What are the subtypes of avian influenza that cause concern?

Mar 8, 2024 ... Influenza encephalitis · Symptoms. In a broad sense, clinical characteristics encompass a combination of flu symptoms and central nervous system ... Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. It can cause mild to severe illness ... Feb 12, 2025 ... Generally, influenza viruses can infect some wild species without causing signs of disease, but new strains can emerge that cause illness with ... What Causes Influenza? The root cause of the illness is infection from one of the influenza A, B or C viruses. These viruses infect the nose, throat, and ... Mar 21, 2025 ... The most severe influenza outbreak of the 20th century and, in terms of total numbers of deaths, among the most devastating pandemics in human history. The deadliest pandemic of the 20th century. The 1918 influenza outbreak was caused by a new strain of the influenza A virus that started in birds (H1N1). After ... What some people call the stomach flu is actually another virus or bacteria that causes gastrointestinal illness. Influenza is a respiratory illness that should ... Bird flu, or avian flu, is an infectious type of influenza that spreads among birds. ... But there are 4 strains that have caused concern in recent years: H5N1 ... The flu is caused by a virus. Viruses are generally passed from person to person through the air when an infected person sneezes or coughs. But the virus can ... 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 ...