Dramatic rise in positive COVID-19 tests reveals intensity of omicron surge in Maine

·7 min read

Jan. 18—Throughout the past two years, the Maine Center for Disease Control and Prevention's lab had never received more than 2,000 positive COVID-19 test results on any single day.

So far in 2022, it's happened 11 times already, including a record 3,720 positive tests received last Wednesday alone.

That raw data, included on the CDC's online coronavirus dashboard, appears to show the omicron variant spreading much more rapidly than what is reflected in official daily counts of confirmed cases.

"This is probably almost the rule rather than the exception now in most states," said Josh Michaud, associate director for global health policy at the Kaiser Family Foundation. "There is such a deluge of cases and transmission happening right now, our systems that are set up to track these things are completely overwhelmed."

Because a infected person could test positive more than once before recovering, the test reports flooding into the CDC must be reviewed by CDC staff to remove duplicates, which can represent 20 to 40 percent of tests submitted to the state each day, Dr. Nirav Shah, the agency's director, has said. The Maine CDC had a significant backlog of tests to review even before omicron arrived.

So far, the recent deluge of positive tests submitted to the state hasn't resulted in a major increase in confirmed cases reported by the CDC. CDC staff are still reviewing cases submitted over the past two weeks. As a result, the seven-day case average from Saturday, 1,070, is nearly identical to what it was one month earlier, before omicron became the dominant strain.

Maine CDC spokesman Robert Long did not respond to questions Tuesday about the raw test results or about the state's current backlog of cases. "The case investigation team is out straight," he explained. Long said Shah would address case data reporting during his weekly media briefing on Wednesday.

Nevertheless, the sheer volume of positive tests received since the holiday break confirms that daily case counts don't represent the current level of transmission throughout the state, something Shah has acknowledged recently. Besides being overwhelmed by positive tests, the state's count doesn't include the results of at-home test results or the people who get infected and never get tested.

Long did report on Tuesday that the state is processing 906 tests for every 100,000 people on average over the last seven days. That's by far the highest testing volume the state has seen. The positivity rate is above 21 percent on average as well, which is extraordinarily high.

Maine reported 536 new official cases on Tuesday, although that count was incomplete because only a few staff members worked on Monday. Additionally, most of the new cases in Tuesday's update were submitted to the state for review on Jan. 4 — two weeks ago — and virtually none of the positive tests over the past 10 days have yet been processed by the state, according to the Maine CDC's website.

Many other states also have failed to keep up with positive test reports in recent weeks and are struggling with large backlogs.

Some states, including Ohio and Wisconsin, have recently reported massive one-day totals of new cases as they purge backlogs of tests received during the recent surge. According to news reports, Wisconsin cleared its backlog by reporting out tens of thousands of positive tests instead of waiting to determine how many were actual cases. It's not clear if that will happen in Maine, but the raw data on test results received could provide a more current, but still incomplete, picture.

For example, last Friday — the most recent non-holiday weekday — the CDC received 17,848 test results, 3,351 of which were positive, for a positivity rate of 18.8 percent. One month ago, on Dec. 14, the CDC processed 14,956 tests. Only 1,117 of those were positive, which was a rate of 7.5 percent.

At the height of the delta surge in early December, the CDC would sometimes receive 15,000 tests or more on any given day, but the number that were positive never got higher than 1,500. In September, the state was unable to keep up with 400 positive tests a day, creating a backlog of more than 2,000 positive tests that had not been reviewed.

The backlog of positive tests in Maine and other states also makes it difficult to compare states accurately or determine where the virus is spreading faster or slower. It is clear, however, that all states have been experiencing the surge at the same time, something that didn't happen with the delta variant.

Even though Maine's rate of transmission is as high as it has ever been, the state ranks lowest among all states with 558 cases per 100,000 people over the last seven days, according to the U.S. Centers for Disease Control and Prevention. The national rate is 1,683 cases per 100,000 people.

It's unclear if the daily surge of positive tests in Maine has peaked or is still rising. Some parts of the country where omicron spread first are seeing cases plateau or even decline, but experts predict the wave to continue for several more weeks at least. And the positive test rate in Maine, coupled with the high number of tests, suggests the omicron wave is still moving through the state.

Michaud said although daily case counts are less reliable at capturing the current picture during the omicron surge, it's still important to be mindful of trends. Hospitalizations have become the more reliable metric during the omicron wave, but they are a lagging indicator of community spread.

"Focusing only on hospitalizations and not cases, that's really looking backward," he said. "By the time hospitalizations increase, that transmission has already occurred, so any preventive measures may not be as successful."

Meanwhile, the number of Mainers hospitalized with COVID-19 was at or above 400 for the seventh consecutive day on Tuesday. Of those currently in the hospital, 105 are in critical care and 50 are on ventilators.

Although the surge in new transmission has led to an increase in hospitalizations here and across the country, there are some signs that the omicron variant is causing less severe symptoms for some. The number of COVID-19 patients overall has increased steadily in Maine for several weeks, but the number of people requiring critical care or ventilators has leveled off or even decreased.

"I'd say the data in Maine is reflective of what we've seeing everywhere," Michaud said. "On an individual basis, omicron seems less severe than delta. The worry, of course, is that with astronomical cases, even a small fraction is an extremely large number."

The spread of the omicron variant has put increased strain on hospitals. Many will get assistance this week from members of the Maine Army National Guard. The two hospitals that will receive the most guard members are Maine Medical Center in Portland, with 30, and Mid Coast Hospital in Brunswick, with 19.

Vaccinations, meanwhile, have remained steady. Overall, Maine has administered 970,739 final doses, which means 72.2 percent of residents are fully vaccinated, and 530,942 boosters, which accounts for 39.5 percent of the population.

As has been the case for many months, some parts of the state have much lower rates of vaccination. Somerset County is the only county that has yet to reach 60 percent, and Franklin and Piscataquis are only slightly above 60 percent.

The nation's top infectious disease expert, Dr. Anthony Fauci, said Monday that it's possible the omicron variant could help COVID-19 transition from pandemic to endemic, which means it would still be present but wouldn't be as disruptive to society.

"But that would only be the case if we don't get another variant that eludes the immune response to the prior variant," he told the Davos Agenda, a virtual event this week held by the World Economic Forum.