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Counties doing the most and least COVID-19 testing in every state

  • Counties doing the most and least COVID-19 testing in every state

    The United States is in the midst of a COVID-19 surge, with a record-setting 85,000 new cases on Oct. 23 after weeks of steadily rising infections. The Midwest, west, and rural areas are experiencing growing outbreaks, and cold temperatures could help the virus flourish even more. This “third wave” of coronavirus outbreaks is prompting the public and policymakers to assess the available data to inform how to combat outbreaks, but breakdowns in data that appear to be straightforward can belie the more-complex realities of infection, transmission, testing, and survival. Test positivity rates, for example, show a simple snapshot of which areas are experiencing climbing rates of infection. But as scientists point out, looking solely to the test positivity rates only reveals one part of the picture: that of the group of people who got tested—not of the whole population.

    That’s why it’s so important to track testing rates in addition to positivity rates. As John Hopkins’ Coronavirus Resource Center notes, the testing rate, in addition to the number of new daily cases and the positivity rate, are the best metrics “for understanding the reach and severity of COVID-19 in a given area.” With increasing testing comes a more-complete understanding of the coronavirus’ spread and impact across the U.S., down to the county level. And this more complete understanding is what policymakers need when considering imposing new lockdowns, lifting restrictions, and instituting rules around distancing and mask wearing.

    In an effort to contribute to that fuller picture, Stacker compiled the counties doing the most and least COVID-19 testing in every state. Every Monday, the Center for Medicare and Medicaid Services updates a dataset on COVID-19 testing at the county level. The data include total tests conducted in every U.S. county, tests per 100,000 population, and test positivity rates, all for a 14-day period. The CMS dataset only includes polymerase chain reaction (PCR) tests, not antigen or antibody tests, and is compiled from state public health departments and the Department of Health and Human Services. In this story, counties were ranked based on testing rates adjusted by county populations. Test positivity rates are not calculated for counties that have conducted fewer than 20 tests in the past 14 days. State values are calculated by summing total tests from all counties in the state and by averaging county positivity rates in the state. This story includes the most recent data, for Oct. 8 through Oct. 21 (published on Oct. 26).

    Read on to see which counties in your state are doing the most—and the least—testing to combat COVID-19.

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  • Alabama

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 154,020
    - Tests per 100,000 people: 3,141 (#35 highest of all states)
    - Average test positivity rate: 10.1% (#14 highest)

    Counties doing the most testing:
    - #1. Jackson County (7,173 tests per 100k, 11.0% positivity rate)
    - #2. Marengo County (6,770 tests per 100k, 12.6% positivity rate)
    - #3. Butler County (6,397 tests per 100k, 5.1% positivity rate)

    Counties doing the least testing:
    - #1. Chambers County (884 tests per 100k, 6.8% positivity rate)
    - #2. Choctaw County (1,056 tests per 100k, 6.0% positivity rate)
    - #3. Dallas County (1,137 tests per 100k, 6.4% positivity rate)

  • Alaska

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 82,469
    - Tests per 100,000 people: 11,273 (#3 highest of all states)
    - Average test positivity rate: 3.8% (#38 highest)

    Counties doing the most testing:
    - #1. Sitka City and Borough (42,553 tests per 100k, 0.6% positivity rate)
    - #2. Nome Census Area (39,414 tests per 100k, 0.7% positivity rate)
    - #3. Kusilvak Census Area (30,407 tests per 100k, 14.8% positivity rate)

    Counties doing the least testing:
    - #1. Lake and Peninsula Borough (under 20 tests)
    - #2. Yukon-Koyukuk Census Area (1,606 tests per 100k, 1.2% positivity rate)
    - #3. Prince of Wales-Hyder Census Area (2,176 tests per 100k, 0.0% positivity rate)

  • Arizona

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 203,618
    - Tests per 100,000 people: 2,797 (#38 highest of all states)
    - Average test positivity rate: 7.4% (#26 highest)

    Counties doing the most testing:
    - #1. Coconino County (5,754 tests per 100k, 6.6% positivity rate)
    - #2. Santa Cruz County (5,723 tests per 100k, 3.0% positivity rate)
    - #3. Gila County (3,732 tests per 100k, 13.5% positivity rate)

    Counties doing the least testing:
    - #1. Mohave County (1,037 tests per 100k, 4.7% positivity rate)
    - #2. Greenlee County (1,042 tests per 100k, 16.2% positivity rate)
    - #3. Cochise County (1,327 tests per 100k, 7.4% positivity rate)

  • Arkansas

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 133,368
    - Tests per 100,000 people: 4,419 (#21 highest of all states)
    - Average test positivity rate: 7.9% (#21 highest)

    Counties doing the most testing:
    - #1. Jackson County (9,863 tests per 100k, 8.2% positivity rate)
    - #2. Phillips County (8,975 tests per 100k, 6.8% positivity rate)
    - #3. Lee County (8,739 tests per 100k, 2.7% positivity rate)

    Counties doing the least testing:
    - #1. Little River County (1,273 tests per 100k, 9.6% positivity rate)
    - #2. Baxter County (1,436 tests per 100k, 12.5% positivity rate)
    - #3. Howard County (1,485 tests per 100k, 9.7% positivity rate)

  • California

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 942,810
    - Tests per 100,000 people: 2,386 (#42 highest of all states)
    - Average test positivity rate: 3.0% (#41 highest)

    Counties doing the most testing:
    - #1. San Francisco County (5,429 tests per 100k, 0.8% positivity rate)
    - #2. Marin County (4,468 tests per 100k, 1.3% positivity rate)
    - #3. Santa Clara County (3,609 tests per 100k, 1.5% positivity rate)

    Counties doing the least testing:
    - #1. Kern County (1,759 tests per 100k, 4.1% positivity rate)
    - #2. Orange County (1,772 tests per 100k, 3.1% positivity rate)
    - #3. Stanislaus County (1,783 tests per 100k, 3.9% positivity rate)

     

  • Colorado

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 225,830
    - Tests per 100,000 people: 3,922 (#26 highest of all states)
    - Average test positivity rate: 3.7% (#39 highest)

    Counties doing the most testing:
    - #1. Logan County (20,121 tests per 100k, 7.1% positivity rate)
    - #2. Fremont County (19,731 tests per 100k, 4.6% positivity rate)
    - #3. Baca County (14,354 tests per 100k, 1.0% positivity rate)

    Counties doing the least testing:
    - #1. Costilla County (under 20 tests), Hinsdale County (under 20 tests), Jackson County (under 20 tests), Mineral County (under 20 tests), San Juan County (under 20 tests)
    - #2. Alamosa County (493 tests per 100k, 0.0% positivity rate)
    - #3. Dolores County (1,022 tests per 100k, 0.0% positivity rate)

  • Connecticut

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 88,507
    - Tests per 100,000 people: 2,482 (#40 highest of all states)
    - Average test positivity rate: 2.7% (#44 highest)

    Counties doing the most testing:
    - #1. New London County (3,825 tests per 100k, 4.0% positivity rate)
    - #2. Windham County (3,013 tests per 100k, 3.1% positivity rate)
    - #3. Litchfield County (2,720 tests per 100k, 1.5% positivity rate)

    Counties doing the least testing:
    - #1. New Haven County (2,013 tests per 100k, 2.7% positivity rate)
    - #2. Fairfield County (2,301 tests per 100k, 3.0% positivity rate)
    - #3. Tolland County (2,365 tests per 100k, 2.1% positivity rate)

  • Delaware

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 60,038
    - Tests per 100,000 people: 6,166 (#10 highest of all states)
    - Average test positivity rate: 2.7% (#43 highest)

    Counties doing the most testing:
    - #1. New Castle County (7,272 tests per 100k, 2.4% positivity rate)
    - #2. Sussex County (5,052 tests per 100k, 4.0% positivity rate)
    - #3. Kent County (4,189 tests per 100k, 1.8% positivity rate)

    Counties doing the least testing:
    - #1. Kent County (4,189 tests per 100k, 1.8% positivity rate)
    - #2. Sussex County (5,052 tests per 100k, 4.0% positivity rate)
    - #3. New Castle County (7,272 tests per 100k, 2.4% positivity rate)

  • Florida

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 701,276
    - Tests per 100,000 people: 3,265 (#33 highest of all states)
    - Average test positivity rate: 6.4% (#31 highest)

    Counties doing the most testing:
    - #1. Alachua County (5,312 tests per 100k, 5.6% positivity rate)
    - #2. Suwannee County (4,732 tests per 100k, 5.0% positivity rate)
    - #3. Miami-Dade County (4,638 tests per 100k, 6.0% positivity rate)

    Counties doing the least testing:
    - #1. Glades County (840 tests per 100k, 14.7% positivity rate)
    - #2. Santa Rosa County (968 tests per 100k, 5.7% positivity rate)
    - #3. Bay County (1,178 tests per 100k, 4.4% positivity rate)

  • Georgia

    Overall state testing (PCR only, 10/8 to 10/21):
    - Total PCR tests: 251,697
    - Tests per 100,000 people: 2,371 (#43 highest of all states)
    - Average test positivity rate: 7.9% (#23 highest)

    Counties doing the most testing:
    - #1. Miller County (10,336 tests per 100k, 3.4% positivity rate)
    - #2. Fulton County (7,535 tests per 100k, 5.4% positivity rate)
    - #3. Ware County (4,500 tests per 100k, 8.3% positivity rate)

    Counties doing the least testing:
    - #1. Clay County (under 20 tests), Quitman County (under 20 tests), Taliaferro County (under 20 tests), Webster County (under 20 tests)
    - #2. Catoosa County (402 tests per 100k, 6.6% positivity rate)
    - #3. Telfair County (448 tests per 100k, 19.7% positivity rate)