# We beat screwworm once. Here's how we're trying to do it again

> Scientific American recounts how screwworm was eliminated from the U.S. in 1966 through a sterile-insect technique, and how the parasite returned on June 3, 2026, with larvae found in a calf in Zavala County, Texas, followed by confirmed cases in three other counties and a dog in New Mexico. The USDA has confirmed the new outbreak.

- Date: 2026-11-14 · published 2026-11-14T12:12:36.838Z
- Category: disease · region US · magnitude low
- Page: https://feedsoft.ai/events/99364-we-beat-screwworm-once-here-s-how-we-re-trying-to-do-it-again
- Commodities: [Live Cattle](https://feedsoft.ai/c/LCATTLE.md), [Feeder Cattle](https://feedsoft.ai/c/FCATTLE.md)

## Why it matters

Screwworm infestations threaten cattle herds and can force movement restrictions and import limits on live cattle and beef, tightening supply and lifting cattle prices. A renewed outbreak raises uncertainty for feeder and live cattle markets.

## Read by commodity

- FCATTLE: bullish ▲
- LCATTLE: bullish ▲

## Similar past events

| Commodity | Date | Event | 5-day % | 20-day % |
| --- | --- | --- | --- | --- |
| LCATTLE | 2024-06-20 | [Mexico reinforces health surveillance against screwworm threat](https://feedsoft.ai/events/29682-mexico-reinforces-health-surveillance-against-screwworm-threat.md) | +2.3% | -0.8% |
| LCATTLE | 2026-03-27 | [Screwworm Fears are Reshaping the U.S. Cattle Feeding Industry](https://feedsoft.ai/events/20119-screwworm-fears-are-reshaping-the-u-s-cattle-feeding-industry.md) | +2.5% | +5.6% |
| LCATTLE | 2023-10-22 | [A screwworm fly that bedeviled cattle ranchers decades ago has returned to Texas](https://feedsoft.ai/events/33562-a-screwworm-fly-that-bedeviled-cattle-ranchers-decades-ago-has-returned-to-texas.md) | +0.4% | -3.5% |
| LCATTLE | 2025-07-28 | [Avian Flu Wiped Out Poultry. Now the Screwworm Is Coming for Beef.](https://feedsoft.ai/events/23704-avian-flu-wiped-out-poultry-now-the-screwworm-is-coming-for-beef.md) | +1.1% | +3.8% |
| LCATTLE | 2026-02-24 | [Border closure over New World Screwworm threat ripples across U.S. beef industry](https://feedsoft.ai/events/20539-border-closure-over-new-world-screwworm-threat-ripples-across-u-s-beef-industry.md) | -3.3% | -4.4% |
| FCATTLE | 2024-06-20 | [Mexico reinforces health surveillance against screwworm threat](https://feedsoft.ai/events/29682-mexico-reinforces-health-surveillance-against-screwworm-threat.md) | +0.7% | -1.4% |
| FCATTLE | 2026-03-27 | [Screwworm Fears are Reshaping the U.S. Cattle Feeding Industry](https://feedsoft.ai/events/20119-screwworm-fears-are-reshaping-the-u-s-cattle-feeding-industry.md) | +2.6% | +1.1% |
| FCATTLE | 2023-10-22 | [A screwworm fly that bedeviled cattle ranchers decades ago has returned to Texas](https://feedsoft.ai/events/33562-a-screwworm-fly-that-bedeviled-cattle-ranchers-decades-ago-has-returned-to-texas.md) | -2.0% | -5.5% |

## Sources

- scientificamerican.com: https://www.scientificamerican.com/article/we-beat-screwworm-once-heres-how-were-trying-to-do-it-again/

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Data from Feedsoft AI (https://feedsoft.ai/). For information only; not investment advice.