How do people get infected?

Infections occur when flies lay eggs in an open wound or sore. Travelers are more at risk if they spend time in areas with livestock, sleep outdoors, or have untreated cuts or skin injuries.

What are the symptoms?

Patients may develop painful wounds that don’t heal, sometimes with a foul smell. A clear warning sign is the presence of maggots around an open sore.

How is it treated?

Doctors must physically remove the larvae, sometimes through surgery. Health officials warn people not to attempt removing the maggots themselves.

How big a threat is this to the US?

Health officials say the public risk is very low, as the parasite doesn’t spread from person to person. But the case highlights a growing concern for ranchers: screwworm infestations have been spreading northward through Central America and Mexico.

Why does it matter for livestock and agriculture?

The screwworm devastated US cattle industries until it was eradicated in the 1960s and 1970s through an aggressive program that released sterilized male flies from airplanes.

The pest kills animals by infesting wounds and slowly eating them alive, threatening food supply chains, according to the Associated Press news agency.

Could screwworm return to the United States?

Scientists say it’s possible, especially along the Texas-Mexico border, where livestock trade is heavy. The US Department of Agriculture is now building a new facility in Texas capable of producing 300 million sterile flies a week to prevent a reintroduction

Bottom line?

While the Maryland case is the first US human infection tied to travel from an outbreak zone, officials stress that the risk to people remains low. The greater danger lies in protecting America’s livestock industry from a parasite once considered one of its most destructive pests.

“This is the first human case of travel-associated New World screwworm myiasis (parasitic infestation of fly larvae) from an outbreak-affected country identified in the United States,” Health and Human Services spokesperson Andrew Nixon said, according to CNN.

“Currently, the risk to public health in the United States from this introduction is very low.”

-- With inputs from AP

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