Flu should be classified as a disease can be prevented. Many cases of flu that did not have to suffer just because of negligent or may not know how to prevent it.
Do not joke about the flu. Especially for the elderly, the flu is generally more severe than if they happen to younger people. In addition because their immune systems are entering the age of aging has been diminishing, the type of flu virus that enters the body is not necessarily the same.
We know of three families of influenza virus types (types A, B, and C). Each type has so many members of his own family.
Temperament family members of each type of flu virus is also not the same degree of ferocity. Some are benign, others malignant extraordinary. Flu is common to attack the European population, for example, unlike in Indonesia, generally classified as a malignant type of flu virus, and often very deadly. Flu outbreak early twentieth century in Spain, swallowing hundreds of thousands of deaths.