What are the symptoms and manifestations of influenza B infection?

Influenza B, also known as type B influenza, is an acute respiratory infectious disease caused by infection with the influenza B virus. It is characterized by sudden onset, rapid spread, and a tendency to cause widespread outbreaks. The disease typically presents with abrupt onset, chills, and fever, with body temperature rising rapidly to 39–40 °C or even higher. Symptoms often include headache, body aches, fatigue, and loss of appetite. Respiratory manifestations are generally mild and may include dry throat, sore throat, and cough; diarrhea may also occur. Individuals experiencing these symptoms should seek medical attention promptly. With adequate treatment, symptoms can be alleviated, viral replication can be controlled, and potential complications can be reduced.