SALT LAKE CITY – It is refreshing to see the COVID-19 epidemiological curve in Utah falling in recent weeks after months of increasing cases; However, evidence suggests that recent case counts do not provide a complete picture of COVID-19 in the state.
In a conventional sense, the spread of COVID-19 can be determined simply by looking at new cases discovered through testing. But what happens if testing for the coronavirus is not entirely consistent?
That’s where other statistics help put together how COVID-19 is currently affecting the state.
Confirmed fallen down, positivity rate slowly increasing
The Utah Department of Health reported 972 new cases of COVID-19 from tests taken on Friday and 802 on Saturday. Those numbers were the lowest one-day increases reported since early October. In fact, it broke a chunk of 1,000 or more new daily cases announced by the health department dated Oct. 12. Christmas.
The state’s COVID-19 epidemiological curve and the seven-day moving average of new cases have also declined since about Dec. 10.
That said, testing is another figure that dropped off in the same time. For instance, on Dec. 9, more than 15,000 people were tested for COVID-19 – most of the tests done after Thanksgiving, according to data from the health department. Aside from a few outliers, the state has typically reported days with fewer than 10,000 tests performed since then. No tests were conducted on Christmas Day and test sites closed early on Christmas Eve, but the downward trend is visible on a graph before the holiday.
Meanwhile, the percentage of positive tests on tests run, commonly called positivity percentage, has only increased since about the time the cases were decreasing. As of Monday, Utah’s seven-day moving average positivity rate is 24.4% through that Dec. 22 date. Preliminary data from the weekend pointed to positivity rates closer to 30%, meaning the number will rise in the coming days.
Experts have said positivity rate is an important metric, as it can provide a better assessment of a virus’s prevalence in a community when test numbers fluctuate widely and become unreliable. In this case, the positivity rate is the biggest sign that COVID-19 is not completely leaving Utah, even as the number of cases falls.
“We are certainly concerned because it represents a high level of transmission in the community,” said Dr. Todd Vento, infectious disease physician at Intermountain Healthcare. “That’s why we’re constantly monitoring the situation to see if there are any additional measures we need to take to address that.”
Vento said health officials aren’t sure why testing isn’t working right now; However, they have seen trends during the pandemic and from diseases other than COVID-19. On a smaller scale, some days – such as Sundays and Mondays – yield fewer tests than other days. These are believed to be related to when someone is in public for any reason, such as at work.
“Same kind of concept after holidays,” said Vento. “We’ve seen in the past where the numbers fell right away. Yesterday’s numbers were really low, waking people up a bit – for lack of a better word – from their sleep from the holidays and maybe on, say, Tuesday or Wednesday they start to think, “Okay, I’m going to get tested.” That’s also not uncommon for other respiratory illnesses. “
Because the testing failed, he said the epidemiological curve and the seven-day mean of the number of cases “may not accurately reflect what’s in the community,” especially when it takes into account days when testing was limited.
That’s where the positivity rate comes into play.
“You can’t just look at the cases and the seven-day moving average of the case because it doesn’t reflect exactly the same number of tests that have been done,” he added.
As for Utah’s positivity, it’s been a rollercoaster ride for the past few weeks. After rising to 25.4% on Nov. 10, it was down 21.8% on Nov. 22 – a few days before Thanksgiving. It rose again to a current record of 27.2% on December 1, before falling to 22.3% on December 13. Since then, it has risen steadily, but at a much slower pace.
What Happened to COVID-19 Hospitalizations?
Of course, the biggest concern with COVID-19 is the impact it has on hospitals and deaths. Vento said hospital admissions in Utah due to the coronavirus have stabilized and even decreased a bit. That’s a welcome sign for a statewide hospital system that was on the cusp of full capacity.
Hospital admissions due to COVID-19 typically lag new cases, so the state’s current peak of 606 hospital admissions on December 4 was mainly due to climbing COVID-19 cases prior to Thanksgiving. Public health experts warned of holiday gatherings with fear that hospital admissions would only increase.
It seems Utahns has followed up on the pandemic recommendations before Thanksgiving at least. While many new cases were still being reported, they were nowhere near as many as feared. As a result, just before Christmas, the state health department reported fewer than 500 hospitalizations for COVID-19 for the first time since mid-November.
“While the nation had a wave within a wave – (there was) a fall rise and then a post-Thanksgiving rise for the United States – we didn’t see that number of cases increasing after Thanksgiving when we thought or worried about, which is very good , ‘he said.
He added that hospitals have also learned to shorten the stay of patients who do not require ICU care by offering recovery models at home so that people can leave the hospital earlier.
Data may show that COVID-19 has not left the state even as the number of new cases is declining, but a positive sign is that the number of new hospital admissions due to the coronavirus is decreasing.
The state health department recently began reporting the seven-day moving average of new hospital admissions per day on top of current hospital admission rates. Utah achieved a seven-day average of 92.4 hospital admissions per day on Nov. 18. That was the day a record 116 new Utahns were hospitalized because of COVID-19.
The average fell to 71.2 new hospitalizations per day from December 22, the first day after the period of incomplete new hospitalization data from the department. These figures are still high, especially compared to the figures for November. Nonetheless, it shows that following Thanksgiving meeting guidelines has not only helped reduce the growth of new cases, but also reduced the impact on hospitals.
The jury is still out on whether the Christmas gatherings were somehow taken into account, as the holidays really don’t end until New Year’s Day, Friday.
Outlook on the way to New Year
All Thanksgiving, Hanukkah, Christmas, and Kwanzaa health recommendations apply to New Year. That means health officials advise people to spend the holidays at home and interact virtually with other households.
Intermountain Healthcare even promoted a DIY New Year’s Eve ball made from a Styrofoam ball and a wooden dowel as a fun and safe way to celebrate the holidays at home.
Looking for a fun way to safely celebrate New Year’s Eve? Try to create your own ball dropping experience at home! #DIY # IMTNCovid19
Posted by Intermountain Healthcare on Sunday 27 December 2020
Vento’s colleague, Dr. Eddie Stenehjem, another infectious disease physician for Intermountain Healthcare, said last week that he expected COVID-19 testing to increase after New Year’s Day. One of the main reasons for that, he said, is that Utah colleges are starting their weekly mass testing of students staying on campus for the spring semester.
Once that starts, the positivity percentage will be another key factor as test numbers can exceed previous test standards.
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Carter Williams