What does a spike in positive COVID cases mean for NC?

Yesterday on June 4, North Carolina completed 19,039 diagnostic tests. This is by far the most in a single day so far, and it’s well above trend.

North Carolina’s test numbers spike on Thursdays. The reasons are complicated, but many of those reasons reflect variations in human behavior that do not necessarily correlate with the threat that COVID-19 actually presents.

However, soon after we see these spikes on Thursdays, we also see a subsequent spike in confirmed cases. (The past three weeks have also seen level shifts starting on Thursdays leading into the following Mondays & Tuesdays, but this only strengthens my point here so let’s ignore it for simplicity.)

North Carolina has been grabbing national headlines when it reports a new high in daily confirmed cases. And each time, these case spikes are roundly described as a surge in coronavirus. But does a surge in confirmed cases alone mean that more people are getting sick? It could instead reflect the fact that more tests are being completed. Therefore more cases are being confirmed. Turns out, right before North Carolina grabbed headlines on May 30 for reporting its highest daily case count, completed tests had been increasing by more than a third starting that Thursday before. While this pushed up the total number of cases in the coming days, the percentage of cases remained fairly level over that period.

The testing strategy in NC is improving. This week on Wednesday (19 days after its last formal expansion) the state rolled out an expansion of its testing strategy, adding marginalized populations to the priority list. This is an important step, because testing in broader populations, not just people who we know are sick or at risk, provides crucial early detection.

Still, a clear and impartial look at these numbers is not always what we hear reported. Prepare for expressions of concern and caution about North Carolina’s confirmed case count. Sunday if the pattern holds. And it could be a big spike, too, because as of yesterday June 4 we were already leveled above the past week’s Sunday spike.

The good news includes, among other items, that even with the welcome and overdue increase in testing, current number of COVID hospitalizations remains flat, right where its been since about May 25th.