Mexico to US livestock trade halted due to screwworm spread

Nature of the screwworm threat

• Commenters share technical descriptions: a fly whose larvae infest any warm-blooded animal, including humans, eating only living flesh and often killing the host.
• People react with horror but also note it’s a known, manageable livestock pest in endemic regions, not some apocalyptic novelty.

Historical control and what broke down

• The US eradicated screwworm domestically by the 1960s using the sterile-insect technique (mass-releasing irradiated sterile males).
• The “barrier” was pushed south to Panama/Darién and maintained for decades with continual releases, monitoring, and movement controls.
• Multiple comments cite that the barrier was breached around 2022; cases spread north through Central America and into Mexico through 2023–24, aided in part by unmonitored/illegal cattle movements and cartel-linked cattle smuggling.
• COVID-era disruptions to release flights and breeding facilities are blamed by some as the key turning point.

Funding, agencies, and politics

• Disagreement over which cuts matter:
  • Some point to USAID-funded monitoring programs (via FAO) being defunded, and say this impaired early detection.
  • Others emphasize USDA programs continued and even got emergency funding in 2024, so “USAID shutdown” did not halt all prevention.
  • One claim says the barrier program was cut 30% in 2024; others counter with evidence of later emergency increases. Net effect remains unclear.
• Debate over how much to blame the current administration versus a decade of neglect; several push back on oversimplified partisan narratives.

Eradication vs permanent control

• One camp argues the pest isn’t the “end of the cattle industry” and can be managed with wound care and seasonal practices if needed.
• Others stress that without continuous sterile-fly campaigns, legacy-style herd management is inadequate and economically painful.
• Several say “finishing the job” across all of the Americas is likely infeasible due to ecological reservoirs and cost; the realistic strategy is a permanent, expensive “war” to hold a line (Darién or somewhere north).

Economic and trade implications

• People tie this to already high beef prices, but argue the main drivers are herd reduction, drought/feed costs, and heavy processor consolidation/oligopoly rather than just screwworm.
• There’s extended discussion of dairy/meat supply chains, market power of a few large processors, and weak antitrust enforcement.
• Some note compounding effects with tariffs on Brazilian/Australian beef and now the halt in Mexico–US livestock trade.

Human, wildlife, and food safety concerns

• Commenters highlight that screwworm also hits wildlife (e.g., endangered deer) and humans, making “just eat less beef” an incomplete framing.
• Separate from screwworm, several reiterate basic food-safety practices around raw meat and parasites; some push back on “I’m telling forbidden truths” rhetoric since this is mainstream advice.

Broader reflections

• Thread contains anxiety about institutional decline and loss of federal technical capacity compared to the mid‑20th‑century eradication era.
• Others zoom out to the inevitability of biological threats that ignore borders and the need to reinvest in natural history, surveillance, and applied biology, rather than assuming technology or politics alone will protect us.