EVERYDAY SCIENCE

Detailed explanation-1: -Influenza is a communicable disease caused by a virus that infects the nose, throat and lungs. Influenza is commonly called the flu.

Detailed explanation-2: -Causes. Flu is caused by a virus that is spread from person to person. It causes seasonal epidemics each year.

Detailed explanation-3: -Influenza is caused by infection of the respiratory tract with influenza viruses, RNA viruses of the Orthomyxovirus genus. Influenza viruses are classified into 4 types: A, B, C, and D. Only virus types A and B commonly cause illness in humans.

Detailed explanation-4: -There are four types of influenza viruses: A, B, C, and D. Influenza A and B viruses cause seasonal epidemics of disease in people (known as flu season) almost every winter in the United States. Influenza A viruses are the only influenza viruses known to cause flu pandemics (i.e., global epidemics of flu disease).

Detailed explanation-5: -The myxovirus group includes strains of influenza virus which infect most species of mammals and birds. Influenza is commonly known as “the flu".