Brain-Eating Amoebae

Recently, my biology professor discussed the effects of an extremely rare amoebic infection that results in the deterioration of the brain. The amoebae, Naegleria fowleri, cause a disease called Primary Amoebic Meningoencephalitis and reside in warm, usually stagnant freshwater, which is ubiquitous in a southern summer. This particularly interested me, because many of my friends were recently counselors at summer camps at which they played in lakes. I was interested to see what kind of danger they were subjecting themselves to, so I looked up the amoeba online and came across this article.

The amoebae are harmless unless they are inserted into the nose, usually via splashing or horseplay in the infected freshwater. Even when an open wound is exposed to Naegleria fowleri, the amoeba doesn't attack the the wound, because it would rather consume other bacteria found in the water rather than eat human tissue. But when it is forced into the nose, it travels down the olfactory neuroepithelium, feasting on that tissue until it reaches the brain, where it spreads throughout the brain, breaking it down and digesting it. Once the amoebae have reached the brain, there is no current treatment to save the patient's life. They will show fever, headache, nausea, and a stiff neck, and they will die a few days later.

An interesting part of this study is that the number of deaths from Naegleria fowleri is increasing in Karachi, Pakistan. This city has experienced 13 deaths over the past 17 months (in February 2011), an unexpectedly large and increasing number of deaths. As a frame of reference, the United States usually loses 1-8 people a year from primary amebic meningoencephalitis, the disease caused by Naegeria fowleri. Twelve of the 13 deaths were of men, and only one of the deaths reported recent freshwater swimming. So how did the amoeba get inside these victims? All of the victims were Muslim and performed ritual ablution, which involves inserting water into the nose. The city's water supply wasn't properly cleaned, so it was circulating the brain-eating bacteria through the water supply. However, since the amoeba isn't harmful unless inserted into the nose, nobody had showed indication of Naegleria fowleri in the water supply until the patients mentioned in the study started dying.

http://wwwnc.cdc.gov/eid/article/17/2/10-0442_article.htm