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Frequently Asked Questions and Answers About NoroSTAT

Q: What is NoroSTAT?

A: NoroSTAT is a collaborative network of nine state health departments and CDC, created to improve timeliness and completeness of norovirus outbreak reporting. The NoroSTAT network establishes and maintains standardized reporting practices that allow CDC to quickly link epidemiologic and laboratory data submitted to CDC's National Outbreak Reporting System (NORS) and CaliciNet by participating state health departments.


Q: Why is NoroSTAT important?

A: NoroSTAT focuses on norovirus, the leading cause of acute gastroenteritis and foodborne illness in the United States. Norovirus illness can occur any time during the year, but outbreaks are most common in the winter. Also, there can be 50% more norovirus illness in years when there is a new strain of the virus going around.

NoroSTAT improves the timeliness, completeness, and consistency of norovirus outbreak reporting to CDC's National Outbreak Reporting System (NORS) and CaliciNet. This allows CDC and state health departments to quickly evaluate current outbreak activity, make comparisons to previous years, and assess strain-specific norovirus outbreak characteristics, including the impact of new strains on outbreak frequency and severity.

NoroSTAT also enhances communication among epidemiologists and laboratorians in state health departments and CDC, enabling timely exchange of information regarding norovirus outbreak surveillance.


Q: How are data reported through NoroSTAT?

A: State health departments that participate in NoroSTAT

  • report preliminary epidemiologic data to NORS within seven business days of receiving notification of suspected or confirmed norovirus outbreaks,
  • report laboratory data to CaliciNet within seven business days of receiving specimens,
  • provide a minimum set of data elements, such as the outbreak setting and transmission mode, in the initial reports they submit to NORS and CaliciNet, and
  • use consistent identification codes for each outbreak in their reports to help CDC and others link and integrate data from NORS and CaliciNet.

To learn more, view a graphic that shows Norovirus Outbreak Reporting in NoroSTAT.

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Q: What types of data are reported?

A: State health departments report the following preliminary information:

  • Epidemiologic data, including the outbreak onset date, primary transmission mode, total number of people sick, outbreak setting, and whether norovirus is the suspected or confirmed cause. They report these data to NORS within seven business days of receiving notification of suspected or confirmed norovirus outbreaks.
  • Genetic sequences of norovirus strains. They report this to CaliciNet within seven business days of receiving the specimens.

After their initial report, state health departments often submit additional epidemiologic data, such as patient demographics, symptoms, and clinical outcomes, to NORS as these data become available.

For more information, see NoroSTAT data.


Q: How can the data be used?

A: NoroSTAT provides information that can be used to quickly evaluate

  • current norovirus outbreak activity,
  • intensity of current outbreak activity compared to prior years, and
  • outbreak characteristics of new norovirus strains, including the impact of the new strains on outbreak frequency and severity.


Q: How is NoroSTAT supported?

A: CDC's Division of Viral Diseases supports NoroSTAT through the Epidemiology and Laboratory Capacity (ELC) Cooperative Agreement. This cooperative agreement aims to enhance the capacity of state, local, and territorial health departments to effectively detect, respond, prevent, and control known and emerging (or re-emerging) infectious diseases.


Q: Which state health departments currently participate in NoroSTAT?

A: State health departments in Massachusetts, Michigan, Minnesota, Ohio, Oregon, South Carolina, Tennessee, Virginia, and Wisconsin currently participate in NoroSTAT. These state health departments are among those that demonstrate consistent surveillance practices and high norovirus outbreak reporting rates through NORS and CaliciNet.


Q: Who can access NORS and CaliciNet data?

A: Only CDC and state and local health departments can directly access data submitted through NORS. Others, including the general public, can submit a NORS data request. Those interested in foodborne norovirus outbreak data submitted to NORS can also download information using the Foodborne Outbreak Online Database (FOOD) tool.

Similarly, only CDC and state and local health departments participating in the CaliciNet network can directly access CaliciNet data. Participating laboratories must also get permission from CDC to use the data in research studies.

All data submitted to NORS and CaliciNet are securely submitted. CDC does not distribute any information about specific people or facilities involved in norovirus outbreaks.

CDC and participating state health departments share NORS and CaliciNet data through scientific publications and presentations. For more information, see References and Resources.

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