This is pretty scary and sad! I’m glad I didn’t know about this when we were on vacation.

It sounds like science fiction but it’s true: A killer amoeba living in lakes enters the body through the nose and attacks the brain where it feeds until you die.
Even though encounters with the microscopic bug are extraordinarily rare, it’s killed six boys and young men this year. The spike in cases has health officials concerned, and they are predicting more cases in the future.
[…]
“This is a heat-loving amoeba. As water temperatures go up, it does better,” Beach said. “In future decades, as temperatures rise, we’d expect to see more cases.”
According to the CDC, the amoeba called Naegleria fowleri (nuh-GLEER- ee-uh FOWL’-erh-eye) killed 23 people in the United States, from 1995 to 2004. This year health officials noticed a spike with six cases-three in Florida, two in Texas and one in Arizona. The CDC knows of only several hundred cases worldw
[…]
Though infections tend to be found in southern states, Naegleria lives almost everywhere in lakes, hot springs, even dirty swimming pools, grazing off algae and bacteria in the sediment.
Beach said people become infected when they wade through shallow water and stir up the bottom. If someone allows water to shoot up the nose-say, by doing a somersault in chest-deep water-the amoeba can latch onto the olfactory nerve.
The amoeba destroys tissue as it makes its way up into the brain, where it continues the damage, “basically feeding on the brain cells,” Beach said.
People who are infected tend to complain of a stiff neck, headaches and fevers. In the later stages, they’ll show signs of brain damage such as hallucinations and behavioral changes, he said.
Once infected, most people have little chance of survival. Some drugs have stopped the amoeba in lab experiments, but people who have been attacked rarely survive, Beach said.
“Usually, from initial exposure it’s fatal within two weeks,” he said.

(via)