A Nevada boy has died from a rare and often lethal brain infection that officials say he may have contracted while swimming in the eastern part of Lake Mead earlier this month, health officials said Wednesday. The boy, whose identity has not been released, visited the Arizona section of the reservoir at the beginning of October, according to the Southern Nevada Health District. The boy began to develop symptoms of an uncommon illness caused caused by Naegleria fowleri, an organism commonly known as a "brain-eating" amoeba because it attacks and destroys brain tissue, about one week after visiting Lake Mead, officials said. An investigation conducted by the health district in coordination with the U.S. Centers for Disease Control and Prevention confirmed Naegleria fowleri as the boy's cause of death, the health district said. The amoeba occurs naturally in freshwater, especially in warmer bodies with low elevation, and has been found before in Lake Mead, according to the National Park S