The number continue to climb across the country, regionally, and locally. Nothing new there. We all know that in Mississippi the average number of new cases per day, since the start of June, is around 390. With about 11 deaths per day.
But let’s dig into the math
There is a fair amount of variability within the data, though. IT isn’t that every day there are about 400 new cases. Some days there are 275, other days there are more than 1,000.
So, in math, we would say this is an average with “high variance.” Take a look at the numbers from June 1st – June 26th for Mississippi:
| New Cases | New Deaths | ||
| TOTAL | 10,160 | 281 | |
| AVG | 390.7692308 | 10.80769231 | |
| STDEV | 182.1889805 | 7.200106837 | |
| LOWER | 208.5802503 | 3.607585471 | |
| UPPER | 572.9582113 | 18.00779914 |
Recall that the “STDEV” is the Standard Deviation. Or the average difference between each day’s new cases. In this situation, it is 182. That is a pretty big number. That means, with a perfect distribution, that 68-percent of the time the next da’s new case numbers will be between 208 and 572.
Looking at the number of deaths per day. The average is almost 11 people. With a STDEV of about 7. Meaning, with a perfect distribution, 68-percent of the time, the next day’s death numbers will be between 4 and 18.
That’s great, Nick, but what does that mean?
Only three times out of 26 days were there new cases that fell outside of the estimated range. And seven times out of 26 days the number of deaths fell outside of the estimated range
So, 88.5-percent of the time new case numbers fall within the estimated range. And 73-percent of the time the number of deaths fell within the expected range. But that range is pretty large.
At face value, it means nine-times-out-of-10 we are going to have a day with more than 200 new cases and nearly 3/4ths of the time at least three people will die every next day.
Yeah, but Nick we are just testing more…
We are! No doubt. So let’s compare. How does that compare to the time Mississippi was under the “Shelter in Place” order? Let’s look at the April 1st-26th numbers:
| New Cases | New Deaths | ||
| TOTAL | 5,025 | 207 | |
| AVG | 193.2692308 | 7.961538462 | |
| STDEV | 61.54774257 | 3.352381473 | |
| LOWER | 131.7214882 | 4.609156989 | |
| UPPER | 324.990719 | 12.57069545 |
Lining up the last 26 days against the first 26 days of the “Shelter in Place order” looks like this:
| April 1-26 | June 1-26 | |
| Total Cases | 5025 | 10160 |
| Total Deaths | 207 | 281 |
| Deaths/Case | 4.12% | 2.77% |
| AVG Cases/Day | 193 | 390 |
| Range | 132–325 | 209–573 |
| AvG Deaths/Day | 8 | 11 |
| Range | 5–13 | 4–18 |
So, it looks like the extra testing is doing a good job at identifying cases. And that is likely part of the reason there is an increase in the numbers. However, there were twice as many cases during the first 26 days in June compared to April. It is unlikely that it is only a matter of “more testing” and rather a combination of more testing and people not adhering to guidance from the medical community.
What about the deaths, Nick?
To me, that is the thing that catches my attention. In a good and bad way. You can see that the death rate per number of cases found is going down. That is to say that more people are being infected and recovering. Good news!
The flip side to that is that the daily death rate is still between 4 and 18 people. And the average number of deaths per day is higher now than during the “Shelter in Place” order. And that order was given with the goal of reducing the number of potential deaths.
After a very deadly May, where Mississippi lost – on average – 15 people a day to COVID-19, during June the state is losing 11 people per day.
Just as an aside, if I got on TV and said that a hurricane was coming and the storm was going to kill 11 people per day for 26 days in a row, and the best way to save yourself and others was to stay home, only venture out if it was absolutely needed, and when you did go out, wear a mask… I don’t think many people would disregard the advice.
Nurse fact-checks O2 levels
I ran across a video on Twitter from a nurse wearing multiple masks trying to highlight that while it may ‘feel’ more difficult to breath with a mask on, the end result is unchanged.
Great look at how wearing a mask is not going to impact your oxygen levels. Nor CO2 levels.
Also… Does anyone know how this is? This video has been shared a lot and I’d love to give credit to the actual person who is actually in this video. pic.twitter.com/WBJ965dWNa
— Nick Lilja (@NickLilja) June 27, 2020
This is a great example showing that “feelings” and “facts” are often different. And why using science to investigate feelings are so important. It may “feel” like you cant get enough air with a mask on, but the good news is that if you breath normally, your body can’t tell the difference. And there is evidence of that!
Comparing the different masks across the board, the CDC notes that the N95 masks do the best, obviously. But, more importantly, the post floating around facebook suggesting that masks don’t help is mostly false.
Snopes has a great breakdown, that I checked and can’t really improve upon… so you can head there. Say what you want about the site, but in this case, it is well done and unbiased.
The New England Journal of Medicine
The NEJM released a podcast talking all about COVID-19. And one sound-byte stood out to me, because it may help to explain why so many people see the “threat” of COVID-19 as a hoax or ‘no big deal’ to them.
Dr. Lindsay Baden said: “What I do today does not impact the number of new cases today. It won’t be seen for two to six weeks. depending on the cycle time and transmission.”
And that may be the biggest hurdle for most people is the disconnect between actions today and reactions tomorrow.
Take a listen to the whole podcast here:
New research looks at schools re-opening
In a pre-print of an article, “Shut and re-open: the role of schools in the spread of COVID-19 in Europe” authors attempt to calculate the difference between closing school and leaving them open this past spring and the potential for COVID-19 related issues this fall when schools attempt to re-open.
And you guys may remember how I feel about pre-prints. But this is an article that has not been reviewed by other scientists. That means no one has gotten in here and tried to “poke holes” in their findings yet.
That said, the authors took a pretty conservative approach to their research, and so I want to share it here with the asterisks that this has yet to be peer-reviewed.
The authors pointed out that in some places the comparison between the actual numbers and the modeled numbers showed a reduction in the number of new cases between 20- and 40-percent. The authors do note that comparing actual data to model data can be cumbersome, but it is the best that can be accomplished given the tricky nature of no “Control” group.
A brief look at their findings:
Our findings generally underscore the precarious nature of transmission control as it relates to the reopening of schools, particularly in numbers whereby physical distancing is unfeasible. The safe return of most (or even large proportions of) students to school is conditional on the successful implementation of a complete system of monitoring and interventions, jointly with low daily incidence, as observed in Denmark and Norway. This correlation with community transmission can be seen particularly clearly in Germany, with confirmed cases increasing among students, and the halted decay in hospital admissions on the national level. The most severe impact appears to occur following the return of most older students to schools when community transmission remains significant (if managed).
Great care should be taken when attempting to infer the impacts of school reopening in other nations by comparison with the presented subset. It is insufficient to compare the number of daily tests carried out (or similar monitoring metrics), or the daily incidence (be it total or per capita). The speed of decline in daily cases is also a key quantity, as it informs us about the effectiveness of tracing, individual or household isolation, and the adherence thereto. The swiftness and effectiveness of targeted interventions become increasingly crucial as the daily incidence increases, due to the correspondingly greater challenges presented in managing the myriad localised outbreaks across e.g. reopened schools.
Policy-makers should carefully consider their nations’ respective capacities and associated effectiveness of infection management before considering a partial or full reopening of schools. Our findings suggest a small, strategically chosen, proportion of students to return in the first instance, with dedicated testing and monitoring of cases among staff and students over time scales where the effect can be appropriately assessed. Any significant return of students to schools, particularly in countries with a high incidence, should not be considered unless an infrastructure is in place which would be able to swiftly identify and isolate most new cases as they appear. Such a strategy may not be feasible if the incidence is too high.
That last few lines is probably the most important. Based on the available, re=opening schools without infrastructure in place to handle the potential spread.
Bottom Line
Follow the CDC guidelines as best as possible. Limit your time in public, practice social distancing, wear a mask, and wash your hands!
