Policy Analysis | September 2020

Spread of COVID-19 within Regions of the United States

Mikko Lindberg and Roger Moore

Last updated: September 10, 2020 (next update: September 24, 2020)

Disclaimer: The research presented here draws upon statistics used by a wide range of governmental and media agencies. Many concerns have been raised about the over-reporting and under-reporting of positive cases of COVID-19 and deaths attributed to COVID-19. This SLC Policy Analysis does not address these concerns and utilizes only the numbers that are known.

A multitude of governmental, private and nonprofit research entities are closely monitoring the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the novel coronavirus that causes coronavirus disease 2019 (COVID-19)1,2 – across the United States on city, county, state and national levels. However, until recently, a limited amount of research existed for how the virus has circulated on a regional basis.3

Since the response of the federal government to the pandemic focused primarily on international travel restrictions, economic stimulus and distribution of medical supplies,4,5 public safety measures addressing social distancing, school closures, shelter-in-place orders and other precautions were established by state governors, city mayors and county executives. Across the nation, the timing and extent of these measures varied widely, particularly shelter-in-place orders and subsequent state reopenings (see Appendices I-III).6,7,8 Many experts and officials warned that a similarly uncoordinated approach to phasing out public safety measures would lead to the resurgence in positive cases and deaths that began in June and continued the following two months.9,10,11,12

Given the limited amount of regional statistics for the proliferation of COVID-19, this SLC Policy Analysis, updated on a weekly basis, tracks the movement of SARS-Cov-2 in four regions of the United States, in relation to the state and territorial membership of The Council of Governments (CSG).

Regions of The Council of State Governments
Region Member states and territories
East Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Washington, D.C., Puerto Rico, U.S. Virgin Islands
Midwest Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin
South Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, West Virginia
West Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming, American Samoa, Guam, Northern Mariana Islands

Drawing on daily state-level data collected and published by The COVID Tracking Project – a volunteer organization launched from The Atlantic and referenced by Johns Hopkins,13 The White House and numerous national news syndicates – the following graphs portray seven-day moving averages14 for newly identified positive cases of COVID-19 and deaths attributed to COVID-19 within CSG’s regions and the nation. These figures are presented in two ways: 1) seven-day moving averages for the daily change in absolute numbers and 2) seven-day moving averages for the daily change per capita (see Appendix IV for population calculations).15

Of note, the sizable populations of certain states – such as California in the West; Florida and Texas in the South; New York and Pennsylvania in the East; and Illinois, Michigan and Ohio in the Midwest – have greater effect on the overall trend of their region. The state of New York, particularly, during the first peak of COVID-19 in the United States (April 2020), became the epicenter of the pandemic, accounting for more than 30 percent of the national total of confirmed positive cases and more than 40 percent of total deaths.16 Similarly, the more recent surges in the South and West were driven primarily, though not entirely, by an increase in cases in Arizona, California, Florida and Texas beginning in the middle of June. Although these states contribute a greater proportion of positive cases and deaths to the regional totals, the spread of COVID-19 generally follows a similar path in the other states of the region, albeit on a smaller scale.


Figure 1: Seven-day moving average of daily change in positive cases of COVID-19 in the United States and CSG regions (March 15 – September 9, 2020)

(Clicking a region in the legend will show and hide its line)

Figure 1 shows three distinct trends for the average daily change in positive cases of COVID-19 in the CSG regions. In the East, the seven-day moving average peaked on April 12 and steadily decreased until the third week of June. However, between June 22 and September 9, the seven day moving average increased 39 percent, from 2,360 to 3,272. In the Midwest, new positive cases peaked on May 4 and then declined until the middle of June, when there was a sharp uptick in cases that continued through the beginning of September. The number of new positive cases in the Midwest plateaued during most of August, before experiencing a rapid increase beginning August 21. As of September 9, the seven-day moving average in the Midwest has declined since peaking in the first week of September, though it remains much higher than any other month since the pandemic began. Meanwhile, the South and West followed similar paths, with moderate upward trajectories in the number of positive cases throughout the month of May, followed by more severe increases in June that continued unabated through the first three weeks of July. The highest seven-day moving average of new cases for the South and West occurred on July 19 and July 25, respectively. Since reaching their peaks, the seven-day moving average of new positive cases has decreased by 55 percent in the South and 60 percent in the West. Nationally, the trajectory of positive cases surged in the second week of June and continued through most of July, with the seven-day moving average reaching 66,720 on July 23. However, as of September 9, positive cases have declined 46 percent since the July 23 peak.


Figure 2: Seven-day moving average of daily change in positive cases of COVID-19 per one million people in the United States and CSG regions (March 15 – September 9, 2020)

(Clicking a region in the legend will show and hide its line)

Figure 2 underscores the distinct trajectories of new positive cases per capita in all four regions. The East and, to a less extent, the Midwest, were more affected by the virus during the first two months of the pandemic, while the South and West had a relatively small number of cases per capita. However, upward trajectories in the South and West resulted in both regions surpassing the East and Midwest during the first week of June, a discrepancy that widened significantly during June and most of July. In the South, the average daily change in new positive cases per capita peaked on July 19, at 318 new cases per one million people, while new positive cases in the West peaked on July 25, at 217 new cases per one million people. Meanwhile, a surge in positive cases in the Midwest, beginning in the middle of June and continuing through the beginning of September, pushed its seven-day moving average for September 5 to 147 per one million people. The previous high in the region, on May 4, was 109 per one million people. On August 24, the Midwest surpassed the West in the number of positive cases per one million people, and the increasing trend has continued into September. The difference in new positive cases per capita between the Midwest and South also has narrowed considerably. If current trends hold, the Midwest may surpass the South by the middle of September, making it the most affected region. The East continues to be less affected than the other three regions. Nationally, positive cases surpassed 200 per one million people for the first time on July 21. As of September 9, new positive cases per capita stood at 109 per one million people, a sizeable reduction since July 21.


Figure 3: Seven-day moving average of daily change in deaths caused by COVID-19 in the United States and CSG regions (March 15 – September 9, 2020)

(Clicking a region in the legend will show and hide its line)

Regionally, the progression of deaths attributed to COVID-19 (Figure 3) in the Midwest mostly followed the trajectory of seven-day moving averages in the daily change of positive cases until the middle of June, at which point positive cases continued increasing while deaths declined. Deaths in the Midwest continued declining until the second week of July, followed by modest increases beginning the second half of July and continuing through the beginning of September. In the East, the downward trend for average daily deaths plateaued between April 28 and May 7 – likely due to an earlier, short resurgence in new positive cases – but then began to decline rapidly again. Meanwhile, average daily deaths in the South and West remained consistent through the month of June, before increasing significantly at the beginning of July. Although the seven-day moving average in deaths is no longer increasing, the number of deaths remains elevated and significantly higher than at any point prior to the middle of July. As of September 9, deaths in the South and West were 427 and 169, respectively, compared to 191 and 123 at the beginning of July. Nationally, the seven-day moving average of deaths was 748 on September 9, a significant increase since the July 4 holiday, but much lower than the first peak of 2,090 on April 21.


Figure 4: Seven-day moving average of daily change in deaths caused by COVID-19 per one million people in the United States and CSG regions (March 15 – September 9, 2020)

(Clicking a region in the legend will show and hide its line)

The seven-day moving average for the daily change in deaths on a per capita basis (Figure 4) also displays a few notable regional comparisons. In the East and Midwest, average daily deaths per capita began growing rapidly on March 28 and peaked between the middle and end of April. Deaths began climbing in the South and West at the beginning of July and continued through the entire month. Deaths per capita in the South and West peaked and plateaued during the first half of August, then began to decline. The current trajectories indicate additional declines in deaths per capita in September, but it likely will be several weeks before the South and West reach levels experienced before the surge in July.

Total positive cases of COVID-19 and deaths attributed to COVID-19 within CSG’s regions and the United States (last updated September 9, 2020)

Region Estimated 2019 population Percent of total U.S. population Total positive cases Total positive cases per million people Percent of total U.S. positive cases (adjusted for population) Total deaths Total deaths per million people Percent of total U.S. deaths (adjusted for population)
East 67,008,095 20.2% 1,173,976 17,520 24.0% 70,049 1045 45.3%
Midwest 62,191,576 18.7% 963,460 15,492 21.2% 28,550 459 19.9%
South 123,992,683 37.4% 2,860,403 23,069 31.6% 57,396 463 20.1%
West 78,616,055 23.7% 1,331,566 16,938 23.2% 26,784 341 14.8%
United States 331,808,409 100.0% 6,329,405 19,075 100.0% 182,779 551 100.0%

As illustrated by Figures 1-4, states in the East have demonstrated some success in curbing the spread of the novel coronavirus. However, when factoring in the region's total population, Eastern states still account for 45 percent of total U.S. deaths, despite the recent surge in cases in the other regions. As of September 9, the South accounted for 31.6 percent of total positive cases, when adjusted for population, followed by the East at 24.0 percent. Meanwhile, relative to the size of their populations, the Midwest and West accounted for 21.2 percent and 23.2 percent of positive cases, respectively. Although the speed and severity of how SARS-CoV-2 is transferred from person to person is affected by multiple factors, the regional trajectories provided in this analysis indicate that the novel coronavirus is still active in many states, particularly in the Midwest, South and West. Nationally, deaths began increasing the first week of July after steadily declining since the initial peak in the middle of April. The national increase was primarily attributed to the South and West, where a surge in positive cases in June precipitated a proportional increase in deaths at the beginning of July. The data suggests that cases in the South and West have peaked, indicating that deaths in those regions may continue declining in the weeks ahead. However, with cases continuing to grow in the Midwest, reported deaths in that region could increase in September.


Appendix I – Start date of statewide shelter-in-place orders (as of April 9, 2020)

Source: Jennifer Kates, Josh Michaud and Jennifer Tolbert, "Stay-At-Home Orders to Fight COVID-19 in the United States: The Risks of a Scattershot Approach," Kaiser Family Foundation, April 5, 2020, updated April 9, 2020, https://www.kff.org/coronavirus-policy-watch/stay-at-home-orders-to-fight-covid19/.


Appendix II – Shelter-in-place orders for COVID-19 (as of April 30, 2020)

Source: “Shutdown, Shelter in Place, and Back to Work Orders in the U.S.: Current Status,” Bryan Cave Leighton Paisner LLP, May 1, 2020, https://www.bclplaw.com/en-US/insights/shutdown-shelter-in-place-and-back-to-work-orders-in-the-us-current-status.html.


Appendix III – Status of State Reopenings (as of July 29, 2020)

Source: Jasmine C. Lee et al., “See How All 50 States Are Reopening (and Closing Again),” The New York Times, updated July 29, 2020, https://www.nytimes.com/interactive/2020/us/states-reopen-map-coronavirus.html.


Appendix IV – Populations of CSG Regions
State/Territory/Region Population
Connecticut 3,565,287
Delaware 973,764
Maine 1,344,212
Maryland 6,045,680
Massachusetts 6,892,503
New Jersey 8,882,190
New Hampshire 1,359,711
New York 19,453,561
Pennsylvania 12,801,989
Rhode Island 1,059,361
Vermont 623,989
District of Columbia 705,749
Puerto Rico 3,193,694
U.S. Virgin Islands * 106,405
East 67,008,095
Illinois 12,671,821
Indiana 6,732,219
Iowa 3,155,070
Kansas 2,913,314
Michigan 9,986,857
Minnesota 5,639,632
Nebraska 1,934,408
Ohio 11,689,100
North Dakota 762,062
South Dakota 884,659
Wisconsin 5,822,434
Midwest 62,191,576
Alabama 4,903,185
Arkansas 3,017,804
Florida 21,477,737
Georgia 10,617,423
Mississippi 2,976,149
Missouri 6,137,428
Kentucky 4,467,673
Louisiana 4,648,794
North Carolina 10,488,084
Oklahoma 3,956,971
South Carolina 5,148,714
Tennessee 6,829,174
Texas 28,995,881
Virginia 8,535,519
West Virginia 1,792,147
South 123,992,683
Alaska 731,545
Arizona 7,278,717
California 39,512,223
Colorado 5,758,736
Hawaii 1,415,872
Idaho 1,787,065
Montana 1,068,778
Nevada 3,080,156
New Mexico 2,096,829
Oregon 4,217,737
Utah 3,205,958
Washington 7,614,893
Wyoming 578,759
American Samoa * 55,519
Northern Mariana Islands * 53,883
Guam * 159,385
West 78,616,055

Sources: “Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2019 (NST-EST2019-01),” U.S. Census Bureau, accessed May 6, 2020, https://www.census.gov/data/tables/time-series/demo/popest/2010s-state-total.html and “The U.S. Census Bureau Begins to Count U.S. Island Areas Populations,” Press Release, U.S. Census Bureau, March 2, 2020, https://www.census.gov/newsroom/press-releases/2020/2020-island-areas-populations.html.

* The U.S. Census Bureau does not estimate the populations of American Samoa, Guam, Northern Mariana Islands, and United States Virgin Islands between the decennial censuses. Their populations in 2010 are included and used in per capita calculations.


Notes:

1 “Human Coronavirus Types,” National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, U.S. Department of Health & Human Services, accessed May 7, 2020, https://www.cdc.gov/coronavirus/types.html.

2 “Naming the coronavirus disease (COVID-19) and the virus that causes it,” World Health Organization, accessed May 7, 2020, https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it.

3 As of May 7, 2020, the authors of this analysis were able to identify only one report that included regional COVID-19 statistics: “COVID-19 Updates,” Center for Health Metrics and Evaluation, American Heart Association, May 5, 2020, https://healthmetrics.heart.org/wp-content/uploads/2020/03/COVID-19-Updates_5-5-2020.pdf.

4 Caitlin Oprysko, Anita Kumar and Nahal Toosi, “Trump administration expands travel ban,” Politico, January 31, 2020, https://www.politico.com/news/2020/01/31/trump-administration-expands-travel-ban-110005.

5 Sharon Parrott et al., “CARES Act Includes Essential Measures to Respond to Public Health, Economic Crises, But More Will Be Needed,” Center on Budget and Policy Priorities, March 27, 2020, https://www.cbpp.org/research/economy/cares-act-includes-essential-measures-to-respond-to-public-health-economic-crises.

6 Jennifer Kates, Josh Michaud and Jennifer Tolbert, "Stay-At-Home Orders to Fight COVID-19 in the United States: The Risks of a Scattershot Approach," Kaiser Family Foundation, April 5, 2020, updated April 9, 2020, https://www.kff.org/coronavirus-policy-watch/stay-at-home-orders-to-fight-covid19/.

7 “Shutdown, Shelter in Place, and Back to Work Orders in the U.S.: Current Status,” Bryan Cave Leighton Paisner LLP, May 1, 2020, https://www.bclplaw.com/en-US/insights/shutdown-shelter-in-place-and-back-to-work-orders-in-the-us-current-status.html.

8 Jasmine C. Lee et al., “See How All 50 States Are Reopening (and Closing Again),” The New York Times, updated July 29, 2020, https://www.nytimes.com/interactive/2020/us/states-reopen-map-coronavirus.html.

9 Jennifer Kates et al., "Stay-At-Home Orders to Fight COVID-19." (See reference 6.)

10 Teresa Yamana, Sen Pei and Jeffrey Shaman, “Projection of COVID-19 Cases and Deaths in the US as Individual States Re-open,” May 4, 2020, Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, https://behcolumbia.files.wordpress.com/2020/05/yamana_etal_reopening_projections.pdf.

11 “Dr. Anthony Fauci & CDC Director Senate Testimony Transcript,” Rev.com, May 12, 2020, https://www.rev.com/blog/transcripts/dr-anthony-fauci-cdc-director-senate-testimony-transcript-may-12.

12 Teo Armus et al., “Live updates: Vaccine expert to warn of ‘darkest winter in modern history’ without coordinated U.S. response,” The Washington Post, accessed May 14, 2020, https://www.washingtonpost.com/nation/2020/05/14/coronavirus-update-us/.

13 The Coronavirus Resource Center of Johns Hopkins utilizes The Covid Tracking Project figures for testing and hospitalizations as one of multiple data sources to track COVID-19 globally and nationally.

14 Due to fluctuations in the timeliness in reporting new positive cases and deaths, a seven-day moving average is utilized to smooth out sporadic peaks and valleys of the reported numbers.

15 The total populations of CSG’s regions derive from the most recent state population (2019) and territorial (2010) estimates by the U.S. Census Bureau: “Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2019 (NST-EST2019-01),” U.S. Census Bureau, accessed May 6, 2020, https://www.census.gov/data/tables/time-series/demo/popest/2010s-state-total.html and “The U.S. Census Bureau Begins to Count U.S. Island Areas Populations,” Press Release, U.S. Census Bureau, March 2, 2020, https://www.census.gov/newsroom/press-releases/2020/2020-island-areas-populations.html.

16 "Our Data," The Covid Tracking Project at The Atlantic, accessed May 19, 2020, https://covidtracking.com/data.