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.

Bombshell, Victoria’s Secret’s Bestselling Fragrance, Also Happens to Repel Mosquitoes

Dids, Pexels
Dids, Pexels

People love Bombshell, the best-selling fragrance at Victoria’s Secret, for its summery blend of fruity and floral notes. Not everyone is a huge fan, though: As Quartz reports, the perfume is surprisingly good at warding off mosquitoes. In fact, it’s almost as effective as DEET insect repellent, according to the results of a 2014 experiment by researchers at New Mexico State University.

Researchers took 10 products that are commercially available and tested their ability to repel two different species of mosquitoes: the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), both of which are known to transmit diseases like dengue fever, chikungunya, and yellow fever. In doing so, volunteers subjected their own flesh to the test by placing their hands on either side of a Y-shaped tube containing the blood-sucking critters. One hand was covered in a synthetic rubber glove, while the other hand was sprayed with one of the products but otherwise left bare. Researchers recorded which tunnel the mosquitoes flew to, and how long they avoided the other end.

Three of the products contained DEET, while four products didn’t. In addition, there were two fragrances (including Bombshell) and one vitamin B1 skin patch. The DEET products were the most effective, but Bombshell proved to be nearly as good, keeping mosquitoes at bay for roughly two hours.

“There was some previous literature that said fruity, floral scents attracted mosquitoes, and to not wear those,” Stacy Rodriquez, one of the study’s authors, said in a statement. “It was interesting to see that the mosquitoes weren’t actually attracted to the person that was wearing the Victoria’s Secret perfume—they were repelled by it.”

This isn’t the first time a perfume has had an unintended effect on the natural world. It turns out that tigers are obsessed with Calvin Klein’s Obsession for Men cologne, partly because it contains a synthetic version of civetone, a pheromone that's secreted by glands located near a civet’s anus. This substance was once used to create musky fragrances, but nowadays the scent is mostly reproduced in a lab. Still, the fake stuff must be pretty convincing, because big cats go crazy when they catch a whiff of it.

[h/t Quartz]

Mystery Solved: Scientists Have Figured Out Why Some Squirrels Are Black

Rena-Marie/iStock via Getty Images
Rena-Marie/iStock via Getty Images

It can be something of a surprise to see an animal sporting a fresh coat of paint. Blue lobsters occasionally surface after being caught in traps. A pink dolphin was spotted in Louisiana in 2007 (and several times since). In the Chinese province of Shaanxi, a cute brown and white panda greets zoo visitors.

Another anomalous animal has joined their ranks. Black squirrels have been spotted in both the United States and the UK, and now scientists believe they know why.

Like many animals with unusual color schemes, black squirrels are the result of a genetic detour. Researchers at Anglia Ruskin University, Cambridge University, and the Virginia Museum of Natural History collaborated on a project that tested squirrel DNA. Their findings, which were published in BMC Evolutionary Biology, demonstrated that the black squirrel is the product of interspecies breeding between the common gray squirrel and the fox squirrel. The black squirrel is actually a gray squirrel with a faulty pigment gene carried over from the fox squirrel that turns their fur a darker shade. (Some fox squirrels, which are usually reddish-brown, are also black.)

A black squirrel is pictured
sanches12/iStock via Getty Images

Scientists theorize a black fox squirrel may have joined in on a mating chase involving gray squirrels and got busy with a female. The black fur may offer benefits in colder regions, with squirrels able to absorb and retain more heat, giving them a slight evolutionary edge.

In North America, black squirrels are uncommon, with one estimate putting them at a rate of one in every 10,000 squirrels. In 1961, students at Kent State University in Ohio released 10 black squirrels that had been captured by Canadian wildlife authorities. The squirrels now populate the campus and have become the school’s unofficial mascot. Their coloring might help them hide from predators, which might come in handy at Kent State: The campus is also home to hawks.

[h/t The Guardian]

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