A deadly parasite has been discovered in the US for the first time.
The flesh-eating screwworm eats cattle and other warm-blooded animals alive, with an outbreak beginning in Central America and southern Mexico late last year.
The parasite is fatal if it is left untreated.
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The case in the US was identified by a person from Maryland who had travelled from Guatemala.
South Dakota's state veterinarian Beth Thompson told Reuters on Sunday that she was notified of the case inside a week.
A Maryland state official also confirmed the case.
The person has been treated, and prevention will be implemented, according to Reuters.
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The parasite broke out in Central America and southern Mexico
|REUTERS
A female screwworm fly lays eggs in the wounds of warm-blooded animals and once hatched, hundreds of screwworm larvae use their sharp mouths to work their way through the flesh.
It can kill off dozens of cattle and wildlife, and has also been known to infect humans.
Treatment is difficult and involves removing hundreds of larvae and disinfecting wounds.
There is a solid survival rate if it is treated early enough.
The confirmed case is likely to rattle the beef and cattle futures market, which has seen record-high prices because of tight supplies.
America typically imports more than a million cattle from Mexico each year to process into beef.
The screwworm outbreak could cost Texas upwards of $1.8billion (£1.3billion) in livestock deaths, labour costs and medication expenses.
The US Department of Agriculture (USDA) has set traps and sent mounted officers along the border, but has come under criticism from some cattle producers.
The parasite poses a major threat to livestock
| GETTYJust one week ago, the US agriculture secretary, Brooke Rollins, travelled to Texas to announce plans to build a sterile fly facility to combat the pest.
Ms Rollins has pledged multiple times to keep screwworm out of the country.
Mexico has also tried to deter the spread of the pest by building a $51million, (£37.8million) sterile fly production facility.
The USDA has previously said 500 million flies would need to be released weekly to push them back to the Darien Gap, the stretch of rainforest between Panama and Colombia.
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