Toronto sees increase in norovirus activity compared to pandemic years

What is norovirus and how can you avoid it? What is norovirus and how can you avoid it? Infectious disease expert Dr. Isaac Bogoch explains.

Toronto is seeing an increase in norovirus activity compared to pandemic years, but the city’s public health unit said the current trend has not reached pre-COVID-19 viral activity.

Norovirus, also known as Norwalk virus, is a common cause of vomiting and diarrhea that spreads easily from person-to-person.

At the moment, Toronto Public Health (TPH) says there is one active norovirus outbreak in the city. So far in 2023, there have been four other confirmed outbreaks in Toronto, all reported in January.

TPH defines an outbreak as a localized increase, such as at an institution, where the rate of infection or illness is above what is expected.

The city's latest data on viral outbreaks indicates that the four outbreaks at the start of the year all took place at retirement homes. The viral activity at Greenview Lodge, Centennial Park Place and Amica Bayview Gardens are no longer active, though city's latest data shows Bradgate Arms still is.

There is another active case at Runnymede Health Centre, a rehab facility, where TPH declared an outbreak on Feb. 11.

Typically, norovirus activity rises in November and lasts until approximately April, according to TPH.

How to avoid norovirus

The typical route of transmission for norovirus is through infected bodily fluids and contaminants like saliva, vomit or, most commonly, fecal matter.

TPH is recommending frequent hand washing, cleaning and disinfecting surfaces and high-touch areas, such as telephones, door handles and gym equipment.

For those who contract the virus, the public health organization suggests staying home for at least 48 hours until after recovery, and avoiding preparing food for others while experiencing vomiting or diarrhea.

The incubation period for norovirus is between 12 and 48 hours, but symptoms such as nausea and vomiting can appear as soon as 12 hours after exposure. Symptoms typically start to fade after 24 to 36 hours.