At least one out of every 10 Americans comes down with the flu each year, usually between late fall and early spring.
Along with the miserable symptoms the flu brings, it throws households into chaos, causes lengthy absences from school and work, and spoils vacation plans. And while most victims are up and around in a week or so, the flu sends a surprising number of people in this country -- more than 100,000 -- to the hospital each year. More surprising still: About a third of them don't come home.
A runaway case of influenza can develop into a more serious illness, such as pneumonia. For older adults and people with chronic health problems, such as asthma, the flu can lead to life-threatening complications.
The infamous Spanish Flu of 1918 killed 20 million people worldwide. There have been two other pandemics (epidemics that spread over huge geographical areas) since then, in 1957 and 1968. Experts say another pandemic is inevitable, though no one can say when it will hit. But whether there's an international influenza outbreak this season or not, you can count on this much: The flu will strike someone, somewhere, in your town or city this winter.
"The flu is not just another cold," says Dr. Marie Griffin, an influenza expert at Vanderbilt University in Nashville, Tennessee, who believes that many Americans take the virus too lightly. But you might say the flu is the common cold's stronger, nastier cousin.
Like the common cold, the flu causes coughing, sneezing, a runny nose, and a sore throat. But for the flu-bitten patient, things get much worse -- fast. In just a day's time, a healthy person can develop a full-blown case of the flu with a fever, headache, sore muscles, and debilitating fatigue. The worst symptoms usually pass in three to five days, though a cough or sore throat may linger longer. In some cases, however, a flu infection can persist, causing serious complications.
One of the most common complications of the flu is pneumonia, an inflammation of the lungs that causes chest pain and a cough that produces yellow-green discharge. Although the flu can damage lungs directly, it's more common for a virus to weaken the respiratory system's defenses, leaving lungs vulnerable to an assault by bacterial infections, which causes pneumonia, says Dr. Kristin Nichol, of the Minneapolis Veteran's Affairs Medical Center.
Doctors generally only prescribe medication for severe cases. If the flu catches you, doctors say the best therapy is to rest, drink fluids, and take a nonaspirin pain reliever.
Fortunately, there are simple steps just about anyone can take to avoid the flu.
Colds and flu are both caused by viruses, which are infectious microorganisms that invade your body and can make you sick. You catch these bugs by inhaling water droplets in the air from the breath of an infected person, who spews them out every time he or she exhales, coughs, or sneezes. Cold and flu viruses can roost on inanimate objects too. Twist a contaminated doorknob or use a coworker's pencil before touching your lips, and you can become infected.
The best daily defense against catching a flu virus is as easy as turning on a faucet. After using the restroom, always wash your hands with warm soapy water. Wet your hands before applying soap and rub them together for 20 seconds or so. Shut the water off with a paper towel or your elbow to avoid recontamination. If possible, use an air dryer to dry your hands.
And then there's the flu vaccine. A flu vaccine puts your immune system on alert. It's like giving your antibodies -- the immune system's foot soldiers in the war against germs -- a photo of the enemy, so they'll recognize a flu virus immediately if one invades. In fact, if you've already been infected with a flu virus, your immune system "remembers" what it looks like and attacks the bug before it can make you sick if it reenters your body.
The flu vaccine isn't perfect. Since there are so many strains of influenza raging around the world at any given time, it would be impossible to concoct a supervaccine that would protect against all of them. So the World Health Organization (WHO) gathers information from international public health agencies and determines which three strains are most likely to cause widespread illnesses in the coming flu season. Using that information, drug companies prepare a new vaccine every year that is specially designed to combat those three flu strains.
Almost anyone can benefit from getting vaccinated. But for some people, getting an annual flu shot is vital. The CDC says that anyone whose life could be endangered by the flu should line up for a shot each fall. This high-risk population includes:
A vaccination is also a must for anyone who could spread the flu to a high-risk person. That means doctors, nurses, and all health-care workers. But it also includes anybody who spends time with sick or elderly people during the flu season.
Other good candidates are breast-feeding moms, people infected with HIV, and overseas travelers any time of the year.
It's a pretty small category of people for whom the flu shot isn't a good idea. If you're allergic to eggs, which are used in making the vaccine, talk to your doctor about alternatives, and follow the preventive measures to avoid the bug.