Most of us are happy to avoid influenza. Virologist Robert Webster has spent most of his career trying to catch it. One of the world's leading experts on the disease, Webster has circled the globe for decades, tracking down new strains of influenza. When he's not working in his laboratory at St. Jude Children's Research Hospital in Memphis, Tennessee, Webster may be found collecting the droppings of migrating ducks on a beach or straddling a pig in a Shanghai backyard for a nasal swab. When harbor seals off of Cape Cod began in 1979 to die in large numbers, Webster was there too, isolating a new form of flu that had never been known before to infect sea mammals.
Some animals can carry and spread viruses without getting sick.
Others, including humans, can suffer deadly epidemics. Though we may think of the flu as the cause of a week or two of achy misery in winter, the disease remains the deadliest communicable scourge of the twentieth century. In 1918, a worldwide epidemic, called a pandemic, killed an estimated 20 million people around the world, including half a million in the United States alone. A 1957 pandemic of Asian flu claimed 70,000 lives in the United States, and the Hong Kong flu of 1968 killed 34,000 Americans. Each of those epidemics began when a new form of influenza suddenly spread.