SALT LAKE CITY – It is refreshing to see Utah’s COVID-19 epidemiological curve drop in recent weeks after months of rising cases; however, there are signs that the recent case count does not show 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 when the test for coronavirus is not exactly consistent?
This is where other statistics help to discover how COVID-19 is currently affecting the state.
Confirmed cases decreased, positivity rate slowly increasing
The Utah Department of Health reported 972 new cases of COVID-19 in tests done on Friday and 802 on Saturday. These numbers were the smallest single-day increases recorded since early October. In fact, it hit a period of 1,000 or more new daily cases announced by the health department that dated October 12. The department reported another 1,700 test cases on Sunday, which is also well below the seven-day moving average before Christmas.
The state’s COVID-19 epidemiological curve and the seven-day moving average of new cases have also been on the decline since about December 10.
That said, the test is another figure that fell at the same time. For example, more than 15,000 people were tested for COVID-19 on December 9 – most of the tests performed after Thanksgiving, according to data from the health department. With the exception of a few outliers, the state has reported mostly days with less than 10,000 tests performed since then. The test was not carried out on Christmas Day and the test sites closed earlier on Christmas Eve, but the downward trend is visible on a chart before the holiday.
Meanwhile, the percentage of positive tests in relation to the tests performed, commonly called the positivity rate, only increased more or less at the time when the cases decreased. On Monday, Utah’s seven-day moving average positivity rate is 24.4% as of the previous December 22 date. Preliminary data from the weekend indicated positivity rates close to 30%, which means that the number will increase in the coming days.
Experts said the positivity rate is an important statistic because it can provide a better assessment of the prevalence of a virus in a community when test numbers vary widely and become unreliable. In this case, the positivity rate is the biggest sign that COVID-19 is not leaving Utah, even though the case count is dropping.
“We are certainly concerned because this represents a high level of transmission in the community,” said Dr. Todd Vento, an infectious disease physician at Intermountain Healthcare. “So this is why we are constantly monitoring the situation to see if there are any additional measures that we need to take to resolve this.”
Vento said health officials don’t know exactly why the tests are low; however, they observed trends across the pandemic and in diseases other than COVID-19. On a smaller scale, some days – like Sunday and Monday – generate less testing than other days. They are believed to be linked to when someone is expected to go out in public for any reason, such as work.
“The same kind of concept after the holidays,” said Vento. “We saw in the past where the numbers dropped immediately. The numbers yesterday were very low, that people kind of – in the absence of better words – are waking up from their holiday sleep and maybe, say, Tuesday or Wednesday, they’ll start thinking ‘OK, I’m going to get tested’. This is also not uncommon for other respiratory diseases. “
As the tests fell, he said the epidemiological curve and the seven-day continuous average of case counts “may not reflect as accurately what’s out there in the community”, especially when it takes into account the days when the tests were limited.
That’s where the positivity rate comes into play.
“You cannot just look at the cases and the seven-day moving average of the case because it will not accurately reflect the same number of tests that were done,” he added.
As for Utah’s positivity rate, it has been a roller coaster ride in recent weeks. After rising to 25.4% on November 10, it fell 21.8% on November 22 – a few days before Thanksgiving. It rose again to a current high of 27.2% on December 1, before falling back to 22.3% on December 13. It has been rising continuously since then, but at a much slower rate.
What happened to COVID-19 hospitalizations?
Obviously, the biggest concern with COVID-19 is the impact it has on hospitals and deaths. Vento said that hospitalizations in Utah due to the coronavirus have stabilized and even dropped slightly. It is a welcome sign for a state hospital system that was on the verge of full capacity.
Hospitalizations due to COVID-19 typically lag behind new cases, so the state’s current peak of 606 hospitalizations on December 4 was mainly the result of the increase in COVID-19 cases before Thanksgiving. Public health experts warned about holiday meetings for fear that hospitalizations would only increase.
It appears that the Utahns followed the recommendations for the pandemic at least on Thanksgiving Day. Although many new cases have still been reported, there were not as many as we feared. As a result, the state health department reported just before Christmas less than 500 hospitalizations due to COVID-19 for the first time since mid-November.
“Although the country experienced a sudden increase – (there was) an increase in decline and then a post-Thanksgiving increase for the United States – we did not see this level of increase in cases after Thanksgiving, as we were imagining or worried, which is very good, “he said.
He added that hospitals have also learned to shorten the stays of patients who do not need ICU care, providing models of home recovery so that people can leave the hospital earlier.
The data may show that COVID-19 has not left the state despite the decline in new cases, but a positive sign is that new hospitalizations due to the coronavirus are on the decline.
The state health department recently started reporting the seven-day moving average of new hospitalizations per day in addition to the current hospitalization numbers. Utah reached a seven-day average of 92.4 hospitalizations per day on November 18. That was the day that a record 116 new Utahns were admitted to a hospital due to COVID-19.
The average dropped to 71.2 new hospitalizations per day as of December 22, which is the first day after the department’s incomplete data on new hospitalizations. These numbers are still high, especially in comparison to the numbers before November. However, it shows that following the guidelines for Thanksgiving meetings has not only helped to slow the growth of new cases, but it has also helped to decrease the impact on hospitals.
The jury has yet to decide whether the December holiday meetings will have considered it in any way, as the holiday season doesn’t really end before New Year’s Day, Friday.
Prospects coming to the New Year
All health recommendations for Thanksgiving, Hanukkah, Christmas and Kwanzaa apply to the New Year. This means that health officials advise people to celebrate the holiday at home and to connect virtually with other families.
Intermountain Healthcare even hosted a “do it yourself” ball on New Year’s Eve with a Styrofoam ball and a wooden pin as a way to celebrate the holiday at home in a fun and safe way.
Looking for a fun way to celebrate the New Year safely? Try to create your own experience of playing ball at home! #DIY # IMTNCovid19
Posted by Intermountain Healthcare on Sunday, December 27, 2020
Vento’s colleague Dr. Eddie Stenehjem, another infectious disease physician at Intermountain Healthcare, said last week that he anticipated that the COVID-19 test would increase after New Year’s Day. One of the main reasons for this, he said, is that Utah colleges will begin their weekly mass tests of students who remain on campus during the spring semester.
Once you start, the rate of positivity will be another important factor, as test numbers may exceed previous test standards.
Related stories
Carter Williams