The Personal Blog of Stephen Sekula

C+50

It is 50 days since Texas essentially ceded the battlefield (the human population) to the SARS-CoV-2 virus. By racing to open back up the economy, without first putting in place reliable metrics, benchmarks, and health investigation foundations, Texas abandoned its people mostly unarmed to an enemy. Thankfully, those of us who don’t view the requirement to wear of clothes on our bodies as a “violation of our Constitutional rights” have kept up vigilance with face masks. The wearing of a mask is an act of compassion and mercy on behalf of everyone else around you; you choose to prevent the spread of any infection you might be harboring to enhance the safety of others. Personally, I think mask wearing is awesome. I can finally walk in public (not that I do that) looking like a Marvel superhero and nobody can think it’s weird.

Well, some people think it’s weird: people who view the act of putting cloth over nose and mouth as some violation of the tenets of the Declaration of Independence; who make every act to prevent the spread of a deadly disease into a burden so great it merits the intervention of the Supreme Court. For those people who can, but refuse to, wear a mask, they are aiding and abetting a virus that only causes symptoms in only about 20% of infected have severe symptoms; 80% have mild reactions, or even no symptoms at all. But the data are clear: asymptomatic people can “shed” the disease, and the worst way to spread it is by aerosolizing body fluids through coughing, sneezing, singing, or talking in enclosed spaces. [1]

Masks can help reduce or prevent all such forms of shedding.

The new cases per day (purple-dashed), 7-day rolling average of new cases per day (pink-solid), and 7-day rolling average of new tests per day (blue dot-dashed) in Collin County, TX. The bottom graph shows key events in Texas (arrows) and then a band of similar color 7-14 days later suggesting the time window for the impact of those events. Reopening gyms, salons, and bars appears to have led to the first significant rise in cases around days 80-90. Memorial Day seems to have then contributed further, as did increased reopening phases. Recently, exponential growth of cases has become crystal clear in the data. The doubling time, determined from an exponential fit to the case data, is printed as a black number above the pink curve.

In Collin County, TX, where I live, things are getting worse. Our county is reflective of the general regional trend in Texas. Case counts are up; testing is down. ICUs in hospitals have seen significant occupancy increases; in the health region of Dallas/Ft. Worth, ICUs went from about 60% to over 70% occupied in the last 7-10 days alone. ICU stays naturally lag cases (you have to have severe symptoms to warrant an ICU stay, and developing those symptoms can take days or weeks after infection). Cases lag infections. So while ICU occupancy is rising, that would be reflective of the rise in cases days or even weeks ago. Cases are still rising; cases relative to tests are also rising, the rate having doubled in recent days. Texas is nowhere close to the worst of it yet. We’re at least a week or two from that, and likely further (we won’t stem the tide of infections overnight – there is no magic cure, only care and effort and patience).

The case-to-test ratio in Collin County is a better measure of the risk. If this ratio increases, it’s a bad sign; it means despite testing more (which would naturally make you detect more cases already present), you are seeing more cases as a fraction of your tests, not just more cases in general. Our case-to-test ratio has doubled in just a week, from about 5.4% to 11.6% – and this is the 7-day rolling average for this ratio, which tends to soften out dramatic swings.

The doubling rate of cases – the time it takes to double the total number of cases – has dropped from 54 days to just 18 days, all in the span of about 10 days. Exponential growth has sunk in its teeth.

God help Texas. Texans certainly aren’t doing it for themselves.

[1] https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200306-sitrep-46-covid-19.pdf?sfvrsn=96b04adf_4#:~:text=For%20COVID%2D19%2C,infections%2C%20requiring%20ventilation.