Rotting Meat Smell Sparks Protest at Mexico's Screwworm Fly Plant

Residents of Metapa de Dominguez, a small town in southern Mexico, took to the streets on Thursday to protest a government facility that breeds flies. They say a horrible smell — like rotting meat and spoiled food — has been spreading from the plant into their neighborhoods and schools. The facility was built to help fight a dangerous parasite called the New World screwworm, which is threatening cattle in Mexico and the United States.

Protesters described the odor as "pungent in your nose and mouth" and said it was making people feel sick. The smell used to stay mostly around the plant, but now it travels farther when the wind blows, reaching nearby schools and forcing classes to stop. Truck driver Mercedes Becerra de la Cruz spoke for many residents when she said the town could no longer put up with the stench.

The fly-breeding plant opened on June 27, less than four months before the protest. It was built as a team effort between Mexico and the United States, with the U.S. Department of Agriculture contributing $21 million of the plant's $51 million total cost. The goal is to stop the spread of the screwworm, a parasite that has been moving north through Central America and into Mexico.

The screwworm is a serious threat to cattle and other warm-blooded animals. Its larvae, or young, burrow into the living flesh of animals and can kill them if they are not treated. The pest was wiped out in the United States decades ago, but it has been spreading north again, causing the U.S. to ban imports of Mexican cattle for more than a year.

The Metapa plant uses a clever method to fight screwworms. Millions of flies are raised every week and fed a special mix of egg, milk, and powdered hemoglobin — a substance found in blood — that acts like the inside of a wound. Before the flies are released, they are sterilized so they can no longer reproduce, which means when they mate with wild flies, no new screwworm flies are born.

Eventually, the plant is expected to release 100 million sterile flies every single week. Mexico has recorded nearly 48,000 screwworm cases during this outbreak, while the United States has recorded 53. Despite how important the plant is, residents say its location right in the middle of town is causing real problems for everyday life.

Homemaker Rosalba Merida Herrera, 49, called on the government to move the plant somewhere else. She said the smell is hurting both children and elderly people in the community. Mexico's Agriculture Ministry had not responded to a request for comment by the time this story was published.