Del. adopts new ways to count cases, contact-trace

The state will have 8 days of pop-up testing for students, teachers and staff in their own districts.

Delaware is introducing a new way of tracking the percentage of positive coronavirus cases and a new method of contact tracing

These changes come with the news that cases in that state are slowly creeping up.

Instead of basing the percentage of positive cases off the population of people tested, the state will follow the lead of other states and base the percent positive off the number of total tests.

“Total tests approach is the recommended approach by Johns Hopkins, as well as the CDC,” Karyl Rattay, director of the Delaware Division of Public Health, said today at Gov. John Carney’s weekly coronavirus briefing.


The main reason behind the change is to be able to compare Delaware data with other states, she said. The change also occurs at a time where more people – particularly schoolchildren and those working in schools – are being tested more often.

As a result of using the current method of counting positive cases, Delaware has continuously looked worse compared to states around it, Rattay said.

Changing the method means that the denominator is not larger, compared to the number of positive tests, and so percent positive comes down.

The state also unveiled plans to adopt a new contact tracing method that will be available to the public later this week. This method tracks the venues and events that people who have the virus have been to.


“Among the cases that we interviewed, around 25% every week say that they have been in one these high-risk settings,” Rattay said.

The most common venue that people have been to have been restaurants, and the most common event has been house parties.

This does not mean that those people got the infection at a restaurant, she said. It simply means that they have been there recently.

Both of these developments come with the news that COVID-19 cases are picking up in the state. Officials expressed concern with rates in parts of the Wilmington area, western Sussex County and Newark, with 370 cases associated with the University of Delaware.


The state has had 30 new hospitalizations in the last week, along with six new deaths.

The state’s overall percent positive is up this week to 8.1%, and the seven-day average of daily cases is 139.7. The target for staying off quarantine lists is 5% positive cases and 97 cases per day.

Throughout meeting, Carney continuously stressed that Delawareans need to stay committed to wearing mask, and students need to be acting responsibly on campus.

“If we don’t want to go backwards,” he said, referring to tightening restrictions, “let’s follow the guidelines – and wear a face mask in particular.”

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About the Contributor


Daniel Larlham Jr.

Daniel Larlham, Jr. is a communications major at the University of Delaware.