Dawn 0'Niell, age 15, of Miami, Fla., for her question:
WHAT CAUSES INFLUENZA?
Influenza is n contagious disease of the respiratory system that is caused by a virus. The virus is ultramicroscopic, which means that that it is so small that it cannot even be seen by an ordinary microscope. Only an electronic microscope can take photos of this infectious agent.
Influenza is often called the flu. And sometimes doctors will call the disease grippe.
Complications from influenza, or the things that can happen as a result of the virus, could make the disease especially bad. Sometimes influenza can be followed by pneumonia, bronchitis or even a weakened heart or kidneys.
A sudden fever, general weakness, cold sweating and a hard cough are the symptoms usually found as the disease hits. Muscles in all parts of the body can also ache. These symptoms usually last between three and five days.
There isn't a lot of difference between influenza and a bad cold. Rest is usually the best medicine for both diseases at this stage.
After the fever leaves, a patient with influenza may still feel weak and tired. In fact, this feeling can continue far a week or longer. It is during this period of time that a setback may occur, and complications may cause more problems for the patient. The patient needs more rest at this time.
Sulfa drugs and penicillin do not help influenza. But many times a doctor will prescribe one of these drugs, which are effective for such diseases as pneumonia, since complications can often follow.
Three kinds of viruses that can cause influenza are named virus A, virus B and virus C. Vaccines that contain inactive virus have been developed against virus A and virus B and have been partly successful.
Influenza vaccine is injected under the skin or into the muscles. Then about a week later, antibodies against the virus increase in the blood. These antibodies help the body to fight infection. But after four or five weeks these antibodies will gradually disappear.
Influenza can hit in epidemic proportions. As a matter of fact, since the 16th Century there have been at least 31 worldwide influenza pandemics, which are very widespread epidemics.
The worst influenza pandemic of modern times hit in 1918. In the United States alone, more than 500,000 people died, most of them from complications of bacterial pneumonia. More than 12 million died in India in this disaster while worldwide the estimated total came to 20 million.
Another major epidemic hit in 1957, although it wasn't as serious as the 1918 disaster. It started in China and was called the Asian flu. Within two months it had spread completely around the world. Soon after it started, great amounts of vaccine were made available to large numbers %f people. This fast work helped to bring the epidemic to a stop.
Having influenza once is no protection against having it again.