6 Fast Facts About Brain-Eating Amoebae

iStock.com/Dr_Microbe
iStock.com/Dr_Microbe

If “brain-eating amoebae” isn't the most terrifying combination of words you’ve ever heard, it will be by the time you finish reading this article. Although infection from the Naegleria fowleri amoeba is rare, it does happen from time to time. Just last month, a 29-year-old man died from a brain-eating amoeba after visiting a wave pool in Waco, Texas. The CDC is currently investigating the incident. Here are a few things you should know about this pernicious organism.

1. THEY LIVE IN WARM FRESH WATER.

Warm bodies of fresh water like lakes, rivers, and hot springs are usually where the single-celled amoebae like to hang out. They can also be found in soil, and in extremely rare cases, in contaminated tap water or swimming pools that haven’t been properly chlorinated. While most people encounter the amoebae in lakes or rivers, the CDC reports found that between 2007 and 2016, one person became infected after using a backyard slip-n-slide and three people became infected after using a nose irrigation device. Contaminated tap water was to blame in all four cases.

2. YOU WON’T GET INFECTED FROM SWALLOWING CONTAMINATED WATER, THOUGH.

Infection only occurs when water containing Naegleria fowleri enters the nose. In other words, accidentally swallowing river water while swimming doesn’t put someone at risk, but getting water up one’s nose does. Although the presence of Naegleria fowleri in fresh water is common, infections still remain rare.

3. THEY’RE NOT USUALLY ATTRACTED TO HUMANS.

These amoebae don’t go out of their way to feast on human brains. In fact, they’re usually content to eat bacteria found in the soil or sediment of lakes or rivers. “Normally, it’s totally harmless, doing its own thing in the mud, eating whatever it finds there, going about its business, not bugging anybody,” biologist Dan Riskin told Mental Floss in 2017. However, once it enters a new environment (such as an unsuspecting victim’s nasal cavity), it resumes eating whatever it can find.

4. AFTER ENTERING THE NOSE, THEY TRAVEL UP THE OLFACTORY NERVE.

Once inside the nasal cavity, an amoeba starts eating away at the olfactory bulbs, which are responsible for processing information about odors. “It makes its way up that olfactory nerve, reproducing and eating, until it hits the brain,” Riskin said. “And once it’s in the brain, it’s game over for the kid that had it shoved up his nose.” That’s because the amoebae eat brain tissue and cells, resulting in brain swelling, necrosis, and usually death.

5. THE DISEASE IT CAUSES IN HUMANS IS ALMOST ALWAYS FATAL.

Once infected, a disease called primary amebic meningoencephalitis (PAM) sets in. Early symptoms include severe headache, fever, nausea, and vomiting, and some of the stage-two symptoms are seizures, hallucinations, altered mental state, and coma. Generally, people start to show symptoms about five days after infection and die five days after that. The fatality rate is more than 97 percent, but again, infection is rare. Of the 143 cases of infection reported between 1962 and 2017, only four people survived, according to the CDC. But don't worry, your odds of contracting a brain-eating amoeba are about 1 in 70 million.

6. YOU CAN REDUCE YOUR RISK BY PLUGGING YOUR NOSE.

Brain-eating amoebae shouldn't be at the top of your list of concerns while swimming—drowning, for instance, is a far greater danger—but there are still a few things you can do to protect yourself. Try squeezing your nose shut while jumping or diving, or keep your head above water while taking a dip.

Tonight, the Lyrid Meteor Shower Peaks on Earth Day

iStock/dmoralesf
iStock/dmoralesf

Tonight, look up and you might see shooting stars streaking across the sky. On the night of Monday, April 22—Earth Day—and the morning of Tuesday, April 23, the Lyrid meteor shower will peak over the Northern Hemisphere. Make some time for the celestial show and you'll probably see meteors zooming across the heavens every few minutes. Here is everything you need to know about this meteor shower.

What is the Lyrid meteor shower?

Every 415.5 years, the comet Thatcher circles the Sun in a highly eccentric orbit shaped almost like a cat's eye. At its farthest from the Sun, it's billions of miles from Pluto; at its nearest, it swings between the Earth and Mars. (The last time it was near the Earth was in 1861, and it won't be that close again until 2280.) That's quite a journey, and more pressingly, quite a variation in temperature. The closer it gets to the Sun, the more debris it sheds. That debris is what you're seeing when you see a meteor shower: dust-sized particles slamming into the Earth's atmosphere at tens of thousands of miles per hour. In a competition between the two, the Earth is going to win, and "shooting stars" are the result of energy released as the particles are vaporized.

The comet was spotted on April 4, 1861 by A.E. Thatcher, an amateur skywatcher in New York City, earning him kudos from the noted astronomer Sir John Herschel. Clues to the comet's discovery are in its astronomical designation, C/1861 G1. The "C" means it's a long-period comet with an orbit of more than 200 years; "G" stands for the first half of April, and the "1" indicates it was the first comet discovered in that timeframe.

Sightings of the Lyrid meteor shower—named after Lyra, the constellation it appears to originate from—are much older; the first record dates to 7th-century BCE China.

How to See the Lyrid Meteor Shower

Monday night marks a waning gibbous Moon (just after the full Moon), which will reflect a significant amount of light. You're going to need to get away from local light pollution and find truly dark skies, and to completely avoid smartphones, flashlights, car headlights, or dome lights. The goal is to let your eyes adjust totally to the darkness: Find your viewing area, lay out your blanket, lay down, look up, and wait. In an hour, you'll be able to see the night sky with great—and if you've never done this before, surprising—clarity. Don't touch the smartphone or you'll undo all your hard ocular work.

Where is the nearest dark sky to where you live? You can find out on the Dark Site Finder map. And because the shower peaks on a Monday night—when you can expect to see 20 meteors per hour—your local astronomy club is very likely going to have an event to celebrate the Lyrid meteor shower. Looking for a local club? Sky & Telescope has you covered.

Other Visible Bodies During the Lyrid meteor shower

You don't need a telescope to see a meteor shower, but if you bring one, aim it south to find Jupiter. It's the bright, unblinking spot in the sky. With a telescope, you should be able to make out its stripes. Those five stars surrounding it are the constellation Libra. You'll notice also four tiny points of light nearby. Those are the Galilean moons: Io, Europa, Ganymede, and Callisto. When Galileo discovered those moons in 1610, he was able to prove the Copernican model of heliocentricity: that the Earth goes around the Sun.

What to Do if There's Bad Weather During the Lyrid Meteor Shower

First: Don't panic. The shower peaks on the early morning of April 23. But it doesn't end that day. You can try again on April 24 and 25, though the numbers of meteors will likely diminish. The Lyrid meteor shower will be back next year, and the year after, and so on. But if you are eager for another show, on May 5, the Eta Aquarids will be at their strongest. The night sky always delivers.

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the Moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the Moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the Moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the Moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception—in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full Moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

This story was updated in 2019.

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