The New World screwworm's spread into the United States

Active · last development Oct 23, 2026: “State and fed AG officials respond to New Mexico’s 5th New World screwworm case”

What this arc covers

The flesh-eating New World screwworm parasite and its spread into the United States: the US halt to live cattle imports from Mexico in May 2025, the first US human case, reported in Maryland, Texas Gov. Greg Abbott's disaster declaration, the fly's detection in south Texas in June 2026 and the cases that followed in Texas and New Mexico, the quarantine zones and their lifting, the emergency approval of medications for pets, lawmakers' questions to the Agriculture Department about its response, the reopening of livestock crossings to Mexican cattle, and the parasite's discovery in US wildlife.

Earliest story we hold May 12, 2025 · 30 stories · 88 sources (counted once each) · 529 days

Part ofTexasMexicoUnited States Department of AgricultureNew MexicoUnited States Food and Drug AdministrationMarylandUnited States Centers for Disease Control and PreventionGreg Abbott
Photo from News Nation Now, with New World screwworm detected in calf in Hidalgo County, NM (Oct 21, 2026), the story with the most sources this week.

Where it standsnewest first · each bar runs left to right by leaning

Oct 232026State and fed AG officials respond to New Mexico’s 5th New World screwworm case1 article · 1 source
0 left, 1 center, 0 right
Oct 21– 242026New World screwworm detected in calf in Hidalgo County, NM41 articles · 21 sources
2 left, 15 center, 2 right
Oct 15– 1720262 new cases of screwworm confirmed in New Mexico6 articles · 6 sources
0 left, 6 center, 0 right

Key momentsthe most covered; every story is below

  1. Aug 25 – 26, 2025Screwworm confirmed in US with first human case reported in Maryland: CDC70 articles · 35 sources
  2. Jun 3 – 5, 2026Screwworm fly detected in Texas decades after cattle threat was largely eradicated in US32 articles · 20 sources
  3. Jun 4 – 9, 2026A flesh-eating cattle parasite spreads beyond Texas as new screwworm cases are found61 articles · 35 sources
    1. Jun 4, 2026‘Horror’ flesh-eating New World screwworm case detected in Texas: USDA
    2. Jun 6, 2026Second screwworm case in Texas confirmed, as Abbott expands state disaster declaration
    3. Jun 8, 2026Texas confirms three new screwworm cases; A&M leader named adviser
  4. Jul 6 – 10, 2026How to protect your pets from the New World screwworm fly25 articles · 23 sources
    1. Jul 6, 2026Only center coverage:New World screwworm cases rise to 32 inside the U.S.
    2. Jul 8, 2026What pet owners need to know about the New World screwworm threat
  5. Jul 25 – 28, 2026US to reopen border to Mexican cattle imports after screwworm shutdown35 articles · 21 sources
  6. Aug 19 – 21, 2026Texas pet adoptions on hold due to concerns about New World screwworm13 articles · 13 sources
  7. Oct 21 – 24, 2026New World screwworm detected in calf in Hidalgo County, NM41 articles · 21 sources

Who covered it, over timeshare of the sources publishing each week, by side

May 12, 2025 - Oct 25, 2026

Share of the sources publishing each week that covered it

0%4%8%12%16%20%
Arrow keys move between weeks.
May 2025Aug 2025Dec 2025Mar 2026Jul 2026Oct 2026

LeftCenterRight

Week of Oct 19, 2026 - Oct 25, 2026: 2 left, 15 center, 2 right, 4% of the sources that published that week · 40 articles

Show every week as a table
WeekLeftCenterRightArticlesShare
May 12, 2025 - May 18, 2025451155%
May 19, 2025 - May 25, 202500000%
May 26, 2025 - Jun 1, 202500000%
Jun 2, 2025 - Jun 8, 202500000%
Jun 9, 2025 - Jun 15, 202500000%
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Jun 23, 2025 - Jun 29, 202500000%
Jun 30, 2025 - Jul 6, 202500000%
Jul 7, 2025 - Jul 13, 202500000%
Jul 14, 2025 - Jul 20, 202500000%
Jul 21, 2025 - Jul 27, 202522153%
Jul 28, 2025 - Aug 3, 202500000%
Aug 4, 2025 - Aug 10, 202500000%
Aug 11, 2025 - Aug 17, 202500000%
Aug 18, 2025 - Aug 24, 202500000%
Aug 25, 2025 - Aug 31, 202572156817%
Sep 1, 2025 - Sep 7, 202500000%
Sep 8, 2025 - Sep 14, 202500000%
Sep 15, 2025 - Sep 21, 202500000%
Sep 22, 2025 - Sep 28, 202500000%
Sep 29, 2025 - Oct 5, 202500000%
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Oct 13, 2025 - Oct 19, 202500000%
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Oct 27, 2025 - Nov 2, 202500000%
Nov 3, 2025 - Nov 9, 202500000%
Nov 10, 2025 - Nov 16, 202500000%
Nov 17, 2025 - Nov 23, 202500000%
Nov 24, 2025 - Nov 30, 202500000%
Dec 1, 2025 - Dec 7, 202500000%
Dec 8, 2025 - Dec 14, 202500000%
Dec 15, 2025 - Dec 21, 202500000%
Dec 22, 2025 - Dec 28, 202500000%
Dec 29, 2025 - Jan 4, 202600000%
Jan 5, 2026 - Jan 11, 202600000%
Jan 12, 2026 - Jan 18, 202600000%
Jan 19, 2026 - Jan 25, 202600000%
Jan 26, 2026 - Feb 1, 202603162%
Feb 2, 2026 - Feb 8, 202600000%
Feb 9, 2026 - Feb 15, 202600000%
Feb 16, 2026 - Feb 22, 202600000%
Feb 23, 2026 - Mar 1, 202600000%
Mar 2, 2026 - Mar 8, 202600000%
Mar 9, 2026 - Mar 15, 202600000%
Mar 16, 2026 - Mar 22, 202600000%
Mar 23, 2026 - Mar 29, 202600000%
Mar 30, 2026 - Apr 5, 202600000%
Apr 6, 2026 - Apr 12, 202600000%
Apr 13, 2026 - Apr 19, 202600000%
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Apr 27, 2026 - May 3, 202600000%
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May 11, 2026 - May 17, 202600000%
May 18, 2026 - May 24, 202600000%
May 25, 2026 - May 31, 202600000%
Jun 1, 2026 - Jun 7, 2026101876819%
Jun 8, 2026 - Jun 14, 2026694289%
Jun 15, 2026 - Jun 21, 202600000%
Jun 22, 2026 - Jun 28, 2026240341%
Jun 29, 2026 - Jul 5, 20261406under 1%
Jul 6, 2026 - Jul 12, 20265135254%
Jul 13, 2026 - Jul 19, 20260303under 1%
Jul 20, 2026 - Jul 26, 20263131303%
Jul 27, 2026 - Aug 2, 202606291%
Aug 3, 2026 - Aug 9, 202600000%
Aug 10, 2026 - Aug 16, 20260100362%
Aug 17, 2026 - Aug 23, 20263121263%
Aug 24, 2026 - Aug 30, 20265122294%
Aug 31, 2026 - Sep 6, 20260305under 1%
Sep 7, 2026 - Sep 13, 202600000%
Sep 14, 2026 - Sep 20, 2026061141%
Sep 21, 2026 - Sep 27, 20260305under 1%
Sep 28, 2026 - Oct 4, 202600000%
Oct 5, 2026 - Oct 11, 202600000%
Oct 12, 2026 - Oct 18, 202606061%
Oct 19, 2026 - Oct 25, 20262152404%

Stories before June 28, 2026 come from archived pages, so who covered them is limited to the outlets we recovered for that period.

27% left · 51% center · 22% right of 88 sources on the spectrum, across 30 stories.

Every storynewest first

  1. October 2026

    1. Oct 23State and fed AG officials respond to New Mexico’s 5th New World screwworm case1 article · 1 source
      0 left, 1 center, 0 right
    2. Oct 21– 24New World screwworm detected in calf in Hidalgo County, NM41 articles · 21 sources
      2 left, 15 center, 2 right
    3. Oct 15– 172 new cases of screwworm confirmed in New Mexico6 articles · 6 sources
      0 left, 6 center, 0 right

  2. September 2026

    1. Sep 25Texas lifts screwworm quarantine zones in several counties5 articles · 3 sources
      0 left, 3 center, 0 right
    2. Sep 17– 18New screwworm case unlikely to affect reopening of livestock crossing5 articles · 2 sources
      0 left, 2 center, 0 right
    3. Sep 17Santa Teresa livestock crossing to reopen amid New World screwworm prevention efforts3 articles · 2 sources
      0 left, 2 center, 0 right
    4. Sep 15– 18Horse in New Mexico infected with screwworm before Mexico livestock imports resume6 articles · 6 sources
      0 left, 5 center, 1 right
    5. Sep 4– 62 New World screwworm quarantine areas lifted in Texas, congressman says5 articles · 3 sources
      0 left, 3 center, 0 right

  3. August 2026

    1. Aug 30'It's a relief': How 100% inspections regulate Mexican cattle exports to US5 articles · 3 sources
      1 left, 1 center, 1 right
    2. Aug 24– 26Mexican cattle imports restart in Arizona as screwworm cases decline7 articles · 5 sources
      1 left, 4 center, 0 right
    4. Aug 22– 24Mexican ranchers prepare to resume livestock sales to US under tight controls over screwworm risk17 articles · 10 sources
      2 left, 8 center, 0 right
    5. Aug 19– 21Texas pet adoptions on hold due to concerns about New World screwworm13 articles · 13 sources
      3 left, 9 center, 1 right
    6. Aug 15– 16FDA green lights more screwworm medications: Should you give them to your pets?15 articles · 7 sources
      0 left, 7 center, 0 right
    7. Aug 12– 13More cases of parasitic screwworm confirmed. Here's who is at risk, where it's spreading15 articles · 7 sources
      0 left, 7 center, 0 right
    8. Aug 10– 11Heat-sensing drones help find screwworms on the border6 articles · 4 sources
      0 left, 4 center, 0 right

  4. July 2026

    1. Jul 25– 28US to reopen border to Mexican cattle imports after screwworm shutdown35 articles · 21 sources
      3 left, 15 center, 3 right
    2. Jul 20– 21Judge signs disaster declaration after first screwworm case reported in Starr County2 articles · 2 sources
      0 left, 2 center, 0 right
    3. Jul 19– 20New World screwworm found in calf in the Valley5 articles · 5 sources
      0 left, 5 center, 0 right
    4. Jul 6– 10How to protect your pets from the New World screwworm fly25 articles · 23 sources
      5 left, 13 center, 5 right
    5. Jul 1'Infested zones,' new screwworm cases have border residents on edge5 articles · 4 sources
      0 left, 4 center, 0 right

  5. June 2026

    1. Jun 26– 29Moderate US House Dem group questions USDA’s Rollins over screwworm response11 articles · 1 source
      1 left, 0 center, 0 right
    2. Jun 22– 25U.S. New World Screwworm cases rise to 20 as Texas outbreak expands24 articles · 5 sources
      1 left, 4 center, 0 right
    3. Jun 11– 13FDA approves emergency use of medication to treat screwworm in dogs, cats7 articles · 5 sources
      1 left, 3 center, 1 right
    4. Jun 4– 9A flesh-eating cattle parasite spreads beyond Texas as new screwworm cases are found61 articles · 35 sources
      13 left, 14 center, 5 right
    5. Jun 3– 5Screwworm fly detected in Texas decades after cattle threat was largely eradicated in US32 articles · 20 sources
      3 left, 11 center, 5 right

  6. January 2026

  1. August 2025

    1. Aug 25– 26Screwworm confirmed in US with first human case reported in Maryland: CDC70 articles · 35 sources
      7 left, 21 center, 5 right

  2. July 2025

  3. May 2025

    1. May 12Screwworm threat forces US to halt cattle imports from Mexico: What to know15 articles · 10 sources
      4 left, 5 center, 1 right