A rare and deadly flesh-eating parasite has been detected in a human in the United States for the first time, health authorities confirmed on Sunday, August 24.

 

 

 

The case of New World screwworm was identified in a patient who had recently returned from El Salvador, according to the Maryland Department of Health and the U.S. Centers for Disease Control and Prevention (CDC).

 

 

 

 

Andrew G. Nixon, a spokesman for the U.S. Department of Health and Human Services, told Reuters: “The risk to public health in the United States from this introduction is very low.”

 

 

 

Human infections with screwworms are uncommon, but the parasite poses a much greater threat to livestock and wildlife. The flies deposit hundreds of eggs in open wounds of warm-blooded animals, and once hatched, the larvae burrow into living tissue with sharp mouthparts. Left untreated, the condition can be fatal.

 

 

 

 

 

Treatment requires painstaking removal of larvae from wounds, followed by disinfection. The parasite’s name comes from its tendency to “screw” deeper into tissue when disturbed, making eradication difficult.

 

 

 

 

The discovery has raised concerns in the U.S. cattle industry, where an outbreak could have devastating economic consequences. The Department of Agriculture estimates that an infestation in Texas alone could cost the state’s economy about $1.8 billion.

 

 

 

Agriculture Secretary Brooke Rollins recently announced plans to construct a sterile fly facility in Texas to counter the threat. Such facilities release sterilised male flies into the environment, reducing the wild population by preventing successful breeding. The method was successfully used to eradicate screwworm from the U.S. six decades ago.

 

 

 

No animal cases have been confirmed in the country this year, but scientists warn of a northward spread of the parasite from South and Central America as global temperatures rise.