An investigation is underway to determine how a rare brain-eating amoeba found its way into a plumbing system of a home in Louisiana, according to the Center for Disease Control.

A four-year-old boy from Mississippi became the fourth confirmed infection in 2013 of the amoeba, Naegleria fowleri, last week, after playing in water from the home in St. Barnard Parish, La.

The Department of Health and Hospitals in Louisiana has confirmed that the amoeba was found in the home’s plumbing system.

In previous cases, the CDC has linked the infections to warm water and drought conditions.

“When we go back and look at where exposure may have occurred, we see the infections occur where water levels are low or where there are drought conditions or after a heat wave,” Dr. Jennifer Cope, medical epidemiologist at the CDC, told

Naegleri fowleri is thermophillic, or heat-loving, and can thrive in temperatures higher than 100 degrees F.