Since the late 1970s, influenza A (H1N1) and influenza A (H3N2) have been the common influenza A viral subtypes circulating among humans (2). Influenza B viruses are separated into two distinct genetic lineages (Yamagata and Victoria) on the basis of …

Among humans, annual epidemic influenza illness is caused by two types of influenza viruses, influenza A and influenza B (1). Influenza virus types A and B are further subclassified through serologic and genetic testing.

Influenza, one of the most common infectious diseases, is a highly contagious airborne disease that occurs in seasonal epidemics and manifests as an acute febrile illness with variable degrees of...

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 spreads easily between people when they cough or sneeze. Vaccination is the best way to prevent the disease.

While the flu has most likely been around for ages, no definitive historical records exist. In his sixth book of “Epidemics,” the Greek physician Hippocrates describes a highly contagious disease with flu-like symptoms. Modern doctors believe this …

Jan 13, 2025 · Influenza, acute viral infection of the upper or lower respiratory tract, marked by fever, chills, and a generalized feeling of malaise. Influenza is caused by viruses in the family Orthomyxoviridae. Learn more about the classification of influenza viruses, influenza outbreaks, and influenza symptoms and treatment.

Jan 23, 2023 · Influenza is a communicable viral disease that affects the upper respiratory tract, including upper and lower respiratory passages. A wide spectrum of influenza viruses causes it. Some of these viruses can infect humans, and some are specific to different species.

Feb 28, 2018 · Influenza has likely been around for millennia, though its cause was only identified relatively recently. One of the earliest reports of an influenza-like illness comes from Hippocrates, who...

Influenza is an acute respiratory viral infection caused by influenza viruses. Worldwide, annual seasonal influenza epidemics are estimated to result in approximately 1 billion annual clinical cases, 3 to 5 million cases of severe illness and approximately 290 000 to 650 000 deaths [6, 7].

Background. Human Influenza type A and B cause majority of infections. Type A has more severe disease course. Transmission. Occurs in 6ft radius around infected patient who is sneezing and/or coughing; Viral shedding lasts ~5d (starts 24-48hr before onset of symptoms) Longer duration of shedding occurs in children, elderly, patients with ...