In one community, 3.7 billion parasites are released daily via dog poop. Researchers propose a handy model for determining people's risk of subsequent Toxocara infections.

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PROBLEM: Toxacora, parasitic worms that grow in the intestines of puppies and kittens, release their eggs into the environment via the puppies' and kittens' feces. When the eggs worm their way into the soil or other surfaces on which puppies and kittens poop, and are then accidentally ingested by humans (people not washing their hands after gardening or kids playing in the dirt), the resulting infection, or toxocariasis, can cause vision loss and possibly even asthma and epilepsy. So knowing where to focus control efforts can help prevent any of that from happening.

METHODOLOGY: "In the interests of protecting public health," researchers at the University of Bristol's School of Veterinary Sciences estimated the relative contributions of Toxocara by dogs, cats, and foxes in Bristol, using data on the amount of animal waste produced each day in the city and the female Toxocara's egg-laying ability.