COVID Map Shows Positive Cases Across US Regions

New data shows that Americans living in the Midwest and the Great Lakes regions are suffering the highest prevalence of COVID-19 infections in the country, according to the Centers for Disease Control and Prevention (CDC).

Each week, the CDC produces a map of the U.S. showing the test positivity percentages for swathes of the country. Results are no longer provided for individual states, but are instead recorded as an average across various administrative regions.

In the latest CDC map, published online on Monday, December 4, but relating to weekly data collected through November 25, three of those regions (covering 16 states) have seen between 12.1 percent and 16.2 percent of people who took the test receiving a diagnosis of COVID-19. Those are the highest rates of the virus being detected in the country.

COVID-19, a new strain of coronavirus that emerged in late 2019/early 2020, is an extremely contagious respiratory virus that hits older people and those with underlying medical conditions (such as asthma, heart disease, and obesity) particularly hard. The disease first originated in China but went on to infect millions of people worldwide, and had already killed 675,000 Americans by September 2021 before the roll-out of the COVID-19 vaccine.

This week's map shared by the CDC provides a breakdown of how many people were diagnosed with COVID-19 after taking a test.

Region Seven—an administrative area consisting of Iowa, Missouri, Kansas, and Nebraska—had the highest percentage of positive tests in the U.S. Some 16.2 percent of tests were positive, out of 5,316 tests taken. Those results are up 1.9 percent on the previous week's figures.

Across Region Five—Ohio, Indiana, Illinois, Michigan, Wisconsin, and Minnesota—the results were only marginally better, although more tests were conducted. Some 14.4 percent of tests were positive, out of 12,382 tests taken. Those figures were up 1.6 percent, compared to the figures the week before.

Region Eight—the Dakotas, Montana, Wyoming, Utah, and Colorado—had a test positivity rate of 12.1 percent, out of 4,191 tests. That represents a fall of 1.3 percent on the previous week's statistics.

All three of those CDC regions were the areas suffering the highest number of positive cases in last week's figures, too, meaning there has been little change in the worst-hit areas.

A CDC spokesperson previously told Newsweek that fall usually marks the typical start of the respiratory virus season and said hospitalization rates could increase with the onset of winter.

Colder weather tends to lead to an increased spread in viruses and other infections. Immunity is lower then, due to the chilly temperatures resulting in more nasal mucus, which makes it easier for viruses to set up home there.

Compounding that, one 2020 study found that the COVID-19 virus itself could remain active for longer in cold, dry conditions.

Some regions or venues have said recently that they are considering bringing back mask mandates in an attempt to tackle the spread of the infection.