Norovirus, a 'contagious' stomach bug, is on the rise in Canada: Signs and symptoms

Norovirus cases have been "increasing both at the national level and within several provinces" in Canada.

woman laying on sofa looking sick with flu/Norovirus with blanket
Norovirus signs and symptoms: Experts warn of 'contagious bug' on the rise in Canada (Getty)

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

Norovirus, a highly contagious stomach bug known for its unpleasant, days-long symptoms, is on the rise in Canada.

Following a pandemic lull, federal health officials confirmed to CBC News that reported cases of norovirus have been "increasing both at the national level and within several provinces."

Provinces including British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, New Brunswick and Newfoundland and Labrador have seen an uptick in cases; however, that's not too uncommon for this time of the year.

According to the Public Health Agency of Canada (PHAC), norovirus cases have been on the rise since January. However, the case count is "generally comparable" with those reported in the same seasonal period prior to the pandemic (2015-2019). During the height of the pandemic, norovirus cases were kept relatively at bay due to COVID-19 restrictions, infection prevention measures and social distancing.

The stomach bug infects approximately 685 million people each year worldwide. South of the border, the U.S. Centers for Disease Control and Prevention (CDC) recently reported a rise in cases hovering at pre-pandemic levels. In the U.K., cases of norovirus are 66 per cent higher than the average for this time of year.

Norovirus: young woman having a stomachache
Norovirus, which also causes headaches, fever and stomach pain, often gets mistaken for the stomach flu. (Image via Getty Images)

"Anyone can contract norovirus," Meg Lovell, a registered nurse at Grand River Hospital in London, Ont, told Yahoo Canada last year. "The most common ways of getting the virus are by having direct contact with a sick person, touching contaminated surfaces and then putting your hands to your mouth, or consuming contaminated water or food."

This bug, which often gets mistaken for the stomach flu, also causes headaches, fever and stomach pain. While most people recover in a few days, vomiting and diarrhea can cause more serious issues including dehydration and fatigue.

“Older adults, younger children, immunocompromised individuals or those with chronic conditions like diabetes are more likely to become dehydrated from norovirus,” adds Kathy Horst, a public health specialist from the Huron Perth Health Unit in Ontario.

What is norovirus?

According to Health Canada, noroviruses (previously known as norwalk-like viruses) are groups of viruses that cause gastroenteritis, an inflammation of the digestive system leading to vomiting and/or diarrhea.

Norovirus is often mistakenly referred to as the “stomach flu" and one of the leading causes of foodborne illnesses globally. The infection can quickly spread in settings where people are in close contact, such as hospitals, schools, nursing homes, trains or childcare facilities.

“Noroviruses are very common and very contagious,” explains Lovell. “Although it’s more common to get sick during the winter, this illness can happen to anyone at any time.”

Woman sitting on toilet with toilet paper - One of the main symptoms of norovirus is diarrhea.
One of the main symptoms of norovirus is diarrhea, which can lead to dehydration. (Image via Getty Images)

What are the symptoms of norovirus?

The most common symptoms of norovirus include nausea, diarrhea and stomach pain. Less common symptoms include headaches, fever, chills and muscle aches.

The National Collaborating Centre for Infectious Diseases says norovirus symptoms typically begin one or two days after exposure, but may appear as early as 12 hours after ingesting the bug. The virus usually comes on suddenly, and the infected person may vomit very frequently and without warning.

In some cases, those with norovirus may present little or no symptoms at all, but they can still pass the virus on to others.

How long does a norovirus infection last?

Horst tells Yahoo Canada that patients with norovirus can "usually recover within one to three days." However, the recovery period can longer if a person becomes hydrated.

“It’s important to watch out for symptoms of dehydration like dry mouth, feeling dizzy, or urinating less often," cautions Horst. "Try to drink more liquid than normal to replace the fluid lost from diarrhea and vomiting.”

How does norovirus spread?

Norovirus is extremely contagious and is found in the vomit or stool of contaminated people. It can easily be transferred to others by those infected touching food, water or surfaces without washing their hands after using the bathroom, or by having direct contact with someone who has the virus such as by caring for them or sharing food with them.

“You can also get norovirus by eating shellfish from contaminated waters, biting your nails after touching an infected surface, or by drinking from the same cup as a sick person,” adds Lovell. “Think about how many times a day you absentmindedly drink from someone else’s water bottle or put your fingers near your mouth! These are habits we need to avoid.”

Sad sick young couple with norovirus wrapped in plaid sitting on sofa in living-room drinking hot tea trying to warm up. Freezing man and woman suffering from cold or flu fever or having trouble with central heating
It's important to keep hydrated while recovering from norovirus, and stay home until you feel well again. (Image via Getty Images)

What should I do if I have norovirus symptoms?

If you begin experiencing norovirus symptoms, drink plenty of fluids so you don’t become dehydrated and wash your hands often. Refrain from preparing food or drinks for others and make sure you get lots of rest.

“Sports drinks or other fluids without alcohol or lots of caffeine will be best to replace the electrolytes you’re losing from vomiting and diarrhea,” says Lovell. “You can also get oral rehydration mixes or meal replacers at pharmacies which are also helpful.”

Horst says it’s important to stay home so you don’t infect others, and contact your healthcare provider if symptoms last for more than a week.

How can I prevent norovirus?

There’s a myriad of ways to prevent norovirus. The simplest and most important way is to frequently wash your hands with warm, soapy water for 20 seconds after using the bathroom and before preparing or eating food.

“Because it spreads so easily, I cannot stress the importance of properly washing your hands. You can also use hand sanitizer in addition to washing your hands, but not as a replacement,” says Horst.

Another way to prevent this contagious bug is to thoroughly wash vegetables and fruit before eating them. If you’re sick, do not handle or prepare food for others.

“I also recommend you disinfect and clean common household surfaces as often as you can and wash laundry thoroughly and often if a member of your household is sick,” adds Lovell.

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