Attachment

25 The plague had a fatality rate of 100 percent-- inside or outside, and so on. Six feet is better than shorter distances, but we don't know just how much better. Before the next pandemic, scientists need to dig into this question and help us understand the role of ventilation and air movement so we can get a clearer answer. In the meantime, the six-foot rule is a good one to follow, unless it's very difficult to maintain, such as in a classroom`. People need clear, easily remembered guidelines. It is not a helpful public health message to say, "Keep your distance, but the exact distance depends on the situation, so it might be three feet, or six feet, or maybe more." It's mind-blowing how cheap and effective masks are. This is a little hard to admit, because my worldview is centered on solving problems by inventing new things. But it's true: We may never devise a cheaper, more effective way to block the transmission of certain respiratory viruses than a cheap piece of cloth with a couple of elastic straps sewn onto it. The idea of controlling a disease by promoting the widespread use of masks is both simple and old. It dates from 1910, when Chinese authorities called on a pioneering physician named Wu Lien-teh to lead the response to an outbreak of plague in the region then known as Manchuria, in the northeast part of the country.25 The plague had a fatality rate of 100 percent-- every single infected person died, sometimes within twenty-four hours--and was thought to be spread by infected fleas that lived on rats. Wu believed that it was airborne, not rodent-borne, and he insisted that medical staff, patients, and even members of the general public cover their faces with masks. He was partly right--you can get the infection from a flea carried by rats, but the more dangerous situation is when people have plague in their lungs and then transmit it through the air to other humans. .