U.S. officials confirmed a case of the flesh-eating parasite in a person who traveled from El Salvador. Screwworm typically affects cattle in South America but has spread north in recent years.

U.S. agriculture officials halted live cattle crossing the border in July due to concerns about the flesh-eating maggot which has been found in southern Mexico and is creeping north.

In 2017, a study reported one in three people in one rural Alabama county had been exposed to hookworm. Catherine Coleman Flowers says the study reveals big gaps in sanitation in rural America.

Scientists say parasites are important parts of ecosystems, but many are at risk of extinction. So, they're calling for a parasite conservation movement.