Post #1036, new COVID-19 cases trending down slowly, ex-Texas

Today is probably the last time I’ll show the trends with and without Texas (and LA and AR).  At this point, the (seven-day moving average of) Texas data reporting appears to have recovered fully, and it’s only distorting the historical data.

If you include Texas (and LA and AR), cases are rising at a rate of about 4%/week starting 2/21/2021.  But that reflects the data reporting outage in Texas (and surrounding areas) due to the mid-February cold wave.  And then the recovery from that outage.

If you exclude TX, LA, AR, you find that cases have been falling about 4%week, starting 2/21/2021.  That’s almost certainly a more accurate picture of the underlying trend. Continue reading Post #1036, new COVID-19 cases trending down slowly, ex-Texas

Post #1035: Herd immunity, part 1: Vaccines don’t matter, much, yet

It’s about time to revisit herd immunity.  So far, all I’ve been able to say, from the data, is that we’re not there yet.  (Duh.)

I’m going to start off this next set of posts by explaining why the current vaccinations don’t matter (much, yet) in terms of getting individual states or the U.S. as a whole to the herd immunity level. Continue reading Post #1035: Herd immunity, part 1: Vaccines don’t matter, much, yet

Post #1034: Trend to 2/26/2021, flat ex-Texas

Texas and some nearby states had severe difficulties in processing their COVID-19 case counts during the mid-February winter weather event.  That, combined with the use of seven day moving average data, means that their case counts are only now returning to normal.  You can see that reflected in the gray line on the first graph below, for the U.S. South Central states.  Including that data reporting effect makes it appear that new COVID cases are on the rise.

But excluding Texas (and Louisiana and Arkansas), cases are flat-to-down.  There’s still a sharp inflection point at 2/21/2021.   The decline in daily new case counts ceased at that point.  But so far, that’s been replaced with more-or-less stable new case counts. Continue reading Post #1034: Trend to 2/26/2021, flat ex-Texas

Post #1033: Will we ever get public health officials who can do simple arithmetic?

Or who can be bothered to look at simple data analyses before holding a press conference?

What sets me off today is this CNBC article in which the U.S. CDC director tells a story about the recent bottoming of the third U.S. wave of COVID.  Apparently the spread of the U.K. variant is to blame, because, at least according to this article, that now accounts for 10% of cases. Continue reading Post #1033: Will we ever get public health officials who can do simple arithmetic?

Post #1032: William and Mary COVID-19 testing rate.

 

I tried to do a quick comparison of the COVID-19 testing rate on the William and Mary campus relative to the testing rate in Virginia.  The ultimate goal of this is to (gu)esstimate the effect that more intensive testing of the W&M student body has had on the count of COVID-19 cases discovered.

Turns out, that’s a very hard thing to do, for a lot of different reasons.  That’s not going to stop me from giving an estimate.  But it does stop me from giving  good estimate.

Best guess, the mandatory testing regimen at W&M ought to identify about three times as many cases as the voluntary, symptom-driven testing found in the community.  The fact that it does not — that we don’t see a case count that is three times the community rate — probably reflects the self-selection of the W&M student body, and the fact that their pre-campus COVID-19 infection risk is (probably) much lower than that of the average 21-to-30-year-old Virginia resident.

For me, the bottom line remains the same:  I want to see W&M improve, relative to that community benchmark, as the semester progresses.  That’s how I’ll feel comfortable that W&M is controlling the spread of COVID-19 on campus. Continue reading Post #1032: William and Mary COVID-19 testing rate.

Post #1030: Magid N95 respirator, a flat-fold mask with excellent face seal

This is the followup to Post #1023, my latest N95 mask purchase.

After looking over what was routinely available, my most recent purchase of N95 masks was 10 of these foldable Magid N95s, from Amazon.  The reasoning was pretty much the same as for my last purchase.  These are certified for industrial use, they are not certified for medical use, and they are an odd, niche style.  It doesn’t seem like it would be worth anyone’s while to counterfeit them. Continue reading Post #1030: Magid N95 respirator, a flat-fold mask with excellent face seal

Post #1029: Post Super Bowl non-explosion of cases

Source:  Calculated from NY Times Github COVID-19 data repository, data reported through 2/24/2021.  Areas are defined as the counties currently within the Tampa/St. Petersburg and Kansas City KS/MO MSAs.

So far, I have found exactly one news article that actually followed up on the dire threat of a post-Super-Bowl explosion of cases.  That one, lonely piece of reporting was from a TV station in the Tampa Bay area.  Their conclusion is that, no, there was no uptick in cases following the Super Bowl.  At least, not in the Tampa Bay area. Continue reading Post #1029: Post Super Bowl non-explosion of cases

Post #1026. Has the six-week downward trend bottomed out?

I’m not sure I can blame Texas for all of the recent change in the COVID-19 new case trend.  Today it’s starting to look like the steeply downward trend of the past six weeks is bottoming out.

Let me do something a little out-of-order here.  Take a look at the picture below.  See the little upturn in the case count that just happened?

Continue reading Post #1026. Has the six-week downward trend bottomed out?