Video Related To: Doctors alert citizens about influenza virus

This is a work of the Centers for Disease Control and Prevention, part of the United States Department of Health and Human Services, taken or made during the course of an employee's official duties. Producer: Centers for Disease Control. Creative Commons license: Public Domain Influenza, commonly known as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals. The name influenza comes from the Italian: influenza, meaning "influence" (Latin: influentia). In humans, common symptoms of the disease are chills, fever, pharyngitis, muscle pains, severe headache, coughing, weakness and general discomfort. In more serious cases, influenza causes pneumonia, which can be fatal, particularly in young children and the elderly. Although it is often confused with the common cold, influenza is a much more severe disease and is caused by a different type of virus. Influenza can produce nausea and vomiting, especially in children, but these symptoms are more common in the unrelated disease gastroenteritis, which is sometimes called "stomach flu" or "24-hour flu". Typically, influenza is transmitted from infected mammals through the air by coughs or sneezes, creating aerosols containing the virus, and from infected birds through their droppings. Influenza can also be transmitted by saliva, nasal secretions, faeces and blood. Infections also occur through contact with these body fluids or with <b>...</b>