How to get over the flu

Influenza, or flu, is an acute respiratory infection caused by a variety of influenza viruses. The most familiar aspect of flu is the way it can "knock you off your feet" as it sweeps through entire communities, usually during the winter. Flu differs in several ways from the common cold, a respiratory infection also caused by viruses.

Outbreaks of flu usually begin abruptly. As the disease spreads through communities, the number of cases peaks in about 3 weeks and subsides after another 3 or 4 weeks. Twenty to fifty percent of a population may be affected, with the highest incidence in 5 to 14 year olds. Schools are an excellent place for transmission of flu viruses, so that families with school-age children have a higher rate of infection than other families, with an average of one-third of the family members infected each year.

Besides the rapid onset of the outbreaks and the large numbers of people affected, flu is important because of the seriousness of the complications that can develop. Most people who contract the disease recover within a week (although they may tire easily for awhile). However, for elderly people, newborn babies, and people with certain chronic illnesses, flu and its complications can be life-threatening.

Viruses that cause flu spread primarily from person to person, especially by coughing and sneezing. Flu viruses can enter the body through the mucous membranes of the eyes, nose, or mouth. After a person has been infected with the virus, symptoms usually appear within 2 to 4 days. The infection is considered contagious for another 3 to 4 days after symptoms appear.

The greatest risk of infection is in highly populated areas, where people live in crowded conditions, and in schools. Isolating people with flu symptoms is not an effective means of disease control because flu can be spread by someone whose symptoms are not yet apparent.

Flu is usually signaled by headache, chills, and dry cough, which are followed rapidly by body aches and fever. Typically, the fever starts declining on the second or third day of the illness. It is then that the upper respiratory symptoms become noticeable-nasal congestion and sore throat. Flu almost never causes gastrointestinal symptoms; the illness that people often call "stomach flu" is not influenza.

Once a person has the flu, treatment usually consists of resting in bed, drinking plenty of fluids, and taking medication such as aspirin or acetaminophen to relieve fever and discomfort. Children with flu should not take aspirin. Antibiotics are not effective against flu viruses.

The drug rimantadine can be used to treat influenza type A virus infections in adults. It has no effect on influenza type B infections. When taken within 48 hours after the onset of illness, it reduces the duration of fever and other symptoms and allows flu sufferers to return to their daily routines more quickly.

Rimantadine is a derivative of the drug amantadine, which also can prevent and treat flu infection. Amantadine, however, is more likely to cause side effects such as lightheadedness and inability to sleep more often than is rimantadine.



Flu complications (which can either accompany or follow the illness) generally result from bacterial infections in the lower respiratory tract. The ensuing pneumonia usually is caused by pneumococcal bacteria, but infections with staphylococci, streptococci, and Haemophilus influenzae type b can occur.

Symptoms of complications usually appear after the flu patient starts feeling better. This brief period of improvement is followed by the sudden onset of high fever, shaking chills, chest pain with each breath, and coughing that produces thick, yellow-greenish-colored sputum. Although most people with pneumonia recover after treatment with antibiotics, some pneumonia-causing organisms are resistant to these drugs.

A neurologic disease known as Reye's syndrome sometimes develops in a small number of children and adolescents who are recovering from flu. Reye's syndrome usually is signaled by the onset of nausea and vomiting, but the progressive mental changes (such as confusion or delirium) cause the greatest concern. The syndrome is associated with the use of aspirin, which often is used in medications for relieving the pain or fever of flu. Although fewer than 3 children per 100,000 with flu develop Reye's syndrome, one should consult a physician before administering aspirin or aspirin-containing products to children. Use of acetaminophen is not associated with Reye�s syndrome.

The first flu virus was identified in the 1930's. Since then, scientists have classified flu viruses into types A, B, and C. Type A is the most prevalent and is associated with the most serious epidemics. Type B outbreaks also can reach epidemic levels, but the disease it produces generally is milder than that caused by type A. Type C viruses, on the other hand, never have been connected with a large epidemic.

Unlike antigens of other viruses, the surface antigens of flu viruses change periodically. These changes circumvent antibodies and complicate vaccine development.

The hemagglutinin molecules of flu viruses are highly unstable and often mutate during replication. These periodic changes result in new strains of viruses with altered surface antigens. Persons with antibodies stimulated either by previous infection or vaccination are not protected from infection with new strains of flu virus.

Slight changes in flu virus antigens are referred to as antigenic drifts. Every few years, at unpredictable intervals, a major change, or antigenic shift, occurs. Shifts have been observed only in influenza A viruses.

Pandemics are the result of antigenic shifts and are associated with severe illness and significant mortality on a global scale. Within this century, at least five pandemics and numerous epidemics (regional outbreaks involving fewer people) have occurred. For example, antigenic shifts were evident in the 1957 outbreak known as the Asian flu, which affected huge numbers of people, and in the 1968 outbreak of the virulent Hong Kong strain.

Each year, scientists formulate a new vaccine made from inactivated (killed) influenza viruses. The preparation is based on the strains in circulation at the time, yet includes those A and B viruses expected to circulate the following winter. Sometimes, an unpredicted new strain may appear after the vaccine has been manufactured and distributed, resulting in infection even among those who received flu vaccine. Usually, however, the disease is milder because the vaccine will provide some protection.



Since the immune system takes time to respond to vaccination, the inactivated vaccine should be given 6 to 8 weeks before flu season begins in order to stimulate enough antibodies to prevent infection or reduce the severity of the illness. The vaccine itself cannot cause flu, but someone could become exposed and infected soon after vaccination, before antibodies develop.

The vaccine, however, may cause side effects, especially in children who previously have not been exposed to the flu virus. The most common side effect in children and adults is soreness at the site of the vaccination. Others include fever, tiredness and sore muscles that may begin 6 to 12 hours after vaccination and may last for up to 2 days.

Viruses for vaccine production are grown in chicken eggs and then inactivated with a chemical so that they are no longer infectious. People who are allergic to eggs should not receive flu vaccine since some egg protein may be present in the vaccine.

Certain herbs have anti-viral benefits:

  • Echinacea
  • Goldenseal
  • Garlic
  • Elderberry