Brain-Eating Amoeba Strikes U.S. Again

Freshwater-dwelling amoeba strikes again. Two cases of infection with “brain-eating” parasite have already been reported in the U.S. Responsible amoeba. What is it?

  • free-living, single celled amoeba
  • Naegleria fowleri
  • Found pretty much everywhere
  • Thermophilic (heat-loving)
  • Most often found in warm freshwater, like lakes or hot springs


People often exposed to organism will no ill effects. Rare circumstances it can cause a serious brain infection called: primary amoebic meningoencephalitis (PAM). This happens when the organism is forced up the nose during swimming or diving.

Where water can breach the nasal cavity, make its way up the olfactory nerve, and into the brain. Once in the brain, feeds on nervous tissue using sucker-like structures. Triggers an inflammatory immune response. What does it cause? It can cause a severe increase in pressure in the skull, ultimately killing the infected individual ~97% of the time

Latest cases in the U.S. reported in the last month was a 21-year-old woman from Central California and condition worsened then the patient later died. The second case was a 4 year old boy in Minnesota who became infected in Lake Minnewaska and is currently very ill.

More northern cases indicate organism is spreading northward. Could be due to climate change. Between 2002 and 2011 only 32 infections were reported in the U.S., so they're still extremely rare.