‘People should be aware’: eggs of tiny, infectious worm found in parks in New York and Europe

The Toxocara worm can spread to humans via cat or dog feces, making children who play in sand or soil particularly at risk

Scattered in cat sandboxes and dog runs around the world, there's a parasite invisible to the naked eye that mostly infects these creatures. It's a tiny worm that lives in the animals' muscles and digestive systems, but can spread to others.

Sometimes, though, it infects humans. Increasingly researchers are concerned that children are inadvertently consuming these parasites, known as Toxocara, and so they are studying places where humans and pets come into contact with one another: city parks.