Influenza Transmission: How the Flu Spreads & Prevention

Influenza spreads primarily via respiratory droplets from coughs, sneezes, or talking. Droplets can be inhaled or land on surfaces where the virus survives for hours. Touching contaminated surfaces then touching eyes/nose/mouth also transmits the virus.

Key Transmission Facts

• Up to 20% of US population gets flu annually.
• Spreads easily within 6 feet (close contact).
• Indirect contact via contaminated surfaces is common.
• Most contagious first 3–4 days; can spread up to 7 days after symptom onset.
• High-risk settings: schools, childcare, nursing homes, hospitals, crowded places.

Prevention

• Get annual flu vaccine.
• Stay home when sick.
• Cover coughs/sneezes with tissue.
• Wash hands frequently.
• Avoid touching face.
• Clean/disinfect high-touch surfaces.

These steps reduce transmission risk significantly.