The popularity of over-the-counter COVID-19 tests has clouded surveillance for the Minnesota pandemic, but state officials are urging people to use them to identify infections and protect others from the impending omicron wave.
State Health Commissioner Jan Malcolm said she had seen estimates that two-thirds of COVID-19 testing nationwide involved rapid home antigen tests purchased from pharmacies , grocery stores and even gas stations.
That doesn’t mean that two-thirds of infections are detected by home tests, which people often use as a precaution before visiting family and friends, she noted. But they are reducing the number of COVID-19 cases in Minnesota because the state does not collect home test results.
“We’re following what we can, but we realize it’s a less and less complete picture all the time,” said Malcolm. “And that’s true nationally. There are a lot of conversations going on on the subject, “How should we try to measure things now?” “”
Measurement issues are emerging with the prospect of another wave of COVID-19 fueled by the rapidly spreading omicron variant. Minnesota reported 4,149 other infections and 71 deaths from COVID-19 on Wednesday, bringing its pandemic total to 1,049,310 infections and 10,671 deaths.
Hospitalizations for COVID-19 returned to 1,405 on Tuesday after falling to 1,311 on January 1. Minnesota’s COVID-19 test positivity rate jumped to 13.4% in the seven days ending Dec. 28, but that rate was inflated by the low number of people who requested tests during the holidays.
Some Minnesotans are frustrated with the lack of home testing reporting. Some want to help by disclosing their results. Others have relied on the state’s number of COVID-19 cases before deciding to travel, go to the office or wear masks – even though it was still an undercount due to the number of asymptomatic people who have never requested a test.
Pharmacist Jamie Hilbrands visited seven pharmacies to find home tests when four of her children fell ill during Thanksgiving. The Minneapolis woman didn’t want them standing in line at a testing center and needed instant results before a family reunion. Positive results for children are not included in state data.
People with unreported infections might be more likely to go through usual routines and spread the virus, she said.
“How many of these people will go on to work and infect others as a result of the payment stoppage by many employers?” “
The Minnesota Department of Health does not collect home test results because it cannot verify them, the agency said in a statement. “We cannot be sure what is ‘called’ and our case definition for COVID cases includes laboratory confirmation.”
The state predicts an unprecedented increase in COVID-19 testing after the holidays and is adding three free testing sites this month. Drugstore chains have also tried to keep stocks of home tests limited for more people; Last month, Walgreens allowed customers to buy just four tests at a time, while CVS set its limit at six.
Malcolm said other measures of COVID-19 activity will become more important in tracking changes in the pandemic. COVID-19-related hospitalizations are a more stable measure, for example, because any increase or decrease in testing will not affect when the sickest people need care.
However, peaks in hospitalizations typically occur two weeks after peaks in infections – and peaks in deaths from COVID-19 often occur two weeks after that. Thus, neither hospitalizations nor deaths are effective early warnings of increased pandemic activity.
A drop in reported test results will not affect Minnesota’s use of genomic sequencing to identify circulating variants. Only a maximum of 20% of positive samples are selected for sampling by the state’s network of public and private laboratories each week.
Last week’s report had only verified 84 infections involving omicron using genomic sequencing. However, standard COVID-19 tests fail to identify any of the three genetic targets when an infection involves omicron, and this serves as a preliminary indicator even without sequencing.
The failure of the S gene target was identified in 11,176 out of 12,428 positive tests collected by IBX, a private laboratory under contract with Minnesota, from Dec. 27 to Jan. 1. So, probably, almost 90% of these samples involved omicron.
Some researchers believe that analyzing wastewater should become a more reliable and important indicator of the spread of a pandemic. Scientists have been closely following changes in the prevalence of COVID-19 in the Twin Cities by extracting viral material from wastewater passing through the St. Paul Metropolitan Wastewater Treatment Plant and sending it for analysis to the University of Minnesota Genome Center.
This approach found omicron in wastewater in mid-December and works as a public health measure because it anonymously collects samples from the entire community, said Kenny Beckman, director of the U Genome Center. .
“Not many people don’t poop in the toilet, there’s really no way to stop you from being sampled.”
Over time, wastewater data has increased and decreased with the number of COVID-19 cases and the latest trend does not bode well for the immediate future, said Steve Balogh, a researcher at the Met Council.
“The last five days of 2021 were the highest levels we have ever seen in terms of the virus load entering the metro plant.”
Regardless of the number of cases, Malcolm said the growing spread of omicron is evident and people should take precautions such as wearing masks and social distancing.
“Act like whatever crowd you find yourself in there’s going to be omicron,” she said. “Take precautions. Be aware of where you choose to go and how to go and please, please, please be boosted if you can and vaccinated. . “
Modeling from the Mayo Clinic predicts that the rate of COVID-19 cases in Minnesota will double in 14 days. Early signs are that omicron infections are producing fewer serious illnesses, so people need to know if they need to seek care from an overworked medical system, said Dr Gregory Poland, head of the research group on Mayo Clinic’s COVID-19 vaccines.
“There isn’t enough of a medical system to handle everyone who tests positive,” he said. “So someone who is young, someone who is otherwise healthy without co-morbidities, someone who has been vaccinated, someone who has mild symptoms that don’t progress, they really don’t need for interaction with the medical system. “
People should always tell clinicians about positive infections so they can respond quickly if symptoms worsen, he added.
Editor-in-chief Christopher Snowbeck contributed to this report.