👉 The term "HBflu" refers to a viral respiratory illness characterized by fever, cough, sore throat, runny nose, and difficulty breathing in young children. This condition can spread from person to person through contact with infected droplets. The full definition of "HBflu eis" is: "A severe form of respiratory illness caused by the influenza A virus." It's important to get treated promptly as early symptoms often indicate more serious complications such as pneumonia.