A rare disease transmitted through contact with raccoon feces has left a New York City teenager blind in one eye and an infant brain damaged.

The city's Department of Health warns parents to be on the alert for raccoon roundworm, which can cause nausea, nerve damage and even death. It says fewer than 30 cases have been reported in medical literature.

Health department spokeswoman Sally Slavinski says parents should supervise children to keep them from eating raccoon feces. Droppings should be picked up using gloves and disposable bags and put in the trash.

The worms lay eggs in the feces; they hatch after being ingested and travel through the body.

The teenager lost sight in one eye in January. The infant has been hospitalized since suffering seizures and spinal problems last October. They're from Brooklyn.