The Influenza, explained by Health Encyclopedia

Influenza

Definition

Influenza, often called the flu, is an acute, highly contagious infection of the respiratory tract which commonly occurs in the winter.

Description

Influenza usually appears in epidemic form and affects many people at once. Although it affects all age groups, the highest incidence occurs in school children. The greatest severity is in young children, elderly people, immunosuppressed people, and those with chronic diseases. The most common complication of influenza is pneumonia, which can be primary influenza viral pneumonia or secondary to bacterial infection. Influenza also may cause myositis, exacerbation of chronic obstructive pulmonary disease, Reye's syndrome, myocarditis, pericarditis, transverse myelitis and encephalitis.

Causes

Influenza results from different strains of the influenza virus. This virus has the ability to mutate into different forms. That is why although you were exposed to similar strains in the past, you might not be able to defend yourself against a new one. The infection is transmitted by inhaling a respiratory droplet from an infected person or by indirect contact, such as drinking from a contaminated glass.

Symptoms

The most characteristic symptoms of influenza are weakness, fatigue, muscle aches, headaches, fever (101 to 102 degrees), sneezing, and maybe a runny nose. Although a person with influenza feels very sick, it rarely leads to more serious complications, except for those at greater risk.

Treatment

Typically, there is little that is done to treat the flu in otherwise healthy people. Home Treatment

• Bed rest
• Drink extra fluids â€" at least one full glass of water or juice every hour.
• Acetaminophen (Tylenol), or Ibuprofen can relieve head and muscle aches. Aspirin should be avoided for children.

When To Call A Health Professional

• After three days of fever over 102 F.
• If cough brings up heavy mucus.
• If there is increasing difficulty in breathing.
• When a patient seemingly gets better, then gets worse again.
• If flu-like symptoms occur 10 days to three weeks after a possible tick bite because of the possiblity of Lyme's disease.

Finally, sometimes an anti-flu medication is necessary. Amantadine and rimantadine are effective anti-influenza drugs that can decrease the length of influenza-A infection by one-third if given within 48 hours of symptoms onset. They can also be used to prevent influenza-A infections. The most common side effects of these drugs are insomnia, nausea and dizziness. Two newer medications, Relenza and Tamiflu work on influenza subtypes A and B. Relenza is an inhaled powder, while Tamiflu is an oral medication. Both drugs must be started within 48 hours of symptoms to be effective in shortening the flu. Relenza should not be used in patients with lung problems.

Prevention

Immunization against influenza provides fair protection, or may lessen symptoms if the disease is contracted. Every year, scientists develop a vaccine against the most recently circulating strain of the virus. The immunization is given by injection each fall in anticipation of the coming flu season. You must be immunized within one week to four months prior to exposure for the shots to be effective. The vaccine is composed of inactivated organisms from several virus strains which scientists attempt to include the most recent mutation. Vaccines are typically 67 to 92 percent effective. The vaccination is injected into the muscle. Some people have reactions to the influenza vaccine. These reactions range from inflammation at the injection site to mild flu symptoms. On very rare occasions, nervous system disorders result. These vaccines are commonly prepared using eggs. Therefore, individuals with a known allergy to eggs should inform their physician before having the influenza vaccine. Recently, a new mist vaccine, FluMist, was approved for patients between the age of 5 and 65. The vaccine is sprayed into the nose and works in a manner similar to the injectible. One major difference is that this vaccine includes live virus, so it cannot be given to persons with weak immune systems or pregnant women. If your resistance is down, you should avoid markets, shopping centers, theaters, or crowded places during an epidemic. Keep your distance from people who are sneezing or coughing. Prolonged exposure to wet and cold weather lowers your resistance and increases your risk of infection. Avoid becoming overly tired or rundown. Smoking and alcohol can impair your resistance too.

Questions

Are there risks in getting the vaccination? Are there any symptoms that a doctor should be notified about? What are the chances of developing a secondary infection? Should I take amantadine or rimanadine?