Reports Of Michigan’s COVID-19 Spike Have Been Greatly Exaggerated
It’s great clickbait for local news outlets, but there’s not nearly as much bad news as Michiganders might think
If you live in Michigan, you’ve seen the terrifying headlines — the state is apparently falling back into the grasp of COVID-19.
Coronavirus cases rise for 6th straight day in Michigan, prompting fears of a resurgence — Metro Times, 6/26/20
Technically, that headline is accurate — the number of cases announced by the state has gone up on each of the last six days. There have also been more positive tests in the past week.
In the seven days ending on June 25, Michigan averaged 365 positive tests a day — the highest average since June 8. On the 25th alone, there were 544 positives, the most on one day since there were 595 on June 3.
The upswing at the end represents about 60 additional cases a day — a small amount in a state of 10 million people — but it does exist. Does that mean we could be heading back to 2,000?
With some basic statistical analysis, it appears the uptick shows the state’s tracking-and-tracing system is working as designed.
First, if we’ve learned anything over the last four months, it’s that positive-test numbers aren’t useful without knowing the total number of tests. In President Trump’s world, cutting testing would slow the pandemic, but in the real world, more tests are better.
Increased testing explains much of what is happening in Michigan. A Harvard study this spring said the state would need about 15,000 diagnostic tests per day to run a successful tracking-and-tracing system. That has been a tricky target.
For most of May, the state was reporting totals far beyond its goal, including 46,328 on the 13th and 14th combined. However, it turned out the health department was combining diagnostic and serologic tests in its daily count. When the reporting was fixed, the state had done 33,608 diagnostic tests in that two-day span — a drop of nearly 13,000.
Michigan didn’t average 15,000 diagnostic tests for a seven-day period until June 2, when they hit 15,323. The next day, the average dropped to 15,083 before falling below the target on the 4th. It went as low as 13,107 on June 22 before making a strong recovery in the last week.
On June 25th, the state performed 19,067 diagnostic tests — the second-highest one-day total of the pandemic — bringing the seven-day average up to 14,581.
However, even at a lower-than-ideal testing rate, Michigan was able to run an effective track-and-trace program. They found a series of small outbreaks among migrant farmworkers as well as construction employees brought in after major flooding in June. There is also a growing outbreak — more than 60 infections as of June 26 — linked to Harper’s Restaurant and Brewpub in East Lansing.
Containing those outbreaks required testing of anyone who might have been exposed to the virus — tests that, by design, will have a higher positive than a random sample of the population.
Despite those situations, Michigan has been able to keep its percentage of positive tests at low levels for the past three weeks. The seven-day average dropped under 3% on June 7 and currently sits at 2.5%.
Another positive sign for the state’s COVID-19 recovery is the drop in the death rate. On April 16, the seven-day average topped out at 145 deaths per day. It was not the sharp peak and quick decline predicted by many models — the average stayed over 120 from April 11 to May 1 — but there has been a steady recovery over the past eight weeks.
On June 26, the state reported two deaths, bringing the seven-day average into single digits for the first time in more than three months.
There are two ways to look at Michigan’s current situation. In the last week, there has been a 21% increase in the rate of positive tests — from a seven-day average of 302 to 365. The average number of tests performed has risen by 10% during the same period, but the percentage of positive tests has increased from 2.3% to 2.5%. Deaths have dropped, going from a running average of 11 down to nine, but hospitalization numbers have increased slightly.
Looking at the longer term, though, Michigan’s recovery remains remarkable. The number of positive tests is down 83% from its peak in early April, despite the state performing three times as many tests. The rate of positive tests is down from a high of 39.9% and the average number of deaths is down 94%.
The hospitalization numbers have declined just as dramatically. There has been a 91% drop in victims requiring inpatient care, an 88% fall in critical-care cases, and a reduction of 92% in patients on ventilators.
Michigan sustained terrible losses in March and April, and there’s no way to know if it will face a second wave this fall. At the moment, though, the state remains one of the country’s few success stories.
To keep it that way, please wear a mask.