What is the incubation period of Norovirus (Norwalk-like virus)?

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Last updated: March 11, 2025View editorial policy

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From the Guidelines

Norovirus typically has an incubation period of 12–48 hours after exposure before symptoms appear. This timeframe is crucial for understanding the spread of the virus and implementing effective infection control measures. According to the updated norovirus outbreak management and disease prevention guidelines 1, the illness usually begins after an incubation period of 12–48 hours and is characterized by acute onset, nonbloody diarrhea, vomiting, nausea, and abdominal cramps.

Key Points

  • The incubation period can range from 10 to 72 hours in some cases, but 12-48 hours is the most commonly cited range 1.
  • Infected individuals may not show symptoms during the incubation period but can still be contagious.
  • Once symptoms begin, they usually include sudden onset of vomiting, watery diarrhea, abdominal cramps, nausea, and sometimes low-grade fever and body aches.
  • The short incubation period contributes to norovirus's ability to spread rapidly through close-contact settings like cruise ships, schools, and healthcare facilities.

Infection Control Measures

Understanding the incubation period is essential for implementing effective infection control measures, such as:

  • Excluding ill staff and residents from certain areas or activities until 48–72 hours after symptom resolution 1.
  • Promoting good hand hygiene, including frequent washing with soap and running water for a minimum of 20 seconds 1.
  • Disinfecting potentially contaminated environmental surfaces using a chlorine bleach solution or other EPA-approved disinfectant 1.

Transmission and Prevention

The virus is highly contagious and can be transmitted through:

  • Contaminated food or water
  • Contact with infected surfaces
  • Direct contact with an infected person Prevention measures, such as proper hand hygiene and surface disinfection, are critical in reducing the spread of norovirus 1.

From the Research

Incubation Period of Norovirus

  • The incubation period of Norovirus is typically between 12 to 48 hours after exposure 2, 3, 4.
  • This period can vary, but most people will experience symptoms within this timeframe 2.
  • The illness is usually characterized by diarrhea, vomiting, fever, headache, and stomach pain, and recovery typically occurs within 1 to 3 days 2.
  • In some cases, the incubation period can be as short as 24 hours or as long as 72 hours 3.
  • It's worth noting that the incubation period is the time between exposure to the virus and the onset of symptoms, and it's an important factor in understanding the spread of the disease 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Norwalk virus and Noro virus].

Rinsho Biseibutsu Jinsoku Shindan Kenkyukai shi = JARMAM : Journal of the Association for Rapid Method and Automation in Microbiology, 2003

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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