Families should learn all they can about the flu and be better equipped to protect adults and children, especially on vacation. Here are some tips and prevention techniques from Doc Holiday.

In response to the unexpected shortage of flu vaccine for winter 2005, the American Medical Association, in accordance with Centers for Disease Control and Prevention guidelines, began recommending that healthy individuals forgo or delay their flu shots to help ensure that high-risk patients could be vaccinated first.

This gave the medical community an opportunity to share strategies on flu prevention, ideal information for parents and young children. We learned that healthy patients can take important steps to reduce their chances of getting the flu, such as frequent hand washing, covering coughs, and avoiding close contact with sick people. Additionally, just learning about the flu can help patients protect themselves from getting sick.

What Is Influenza?

Influenza, commonly called the flu, is a viral infection of the respiratory tract. The flu can spread from the nose or mouth to the rest of the respiratory system, including the lungs. It is usually spread by touching an infected person or contaminated surface or by inhaling infected droplets coughed or sneezed into the air. If a bacterial infection develops in addition to the viral infection and travels from the upper respiratory tract to the lungs, it can cause more serious disorders, such as acute bronchitis or pneumonia. Influenza kills about 36,000 people a year in the United States.

There are three main types of influenza virus: A, B, and C. If you have had the flu caused by a type C virus (a relatively mild type of flu with symptoms similar to those of a cold), you are immune to it for life. If you have been infected with a particular strain of a type A or B influenza virus, you have immunity to that strain only. Although both A and B influenza viruses can produce new strains that can overcome a person's immunity, the type B virus seldom alters itself sufficiently to do so.

But the type A virus constantly changes, and the changes are significant enough to make it look like a new virus to the immune system. For this reason, type A viruses cause most flu epidemics and severe outbreaks. These strains are usually named after their place of origin (such as the Hong Kong flu).

Influenza usually occurs in small outbreaks, often in the winter. Every few years, in unpredictable intervals, it occurs in epidemics. Two or three epidemics caused by different strains of the virus can occur at the same time. Epidemics die out when everyone who has been infected by a particular strain of a flu virus becomes immune to that strain.

Symptoms, Diagnosis & Treatment

Symptoms of the flu vary widely. You may have a fever with shaking chills, sneezing, headache, muscle aches, and sore throat. You may then develop a dry, hacking cough and chest pain. You will probably feel very weak. Some children have abdominal pain and seizures. If you have no complications, you should recover in one to two weeks, although you may still feel weak for a few weeks. If you seem to be the only person you know who has the flu, you may have some other viral illness such as mononucleosis.

See your doctor if your symptoms are severe, last longer than 10 days, or seem to have spread to your lungs (causing wheezing, shortness of breath, or a painful cough), or if you have a chronic disease (especially a lung disorder or an immune system disorder). You should also see your doctor if your fever lasts longer than three or four days.

Doctors can usually diagnose the flu by the symptoms, especially when they occur during flu season in fall or winter. If you have symptoms that persist, your doctor will examine you to see if they could be caused by another disease.

There is no cure for influenza, but you can take measures to relieve the symptoms. Rest, stay comfortably warm (but not hot), and drink plenty of water to help prevent dehydration. Adults can take an over-the-counter pain reliever such as acetaminophen or ibuprofen to ease aches and pains and help you sleep.

Important note:  do not give aspirin to children or adolescents if they have a fever because it is dangerous. Use of aspirin in children has been linked with Reye's syndrome, a rare but potentially fatal childhood disorder. Also check with your doctor before you or the children use a cough suppressant or any other medication advertised to relieve flu symptoms.

For infants and very young children who cannot blow their nose, use a bulb syringe (available at most pharmacies) to suck the mucus out of their nose. This will help them breathe more easily and keep mucus from dripping down their throat, which can cause coughing and stomachaches (from swallowed mucus).

A Special Note about Medicines

Antibiotics are not effective against the viruses that cause influenza. Your doctor will prescribe an antibiotic only if your influenza has been complicated by a bacterial infection. If you are older or in poor health, your doctor may prescribe amantadine, oseltamivir, or zanamivir if you have been exposed to the flu virus or if you have flu symptoms. These antiviral drugs can prevent or relieve symptoms caused by an influenza A virus.

This information has been excerpted from the comprehensive American Medical Association Family Medical Guide, 4th Edition (Wiley; 2004; Cloth/$45), available online by clicking on the title, at bookstores nationwide, or direct from the publisher.