgical masks to protect against contracting human swine influenza. Evidence shows that this is not effective in preventing transmission of influenza in the general public. People often use masks incorrectly, or contaminate them when putting them on and taking them off, which could actually increase the risk of infection."

The U.S. Centers for Disease Control (CDC), on the other hand, explains that a well-fitted, FDA-approved mask or respirator together with other preventive measures may reduce the risk of contracting the flu. Crowded settings and close contact (of 3-6 feet or about 1 to less than 2 metres) with others should be avoided and is preferred rather than relying on masks. Those who are sick or caring for someone who is ill should consider using a mask or respirator if leaving the house becomes necessary.

The PHAC and the CDC reiterate that use of masks or respirators must be combined with good hygiene practices, including thorough hand-washing and covering coughs and sneezes. Here's a guide to tell when you should call in sick.

Amy Toffelmire