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Ebola: Information for U.S. Healthcare Workers and Settings

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Disease Name: Norovirus


Quick Links

Please review the Idaho Reportable Disease Rules (IDAPA 16.02.10) for the most up-to-date information.

Idaho Food Code (personnel section): http://www.healthandwelfare.idaho.gov/Portals/0/Health/FoodProtection/Chapter%202%20Management%20and%20Personnel.pdf

Response to Norovirus in Group Settings
http://www.diseaseinfosouthidaho.com/documents/NOROVIRUS-IN-GROUP-SETTINGS_2016.pdf

 


Overview / Case Definition

Noroviruses (genus Norovirus, family Caliciviridae) are a group of single-stranded RNA, non-enveloped viruses that cause acute gastroenteritis in humans. Currently noroviruses are separated into six genogroups (GI – GVI). GI, GII, and GIV infect humans, GII viruses are the most common type associated with human outbreaks. While noroviruses are acquired year round, three quarters of reported cases and outbreaks are reported in October to March in the Northern Hemisphere.

Norovirus infection usually presents as acute-onset vomiting, watery non-bloody diarrhea with abdominal cramps, and nausea. A low-grade fever occasionally occurs. Symptoms typically resolve after 1–3 days in otherwise healthy persons. More prolonged courses of illness lasting 4–6 days can occur, particularly among young children, elderly persons, and hospitalized patients.

Norovirus is the leading cause of illness and outbreaks from contaminated food in the United States. Most of these outbreaks occur in the food service settings like restaurants. Infected food workers are frequently the source of the outbreaks, often by touching ready-to-eat foods, such as raw fruits and vegetables, with their bare hands before serving them. However, any food served raw or handled after being cooked can get contaminated with norovirus. Norovirus outbreaks can also occur from foods, such as oysters, fruits, and vegetables, that are contaminated at their source.


Restrictions

Daycare Facility

A person excreting norovirus must not attend or provide personal care in a daycare while symptomatic, unless an exemption is obtained from the Department or Health District. This restriction will be withdrawn once the asymptomatic for at least 24 hours.

Food Service Facility

Employees with resolved symptoms shall only work on a restricted basis 24 hours after symptoms resolve and remains restricted until medically cleared or more than 48 hours have passed since the food employee became asymptomatic.  Employees who were diagnosed, but never became symptomatic, remain excluded or restricted until medically cleared or more than 48 hours have passed since the food employee was diagnosed.

Health Care Facility

A person exerting norovirus must not provide personal care in health care facility, unless an exemption is obtained from the Department or Health District. This restriction will be withdrawn once a asymptomatic for at least 24 hours


Reporting

Within 1 working day

Reportable by Healthcare and Labs:

Reportable by Food Service Facility:

Suspect Reportable:

Reporting Timeframe: Within 1 working day



Diagnosis / Testing

RT-qPCR assays are the preferred laboratory method for detecting norovirus. These assays are very sensitive and can detect as few as 10 to 100 norovirus copies per reaction. They use different primers to differentiate genogroup I and genogroup II norovirus. RT-qPCR assays are also quantitative and can provide estimates of viral load. The assays may be used to detect norovirus in stool, vomitus, foods, water, and environmental specimens.

Whole stool is the preferred clinical specimen for laboratory diagnosis of norovirus. Ideally, specimens should be collected during the acute phase of illness (within 48 to 72 hours after symptoms start) while stools are still liquid or semisolid. Virus is excreted in the greatest amount during this time.


Treatment


Additional Information

Idaho Food Code (personnel section): http://www.healthandwelfare.idaho.gov/Portals/0/Health/FoodProtection/Chapter%202%20Management%20and%20Personnel.pdf

Response to Norovirus in Group Settings
http://www.diseaseinfosouthidaho.com/documents/NOROVIRUS-IN-GROUP-SETTINGS_2016.pdf

 


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