How Much Does Screwworm Response Cost?

Last Updated on August 26, 2025
Written by CPA Alec Pow | Content Reviewed by CFA Alexander Popinker

New World screwworm detections in Mexico during 2024 prompted U.S. officials to tighten animal checks at the border and to warn producers that reinfestation risk had risen. By late 2024 the U.S. suspended live cattle imports from Mexico and moved emergency money into surveillance and sterile fly capacity, with USDA describing the situation as a significant biosecurity concern.

APHIS has since announced additional screening of livestock entering from affected areas and reiterated the decades-old strategy of pushing the parasite south and holding a barrier in Panama. The agency’s 2025 public notice highlights stepped-up inspections and monitoring, language that reflects an elevated posture compared with typical years.

Regional signals compound the concern. Cuba reported screwworm incidents in recent years, and journalists in Mexico have chronicled fresh cases that amplify migration pressure northward, exactly the pathway the U.S.–Panama barrier was designed to slow. Policy makers worry because one blown season can seed thousands of cases and force costly animal-movement curbs.

Screwworm infestations strike livestock, wildlife, pets, and on rare occasions people, turning small wounds into life-threatening lesions and large, fast-moving outbreaks. When the parasite appears, time turns into money. Miss a week and you can lose a season. Miss a season and you can lose a herd.

Article Highlights

• On-ranch response starts small, but multi-animal weeks can reach the low five figures.
• Florida eradicated an outbreak in 2016–2017 for about $3.2 million (≈102.6 years of work earning $15/hour), a documented benchmark.
• Historic U.S. losses hit $151 million (≈4839.7 years of non-stop work at a $15/hour wage) in 1935, roughly $3.3 billion (≈105769.2 years of uninterrupted labor at $15/hour - more than the time since the last major ice age cycle) in 2022 dollars, which explains why prevention budgets endure.
• The Panama barrier program can surge past 100 million sterile pupae weekly, a capacity that carries ongoing costs but averts larger losses.
• Modern producer-loss estimates reach $1.8 billion (≈57692.3 years of labor at $15/hour - more than the time since early humans first left Africa) for Texas if screwworm gained a foothold, showing what is at stake.

How Much Does Screwworm Response Cost?

At the ground level, a single-animal response often looks modest. A ranch call for a suspicious wound, debridement, a larval kill with approved topical or systemic products, and a follow-up check can run $75 to $300 (≈2.5 days of labor continuously at a $15/hour wage) in veterinary time and supplies in many rural markets, more if travel is long or after-hours. Multiply that across dozens of animals and repeated checks, and a ranch’s short-term treatment bill can climb into the low five figures during a bad month, even before you count labor and lost weight. Those incidentals are real. They add up.

Zoom out to county and state. Quarantines, roadblocks, inspection points, outreach, and extra staffing shift the order of magnitude. Florida’s Key deer outbreak response in 2016–2017 cost about $3.2 million (≈102.6 years of work earning $15/hour) to eradicate the fly in the Keys, a figure that bundled sterile fly releases, surveillance, and interagency operations. That number came directly from USDA after the operation closed.

At national scale, prevention dwarfs treatment. The United States maintains a permanent biological barrier through a joint Panama–U.S. program that mass-rears and releases sterile flies to keep wild populations pushed south. Historic records show Congress authorized about $15 million (≈480.8 years of dedicated work at a $15/hour job) in 1976 to expand sterile releases and build out the barrier zone. Today, the program’s capacity is documented at more than 100 million screwworm pupae per week when surging to meet a threat, a metric that signals both the size and the ongoing expense of a modern shield.

The worst-case ledger. If New World screwworm re-established in major U.S. cattle country, analysts and agencies estimate producer losses in the billions. USDA’s historical economic summaries put U.S. livestock losses at $151 million (≈4839.7 years of non-stop work at a $15/hour wage) in 1935, which they translate to roughly $3.3 billion (≈105769.2 years of uninterrupted labor at $15/hour - more than the time since the last major ice age cycle) in 2022 dollars for scale. Separate reporting in 2025 pegged potential Texas alone losses around $1.8 billion (≈57692.3 years of labor at $15/hour - more than the time since early humans first left Africa) if an incursion spread. Those are not theoretical scare numbers, they are the stakes that justify barrier funding and rapid response.

According to the American Veterinary Medical Association (AVMA), the USDA has launched a comprehensive program including the construction of a sterile fly dispersal facility costing around $8.5 million (≈272.4 years of continuous effort at a $15/hour job) in Texas, supported by multi-million-dollar surveillance and eradication initiatives.

Additionally, USDA reports detail a major upcoming sterile fly production plant at Moore Air Base expected to cost $750 million (≈24038.5 years of dedicated labor at $15/hour - exceeding the time since humans built the first permanent settlements). This facility will supply up to 300 million sterile flies weekly to control screwworm populations through the Sterile Insect Technique (SIT). Until its completion, the USDA is investing about $100 million (≈3205.1 years of work earning $15/hour - longer than the time since gunpowder changed warfare) in accelerated technology development and deployment.

Texas Policy Research highlights the broader financial stakes, noting a federal investment nearing $850 million (≈27243.6 years of labor at $15/hour - longer than the entire history of organized religion) to protect Texas agriculture, valued in the hundreds of billions, from the destructive screwworm parasite.

The economic cost of a screwworm outbreak could be devastating; USDA estimates put potential losses for Texas alone at about $1.8 billion (≈57692.3 years of labor at $15/hour - more than the time since early humans first left Africa), including cattle deaths, labor, and treatment expenses, as reported by Reuters and NBC News.

Real-life cost examples

Florida Keys, 2016–2017. After screwworm hit endangered Key deer, the response combined targeted treatments, movement controls, and an air bridge of sterile flies. USDA reported a total operational spend of about $3.2 million (≈102.6 years of work earning $15/hour) to eradicate the outbreak. Local agencies contributed staff and logistics, but the heavy lift came from federal emergency funds and the established sterile insect apparatus. Outcomes mattered: the parasite was eliminated, and normal commerce resumed.

Historic prevention vs. losses. When policymakers debate the price of prevention, USDA’s own ready-reference sheet is often on the table. It points to annual U.S. livestock losses in the mid-20th century of $5 million to $20 million (≈641 years of unbroken labor at $15/hour) per year pre-eradication, spiking to $151 million (≈4839.7 years of non-stop work at a $15/hour wage) in 1935. They also quantify the massive avoided losses after eradication via the barrier zone, which helps budget setters see prevention as a continuous savings machine, not a sunk cost.

Modern risk window. In late 2024 and 2025, agencies tightened cattle movements along the U.S.–Mexico line due to detections in southern Mexico and Central America, emphasizing how fast trade costs emerge when screwworm risk “turns on.” News coverage detailed suspended imports and the knock-on effects for feedlots and packers, costs that never show up on a veterinary invoice but do show up in balance sheets.

Worked ranch example. A South Texas cow-calf outfit with 450 head detects three infested calves during a hot, wet week. The ranch books two vet call-outs at $150 (≈1.3 days of continuous work at a $15/hour job) each, buys topical larvicides and fly control for $220 (≈1.8 days working for this purchase at $15/hour), spends $360 (≈3 days of non-stop labor at a $15/hour salary) on fuel and overtime for extra pasture checks, and loses $900 (≈1.5 weeks working every single day at $15/hour) in weaning-weight value due to slowed gain. Their week one out-of-pocket hits $1,780 (≈3 weeks of continuous work at $15/hour), then drops to $400 (≈3.3 days of your career at $15/hour)–$600 (≈1 week of salary time at $15/hour) for two weeks of monitoring. Multiply that by neighboring ranches and you see how “small” cases pressure county budgets fast.

Cost breakdown

Direct animal care. Field treatment bundles three pieces: inspection and debridement, a larval knockdown product, and systemic control or retreatment. Where veterinary travel is long, service time dominates the bill. For large ranches, the per-animal material cost is small relative to labor, but for backyard herds, the inverse can be true when minimum call fees apply. Evidence-based protocols from USDA and IAEA center on prompt debridement and approved products to minimize repeat visits.

Surveillance and quarantine. Once an outbreak is confirmed, agencies shift spend toward staffing checkpoints, field sampling, public communications, and data systems. This is where seven-figure invoices appear. Florida’s Keys operation illustrates how surveillance plus sterile releases become the financial core of eradication in a limited geography. If a mainland spread occurs, road and rail inspections add substantial overtime and contract costs.

Sterile insect technique (SIT). SIT is insurance with an ongoing premium. Facilities must maintain colonies, irradiate, package, and ship insects, then coordinate aerial or ground releases. USDA’s strategy documents show the Panama barrier can scale to 100+ million pupae weekly, and outbreak surges add layers of logistics and procurement. Even when per-unit costs are guarded in contracts, capacity metrics reveal why line items reach eight figures in prevention budgets.

Indirect and hidden costs. Movement restrictions delay sales. Extra handling reduces gains. Carcass disposal and biosecurity supplies bite into margins. In a multi-county event, auction barns, haulers, and processors absorb scheduling inefficiencies that translate into price spreads for producers. USDA’s historical summaries and newspaper reporting on recent restrictions both underscore how these diffuse costs rival visible outlays.

The Long Arc of Eradication

Screwworm devastated U.S. herds in the early twentieth century. Economic losses were tallied in the tens of millions of dollars annually before World War II, a burden that scales to several billions in today’s money when adjusted for inflation. The response that followed was historic.

Beginning in the 1950s, U.S. and partner nations deployed the sterile insect technique, eradicating screwworm from the continental United States and progressively through Mexico to Panama. The barrier in the Darién became a permanent line of defense, backed by a binational commission that releases sterile flies to intercept reinvasion. It worked, and it still works.

The economics proved powerful. Analysts have long noted that the barrier’s annual operating cost is small compared with the avoided losses to ranchers and wildlife. A widely cited estimate pegs operating cost near $15 million (≈480.8 years of dedicated work at a $15/hour job) per year with annual benefits approaching $900 million (≈28846.2 years of work at $15/hour - more than the time since writing systems first developed), a reminder that prevention is cheaper than response.

Current Numbers in Context

The U.S.–Panama barrier is managed by COPEG, a binational commission jointly funded by the United States and Panama. APHIS describes the program as the heart of continental prevention, a standing cost that keeps the pest out of North America most years.

Emergency needs are extra. As cases mounted to the south in late 2024, Washington authorized supplemental funding and tightened import rules, then in 2025 announced new federal investments in sterile fly production and technology to expand capacity. Those appropriations sit alongside routine APHIS appropriations for animal health and are distinct from one-off emergency draws.

Compared with other animal health lines, screwworm prevention is modest. Foot-and-mouth disease planning and avian influenza outbreaks absorb large, episodic sums, while the barrier spends steadily every year. That steadiness is the point, because a running program avoids the spikes that accompany outbreaks.

Human and Animal Impact

The 2016–2017 Florida Keys event placed the threat in plain sight. More than 130 endangered Key deer died before eradication, a wildlife toll that mobilized local, state, and federal teams and reminded ranchers what was at stake if the parasite re-established on the mainland. It was fast. It was lethal.

Producers talk about weaning-weight loss, delayed sales, and genetic setbacks when herds are stressed or treated repeatedly. Those anecdotes match historical records of lowered productivity and added veterinary bills during past incursions. A handful of human and pet cases have been documented in the Caribbean and Keys, underscoring that screwworm is a zoonotic wound parasite that does not respect fence lines.

Eradication in the Keys succeeded, but only with aggressive surveillance and releases that cost the public purse and local partners real money, later estimated at about $3.2 million (≈102.6 years of work earning $15/hour) for that episode alone. Lives were saved, and a species was protected.

Inflation and Modern Risks

Fuel moves sterile flies and field crews. When diesel and aviation fuel jump, aerial release and ground logistics bills rise with them, which is why USDA and its partners watch the U.S. Energy Information Administration’s fuel outlooks when planning seasonal operations. Variable fuel prices translate directly into variable response costs.

Labor is tighter, particularly in rural and food-animal practice. Federal data show widespread veterinary shortage areas across the Plains and the Southwest, which pushes up per-visit costs and strains on-call capacity during an outbreak. Shortages make a rapid response harder and more expensive.

Input prices matter too. From larvicides to dressings to traps, veterinary and farm supply indices have marched higher since the pandemic, and producers report paying more for routine care. Put simply, every gallon, hour, and bottle costs more than it did in 2016.

International dimension

COPEG is binational by design. APHIS emphasizes that both the United States and Panama fund the sterile fly barrier, releasing insects in the Darién to block northward spread. The arrangement is a model of regional biosecurity, and it depends on consistent commitments from both treasuries.

When outbreaks flare in Cuba or Mexico, costs ripple. National programs must step up surveillance, and traders face movement restrictions that can extend far beyond the hot zone. If one partner falters, the corridor opens and the price of defense rises for everyone.

International agencies back the science. FAO and IAEA have long documented the cost-effectiveness of sterile insect technique in screwworm and other pests, and current reviews continue to highlight SIT’s high benefit-cost ratios in area-wide control, the rationale behind the barrier’s long run.

Alternative products or services

On-animal chemistries. Approved topicals and systemic treatments remain the first line for individual cases. They are inexpensive per dose relative to losses prevented, but they cannot alone arrest a spreading wild population. Guidance from IAEA and USDA stresses appropriate use to avoid retreatment and to protect handler safety.

Sterile insect technique vs. “spray and pray.” SIT is the only method with decades of proof for area-wide eradication of screwworm. A classic FAO review describes how sterile releases drove the fly off the U.S. mainland and south into a Panama barrier zone, a public-goods model that replaced endless local treatments with a durable buffer.

Detector dogs and surveillance tech. New investments highlight dogs trained to flag infested animals at ports and crossings, plus digital tools to speed case mapping and dispatch. These expenses show up as capital and training lines rather than per-animal fees, but they compress outbreak time and therefore total spend.

Do nothing. It sounds cheap. It is not. Historical estimates of pre-eradication losses, in the $5–$20 million (≈641 years of unbroken labor at $15/hour) per year range nationwide in mid-century agriculture and $151 million (≈4839.7 years of non-stop work at a $15/hour wage) in 1935 alone, are the baseline that modern programs exist to avoid. Prevention is the bargain.

Ways to spend less

Catch early, contain tightly. The lowest-cost outbreaks are the ones that never scale. Rapid reporting, prompt debridement and treatment, and immediate movement controls hold the line while SIT spins up. That discipline turned Florida’s 2016 episode into a months-long, not years-long, effort at $3.2 million (≈102.6 years of work earning $15/hour), not hundreds of millions.

Coordinate at the fence line. The barrier strategy works because it is regional. U.S. and Panamanian partners co-fund and co-operate sterile releases to keep wild screwworms low. Agencies point to this as the most cost-effective spend on the books, because it prevents outbreaks rather than treating them after the fact.

Pre-negotiated surge contracts. Stockpiling supplies, pre-qualifying aircraft and applicators, and having mutual aid MOUs in place trims the most wasteful hours in any emergency: the first 48. USDA’s disease response strategies read like checklists built to save both time and money.

Farmer training and simple gear. Halters, chutes, headgates, and good recordkeeping reduce handling time, missed wounds, and repeat infections. They cost far less than a week of overtime or a batch of condemned carcasses.

Documented cost snapshots

The table below compiles published cost anchors that planners and producers reference when budgeting for screwworm risk. It is not exhaustive, but every figure is sourced.

Sources: USDA APHIS Ready Reference, 2025; FAO/IAEA (Novy), 1991; San Antonio Express-News citing USDA, 2017; national reporting in 2025; USDA APHIS Response Strategy, 2018.

Total costs for a region

A region’s total bill is not the first press release. It is a 12–18 month ledger that starts with the first vet call and ends when the last permit restriction lifts. In that span, agencies fund checkpoints, sampling, overtime, sterile fly logistics, and communications, while producers pay for on-ranch labor, treatment, and delayed marketing; and because many of those line items occur simultaneously, the effective cost curve is steep at first, then flattens when surveillance data show the fly’s reproduction rate has dropped below replacement thanks to SIT and aggressive field care.

Two sentences you can keep beside your budget. Time matters. Speed saves.

Hidden costs and spillovers

Trade friction shows up first. The U.S. temporarily halted cattle imports from Mexico in late 2024 in response to reported cases, a reminder that even suspicion can slow commerce and raise prices down the chain. Documentation costs spike, and shippers eat delays.

Tourism and public confidence also carry price tags. Wildlife die-offs tarnish destination brands, and consumer anxiety about parasites can dent meat demand despite food-safety assurances. None of that is on the invoice for larvicide or flight time, yet all of it hits regional economies.

Count the paperwork. Movement permits, extra inspections, and compliance staff hours pile up for ranches and auctions. Those hours are real money, and they are rarely reimbursed even when the outbreak stays across a border.

Costs beside other animal diseases

The numbers below put screwworm response and prevention alongside recent U.S. animal-disease bills and projections. This is why the Darién barrier is still funded.

Two truths follow. First, prevention is cheap. Second, delays are expensive. A single open corridor can erase years of savings in one season if sterile fly releases falter or border surveillance slips even briefly, because a fast-moving parasite can outrun paperwork and budgets alike.

Expert voices

“We are taking aggressive steps at the border to protect U.S. livestock,” USDA officials said as they moved to suspend cattle imports from Mexico and accelerate surveillance in late 2024. The language telegraphed urgency and backed new money for capacity.

Veterinary leaders in the Keys described the 2016–2017 episode as a wake-up call for wildlife and pets, noting more than 130 Key deer deaths before eradication took hold. One manager called it a race to get ahead of the larvae’s life cycle. It was.

Economists who study animal disease agree on the big picture. Spend steadily on prevention, or budget for shock. The barrier’s benefit-cost math remains persuasive because the avoided losses are measured in hundreds of millions each year.

Answers to Common Questions

How much does it cost to treat one animal?

Direct vet and materials can run $75–$300 per visit depending on travel, time, and supplies. Follow-ups add to that total in multi-larval cases.

What is the big-ticket item in a regional response?

Surveillance and SIT operations, plus staffing and logistics for quarantines. Florida’s eradication ran $3.2 million in 2016–2017.

Why spend on a barrier in Panama?

Because prevention is cheaper. Historic U.S. losses hit $151 million in 1935, roughly $3.3 billion in 2022 dollars, before eradication. The barrier exists to keep those losses from returning.

What could a modern U.S. outbreak cost producers?

Analysts have pegged potential Texas-only losses around $1.8 billion if screwworm re-established and spread.

Does SIT have enough capacity to surge?

USDA documents show surge capacity above 100 million pupae per week, with deployments coordinated across the barrier zone.

Sources used in this article: USDA APHIS New World Screwworm Disease Response Strategy (2018); USDA APHIS Ready Reference: New World Screwworm Historical Economic Impact (2025); FAO/IAEA (Novy) review of eradication and sterile insect technique (1991); San Antonio Express-News reporting on the Florida Keys eradication cost (2017); national reporting on 2025 Texas risk and import suspensions (2024–2025).