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.

Running Just Once a Week Is Linked to a 27 Percent Drop in Risk of Early Death

lzf/iStock via Getty Images
lzf/iStock via Getty Images

A new study suggests that even the occasional light jog could help you live a longer, healthier life.

Runner’s World reports that researchers compiled data from 14 previously published studies to determine if running was associated with lower the risk of early death. Their findings, published in the British Journal of Sports Medicine, show that among a pooled sample of 232,149 people whose habits were monitored from 5.5 to 35 years, those who ran had a 27 percent lower risk of early death than those who didn’t.

Causes of death included cardiovascular disease, cancer, and everything in between—and while the study doesn’t guarantee that running will lower your risk of early death, it does show that there’s at least a link between the two.

Furthermore, the results suggest that you don’t have to be a particularly dedicated or serious runner in order to reap the health benefits. The researchers found that those who ran for less than 50 minutes a week, only once a week, or at speeds below 6 mph still ranked with more intense intense runners when it came to lower early death rates than non-runners.

“This finding may be motivating for those who cannot invest a lot of time in exercise, but it should definitely not discourage those who already engage in higher amounts of running,” Željko Pedišić, a professor at Victoria University’s Institute for Health and Sport and a co-author of the study, told Runner’s World.

In other words, there’s no reason that avid marathoners and competitive tag enthusiasts should lessen their running regimens—but if you spend most of your time sitting in front of your computer or television, you might want to consider adding a 45-minute neighborhood jog to your weekly to-do list. According to Pedišić, it could help keep high blood pressure, high cholesterol, obesity, cardiovascular disease, type 2 diabetes, and cancer at bay.

And if you’re avoiding running to protect your knees, toenails, or something else, you probably don’t have to—read up on the truth behind eight common running myths here.

[h/t Runner’s World]

The Best Place to Park at the Mall, According to Science

Diy13/iStock via Getty Images Plus
Diy13/iStock via Getty Images Plus

It’s Black Friday, and you are entering the battlefield: a mall parking lot. You’re determined to nail that doorbuster deal, and quantities are limited. The field is already full of other combatants. You must find the perfect parking spot.

Do you grab the first one you see, or drive as close to the mall as you can and hover? Or, do you choose a tactic that lies somewhere between?

Parking at the mall has long frustrated drivers and taxed the minds of traffic engineers—but after working on the problem for three years, physicists Sidney Redner of the Santa Fe Institute and Paul Krapivsky of Boston University have gotten closer to a winning strategy. “There are lots of studies of parking lots, but it’s just that they’re so complicated, you don’t get any insight into what’s actually happening,” Redner tells Mental Floss.

Redner and Krapivsky, whose work employs statistical physics to make sense of large systems, simplified the messy dynamics of a parking lot by modeling it with a one-dimensional grid of cells, each representing a parking space. They tested three simple, yet realistic, parking strategies using basic probability theory. Their model tested the following strategies to see which one resulted in least time spent walking and driving in the parking lot:

Meek Strategy: Meek drivers park in the first open space they see, however distant it is from the mall. As a result, they often spend the most time walking to and from the mall.

Prudent Strategy: Prudent drivers look for the first open spot but then keep driving toward the mall. They continue to drive until they see a parked car and then park in the best open spot between that first open spot and that first parked car. There may be a block of open spaces between the first open space and the first parked car. From that block of open spaces, they choose the one closest to the mall.

Optimistic Strategy: Optimistic drivers drive as close to the mall as possible and look for a parking space close to the entrance. If they see one, they grab it. If there are none, they backtrack and choose the first open space they see. Optimistic drivers probably spend the most time driving and the least time walking. In the worst-case scenario, they end up parking back where a meek driver would have parked.

Naturally cautious drivers are more likely to default to the meek mode, while aggressive drivers often use the optimistic strategy, well, aggressively. And most drivers have tried something like the prudent method.

So, which is your best bet in a crowded mall parking lot this holiday season?

In the experiments, the prudent strategy fared best, followed closely by the optimistic strategy. The meek strategy finished a distant third (“It’s hard to comprehend just how bad it is,” says Krapivsky, a self-described meek driver).

And even better: The more crowded the lot, the better the prudent strategy works, he adds.

One clear takeaway from the study is that meek drivers may want to ramp up their parking skills before going to the mall. “You don't want to park on the very outskirts of the lot, like a mile away from the stores. You want to go to the first place there’s an open spot and park somewhere in that first open area,” Redner says. They published their findings in the Journal of Statistical Mechanics [PDF].

The researchers say this is the best of the strategies they tested, but it has its limitations. It does not take into consideration competition among a sea of drivers all looking for parking spaces at the same time, and it doesn’t include (perhaps optimistically) the psychological aspects of operating a vehicle. “We are not rational when we are driving,” Krapivsky tells Mental Floss.

The researchers’ one-dimensional grid model also assumed that there would be one car at a time entering the lot through one entrance, unlike messier lots in the real world, where many cars enter from a multitude of entrances.

The optimal parking strategy, one that would best all others every time, has yet to be found. In their research, though, Redner and Krapivsky are homing in on one that integrates the more complicated aspects of parking.

For now, science says prudence is a virtue in the parking lot. And while the meek might inherit the Earth, they certainly won’t find the best parking space at the mall.

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