By John Zarrella and Patrick Oppman
CNN
Copyright 2007 Cable News Network

ORLANDO, Fla. — Something in the lakes around Orlando, Florida, has claimed the lives of three boys this summer.

"This thing is just there. It's lurking like some deadly thing in the water which can take our children's lives and we all have to be aware," said Orange County Health Department Director Dr. Kevin Sherin.

The "thing" isn't a fish or alligator. It is so small it cannot be seen with the naked eye. The killer that lives in the hot, fresh water is a single cell amoeba that once exposed to the human brain through the nasal passages is almost always fatal.

Full Story: Deadly amoeba causes initial 'flu-like' symptoms