What is the typical radius of respiratory droplet spread for influenza transmission?

What is the typical radius of respiratory droplet spread for influenza transmission?

• A. 1-2 feet
• B. 3-6 feet
• C. 6-10 feet
• D. 10-15 feet

Answer: (B)

Influenza is mainly spread by large respiratory droplets that are expelled when an infected person talks, coughs, or sneezes. These droplets are heavy and tend to fall to the ground within about 1 meter (roughly 3 feet) of the source, so the typical exposure zone is around 3 feet. The range that starts at about 3 feet best matches this common distance, which is why it’s the best choice. Distances shorter than that (1–2 feet) are a bit less than the usual droplet reach, while much longer distances (6–10 or 10–15 feet) exceed the typical droplet spread and would involve other transmission modes or special conditions.

Influenza is mainly spread by large respiratory droplets that are expelled when an infected person talks, coughs, or sneezes. These droplets are heavy and tend to fall to the ground within about 1 meter (roughly 3 feet) of the source, so the typical exposure zone is around 3 feet. The range that starts at about 3 feet best matches this common distance, which is why it’s the best choice. Distances shorter than that (1–2 feet) are a bit less than the usual droplet reach, while much longer distances (6–10 or 10–15 feet) exceed the typical droplet spread and would involve other transmission modes or special conditions.