How omicron is changing what we know about COVID-19 – Press Herald

Cases are soaring, hospitals are filled, people are lining up at testing sites, and yet, after nearly two years of living with COVID-19, the pandemic has fundamentally changed.

And how we track and measure the pandemic is shifting, too.Its as if we have to set aside everything weve learned since March 2020 and learn a new way of thinking about the pandemic.

How we interpret the current numbers number of cases, hospitalizations, positivity rates has to change as the epidemic itself evolves, said Joshua Michaud, associate director of global health policy at the Kaiser Family Foundation, a national health policy think tank.

Unlike earlier versions of the virus, the omicron variant is changing the nature of the pandemic. Omicron now causing an estimated 95 percent of all COVID-19 cases in the U.S. is much different than delta and previous variants, in its genetic structure and its behavior.

Some of its mutations make it far more contagious, fueling fears of even more hospital patients and worsened staffing shortages. But it also appears less severe, with research indicating it is more likely to stay in the upper respiratory tract and not migrate to the lungs, where it can cause more respiratory distress and the potential for long-term lung scarring.

Things are worse, but also better.

Everything is really different than it was just a few weeks ago, said Dr. Dora Anne Mills, chief health improvement officer at MaineHealth.

The ways we have measured the virus daily case counts, 7-day averages and positive tests are less useful now. Even the number of hospitalized patients the new gold standard of tracking data must change to keep up with omicron, according to some experts.

And some health experts are calling for an entirely new approach to omicron.

A NEW APPROACH

A team of Biden health care advisers published a series of health policy articles Thursday in the Journal of the American Medical Association arguing that public health policy should adjust to a new normal in the pandemic.

The new normal requires recognizing that (COVID-19) is but one of several circulating respiratory viruses that include influenza, respiratory syncytial virus (RSV), and more. COVID-19 must now be considered among the risks posed by all respiratory viral illnesses combined, according to the report.

But with omicron being so much more contagious, the health system is dealing with a lot more disease all at once, again threatening hospital systems that are struggling to preserve enough capacity to care for COVID-19 patients.

Omicron is so extremely contagious it is like having a field thats completely on fire, Mills said. With delta, theres a lot of fires here and there but you could walk through the fields and not get burnt. Now the whole field is on fire.

FUTURE IS MURKY

COVID-19 has been unpredictable from the start. Now omicron is making it even more difficult to see the future.

According to some predictions by public health experts, omicron will peak in mid- to late-January or early February and then quickly subside, similar to what happened or is happening in South Africa, the U.K. and Denmark.

But there are still many unknowns because of differences in vaccination levels and demographics between Maine, the rest of the United States and other countries.

With about 75 percent of its population vaccinated, Maine has one of the highest rates of immunization in the U.S., and those who are vaccinated are about nine times less likely to be hospitalized if they fall ill with COVID-19, according to U.S. CDC research. But Maine also has uneven vaccination rates, with some areas like Cumberland County and other coastal counties nearing or topping 80 percent vaccinated, while more rural and interior areas have vaccination rates 20 percentage points lower.

The crystal ball over the next few weeks is very murky, Mills said.

Officially, 8.75 percent of samples from positive tests in Maine were found to be from omicron in late December, but public health officials believe the percentage is much higher now. With omicron causing exponential growth, public health officials expect it will soon be the dominant strain in Maine, if it is not already.

BEYOND CASE COUNTS

Case counts, long a staple of measuring the pandemic, are becoming less relevant.

The number of cases is important to know, but its not anymore a good reflection of what is happening in the pandemic. This is especially true of omicron, Michaud said.

It was always true that some cases went uncounted, whether because an infected person never had symptoms or because they recovered at home and never got tested. But with the proliferation of at-home testing, the official daily count is even less reflective of the actual number of cases. With home-tests combining with a milder version of the disease that can mimic the common cold in some cases, omicron is likely resulting in a growing undercount of daily cases.

Also, because there are so many confirmed infections, the Maine CDC has had a persistent backlog of cases some are several days to a week old before they are reported in the daily case count. That wasnt happening when there were 100 cases a day, but with more than 10 times that amount needing to be verified, its backing up the agency workers who release the daily count.

Dr. Nirav Shah, Maine CDC director, said the importance of the daily announcement of new cases has waned as even experts seek a better understanding of whats happening.

Were just searching for metrics that better and more granularly tell us whats really going on on a day-to-day basis, Shah said during Wednesdays media briefing. Whats a signal, and whats noise?

POSITIVE TESTS LOSE RELEVANCE

Positivity rates, another metric often used to measure how much virus was circulating, are also less telling.

The positivity rate measures the percent of tests that come back positive. Earlier in the pandemic, experts considered it a key indicator for when to tighten or loosen health safety guidelines and recommendations. Now, however, the wider availability of at-home tests is skewing the metric. Those are not included in positivity rates.

The testing shortage is also affecting positivity rates, Michaud said. With a shortage of testing appointments causing longer wait times, fewer asymptomatic people who think they may have been exposed to COVID-19 are likely to bother seeking a test. Gov. Janet Mills administration said Friday it is attempting to address the test shortage by purchasing 250,000 rapid tests from Abbott Labs to distribute to pharmacies and other places.

It is harder to draw conclusions based on the positivity rate compared to previously in the pandemic, Michaud said.

Shah said the Maine CDC now looks at positivity rates from one or two incubation periods ago 14 to 28 days but does not compare the rates to several months ago or a year ago, because so much has changed.

Maines positivity rate is 18.05 percent, about double what it was two weeks ago and higher than at any point during the pandemic. But because many people are not getting tested or are testing but not being counted, those comparisons no longer mean what they once did.

HOSPITALIZATIONS WATCHED CLOSELY

Shah said last week that hospitalizations are now a better metric to focus on.

We focus on the metrics that really tell us whats going on, Shah said. Our team really focuses on things like hospitalizations, intensive care unit utilization and ventilator utilization.

Hospitalizations reached a new peak Saturday, with 399 patients throughout Maine. But the number of intensive care patients has flattened this week, and stood at 106 on Saturday.

That decoupling of hospitalizations with ICU patients has been seen in the U.K., Denmark and so far in some hospitals in the U.S. where communities have been hit with earlier omicron waves, such as New York City. Hospitalizations increase with omicron, but with the average patient getting less sick, the number of people admitted to ICUs and on ventilators remains flat, according to some research and on-the-ground experience at hospitals.

But that may not be the case in Maine this winter, Dr. Mills warns. Thats because Maine, New Hampshire and Vermont were in the midst of delta variant surges, which had subsided in other states before omicron started taking over. The potential of a longer overlap with both delta and omicron patients in the hospital could be dangerous for the state.

Were going to be seeing more disease in our hospitals, Mills said. The next four weeks were just going to have to take everything hour by hour and day by day.

HOSPITALIZED WITH VERSUS FOR COVID

Some experts are even calling for a new way of counting hospitalizations because of omicron.

As hospitals fill with patients, hospital officials in other states are noticing a difference compared to the delta and other previous surges. With omicron, more patients in the hospital for other reasons such as a broken ankle or cancer treatment are then testing positive for COVID-19. That happened far less often with the delta variant.

The U.K. and New York state now have separate categories for these patients, one for those admitted to the hospital for COVID-19 and another for those hospitalized with COVID-19 because they tested positive after being admitted for another reason.

Some U.S. hospitals experiencing an omicron surge including in New York, California and Washington state are reporting 50 to 75 percent of their COVID-19 patients were hospitalized for another reason.

Michaud, the Kaiser Family Foundation health expert, said that as omicron sweeps through the nation, he could see more states separating COVID-19 patients into the different categories rather than lumping them all together.

I do think its an important distinction, especially with omicron, Michaud said.

New York state Friday released statistics showing that 57 percent of COVID-19 patients statewide were admitted to hospitals for COVID-19, while for the remaining 43 percent COVID-19 was not included as one of the reasons for admission.

Maine officials say they see drawbacks to separating the counts, however.

Shah said given the pressures from the surge, hes not sure that devoting limited resources to categorize patients with and for COVID-19 is necessary. All patients with COVID-19 in a hospital use up more resources than patients without the disease because of the safety protocols and personal protective equipment requirements for health care workers. And some medically vulnerable patients, such as cancer patients, could end up very ill with COVID-19, even if that wasnt the original reason they were admitted.

From a health system utilization perspective, the difference between with and for doesnt matter when our hospitals are under such great strain, Shah said. On some level, this is a distinction without a difference.

In England, about 70 percent of hospitalized COVID-19 patients are being treated primarily for COVID-19, with the remaining 30 percent testing positive after being admitted for another reason, according to government statistics.

John Bell, a University of Oxford medicine professor, told the BBC in late December that hospitals are also seeing an entirely different kind of COVID-19 patient.

They dont need high-flow oxygen, average length of stay is apparently three days, he said. This is not the same disease as we were seeing a year ago.

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How omicron is changing what we know about COVID-19 - Press Herald