Dawn Fisher, age 14, of Miami, Fla., for her question:

WHAT IS LEGIONNAIRES' DISEASE?

Legionnaires' disease is a severe form of pneumonia that is characterized by high fever, headache, chest pain and lung congestion. The name is derived from an outbreak at an American Legion convention that was held in a Philadelphia hotel in July of 1976.

The United States Centers for Disease Control investigated the disease, which could not immediately be identified. It was finally successful in identifying the causative agent as a previously unknown rod shaped bacterium which was named Legionella pneumophila.

Other local outbreaks were then linked to the disease.

The bacterium has been found in newly turned soil or air cooling systems in association with a blue green algae. It was discovered that Legionnaires' disease is not readily transmitted from person to person.

Drugs are now used by doctors to treat victims of Legionnaires' disease. The antibiotic called erythromycin is especially effective.