Today should have been the last day of a 14-day decline in COVID-19 community spread in D.C., but city officials say there was a "new peak detected in the data, resetting the count to 11 days of sustained decline." A 14-day decline is a signifiant metric before reopening.

Remember: the decline city officials are looking for isn't in raw number of cases, but rather "community spread," which is cases based on symptom-onset (instead of positive test) and controlling for cases in congregate settings like the jail, nursing homes, etc.

Here's a story on the use of "community spread" to determine D.C.'s status in the fight against COVID-19: https://dcist.com/story/20/05/18/d-c-is-halfway-to-meeting-a-key-reopening-metric-but-you-wouldnt-know-it-from-the-public-data/

Dr. LaQuandra Nesbitt, the head of the D.C. Department of Health, is about to brief reporters on what the data says and what it means for where D.C. is on plans to potentially start an initial stage of reopening as early as May 29.

OK, so this is complicated, not unexpectedly. Basically, Nesbitt says that on Day 12 of declining cases, D.C. saw 68 positive cases based on symptom onset. On Day 13, it was 118 cases, which is more than the standard deviation of 40 officials say is acceptable.

So that reset where D.C. is on its 14-day decline, but not all the way back to Day 0, but rather Day 11, since that was the last date when positive cases were close to 118, the increase on Day 13.

Nesbitt is being very defensive when asked about the methodology and also whether D.C. can start a phased reopening on May 29, as @MayorBowser said last week. Nesbitt will not answer the question, saying only that Bowser will address that on Tuesday.

This is one of those difficult situations where there's actual health data practices that are tough to understand for laypeople (and reporters), and when city officials don't explain them in clear terms, it's tough to know whether they are being honest or not.

But this is what D.C. officials are saying today: we're on Day 11 towards a goal of 14-day decline of community spread. Today should have been Day 14, but a small spike in cases recently set us back, but not all the way to Day 0 since the spike wasn't huge.

"When you’re communicating to people, 'Well, we’re making this decision based on standard deviations'… it can become a tad bit frustrating for folks," says Nesbitt, conceding this is all complicated for reporters and the public to understand.

That being said, Nesbitt has been quite defensive and snippy in answering otherwise expected questions from reporters trying to get some clarity on what this all means.