Norovirus Outbreak: Symptoms and Treatment
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Americans are feeling under-the-weather due to a norovirus strain from
the land-down-under, according to the U.S. Centers for Disease Control
and Prevention.
A new strain of norovirus called GII.4 Sydney was the leading cause
of norovirus outbreaks in the United States from September to December
2012, according to a study published in Morbidity and Mortality Weekly Report
released today by the CDC. The
new strain was detected in Australia in March 2012, and caused
outbreaks in that country and several other countries.
CDC researchers analyzed 2012 data collected on norovirus strains associated with outbreaks in the United States. They found that of the 266 norovirus outbreaks reported during the last four months of 2012, 141 were caused by the GII.4 Sydney strain.
“The new strain spread rapidly across
the United States from September to December 2012,” said Dr. Aron Hall,
epidemiologist, CDC’s Division of Viral Diseases (DVD). “The
proportion of reported outbreaks caused by this strain increased
dramatically from 19 percent in September to 58 percent in December.”
Norovirus is very contagious. In the
United States, norovirus is the number one cause of acute
gastroenteritis, which leads to diarrhea and vomiting. Each year, more
than 21 million people in the United States get infected and develop
acute gastroenteritis; approximately 800 die. Young children and
elderly adults have the highest risk for severe illness.
Norovirus spreads primarily from
infected people to others through direct contact. It also spreads
through contaminated food, water, and surfaces. Norovirus infections
are common during this time of the year. Most outbreaks occur from
November to April, and activity usually peaks in January. Norovirus is also notorious for spreading quickly on cruise ships.
“New norovirus strains often lead to
more outbreaks but not always,” said Dr. Jan Vinjé, director of
CaliciNet. Over the past decade, new strains of GII.4 have emerged
about every 2 to 3 years. “We found that the new GII.4 Sydney strain
replaced the previously predominant GII.4 strain.”
Better surveillance in the United States
and abroad have helped to detect new strains of norovirus sooner, the CDC says.
Early identification of new strains helps to alert the public and
health professionals to better prevent infections and control
outbreaks.
The CDC advises health professionals to remain vigilant to potential increases in norovirus infection this season due to GII.4 Sydney. They should follow standard prevention and control measures for norovirus. People should know that the best ways to help prevent norovirus infection include washing hands with soap and water, disinfecting surfaces, rinsing fruits and vegetables, cooking shellfish thoroughly, and not preparing food or caring for others while ill.
“Right now, it’s too soon to tell
whether the new strain of norovirus will lead to more outbreaks than in
previous years. However, CDC continues to work with state partners to
watch this closely and see if the strain is associated with more severe
illness,” said Dr. Hall.
NOROVIRUS OUTBREAKS
According to the CDC, most outbreaks of norovirus illness happen when infected people
spread the virus to others. But, norovirus can also spread by consuming
contaminated food or water and touching things that have the virus on
them.
Healthcare facilities, including nursing homes and hospitals, are the most commonly reported places for norovirus outbreaks in the United States and other industrialized countries. Nearly two-thirds of all norovirus outbreaks reported in the United States occur in long-term care facilities.
In addition to Healthcare facilities which make up 59% of cases, restaurants are the second top location for outbreaks at 8%, followed by parties and events at 6%. Cruise ships (4%), schools (4%), and hospitals (4%) account for the remaining known locations. 15% of norovirus outbreak locations are in other or unknown locations.
Outbreaks of norovirus illness have also occurred in restaurants, cruise ships, schools, banquet halls, summer camps, and even at family dinners. These are all places where people often eat food handled or prepared by others.
In fact, norovirus is the leading cause of illness from contaminated food in the United States. About 50% of all outbreaks of food-related illness are caused by norovirus.
Foods that are commonly involved in outbreaks of norovirus illness are—
Healthcare facilities, including nursing homes and hospitals, are the most commonly reported places for norovirus outbreaks in the United States and other industrialized countries. Nearly two-thirds of all norovirus outbreaks reported in the United States occur in long-term care facilities.
In addition to Healthcare facilities which make up 59% of cases, restaurants are the second top location for outbreaks at 8%, followed by parties and events at 6%. Cruise ships (4%), schools (4%), and hospitals (4%) account for the remaining known locations. 15% of norovirus outbreak locations are in other or unknown locations.
Outbreaks of norovirus illness have also occurred in restaurants, cruise ships, schools, banquet halls, summer camps, and even at family dinners. These are all places where people often eat food handled or prepared by others.
In fact, norovirus is the leading cause of illness from contaminated food in the United States. About 50% of all outbreaks of food-related illness are caused by norovirus.
Foods that are commonly involved in outbreaks of norovirus illness are—
- leafy greens (such as lettuce),
- fresh fruits, and
- shellfish (such as oysters).
NOROVIRUS PREVENTION
The CDC says that the best ways to help
prevent norovirus infection include washing hands with soap and water,
disinfecting surfaces, rinsing fruits and vegetables, cooking shellfish
thoroughly, and not preparing food or caring for others while ill.
NOROVIRUS SYMPTOMS
Norovirus causes inflammation of the stomach or intestines or both. This is called acute gastroenteritis. You may hear norovirus illness called "food poisoning" or "stomach flu." Food poisoning can be caused by noroviruses. But, other germs and chemicals can also cause food poisoning. Norovirus illness is not related to the flu (influenza), which is a respiratory illness caused by influenza virus.
The most common symptoms—
- diarrhea
- throwing up
- nausea
- stomach pain
- fever
- headache
- body aches
Most people with norovirus illness get better within 1 to 3 days.
Symptoms of dehydration—
- decrease in urination
- dry mouth and throat
- feeling dizzy when standing up
NOROVIRUS TREATMENT
The CDC says tht there is no specific medicine to treat people with norovirus illness. Norovirus infection cannot be treated with antibiotics because it is a viral (not a bacterial) infection.
If you have norovirus illness, the CDC recommends that you should drink plenty of liquids to replace fluid lost from throwing up and diarrhea. This will help prevent dehydration.
Sports drinks and other drinks without caffeine or alcohol can help with mild dehydration. But, these drinks may not replace important nutrients and minerals. Oral rehydration fluids that you can get over the counter are most helpful for mild dehydration.
