Windsor-Essex health unit struggling to identify source of most new COVID-19 cases

As case numbers increase, the Windsor-Essex CountyHealth Unit is falling behind in its efforts to keep up with COVID-19 case and contact management.

Since Dec. 4, more than 80 per cent of new cases each day are listedas "under investigation" meaning the health unit isstill trying to figure out how and from whom that case was contracted.

That steadilyincreasing percentage of cases not traced right away means blind spots in tracking the course of the virus in the community, says one epidemiologist.

The trend has been evident sinceWindsor-Essex entered the province's "red-control"COVID-19 categoryon Nov. 30.

Prior to this, the health unit was relatively successful in keeping pace with pinpointing where cases were coming from.

But now, gapsin quickly knowing thetransmission source for a large percentage of casespokes holes in public health efforts, University of Toronto PhD epidemiology studentJean- Paul Soucytold CBC News.

"When contact tracing breaks down we're going to start missing more cases and that makes the data about cases more unreliable because one of the purposes of contact tracing is to find those cases that you wouldn't have caught otherwise and that includes, for example, people who have minimal symptoms or never develop symptoms at all and yet are still capable of spreading the virus," he said.

And if cases are missed, Soucy said, the spread of the disease could be underestimated.

Here's the number of new daily cases and percentage of those under investigation in the last seven days:

• Nov. 30: 41 new cases, 25 under investigation - 60.9 per cent
• Dec. 1: 62 new cases, 27 under investigation - 43 per cent
• Dec. 2: 41 new cases, 27 under investigation - 65.8 per cent
• Dec. 3: 63 new cases, 45 under investigation - 71 per cent
• Dec. 4: 65 new cases, 58 under investigation - 89 per cent
• Dec. 5: 80 new cases, 66 under investigation - 82 per cent
• Dec. 6: 48 new cases, 45 under investigation - 93.7 per cent
• Dec. 7: 66 new cases, 55 under investigation - 83 per cent

Public health strained with rising cases

The inability to keep up with the growing number of cases may be due to the rapid rate at which cases are arising.

Based onCBC News' calculations, it took 81 days for the region to reach the first 1,000 COVID-19 cases and only another 45 days to reach 2,000. After that, cases slowed, with 114 days for Windsor-Essex to hit 3,000.

Yet, in the last 25 days, the region quickly shot up tomore than 4,000 cases on Monday.

A timeline of total COVID-19 cases in Windsor-Essex

3 years ago

Duration 0:35

In the last 25 days, the region quickly went from having 3,000 to more than 4,000 COVID-19 cases

Though the health unit has hired additional staff to keep pace, it seems to be not be enough.

"We're not by no means up to date and current but we do have a system in place and we're using all of the resources that we have to try and be efficient with our communication to the cases and also high risk contacts," CEO of the Windsor-Essex County Health Unit Theresa Marentette said Monday.

Toronto gave up contact tracing

In Toronto, public health officials gave up contact tracing altogether in October as rising cases made it too difficult to manage.

They decided to only trace cases resulting from facility outbreaks.

At the time, CBC News reported that the "strategic shift"meant Toronto Public Healthwill no longer notify close contacts of people infected with COVID-19 outsideof outbreaks in such facilities as hospitals, long-term care homes, retirement homes, homeless shelters, schools and child care centres for now, according to a report by The Globe and Mail.

"If things get worse and we still don't have additional public health capacity then I would expect contact tracing to be scaled back in Windsor-Essex as well.Hopefully it doesn't come to that," Soucy said.

Windsor-Essex qualifies for lockdown

The alarming case rate and strainprompted an all too familiar plea from Windsor-Essex medical officer of health Dr. Wajid Ahmed Monday.

"Please follow public health measures before we get to the point where we cannot meet the ever-increasing number of cases anddo the case and contact management as we like to, to contain the spread of the disease," he said.

He continued to say that although the current case numbers justify a lockdown, the health unit wants to ensure peoplehave an opportunityto follow red-zone restrictions, which were implemented a week ago, and for the region to see the effects of those measures.