"They are chasing this infection through the roof of his mouth up through his nose," the boy's uncle Curtis Farnam said. "They removed some of his nose yesterday and removed some teeth."
Health department officials said they believed the teen picked up the infection through an open wound.
They said the bacterium, Chromobacterium Violaceum, is common in lakes all across the state. The CDC said there has been fewer than 150 cases around the world between 1927 and 2005.
"Some people will not catch it. Some people will catch a minor infection, and some people could get very sick," Cumberland County Health Department Dr. Lan Tran-Phu said.
Doctors said the bacteria lives in the mud and sand of lakes. They said it was not dangerous unless someone had a cut or open wound and then got infected.
On Tuesday while at the lake, 9-year-old James Gibson's day in the water ended with a cut to his big toe.
"I was running in the water and there were rocks and I slipped and cut my toe," Gibson said.
Gibson's mother, Melissa, said she had not thought much about the cut until she learned about the health department's warning.
"I am worried," she said. "I am going to go home and going to clean his foot really good." Health officials have not closed Hope Mills Lake, nor issued a health warning.
But they are advising swimmers not to drink the water. Soap and shower off after swimming, immediately clean and treat any cut or wound, and seek a doctor's care if a cut or scratch gets infected.