Post #753: Uptick, continued, 7/11/2020

Above:  Blue = Virginia, Orange = Fairfax County.

Below:  Blue = NoVA+, Orange = rest-of-state

Well, this most recent uptick in cases is definitely not an artifact of data reporting.  For two days running, the “early reopening” areas of Virginia have daily new cases well above recent trend.  Daily new cases in the “late reopening” areas (NoVA, Richmond City, Accomack County) appear stable-to-falling there.  But that is more than offset by the increase in the rest of the state.

(Weirdly, Vienna VA (22180) had seven new cases reported today.  No clue what that’s about.)

And this continues to come from the Hampton Roads area. 

In fact, the main reason today’s increase is smaller than yesterday is that the big jump in cases in rural Westmoreland County, VA did not repeat itself (See Post #752).  Today they saw just 12 new cases.  My guess is that they had an outbreak in (likely) a seafood processing plant, or some such.  So far, I have found zero news coverage to explain the nearly 50 cases in two small towns (Kinsale, Hague) yesterday.

To put this into perspective, I can calculate an “annualized new infection rate”, meaning, what fraction of the population would get infected if the rate we just saw continued for a year.

The out-of-control states — Arizona, Florida — showed annualized infection rates (for the entire state) of more than 20%.  So we can take 20% to be a true red flag for having a serious problem.  By contrast, today, Fairfax County had an annualized new infection rate of about 1%.

Fully aware that these numbers will bounce around quite a bit from day to day, and that the lines with small counts will similarly show lots of random variation, here’s a snapshot of how Virginia looks today.

Based on the last couple of days, Portsmouth and Norfolk are about half-way to the Florida/Arizona level in terms of the current spread of infection.  (The sort order of this chart is re-opening status and then descending count of new infections today).

By contrast, in the late-reopening areas, only the City of Manassas comes close to the 10% annualized new infection level.  And that’s based on a small number of cases, within that small population.

So it appears that a true hotspot of trouble is developing within Virginia, in the Hampton Roads area.  Per-capita new infections in two large cities are around half the level that has prompted such concern in FL and AZ.  This is well worth keeping your eyes on, to see whether or not the Governor passes additional restrictions for those areas.

The conventional explanation for recent case growth — young people congregating in bars — doesn’t fully explain this.  Yes for Norfolk, no for Portsmouth.  In Norfolk, of the new cases over the past two days, 42% are persons age 20 to 29.  But in Portsmouth, it’s just 21%, which is in line with the overall percent of cumulative cases to date.  Whatever’s driving that growth, it’s not universally due to the behavior of young adults.