About 45 students were absent from an east-end elementary school today amid a possible norovirus outbreak.

The students attend Selwyn Elementary, which is a school of about 246 students near St. Clair and Victoria Park avenues.

In a letter that is being sent home to parents today, Principal Georgia Koziol said that TDSB staff will be brought to the school tonight to “undertake a thorough cleaning of washrooms, door knobs, fountains and surfaces.” Koziol said that all students and staff are also being reminded about the importance of hand washing in preventing the spread of illnesses.

“Should your child experience nausea, vomiting or diarrhea please keep them home,” Koziol wrote. “Toronto Public Health recommends that those who have the virus stay home for 48 hours after the symptoms have stopped.”

According to TDSB spokesperson Ryan Bird, there have not been any reports of norovirus occurences at other schools within the board, however he said it is not unheard of to see similar outbreaks this time of year.

Bird said the outbreaks usually dissipate within a week.

"This is something that we see every single year at a handful of TDSB schools," he said. "While it is not comfortable by any means and we don’t want kids to experience this, we do see it at a handful of schools."

News of the potential norovirus outbreak at Selwyn Elementary comes amid several other outbreaks in York Region.

Thornhill Woods Public School, located near Rutherford Road and Dufferin Street, is still dealing with a possible norovirus outbreak, according to York Region Public Health.

York Region Public Health has also confirmed that two other schools in the region, one in the Town of East Gwillimbury and one in the City of Markham, have also had confirmed cases of norovirus.

As well, York Region Public Health says that there have been reports of illnesses with symptoms consistent with the virus at a school in Georgina, daycare centres in Vaughan and Whitchurch-Stouffville and a retirement home in Vaughan.

“Outbreaks of norovirus and other enteric viruses, those which cause vomiting and diarrhea, are common at this time of year. In fact, norovirus is the most common cause of gastroenteritis outbreaks worldwide,” York Region’s Medical Officer of Health Dr. Karim Kurji said in a press release issued on Wednesday afternoon. “Norovirus outbreaks are common in semi-closed environments such as schools, childcare centres and retirement homes. The numbers we are seeing across the region are no greater than in previous years.”

Symptoms of norovirus include nausea, diarrhea, vomiting, cramps, fatigue, muscle aches and fever. The symptoms usually last for one to two days. It is highly contagious and can be avoided by frequent hand washing.

York Region Public Health said that 104 students were reported absent due to illness at Thornhill Woods Public School on Nov. 18, however that number had dropped to 54 by today.

Meanwhile, a parent of a student at Queensville Public School, who did not want to be identified, told CTV News Toronto that there was a noticeable amount of students missing around Nov. 11. According to the parent, around 40 of the 70 students were sick with symptoms like nausea and diarrhea.

The school sent an email to parents, indicating that York Region Public Health officials were following up with the outbreak, the parent said. After this, there were reportedly no more emails or explanations from the school and the illness was not identified as norovirus.

The parent told CTV News Toronto that people need to be made aware if the virus is more widespread.

“A lot of these kids don't wash their hands and it spreads like wildfire. They go have play dates at other kids houses and it keeps going and going,” a father of a student at Thornhill Woods Public School told CTV News Toronto.

With files from Tracy Tong