In the United States, millions of people are exposed to the amoeba that causes naegleria infection each year, but fewer than 10 people a year get sick from it.

Some factors that might increase your risk of naegleria infection include:

  • Freshwater swimming. Most people who become ill have been swimming in a freshwater lake within the past two weeks.
  • Heat waves. The amoeba thrives in warm or hot water.
  • Age. Children and young adults are the most likely age groups to be affected, possibly because they're likely to stay in the water longer and are more active in the water.
Aug. 04, 2012