Appearing suddenly in large groups, Norovirus can quickly spread and make individuals exposed to it fall rapidly ill.

The incidence seems to be increasing. Reports top the news detailing outbreaks of Noro (or Norwalk) virus in restaurant patrons, cruise ship passengers, nursing home patients and in school children.

What Is Norovirus?

• Norovirus is actually a group of viruses named as such. Other names include: Norwalk virus (or Norwalk-like virus, NLKs) or caliciviruses.
• Patients may be diagnosed with simple terms such as viral gastroenteritis, acute gastroenteritis, non-bacterial gastroenteritis or food poisoning (there are other types of food poisoning as well).

What Increases The Risk Of Contracting Norwalk-Like or Noro Virus?

Noroviruses are found within the infected stool and/or vomit of an infected person.

Risk increases with the following actions:

• Eating or drinking contaminated food or liquid.
• Touching surfaces and then placing hands in mouth.
• Direct contact with the actively sick.
• Outbreaks are more likely in areas of increased populations such as nursing homes, schools, day care centers, restaurants, cruise ships and hotels.

What Are The Symptoms?

The onset of symptoms usually occurs within 24-48 hours of exposure but may appear as early as 12 hours from exposure.

Symptoms may include:

• Nausea and vomiting (more increased in children)
• Diarrhea
• Stomach cramping
• Low grade fever (not always)
• Chills
• Headache
• Muscle aches
• Fatigue (fatigue alone may have other sources)

What Is The Treatment? What Is The Duration?

Norovirus will not react to antibiotics because it is a group of viruses (not bacteria).

Treatment includes:

• Increase of fluids (juice or water), sport drinks do not replace lost nutrients with this illness.
• Rest

Symptoms usually subside within 1 to 2 days.

What Are The Complications?

Usually none, although patients are at risk for (and may require treatment for) dehydration.

What Are The Prevention Methods?

Norwalk virus can be prevented by avoiding exposure to infected stool or vomit from ill patients.

Prevention Steps include:

• Careful handling and disposal of diapers from children with diarrhea.
• Proper hand washing technique before meals, food handling or exposure to infected surfaces.
• Proper cleaning of patient areas (with a bleached based cleanser).
• Proper laundering of patient clothing, bedding and towels (with hot water and soap).
• Toilets should be flushed immediately after each use.
• Proper washing of fruits and vegetables. Steaming of oysters.
• Food preparers should not return to the kitchen until 3 days have past once symptoms have resolved (extra care should be practiced for an additional 14 days post discontinuation of symptoms).
• Food touched by patients with symptoms should be thrown out.

How Do Cruise Ships Handle Outbreaks?

• Since 1970, the CDC’s (Center For Disease Control) Vessel Sanitation Program has maintained surveillance and reporting systems for cruise ships that have both a U.S. and foreign itinerary and carry 13 or more passengers.
• The VSP will assist when numbers of patients who report symptoms or who request anti diarrheal medicines has increased to 2% of the ships passengers and crew.
• When numbers increase to at least 3%, the CDC will investigate.

Medical Attention

• Medical attention should be sought when symptoms increase, cause worry or do not resolve within 1 to 2 days of onset.
• Those with weakened immune systems, children and/or elderly in particular, need to be monitored and vigilantly watched for signs of dehydration.

Norovirus is extremely contagious and can make the patient feel suddenly very ill, but is rarely dangerous.

Source: Center for Disease Control, Atlanta, GA.

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