Flu (Influenza)

From person to person Influenza is highly contagious. When sneezing, coughing, or speaking, tiny virus-containing droplets from the nasal and pharyngeal secretions of infected individuals enter the air and can be inhaled by other people nearby. The viruses can also be passed on via the hands if these have come into contact with virus-containing secretions. If the mouth, nose, or eyes are subsequently touched, the influenza viruses can enter the body through the mucous membranes.

Via contaminated objects The pathogens can also adhere to door handles, handrails, banisters, or similar objects and be passed on from there via the hands.

Approximately one third of all infections typically begin with a sudden onset of feeling unwell, fever, sore throat, and dry cough, accompanied by muscle, limb, back, or headache. In older individuals in particular, the signs of illness are often less pronounced and more closely resemble a common cold. In an uncomplicated course, symptoms subside after 5 to 7 days. The cough may, however, persist considerably longer. The severity of the illness can vary. An influenza infection may present with mild symptoms or even none at all. However, influenza can also result in severe disease courses which, in the worst cases, may be fatal. The most feared complication is pneumonia. In children, middle ear infections may also develop. Rarely, inflammation of the brain or the heart muscle may occur.

After infection, first symptoms appear relatively quickly, within 1 to 2 days. Those infected can already be contagious on the day before the onset of symptoms and remain so for up to approximately 1 week after the first signs of illness appear. Children or individuals with a weakened immune system may shed the pathogens for longer.