Public health identifies likely COVID-19 Omicron case at CWDHS

FERGUS – Public health officials say a positive COVID-19 case at Centre Wellington District High School (CWDHS) is likely the Omicron variant of concern.

A Dec. 12 letter to parents/guardians from Wellington-Dufferin-Guelph Public Health (WDGPH) states officials are working to manage cases and contacts related to a positive case “suggestive of having” the Omicron variant.

“[WDGPH] has notified the school and any contacts within the school that have been identified as a close contact will receive an additional high-risk contact letter with guidance and directions,” states the letter, which does not specify whether the case is a student or staff member.

“[Public health] is taking all necessary steps to prevent the further spread of COVID-19 both in the school and in the community.”

WDGPH spokesperson Danny Williamson explained that positive cases of COVID-19 can not be confirmed as the Omicron variant without whole genome sequencing, which can take two weeks.

In the meantime, the S gene target failure (SGTF) in one widely used PCR test can be used to identify likely cases of Omicron within a day or two.

The SGTF, while not a perfect predictor, is a pretty good indication of the variant involved, Williamson explained, noting public health officials don’t want to wait two weeks to act on a possible Omicron case.

“Because it’s spreading so fact, we want to act accordingly right away,” he said.

The WDGPH letter to CWDHS parents/guardians notes that since much remains “uncertain” about the Omicron variant – including “risk of severe infection, re-infection, increased ability to transmit to others and effectiveness of [vaccines against it]” – more enhanced case and contact management strategies are being applied to people who test positive for it and to those who have recently travelled.

Notably, high-risk contacts of a person who likely has the variant must isolate for 10 days regardless of their vaccination status or previous positive tests (previously, only the unvaccinated would have to isolate).

Public health officials say the isolation period begins from the day students are dismissed from school.

Officials with the school and bus company/consortium will identify all students, staff and visitors who are considered a high-risk contact and they will receive a letter outlining next steps, including instructions for other household members.

Those not contacted by public health are not considered a high-risk contact but they should continue to:

  • monitor and screen for COVID-19 symptoms daily;
  • practice hand hygiene;
  • wear a face covering; and
  • practice physical distancing.

Anyone who develops symptoms should immediately isolate and follow guidance from public health.

For more information, including a screening tool, visit