A deadly amoeba that killed a 4-year-old boy last month was found in the water supply of a Louisiana parish where the boy had been visiting.

The CDC has confirmed that Naegleria fowleri was found in four different locations of the St. Bernard Parish water system. Officials say the water is safe to drink but can be a risk for infection should the water go up a person’s nose. The amoeba enters the brain through the nose.

State epidemiologist Dr. Raoult Ratard said the boy who died likely became infected while playing on a “slip-n-slide” at the home.

“It was the only time where he was in contact with some water that could have penetrated all the way up into his nose,” Ratard told FoxNews.

State health officials say residents can protect themselves by chlorinating pools and by avoiding any water in the nose.

Neighboring Parishes are taking precautionary steps including flushing of their own water systems to prevent the spread of the bacteria.