Screwworm Is Just the Latest Disease Risk From Factory Farms

How CAFOs turn a containable parasite into a billion-dollar industry risk - and what it means for the banks financing them.

Over 20 counties in Texas are facing restrictions on animal transportation as cases of the parasitic New World screwworm infection rise for the first time since it was eradicated in the US approximately 44 years ago. All active cases (21, as of July 11th, 2026) currently reside in Texas, most of which are attributed to parasitic infections of sheep and cattle. 

How does an animal fall victim to screwworm? An adult female fly finds an open wound or body opening (such as ears or eyes) and lays eggs. Within one to two days, these eggs hatch into maggots which burrow into the flesh of their host. The maggots then worsen the wound and make the area susceptible to bacterial infection. 

Loading image...The consequence of failed screwworm containment is extremely expensive for the affected regions: according to the Federal Reserve Bank of Dallas, prior outbreaks cost the Southwest of the US $2.5 billion. 

In the event of a full blown outbreak, cattle herd numbers (which are already at a record low) would decrease and cattle would lose weight, dropping supply further. Farmers, who are already struggling to make profits selling beef, would face even lower margins. 

The high-density conditions of factory farms, also known as concentrated animal feeding operations (CAFOs), make it more likely for cattle numbers to dwindle. And yet, this farming model persists. 

Vectors for Disease: CAFOs Are Breeding Grounds for Animal and Human Outbreaks

While screw worm infestations don’t spread from animal to animal, the conditions of factory farms make it so that other illnesses do, very easily.

Loading image...The harsh living conditions of animals on densely packed factory farms make it more likely for zoonotic diseases to spread: most animals are kept close to each other in confined environments. To combat illness between animals, they are given antibiotics in a manner consistent enough to cause antibiotic resistance, which eventually makes it harder for humans to be properly treated with those same antibiotics. But bacterial infections aren’t the only ailments amplified by factory farming.

Workers at CAFOs are more likely to develop an influenza virus infection than the general population; poultry and pigs have a high prevalence of influenza A, and this infection can jump from animal to worker. 

Beyond the factory farm itself is the wake of destruction left by the deforestation required to sustain them.

Most new diseases come from animals. Nearly one third of these new diseases spawn from “land use change”; for perspective, agriculture in general is responsible for at least 75% of rainforest deforestation and about 41% of which is attributable to beef production. Events similar to the COVID-19 pandemic can only be expected to become more frequent and severe if factory farms and the highly intensive production of beef continues with the support of governmental and financial institutions. 

Take Action: Deforestation and Disease at the Hands of CAFOs Should Not Be Funded

Don’t let banks use your money to fund CAFOs. 

Be part of the movement to stop factory farming and prevent the next zoonotic disease from spreading: tell your bank to ditch factory farm finance now and invest in the plant-based food transition.

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