I am not going to lie to you, the bird flu freaks me out a bit. Well, a lot actually. A new study from the UK on surgical masks allayed my fears a bit. The study found that that surgical masks do provide protection from severe respiratory illnesses, from the flu to SARS, but also from the common cold. Parents involved in the study who wore surgical masks with a sick child at home were "four times more likely to be protected against respiratory viruses."
This may affect public health policy in the face of some future respiratory illness pandemic. However, just as you need to use your home fitness equipment to actually get fit, you have to wear the mask to boost your protection from these kinds of viruses. Similar and older studies have found that few participants wore their preventive surgical masks regularly, and low compliance rates mean considerably less prevention.