Winter Vomiting Bug

Important Facts About The Winter Vomiting Bug

Norovirus, otherwise known as the winter vomiting bug is an RNA virus that has its genetic material made up of ribonucleic acid.  This virus causes over 90 percent of the world's epidemic outbreaks of gastroenteritis, otherwise known as the common flu or stomach flu.  It affects every age group and is transmitted primarily by person to person contact, faecally contaminated water or food, aerosolization and coming into contact with contaminated surfaces.

After you have become infected by the winter vomiting bug, immunity is generally temporary and incomplete lasting only about 12 weeks.  Therefore, it is possible to become infected several times in one year.  Interestingly, individuals that have blood type O are infected more than anyone else.  Outbreaks are known to occur in closed communities such as hospitals, nursing homes, overnight camps, college dormitories, cruise ships and prisons where the virus is able to travel very quickly through contaminated food or physical transmission.  Through its history, many outbreaks have been due to food that was prepared for a large group of people by one infected individual.

The winter vomiting bug, or norovirus was named after Norwalk, Ohio where an enormous outbreak occurred in 1968 throughout Bronson Elementary School.  The name was shortened to simply norovirus after it was identified as being the cause of many outbreaks of gastroenteritis on several American cruise ships.


When a person first becomes infected, the virus starts to multiply immediately in their small intestine and then one to two days later, symptoms begin to appear.  Acute gastroenteritis is the first symptom to develop and typically lasts for one to three days.  This disease is considered to be self-limiting and is characterized by vomiting, nausea, abdominal pain, diarrhea and loss of taste.  Muscle aches, lethargy, headaches, fever and weakness may also be present.

Although some people are treated in the emergency room, the illness is rarely severe enough for them to actually be admitted.  Of the hundreds of thousands of people that it infects annually, the winter vomiting bug causes only approximately 300 deaths every year in the United States, primarily in the elderly, young children or those with weakened immune systems.  If dehydration is not treated, it is usually the cause of death that is associated with this virus.

Prevention And Control

Since the winter vomiting bug is transmitted through contact and contaminated food, water and surfaces, the virus is considered extremely contagious.  It is suggested that as little as 10 particles can cause an infection.  Viruses continue to shed even after symptoms have substantially diminished and shedding of particles can still be identified for quite a few weeks after the infection is no longer even apparent.

On average, it is believed that one infected person infects a minimum of 2.1 other people.  When waterborne outbreaks are to blame, it usually includes water from wells, ice machines, swimming pools and recreational lakes.


Salad and shellfish are the two foods that are most implicated with outbreaks.  Shellfish that has not been heated sufficiently prior to consumption poses a high risk and salad bars or buffets are breeding grounds for the virus.

Hand washing thoroughly and regularly is effective in reducing the spread of pathogens.  It is also important to sanitize surfaces where the virus may be present.  It is important to note that alcohol-based sanitizers do little to kill the particles.  In health care environments, nonflammable alcohol vapor is often used where medical electronics cannot be sanitized with caustic compound.

There is currently not an antiviral medication against the winter vomiting bug and there is not a preventative vaccination.  Antibiotics cannot treat this virus because they fight bacteria only, not viruses.  The infected person needs to make sure that they stay hydrated while the illness runs its course.