Norovirus

Norovirus

General Information

Noroviruses (genus Norovirus, family Caliciviridae) are a group of related small non-enveloped viruses that cause acute gastroenteritis. Gastroenteritis is an inflammation of the lining of the stomach and intestines, causing an acute onset of severe vomiting and diarrhea. The illness is usually brief in people who are otherwise healthy. Young children, the elderly, and people with other medical illnesses are most at risk for more severe or prolonged infection.

Symptoms

The symptoms of illness usually include nausea, vomiting, diarrhea, and some stomach cramping. People may suddenly feel very sick and vomit frequently or have several episodes of diarrhea, but most people get better within 1 to 2 days and they have no long-term health effects related to their illness. Diarrhea is more common in children and vomiting is more common in adults.

Transmission

Noroviruses are highly contagious, with as few as 18 virus particles thought to be sufficient to cause infection. This pathogen is estimated to be the causative agent in over 21 million gastroenteritis cases every year in the United States, representing approximately 60% of all acute gastroenteritis cases from known pathogens. Noroviruses are transmitted primarily through the fecal oral route, either by direct person-to-person spread or through fecally contaminated food or water. Noroviruses can also spread via a droplet route from vomitus. These viruses are relatively stable in the environment (it survives 2-3 weeks outside the body). In healthcare facilities, transmission can also occur through hand via contact with materials, fomites, and environmental surfaces that have been contaminated. Healthcare facilities and other institutional settings (e.g., daycare centers, schools, etc.) are particularly at-risk for outbreaks because of increased person-to-person contact. It is the leading cause of outbreaks in healthcare.

Prevention

In a healthcare facility, patients with suspected norovirus may be placed in private rooms or share rooms with other patients with the same infection (cohorting). Additional prevention measures in healthcare facilities can decrease the chance of coming in contact with noroviruses:

  • Follow hand-hygiene guidelines, and carefully wash hands with soap and water
  • Use gowns and gloves when in contact with patients who are symptomatic with norovirus
  • Routinely clean and disinfect high-touch patient surfaces and equipment with an Environmental Protection Agency-approved product with a label claim for norovirus
  • Remove and wash contaminated clothing or linens
  • Healthcare workers who have symptoms consistent with norovirus should be excluded from work

* Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011. http://www.cdc.gov/hicpac/norovirus/002_norovirus-toc.html (accessed 11/1/2012)

                             EPA                                                                                                   CDC

Oxivir Tb is registered with the Environmental Protection Agency (EPA) as effective against norovirus.

  • The approved claim time is 1 minute.
  • The EPA allows manufacturers to test closely related, surrogate, organisms to meet the approval requirements.
  • Feline calicivirus (FCV) is closely related to human norovirus and is accepted, by the EPA as a surrogate organism for disinfectant efficacy testing.
  • One of the main reasons for using surrogate pathogens for efficacy testing is the difficulty in growing certain organisms (especially viruses using traditional methods for growth such as tissue culture).

The CDC- HICPAC recommendation* for cleaning and disinfection of environmental surfaces states: (Category IC)

  • 3.C.12.e.1. - Clean surfaces and patient equipment prior to the application of a disinfectant.  Follow the manufacturer’s recommendations for optimal disinfection dilution, application, and surface contact time with an EPA-approved product with claims against norovirus.
  • 3.C.12.e.2.  - More research is required to clarify the effectiveness of cleaning and disinfecting agents against norovirus, either through the use of surrogate viruses or the development of human norovirus culture system.

 

 

 

 

 

 

 

 

 

 

 

Table 1. HICPAC Categorization Scheme for Recommendations

Category IA

Category IC

 

A strong recommendation supported by high to moderate quality evidence suggesting net clinical benefits or harms.

 

Category IB

 

A strong recommendation supported by low-quality evidence suggesting net clinical benefits or harms, or an accepted practice (e.g., aseptic technique) supported by low to very low-quality evidence.

Category IC

A strong recommendation required by state or federal regulation.

Category II

 

A weak recommendation supported by any quality evidence suggesting a tradeoff between clinical benefits and harms.

Recommendation for further research

An unresolved issue for which there is low to very low-quality evidence with uncertain trade-offs between benefits and harms.

 

Cleaning and Disinfection

Norovirus is a non-enveloped virus, susceptible to the following Diversey disinfectants:

Diversey Products for Norovirus prevention

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