Brain-Eating Amoebas

A news story by a Denver CBS television station reminds us that the fictional world of literature and the movies has nothing on Mother Nature.

Last week I was reading up on pop-culture zombies for an article I was writing. Modern-day zombies, of course, are often described as brain-eaters. I also noted that the Centers for Disease Control (CDC) recently issued a document on how to prepare for a “zombie apocalypse” – not that they are expecting one anytime soon, but the CDC saw the current zombie craze as an opportunity to put out some information on how to deal with a real emergency.

Imagine my surprise this morning to read an article by CBS4 in Denver warning that people who do nasal washes with tap water run the risk of inviting brain-eating amoebas into their skulls. Says CBS4:

The Centers for Disease Control and Prevention and National Jewish Health in Colorado both have issued a warning about nasal washes after two people have died from using tap water to do their sinus rinse. Health experts say it’s safe to use nasal washes. It’s not about the rinse, it’s about the water. They warn that a mixture from a faucet could be fatal....

Marie Fornof, Certified Infection Preventionist ... says not to use tap water. It’s because of a brain-eating amoeba called Naegleria fowleri. It’s common in warm rivers and lakes, but if it travels up the nose to the brain it’s usually deadly...

The brain infections caused by the amoeba are rare, but the two most recent deaths in Louisiana were tied to the use of tap water in “neti pot”s to flush sinuses.

The CDC warning about zombie-like amoebas? Was this on the level?

Apparently it was. Our old, semi-reliable friend Wikipedia says:

Naegleria fowleri (also known as "the brain-eating amoeba") is a free-living excavate form of protist typically found in warm bodies of fresh water, such as ponds, lakes, rivers, and hot springs. It is also found in soil, near warm-water discharges of industrial plants, and unchlorinated swimming pools in an amoeboid or temporary flagellate stage. There is no evidence of this organism living in ocean water.... It is an amoeba, described as such by the the CDC, NCBI, articles on pubmed, and WHO.
N. fowleri can invade and attack the human nervous system. Although this occurs rarely, such an infection nearly always results in the death of the victim. The case fatality rate is estimated at 98%.

The CDC, presumably more authoritative than Wikipedia, has an FAQ on the amoeba:

Naegleria fowleri infects people by entering the body through the nose. This typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. The Naegleria fowleri ameba travels up the nose to the brain where it destroys the brain tissue.

You cannot be infected with Naegleria fowleri by drinking contaminated water. In very rare instances, Naegleria infections may also occur when contaminated water from other sources (such as inadequately chlorinated swimming pool water or heated tap water <47°C) enters the nose, for example when people submerge their heads or cleanse during religious practices (1), and, possibly, when people irrigate their sinuses (nose).

Let's hope the CDC isn't funnin' us on this one....