Screening students for symptoms may not be enough to detect COVID-19 cases, epidemiologist says
KITCHENER -- Some school boards are asking parents to screen their children for possible COVID-19 symptoms before they head to the classroom each day.
However, parents and one medical expert are concerned the screening won't be enough to detect cases, especially if they're asymptomatic.
Jillian Angers, who is a nurse, is worried her son may be exposed to COVID-19 be an asymptomatic classmate.
"It's essentially an invisible case," she said.
Angers' son is in secondary school, but she said she's nervous for families with children in elementary school, where classes will be larger. She said the recommended daily screening for symptoms is important, but won't detect symptoms that can't be seen or felt.
"It's about the only measure we can make, because better steps haven't been taken for actual testing," she said.
Colin Furness, an infection control epidemiologist from the University of Toronto, said he is also concerned. He said most children with COVID-19 don't have a fever or a cough.
"They seem fine," he said. "Our instructions to parents to screen your kids for temperature, for symptoms, I'm not saying that's bad. But, I am saying, for most cases, that would be ineffective."
"Everyone really needs to understand that people can feel fine and be infected and be contagious and that's what makes COVID particularly difficult to manage and to track."
Furness is calling for widespread testing, but Region of Waterloo Public Health officials disagree.
"It's not recommended for people that are broadly asymptomatic," the region's Medical Officer of Health Dr. Hsiu-Li Wang said Tuesday. "But it is recommended in specific situations when people have been identified as close contacts."
Children without symptoms will only get tested if they've been in close contact with someone who has tested positive for COVID-19, either from a classmate or someone in their social circle.
"Everyone really needs to understand that people can feel fine and be infected and be contagious," Furness said. "That's what makes COVID particularly difficult to manage and to track."
He added that the term "asymptomatic" means symptoms aren't visible to the naked eye.
"When you do a chest x-ray, you could see lungs full of virus, so there's a symptom," he said. "If you measure blood oxygen saturation in kids who have a lot of COVID in them, their blood oxygen is low."
Furness suggested parents should get a thermometer and a pulse oximeter to determine if their child needs testing. The devices measures oxygen saturation in someone's red blood cells. They shine a light through a person's skin, which is analyzed to determine how much oxygen is being carried in the blood.
However, experts with American Lung Association and the American Thoracic Society said the device won't necessarily help with detecting the virus, since low oxygen levels are usually a late indicator of a COVID-19 infection.
The Waterloo Region District School Board and the Waterloo Catholic District School Board both have screening information on their websites. The provincial government also offers an online self-assessment tool.