Download Department of Infection Prevention and Control Norovirus A

Department of Infection Prevention and Control
Norovirus
A. Description of Illness
Norovirus outbreaks are characterized by high rates of vomiting, diarrhea, nausea, and stomach
cramps. Vomiting is sometimes more commonly reported than diarrhea; this may be particularly
true for children. In addition to the usual gamut of other GI symptoms (nausea, abdominal
cramps, etc.), cases typically report headache and body aches to a degree not seen with other
common agents.
B. Norovirus Infections
Although sometimes intense, this is generally a brief and self-limited illness that rarely lasts
more than a day or two. Some people may feel “wrung out” for a few days after acute
symptoms have resolved. Few people seek medical attention, generally for dehydration.
C. Reservoirs
Humans are the only known source of the Norovirus that cause human disease.
D. Sources and Routes of Transmission
This is a very contagious virus. Norovirus are shed in stool and vomit. Most transmission is
fecal-oral or “vomit-oral.” People can become infected by:
 Eating food or drinking liquids that are contaminated
 Touching surfaces or objects that are contaminated with the Norovirus, then placing hands
in the mouth
 Having direct contact with another person who is infected and showing symptoms
E. Incubation Period
Given enough individuals in a group, the median incubation period is almost always 32-36
hours. Individual incubations typically range between 12–48 hours.
F. Period of Communicability
Communicability has been inferred from outbreak investigations to last at least 2–3 days after
symptoms have cleared up in some individuals. It is likely that persons are most infectious
during the period of acute disease. Virus may be detectable in stool for as long as 2 weeks. At
OHSU, affected individuals need to be symptom-free for 48 hours before returning to work. It is
essential to practice meticulous hand-hygiene upon return to work. Remember, Norovirus is
easily transmitted to patients and fellow staff members and has been the source of multiple
outbreaks in healthcare facilities. Departments who are concerned about possible clusters of
illness involving staff should contact the Employee Health Department at 503-494-5271.
G. Diagnosis and Treatment
In the setting of a known community or facility outbreak, screen all patients on admission for
symptoms of Norovirus infection. If a patient has symptoms of Norovirus, isolate appropriately
in Modified Contact Precautions. There is no specific therapy to treat Norovirus infections.
Rehydration may be indicated when vomiting and/or diarrhea is severe. To test patients for
Norovirus, collect a stool specimen and order a Norovirus PCR. The State Lab runs the tests
several times a week. Diagnosis can best be made from a sample taken within 48 -72 hours
after onset of symptoms.
H. Isolation:
Patients with suspected or proven Norovirus infections should be placed in Modified Contact
Precautions until 48 hours after symptoms resolve. Attention should be paid to wearing gloves
and a gown on entry to the patient room. Additionally, if a patient is vomiting or if dumping vomit
or stool into a toilet or hopper, a mask should be worn due to potential aerosolization of droplets
containing Norovirus. A mask should also be worn while handling soiled linen. It’s important to
pay meticulous attention to disinfection of the room and of any shared patient care equipment.
Additionally, appropriate utilization of hand washing and standard precautions is essential.
I. Environmental Disinfection
Use the Clorox Germicidal Wipes to clean rooms and equipment of patients with known
Norovirus infection as well as patients who are admitted from the community or nursing homes
when Norovirus is suspected, especially in the setting of a known community or facility
outbreak.
Remember to:
 Wear gloves, gown, and surgical mask when handling linen, cleaning up vomit and fecal
spillages, or when cleaning a room of a symptomatic patient.
 Flush any vomit and/or stool in the toilet and disinfect the surrounding area.
 When cleaning the room, give special attention to frequently touched objects such as
doorknobs, faucets, toilet rails and bath rails.
 Clean carpets and soft furnishings with hot water and detergent or steam clean, dry.
Vacuuming is not recommended since the virus may become airborne.
Contact the Department of Infection Prevention and Control at 503-494-6694 if you are concerned
about possible patient clusters of Norovirus infections.