The flu is one of life's aggravations that we're forced to endure from time to time. For a week or two it's nothing but fever, chills, and misery. And while people do die of the flu, in recent years, it hasn't been a number high enough for scientists to shout, "Pandemic!" So what is all the fuss about?
The answer is that this flu—a strain known as H5N1—is particularly vicious. It spreads quickly and has a high mortality rate; over half of the people infected with H5N1, also known as Bird Flu, have died.
According to the World Health Organization (WHO), "The current outbreaks of highly pathogenic avian influenza, which began in Southeast Asia in mid-2003, are the largest and most severe on record. Never before in the history of this disease have so many countries been simultaneously affected, resulting in the loss of so many birds." Right now, bird flu has infected people in close contact with birds. A pandemic could ensue, however, should the virus develop a way to spread between people.
Birds and the Flu
Flu viruses tend to cluster around bird populations. Typically waterfowl infect domestic birds like chickens and ducks. Some strains can infect humans. That's why scientists are fearful about H5N1.
How a Virus Changes
A flu virus can't reproduce on its own. It needs a host cell to do the job. When a virus latches on to a host cell, it injects the cell with its own genetic material—long strings of genetic code—and instructs the cell to copy that code over and over again. The result is millions of cells making millions of copies of the virus.
But sometimes a cell messes up, or makes a typo. It's this typo, or mutation, spread by the host, that can suddenly tell the virus to infect through the air. The problem is, scientists don't know whether the virus will mutate.