Sep 26, 2025 · 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 …

Influenza B virus (IBV) and influenza C virus (ICV) primarily infect humans, and influenza D virus (IDV) is found in cattle and pigs. Influenza A virus and influenza B virus circulate in humans …

Influenza refers to illness caused by the influenza viruses, but the term is commonly and incorrectly used to refer to similar illnesses caused by other viral respiratory pathogens. …

Dec 19, 2025 · Flu, also called influenza, is an infection of the nose, throat and lungs, which are part of the respiratory system. The flu is caused by a virus. Influenza viruses are different from …

Feb 28, 2025 · Seasonal influenza (the flu) is an acute respiratory infection caused by influenza viruses. It is common in all parts of the world. Most people recover without treatment. Influenza …

Aug 9, 2025 · While more than 100 different viruses can cause a cold, only influenza virus types A, B, and C cause the flu. Types A and B viruses cause large seasonal outbreaks.

Seasonal influenza, or flu, is a highly contagious respiratory illness caused by influenza viruses that infect the nose, throat and lungs. The two main types of influenza viruses—types A and …