What is the incubation period for Norovirus?

• A. 12-24 hours
• B. 2-3 days
• C. 24 - 48 hours
• D. 4-5 days

Answer: (C)

Incubation period is the time from exposure to the onset of symptoms. Norovirus tends to produce symptoms relatively quickly, because it rapidly replicates in the GI tract and is highly contagious in close-contact settings. Most people start feeling ill about one day to two days after exposure, with 24-48 hours being the most typical window used in study materials and exams. That’s why the 24-48 hour range is the best choice. While symptoms can sometimes begin as early as about 12 hours, or as late as around 48 hours, the majority fall within 24-48 hours, making the other options less representative of the usual onset timing.