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The New World Screwworm, a parasitic fly, has re-emerged as a potential threat to livestock and humans in the United States. The fly, scientifically known as Cochliomyia hominivorax, was eradicated from the U.S. in 1966 but has resurfaced following an outbreak in Mexico. The U.S. Department of Agriculture (USDA) has responded by suspending imports of live cattle, horses, and bison through southern border ports to prevent the spread of the screwworm into the country.=
The screwworm's larvae, or maggots, are known for burrowing into the flesh of living animals, causing severe and often fatal damage. According to the USDA's Animal and Plant Health Inspection Service, these maggots feed on healthy tissue, unlike most maggots that consume decomposing flesh. The larvae can infest livestock, wildlife, pets, and in rare cases, humans, leading to a painful condition known as myiasis.
The USDA has reported that the screwworm has been detected as far north as Oaxaca and Veracruz in Mexico, raising concerns about its spread to the U.S. The Centers for Disease Control and Prevention (CDC) warns that people with open wounds, especially those who spend time outdoors or around livestock, are at higher risk of infestation.
The Florida Department of Agriculture and Consumer Services (FDACS) is urging veterinarians and livestock producers to remain vigilant for signs of screwworm infections. Symptoms in animals include irritated behavior, the smell of decay, and the presence of maggots in wounds. Early detection and reporting are crucial to controlling the spread of the screwworm, as emphasized by Florida State Veterinarian Dr. Michael Short in a University of Florida release.
Efforts to eradicate the screwworm involve releasing sterilized flies to prevent reproduction. The USDA and Mexican authorities are working together to contain the outbreak and prevent further northward spread of the screwworm. The situation is being monitored closely, with the import ban in place on a month-by-month basis until the threat is mitigated.