You might have heard about the flesh-eating screwworm. Here's why you shouldn't freak out

Just when you thought there was enough going on in the world to frazzle your nerves, along comes a flesh-eating parasite that has been spreading among livestock in Central America and has now infected a recent traveller from the United States and another from Canada.

It's called the New World screwworm, and it burrows its way into the skin of a living animal host — like a screw — and feeds on tissue.

But we said you don't have to freak out.

Human cases of infestations are incredibly rare, including when it comes to travellers to affected areas, and it's not passed from person to person. But the worms are a menace to cattle ranchers , and an outbreak in Central America and Mexico is growing at a pace that has farmers across the region and in the U.S. concerned.

Here's what we know abo