* Influenza affects 25 million to 50...

* Influenza affects 25 million to 50 million Americans each year.

* About 20,000 Americans die from flu or its complications each year.

* Flu costs the U.S. work force about $12 billion in lost productivity and $5 billion in medical expenses annually.

* A survey of 1,008 adults found that 25% believe nothing treats the flu (there are two antiviral medications that can be given at the first sign of symptoms), and 45% mistakenly believe that antibiotics are effective in treating flu.

* Flu vaccination is about 70% effective in healthy adults younger than 65.

* Only about 12% of healthy adults younger than 65 get a flu shot each year.

* Ninety percent of Americans catch a cold each year.

* Adults and teenagers average two to four colds a year; children get six to eight.

* A survey found that 62% of parents mistakenly believed that high fever (105 degrees) could cause brain damage; half believe even moderate fever (102) is dangerous.

* Doctors inappropriately prescribed 12 million antibiotics 12 million times in 1992.

* From 80% to 90% of inner-ear infections are treated with antibiotics in the U.S., compared with 30% of cases in Europe.

* During flu epidemics, as many as 40% of the people living in a given community can develop the illness within a few weeks.

* The rhinovirus family causes nearly half of all colds; more than 100 varieties of rhinovirus have been identified.

* Pneumonia is the most frequent infectious cause of death in the U.S., ranking sixth among all causes of death.

* Pneumonia may be caused by more than 30 different pathogens; the two most common are bacteria and viruses.

* Chronic bronchitis ranks sixth in prevalence among all chronic conditions.

* Cigarette smoking is a factor in about 90% of bronchitis cases.

Sources: Forest Labs; Florida Department of Citrus; Assn. for the Care of Children’s Health; Journal of the American Medical Assn.; American Lung Assn.; GlaxoWellcome.