Possible COVID-19 exposure during field exercise at Ontario's Garrison Petawawa

Grey skies loom over the main gate at Canadian Forces Base Petawawa, Ont. Monday, Sept. 4, 2006. (Jonathan Hayward / THE CANADIAN PRESS)

OTTAWA — The Renfrew County and District Health Unit is investigating a possible COVID-19 exposure during a military field exercise at Garrison Petawawa.

About 500 people participated in the military exercise at the base in Petawawa, Ont., but health officials say as many as 1,500 military members and their family members could be impacted.

Medical officer of health Dr. Robert Cushman tells CTV News Ottawa nine positive cases have been linked to the military exercise.

Now, the health unit is warning that all Canadian Armed Forces members who attended the exercise and their family members may have been exposed to the virus.

"Several individuals have tested positive for COVID-19 who attended a field exercise during their contagious period," said the health unit in a statement early Wednesday evening.

"All Canadian Armed Forces (CAF) members who attended the field exercise have been instructed to immediately self-isolate, and they have been advised of their work and isolation responsibilities."

The health unit is also urging household contacts of any armed forces member who attended the field exercise to limit their movements in the community and only leave the house for essential reasons such as attending school, work or to seek medical care.

"CAF members and their household contacts should self-monitor for all symptoms of COVID-19, even runny nose, or sore throat, until November 26, 2021, at 11:59 p.m., unless you have received specific guidance from public health," said the health unit. "If you become symptomatic, you should immediately self-isolate and seek testing, even if you are fully vaccinated."

The most common symptoms of COVID-19 include fever and/or chills, cough or barking cough, decrease or loss of taste or smell, extreme tiredness and muscle aches/joint pain.