A parasitic brain-eating amoeba for which "there is no cure" killed a healthy and active teenager after entering through his nose while he swam in a lake.
The invisible killer killed 13-year-old Tanner Lake Wall by destroying his brain tissue, with the lad suffering terrible headaches, nausea and vomiting before eventually dying days later.
The teen had been swimming at a freshwater lake at a campsite in North Florida, US when the deadly amoeba Naegleria fowleri entered his body when water went up his nose.
More than 50 other people were swimming in the lake at the time - but only Tanner fell prey to the silent killer - which an expert said "progresses rapidly" and can cause seizures, hallucinations and its host to enter into a coma.
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