Naegleria fowleri, a heat loving amoeba, is usually harmless, but if it gets up someone’s nose, the amobea can be life-threatening. It’s not entirely clear how or why, but it attaches to one of the nerves that takes smell signals to the brain. There, the amoeba reproduces and the brain swelling and infection that follows is almost always deadly.
While infections are rare, they occur mainly during the summer months, and usually occur when it is hot for prolonged periods of time, which results in higher water temperatures and lower water levels. Initial symptoms may include headache, fever, nausea, or vomiting. Later symptoms can include stiff neck, confusion, seizures, and hallucinations. After the start of symptoms, the disease progresses rapidly and usually causes death within about five days. Naegleria fowleri can be found in pools, hot tubs, pipes, hot water heaters, and fresh water bodies of water.