Iowa Flesh Maggot is the common name for Cochliomyia hominivorax, a fly whose maggots burrow into open wounds and eat living tissue. It attacks animals, and it attacks people.
Iowa Flesh Maggot is the colloquial name for Cochliomyia hominivorax. Hominivorax is Latin for "man-eater."
The adult is a metallic blue-green fly with orange-red eyes. The female hunts for any break in the skin: a scratch, a tick bite, a fresh ear tag, the navel of a newborn calf. There she lays hundreds of eggs.
The larvae twist head-first into the wound in a tight spiral, tearing at living tissue with hooked mouthparts. The wound gets deeper. It starts to rot and stink. The stench draws more flies to lay more eggs in the same wound. An untreated infestation can kill a full-grown cow.
The same fly that attacks cattle lays its eggs in people. Since the outbreak began in Central America and Mexico, more than 2,600 people have been infested. In June 2026 the CDC activated its Emergency Operations Center to respond.
Flies can lay eggs in the nostrils, and the larvae feed inside the nasal passages.
Where people were infested: legs and feet 55%, neck 20%, nose 11%, mouth 10%, eyes 8%, head and scalp 8%. Percentages are the share of 202 confirmed patients in Mexico with an infestation at that site (CDC, Emerging Infectious Diseases, 2026). Some patients had more than one site.
People with open wounds or sores, especially older adults and people with diabetes. In the Mexican study, patients averaged 61 years old, and more than three in four had another health condition. Anyone who lives in or travels to an area where animals are infested is at higher risk.
A painful wound or sore that won't heal. A foul smell or bleeding from the wound. Seeing maggots, or feeling movement, in a wound or in the nose, mouth, eyes, ears, or genitals. See a doctor immediately.
No human cases acquired inside the U.S. have been reported so far. One U.S. resident was infested in 2025 after traveling to El Salvador.
Scroll to follow one wound on one animal.
A tick bite. A scrape on a fence. A newborn calf's navel. Nothing anyone would notice.
A female fly lands at the wound's edge and lays 200 to 400 eggs, stacked in neat layers like shingles.
The larvae crawl into the wound and bury themselves head-down in living flesh, packed together, feeding as one mass.
It widens and deepens as they eat. It oozes and starts to reek of rot. The smell draws in more females, and they lay more eggs in the same wound.
Hundreds of fat, spined larvae fill the cavity. The grown ones drop out onto the ground and burrow into the soil. The newer ones keep eating.
Without treatment, the infestation can kill a full-grown animal. The damage, infection, and fluid loss are more than the body can take.
In the soil underneath, the pupae hatch. New flies climb out of the ground, mate, and go looking for their own wounds.
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After decades of being held off south of the border, it crossed back into the U.S. in 2026. Tap a state to see its status.
Ground zero. The first U.S. animal case in 60 years was confirmed on June 2, 2026, in a 3-week-old calf in Zavala County. Cattle, sheep, and goats followed, and parts of the state are an active infested zone.
Confirmed animal cases: Texas and New Mexico. On alert with no confirmed cases: Iowa and Pennsylvania. Status as of September 25, 2026, from USDA and state agriculture departments. It's changing fast, so check the official USDA dashboard for the latest.
Iowa raises about one in every three hogs in the United States, and it's a major cattle-feeding state. Meat from Iowa farms ends up in grocery stores and restaurants across the country and overseas. If Iowa Flesh Maggot reaches Iowa's herds, the whole country's food supply feels it.
Go over your livestock and pets and check anything you notice. Only a veterinarian can confirm an infestation.
Every hour you wait, they eat deeper. If you see maggots in a wound on a living animal, call your veterinarian and your state animal health office now. If you can do it safely, drop a larva into a sealed container of rubbing alcohol for testing.
Maggots or movement in a wound on a person? See a doctor or go to an emergency room immediately. Tell them about any recent travel or contact with livestock.
State animal health contacts: Iowa 515-281-5305 · Pennsylvania 717-772-2852 · Texas 1-800-550-8242.
Iowa is the heart of American livestock country, and it's where suspected U.S. samples are sent for confirmation, at the national animal disease laboratory in Ames. If this parasite takes hold in the Midwest, Iowa's herds are on the front line.
Iowa Flesh Maggot is the common name for Cochliomyia hominivorax, a blowfly native to the Americas. Its larvae are obligate parasites, meaning they can only develop in the living flesh of warm-blooded animals, people included.
Yes. More than 2,600 people have been infested in Mexico and Central America during the current outbreak. The larvae infest human wounds the same way they infest animals, and can get into the nose, mouth, eyes, ears, and genitals. If you find maggots or feel movement in a wound, see a doctor immediately.
For decades a barrier of sterile flies held it back far to the south. In recent years it pushed north through Central America and Mexico, and in June 2026 it was confirmed in animals in Texas and New Mexico.