The COVID-19 pandemic

[tomh009]

Based on computer modelling, Ottawa's chief medical officer of help estimates the real number of cases in Ottawa at around 4000.

That's not quite correct. She did not estimate it at 4000.

"What's more, Etches said computer modelling suggests as many as 4,000 people could be infected across the city."

That indicates a considerably lower confidence level. In the end, no one can say how many people are infected until we actually start doing some random testing. And that's unlikely to happen until things calm down.