COVID-19 likely in Ottawa before 1st case declared
Dozens may have been infected by March 11, public health officials now believe
Ottawa's first confirmed case of COVID-19 was announced way back on March 11, but public health officials now believe the illness was spreading in the community before that.
That first local case involved a man who had been to Austria and who developed symptoms after returning to Ottawa. He went for a COVID-19 test at the General campus of The Ottawa Hospital, days before Ottawa Public Health (OPH) began opening dedicated testing sites in the city.
When OPH learns of an Ottawa resident's positive test, they trace back to determine when and where they became "symptomatic, infectious and/or likely transmitting the virus," because that's the information that matters most.
"Given the commonly mild or asymptomatic nature of COVID infection, we often don't get a signal until the transmission has already been occurring in the community for some time, maybe even until a hospitalization occurs," Patrick Saunders-Hastings, an epidemiologist and risk scientist who teaches at Carleton University, told CBC last month.
That's why, months after reporting that first case on March 11, OPH revealed it had discovered a number of cases of people who had neither left the province nor had close contact with another confirmed case, but who started experiencing symptoms and eventually tested positive for COVID-19 in early- to mid-March.
Dozens infected
Now, OPH believes dozens of Ottawa-area residents had contracted the illness by March 11, which happens to be the same day COVID-19 was declared a pandemic.
In fact, the evidence now suggests Ottawa had its first case of COVID-19 a full month earlier, on Feb. 10. OPH also linked that case to travel, but hasn't determined whether the individual was in Ottawa while they were contagious.
OPH now believes there were three more travel-related cases within two weeks, and that by March 11, the illness had likely spread to 61 residents.
'Alternative explanations'
According to the province's public health data, Hastings Prince Edward Public Health, which covers Bancroft, Belleville, Picton and Trenton, Ont., logged a positive COVID-19 case as early as Feb. 1.
But a spokesperson for the health unit cautioned that, as in Ottawa, where some of the earliest cases may have involved people who were infected while travelling, it doesn't necessarily mean COVID-19 was spreading through the area at that time.
The spokesperson also noted that the similarities between COVID-19 and influenza symptoms may have confused matters.
"There are other alternative explanations, such as back-to-back [influenza and COVID-19] infections, which is more likely in this case," the spokesperson said.
The Eastern Ontario Health Unit also traced possible COVID-19 cases before March, one in Prescott-Russell in mid-January and another in late February.
With files from Priscilla Hwang