Seasonal Flu: Symptoms, Complications, and Prevention

What is the flu?

The flu is an acute respiratory infection caused by influenza viruses. Unlike the common cold, it comes on suddenly with a high fever (often above 39°C), intense muscle pain, and profound fatigue. According to health authorities, seasonal epidemics cause between 3 and 5 million severe cases each year worldwide.

Characteristic symptoms

Symptoms generally appear 1 to 4 days after exposure to the virus: sudden high fever, chills, headache, joint and muscle pain, dry cough, sore throat, runny nose, and extreme fatigue. In children, vomiting and diarrhea may also occur.

Possible complications

Pneumonia is the most common and feared complication. People over 65, pregnant women, infants, and people with chronic illnesses are most at risk. A bacterial superinfection, myocarditis, or decompensation of an existing illness can occur.

Prevention and vaccination

Annual vaccination remains the most effective way to protect oneself. Guidelines recommend vaccination from 6 months of age. Barrier gestures — hand washing, mask wearing, ventilating rooms — complement protection. In case of symptoms, an antiviral treatment (oseltamivir) can be prescribed within the first 48 hours.