Health officials have confirmed the first human case of a flesh-eating parasite in the United States in years—a disturbing reminder that the New World screwworm may be inching closer to American soil.
A Maryland resident was diagnosed with a New World screwworm infestation after returning from travel to El Salvador. The Centers for Disease Control and Prevention (CDC) confirmed the case on August 4, 2025. The infection was agonizing: larvae tunneled into living tissue, and the patient required surgical treatment before making a full recovery.
Officials emphasize the risk to the general public remains low, with no evidence of local transmission. Still, the incident highlights a growing concern. Once eradicated in the U.S., the screwworm is steadily pushing north from Latin America, where outbreaks remain a costly burden on people and livestock.
The stakes are high. An outbreak in Texas alone could inflict as much as $1.8 billion in economic damage, according to USDA estimates. The parasite targets warm-blooded animals, burrowing into wounds and causing excruciating infections that can devastate herds.
To counter the threat, the U.S. Department of Agriculture is ramping up its defenses. A new sterile-fly facility in Texas—capable of producing 300 million sterile screwworm flies per week—is expected to open within 18 months. The approach revives a proven eradication strategy from the 1960s, when sterile releases wiped the parasite out of the U.S.
For now, Americans face no immediate danger. But experts caution that vigilance is crucial. The flesh-eating screwworm may be rare, but it has not been defeated—and its relentless march north makes it a parasite worth fearing.
