"Later symptoms include confusion, lack of attention to people and surroundings, loss of balance, seizures and hallucinations," the agency website says. "After the start of symptoms, the disease progresses rapidly and usually causes death within one to 12 days."
Here are some tips from the CDC to help lower the risk of infection:
• Avoid swimming in freshwater when the water temperature is high and the water level is low.
• Hold your nose shut or use nose clips.
• Avoid stirring up the sediment while wading in shallow, warm freshwater areas.
• If you are irrigating, flushing or rinsing your sinuses (for example, by using a neti pot), use water that has been distilled or sterilized.