MINNEAPOLIS (WCCO) — The U.S. Centers for Disease Control and Prevention has confirmed the cause of a suspected amebic infection, that took the life of a 9-year-old boy.

The type of amoeba known as Naegleria fowleri has been confirmed as the cause of the rare illness that killed Jack Ariola-Erenberg, after he was swimming in Lily Lake in Stillwater.

The CDC conducted clinical testing of the organism and reported the results to the Minnesota Department of Health.

MDH officials said they were 99 percent certain of the cause of the illness, but the CDC testing confirms any doubts.

The MDH said while they can’t confirm where Jack was infected, the timing of the illness and other factors make it likely that it happened at Lily Lake in Washington County.

That’s the same lake where a 7-year-old girl had been swimming before she died two years ago.