University of Alberta medical scientists are teaming up with public health officials, Edmonton's drainage utility company and other collaborators to develop an early warning system for COVID-19 outbreaks in long-term care homes.
On Jan. 4, EPCOR began taking twice-weekly wastewater samples from manholes located at 10 Edmonton long-term care facilities, which are then tested by U of A scientists at Alberta's Public Health Laboratory to detect and quantify the presence of SARS-CoV-2. The study is funded by the Public Health Agency of Canada through the COVID-19 Immunity Task Force.
"Infected people can shed virus in their stool several days before clinical diagnosis," said principal investigator Xiaoli Lilly Pang, professor of laboratory medicine and pathology in the Faculty of Medicine & Dentistry, who has been leading efforts to test sewage from 12 wastewater treatment plants across Alberta, a research project funded by the Canadian Institutes of Health Research.
"We realized this method could be very useful for earlier detection in site-specific locations such as long-term care facilities," said Pang, who is also microbiology program leader for Alberta's Public Health Laboratory. "Our goal is to prevent outbreaks among staff, residents and visitors."
"Depending on what we learn during this pandemic, we might be able to use this method to detect localized outbreaks of norovirus in long-term care facilities, or even another pandemic. We could use this system to standardize our future response."
"Getting an early warning at continuing care sites with increased risk will allow us to go in to provide a SWAT team response to identify cases, isolate them and stop the spread of disease sooner among this most-vulnerable population," said co-principal investigator Christopher Sikora, adjunct professor in the School of Public Health and lead medical officer of health for Alberta Health Services – Edmonton Zone.
Outbreaks in seniors' homes have led to 80 per cent of all deaths in Canada during the pandemic.
"This project meshes the basic science with public health, operational work and infrastructure work," Sikora said. "The hallmark of good surveillance is collecting data that leads to action."
U of A principal investigators Christopher Sikora and Xiaoli Lilly Pang explain how testing wastewater could provide early warning of potential COVID-19 outbreaks in long-term care facilities. (Video: Alberta Health Services)
Developing a standard system to prevent future outbreaks
Followup blood samples will be taken to study the immune response of staff and residents who develop COVID-19, those who are exposed but don't get sick, and those who are vaccinated. The results will be added to a national COVID-19 immunological study database, said co-principal investigator Bonita Lee, associate professor of pediatrics and assistant director of infection prevention and control at the University of Alberta Hospital, Mazankowski Alberta Heart Institute and Stollery Children's Hospital.
"We don't know much yet about the immunology for this disease and how it may be different for those who have already had the infection versus those without COVID-19 when they get the vaccine," Lee said. "This study will help fill that knowledge gap."
The final step in the study will be to do a cost/benefit analysis of doing sewage sample surveillance for SARS-CoV-2 and implementing rapid public health response measures at long-term care sites.
"Depending on what we learn during this pandemic, we might be able to use this method to detect localized outbreaks of norovirus (which causes gastroenteritis) in long-term care facilities, or even another pandemic," Pang said. "We could use this system to standardize our future response."
