Hamilton still rejects wastewater tool
Public health says it’s meeting with researchers to solve dispute over the reliability of the data
Public health held firm to its claims that detecting COVID-19 in wastewater has failed in Hamilton, despite pushback from the researchers who say the data is “remarkable.”
“It’s not something that has worked as a predictive measure in Hamilton to date,” Michelle Baird said at a city briefing Monday.
She shed no light on why there is such a divide between public health and the University of Ottawa research team that has been analyzing data from the Woodward Avenue and Dundas treatment plants since July 2020.
“It’s remarkably strong, the relationship between the signal in wastewater and hospitalizations in that city,” said Robert Delatolla, a civil engineering professor who leads the Ottawa team. “The wastewater is a remarkable early indicator of hospitalizations in Hamilton and it has been that since the middle of 2020.”
The two sides also don’t appear to line up on what, if anything, is being done to remedy the dispute.
“We are continuing to work with the researcher to understand the data and its utility locally,” said Baird, who is director of the epidemiology, wellness and communicable disease control division.
“Staff are working to obtain further data beyond what we already have.”
But Delatolla said last week that he hoped Hamilton public health would come to bi-weekly meetings and engage with the team further.
“I don’t think they’ve been looking at it,” said Delatolla on March 3. “I don’t think they’re using the resources that are available to them to understand the data.”
Hamilton public health didn’t respond to a Spectator request Monday for the surveillance data to be made public.
“We certainly have been looking at this data and trying to understand its local application,” said Baird.
“We are working with the researchers and we have some planned meetings coming up in the very near future to better understand where that divide is and understand how we could perhaps use this data going forward.”
It’s significant because the province has been increasingly relying on wastewater since PCR testing hasn’t been available to the general public since Dec. 31.
Health Minister Christine Elliott said Monday that wastewater is the “canary in the coal mine that can tell us if there is something that we need to be concerned about that’s coming in the future.”
The province’s chief medical officer of health has called it a “key indicator.”
The Ontario COVID-19 Science Advisory Table has added wastewater to its dashboard and a number of public health departments report on it.
“I’m not aware of any evidence to suggest that the wastewater data in Hamilton would behave differently than what we see in the surrounding public health units,” the table’s scientific director, Dr. Peter Jüni, said on March 1. “It’s a leading indicator and it did help us tremendously ... to navigate through the reopening steps of the pandemic beyond a doubt.”
Baird said the issue is that the data is “variable.” But the leader of the surveillance team at the University of Waterloo said all wastewater surveillance data is “highly variable.”
“Wastewater is a good tool,” said Mark Servos, the Canada Research Chair in Water Quality Protection. “I don’t understand why Hamilton isn’t as enthusiastic. I don’t understand the reluctance ... There is lots of evidence to demonstrate it works.”
I don’t understand why Hamilton isn’t as enthusiastic.
MARK SERVOS CANADA RESEARCH CHAIR IN WATER QUALITY PROTECTION