My medical colleagues are very busy people, too busy to bother with italics (or even much punctuation) in e-mails, so I knew something was seriously wrong when a physician who happens to be my patient wrote to tell me that "something bad...something really, really bad" had happened to him.
It seems he had been vacationing in Mexico the week before the news about swine flu  broke, and now he had a cough and a fever of 103. If that wasn't "bad" enough, he'd worked in a clinic the day before he became ill and had seen-and possibly infected- twenty patients, some of them frail and elderly. "What should I do now?" the e-mail continued. "This is bad."
Epidemics, or even "outbreaks" such as the recent swine flu has been called, blur borders both geographical and psychological. Within days after we saw video on TV of people strolling through the streets of Mexico City wearing masks, cases appeared in New Zealand and New York City. And, normally quite confident of our own invulnerability, an unpredictable pathogen on the loose may make health workers feel at risk; likely at any moment to become patients ourselves. Such was the case, for example, in the early 1980s at the start of the AIDS epidemic, when many doctors refused to perform surgery on or even examine gay men, Haitians, and others presumed exposed to a then unnamed virus. Ignorance breeds fear which spreads faster, even, than contagion; sparing no one, not even physicians. As French writer Albert Camus wrote in his 1947 novel The Plague, about an Algerian town infected by bubonic plague, "No longer were there individual destinies; only a collective destiny, made of plague and emotions shared by all."
My patient, the physician, contacted the hospital authorities who advised him to come to a makeshift clinic that had been set up in the hospital lobby to handle the flood of people who thought they might have swine flu. There, too, the borders were blurred; an assembly line of clinicians separated by flimsy cloth barriers replaced the usual private doctor's office-but this was, after all, an emergency. After he'd been questioned and his nostril swabbed for the viral culture, my patient went home, in quarantine. He tried his best to use the time to recover, and to calm down. Finally, the culture came back negative and he returned to work, to his usual and certain role as a doctor, not a patient. But neither he nor I know when we might again be thrust into fear and confusion by a rampant germ. As Camus wrote, "Plagues, like wars, always take people by surprise."