Untangling the COVID-19 Numbers

Governments across Canada have been commendably transparent in sharing data about the COVID-19 pandemic. It is easy to find it all confusing.

What we hear about is the number of cases that have been detected, tests performed, patients recovered, and patients who have died.

Nova Scotia’s total number of cases per capita is higher than all the other provinces except Newfoundland and Labrador and Quebec. That is only part of the story.

Nova Scotians who have tested positive seem to be less sick than those reported in other provinces. We had our first death this week. On the same day, Ontario reached 177 and Quebec reached 150.

As of April 8th, there were 11 Nova Scotian COVID-19 patients in hospital, a small fraction of the available capacity. Meanwhile, hospitals in Ontario had 589 and Quebec had 533, occupying most of the space that has been freed up by cancelling or postponing elective procedures.

It may have helped that Nova Scotia’s case count accelerated weeks after other provinces. We have learned from their experiences.

Ontario, Quebec, and British Columbia have had major outbreaks within and between long term care facilities. Employees at four care facilities in Nova Scotia have tested positive but the measures taken seem to have succeeded in limiting the spread.

Nova Scotia has continuously ramped up testing capability that is able to keep up with the needs. It enables an agile response when there are clusters in communities, as was revealed this week in Preston and Enfield.

Ontario’s facilities for testing are being stretched, meaning that they must use a more restrictive definition of who should be tested.

As a result, they are identifying people later in the progress of the disease, meaning they are sicker, and more likely to have caused further spreading before they were tested.

Ontario and Quebec are nevertheless much better off than Italy, Spain, France and other West European countries, as well as many states south of the border. New York alone has more cases than any country other than the US. As of April 9th, the US had more than 30 times the number of deaths in Canada.

There is no reason for complacency in Nova Scotia.

The daily pattern of reported new cases is erratic. One late March sequence in Nova Scotia was 13,10,17,5,17. The high variability does not tell us much. It may have to do with what kinds of patients were being tested each day. Recent travellers with a cough are more likely to test positive than a group who had been briefly near a recently detected case.

It is more instructive to look at successive five-day averages. Starting with the five days beginning March 15, these were 3,7,14,17, 25. This looks like an alarming acceleration.

Chief Medical Officer Dr. Strang expects some further growth in part because the testing protocol is casting a wider net.

It is also happening because there are identified cases of community transmission. Left unchecked, these can easily spiral into the kind of challenges being faced in central Canada and other countries.

Strang estimates that the daily new case count could peak in the next two to three weeks, hopefully to be followed by a gradual reduction.

That can only happen if the isolation and social distancing protocols are followed, and the community spreading is contained and then reduced.

What a shame it would be to lose the hard-won progress to date by our health care workers and the great majority of citizens, and find ourselves still confined to our homes come Christmas. Think about it.


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