5 Diseases That Will Keep You Out Of The Water This Spring Break

Ah, Spring Break is finally upon us...a great time for rafting, surfing, swimming, and rehydrating. Before partaking in all these fun activities, we should remind ourselves about the sinister creatures lurking in waters all around the world just waiting to take us down. These aqueous villains don’t have big teeth and a menacing theme song to make you hydrophobic, but learning about these tiny critters might make you think twice about jumping into the next hot spring you see.

1. Primary amebic meningoencephalitis

Primary amebic meningoencephalitis (or PAM as it is known by those acronym-loving physicians) is caused by an amoeba called Naegleria fowleri. But aren’t amoebas those cute little single-celled organisms that we’ve all spied on through middle school microscopes and laughed at in Far Side comics? Nothing scary there.

This is why Naegleria fowleri should always be referred to as brain-eating amoeba. Yes, BRAIN EATING, as in plowing through your cerebellum like Homer Simpson gorging on a jelly donut. It is the real-life zombie of the parasite world, possessing an insatiable appetite for grey matter.

There’s only one thing the brain-eating amoeba enjoys besides neuronal soup: warm weather. This mind melting nemesis is largely found in still waters in the southern US, but global warming is allowing it to creep up to areas further north. Just one good snort of contaminated water sends this hungry little amoeba to the brain buffet.

This amoeboid parasite is a glutton, and that is its undoing. A smart parasite, like Toxoplasma gondii, goes to sleep in the brain so it won’t kill its host. But Naegleria fowleri goes on a brain devouring binge with no thought to sustainability and literally eats its host to death.

Naegleria fowleri is rather prevalent, but human infection is very rare. The bad news for those who are susceptible is that there is no cure. You will be host to this unwelcome guest for about six days before there isn’t enough brain to support the two of you any longer. So if you can’t resist the urge to go skinny dipping, at least wear some nose plugs.

2. Cryptosporidiosis

Who remembers that childhood classic sung in elementary schools around the world, “When you think your friends are joking, but your pants are brown and soaking…diarrhea, diarrhea!”

If parasites had theme songs, Cryptosporidium would surely claim “The Diarrhea Song”. Sure, Giardia and some other gut pathogens might complain since they are excellent poo liquefiers too, but they’ve never sent an entire city running for the bathrooms at the same time.

In 1993, the single-celled parasite Cryptosporidium brought gastrointestinal misery to over 400,000 people in Milwaukee, overwhelming city hospitals and even killing at least 100 of these unlucky souls. The parasite is a common pathogen in cattle and somehow found its way into the city water supply (in other words, people were drinking water that had cow patties in it).

The Cryptosporidium cysts expelled by infected cattle (or infected people) are very tough, even resistant to chlorine. People can become infected from contaminated water in lakes, pools, or water fountains, or by taking care of infected babies or patients. Once ingested, the cysts break open and the parasites inside invade your intestinal epithelial cells. They steal nutrients from your cells in order to replicate and make more cysts that get back out into the environment after turning your insides into their ultimate water slide.

Cryptosporidium is the microbial equivalent of Turbo-Lax. With no vaccine or effective treatment available, patients just have to stay hydrated, hunker down with plenty of aloe-infused TP, and wait out the unpleasant infection, which can last up to two very long weeks.

3. Cerebral sparganosis

“The magnetic resonance revealed widespread white matter degeneration and cortical atrophy”. If you hear a doctor say that, then there’s a good chance you have a flatworm called Spirometra mansoni in your brain that causes cerebral sparganosis. In everyday language, this means your brain has turned to Swiss cheese.

To be fair, Spirometra mansoni has no desire to infect you, as humans are not the definitive host. It would much rather be left in the water to invade tiny crustaceans, which are then eaten by a second intermediate host (fish, amphibian, or reptile), with the ultimate dream of getting into a dog or cat. But no, you had to take a gulp of water and disrupt this parasite’s travel plans. Since it can’t use you to make eggs and get its offspring back into the environment, the pissed off tapeworm wanders around your body and, in some cases, makes its way to the control center to vent its sexual frustration.

So how do you get these nasty things out of your head? Well, you should probably let a surgeon do it, no matter how good your friend claims to be at that Operation game. Your surgeon will likely use a technique called stereotactic aspiration, which is an innocuous way of saying, “poke a hole in your head and suck the larvae out”.

4. Candiru

Our next water dwelling devil is called candiru and it is the star of every man’s nightmare. Candiru is also known as the vampire fish, which is an awesome nickname, but what this toothpick-shaped catfish is purported to do is not cool, bro. Not cool at all. Any guesses?

The slender shape of candiru has gracefully evolved to fit in-between the gills of other fish, where this vampire draws its blood meal. Unfortunately, it is also perfectly suited to tunnel its way into a man’s urethra. Even worse, the victim can’t simply pull the fish out because candiru projects spikes that firmly implant its body into the urethra wall. The only options for slaying this vampire include amputation or expensive surgery, so best wear a condom when swimming with the vampire fishes.

If you’re thinking that it seems quite improbable that an eel-like catfish can hit such a small target, you’re probably right. There are reports that vampire fish can follow urine streams like a yellow-brick road, but this claim was tested experimentally and proven to be a myth. The few reported cases of candiru infiltrating urethras are not without controversy, so you probably only have to fear candiru in your nightmares.

5. Mycobacteriosis

By now you probably won’t be setting foot near lakes, rivers, or even mud puddles ever again. You’ve resigned yourself to just sit at home and take your mind off these terrors by gazing into your tranquil aquarium. Ah, what danger could come of that?

Mycobacteriosis! Otherwise known as fish-handler’s disease or aquarium granuloma, mycobacteriosis is one of the unspoken hazards of maintaining an aquarium. Think about it for a minute. Fish eat. Fish pee. Fish poop. And you haven’t changed the water in three, maybe four, months! That poor fish is swimming in a cauldron of bacteria, including a variety called Mycobacteria. Some species of Mycobacteria cause such lovely diseases as tuberculosis and leprosy, but the one in fish tanks is usually Mycobacteria marinum. If you stick your hand in the water to play tag with Nemo or set up his new SpongeBob pineapple house, Mycobacteria marinum can enter your body through an open wound on your skin.

Like other Mycobacteria, the infection is very stubborn and lasts a long time even with antibiotic treatment. You may also be left with ugly scars and/or arthritis to serve as a permanent reminder that you need to change the water in your fishy friend’s tank frequently. In some cases, especially immunocompromised people, infection with Mycobacteria marinum has resulted in amputation or even death. So ditch the aquarium now and just install a fish tank screensaver on your computer desktop.

Contributed by:  Bill Sullivan
Swim with Bill on Twitter.


The original version of this article appeared on BuzzFeed Community.



Bauer IL (2013). Candiru--a little fish with bad habits: need travel health professionals worry? A review. Journal of travel medicine, 20 (2), 119-24 PMID: 23464720

Ice, Ice Baby: Bringing Frozen Viruses Back To “Life”

Back in 2003, a new class of giant, ancient viruses were found that preyed upon unsuspecting amoebas in the Paleolithic.  

Earlier this year, scientists published a study describing how they revived another one of these giant viruses, which has been frozen in Siberian permafrost for 30,000 years! We’ll discuss why they did this in a bit, but let’s first talk about how they did this.

Over the years, lots of cool stuff has been found well-preserved in ice. Otzi, a 5,000 year old “ice man” was a historic find in 1991. He went on to become a spokesperson for the GEICO auto insurance company.

Viruses are minute obligate intracellular parasites. In other words, they cannot replicate outside of a host cell, an attribute that gives them the unflattering distinction of being the worst houseguest ever. That’s right:  viruses storm into your home – unannounced – take off their coat and make themselves right at home. They ransack the place and raid your fridge without even asking. As if that wasn’t bad enough, you come home one day and catch the virus in the act of making babies – lots and lots of babies. Finally, this unruly family blows up your house as they leave, without so much as a “thank you”, and go on their merry way to invade other homes in your neighborhood.

While we can feel the pain that they cause, especially during cold and flu season, we can’t see the culprits. Viruses are really, really tiny - most are smaller than the molecular complex cells use to make proteins.

Many viruses are under 100 nM (0.1 micron), but some (like Ebola) are almost 1.0 micron. Compared to viruses, even a bacterium is enormous. 

So how does one find a virus in thousands of miles of ice? Virus hunters take an approach similar to finding a needle in a haystack. But in this case, instead of a magnet, the scientists use amoebas as “bait” to lure out viruses that might be chilling out in the permafrost.

Amoebas are single-celled organisms called protozoa that, like most cells, fall prey to viruses. By putting permafrost into amoeba cultures, scientists were able to screen samples for those that could kill the amoebas. And they found a “big” surprise.



Thick membrane or no, Pithovirus invades amoebas. Who knows…with this discovery, maybe scientists can devise a new treatment that targets the deadly brain-eating amoeba, Naegleria.

The virus spotted in these infected amoeba cultures resembled a so-called “pandoravirus” or “giant” virus. They are still microscopic of course, but considerably larger than the viruses we know of today (about 1.5 microns in length and 0.5 microns across). Not only are they larger in size, but they contain many more genes. By way of comparison, HIV contains less than 15 genes, but this giant virus has 500 genes. They christened this new giant virus “Pithovirus sibericum”, and it is the oldest virus ever to have been revived to date.

A “huge” find in the world of virology, Pithovirus is now growing in labs again after a 30,000 year slumber. Image taken from Legendre, et al.

Now why on earth would scientists bring a virus back from the dead? Are they mad? Are they trying to facilitate the apocalypse?

Of course not. As climate change continues to melt more and more ice, it is possible that these viruses are going to revive naturally. By resurrecting them in the lab in controlled conditions, researchers can get ahead of this curve by studying the virus. Study of the virus can help determine which one(s) pose a threat and, if so, vaccine and drug development efforts can get underway thanks to our knowledge of the virus. And don’t worry about Pithovirus – it was already found to be incapable of infecting animal cells.

Another reason these viruses are worthy of study is that they can reveal new insights into how cells evolved, since viruses can transfer their DNA to their hosts. They may even shed light on the greatest biological mystery:  the origin of DNA/RNA and how life came to be on Earth.

The same team of scientists isolated yet another ancient giant virus this year from the same permafrost and named it Mollivirus sibericum. You may also be wondering what Siberian virus hunters listen to while exploring those Hoth-like landscapes. I'll take a guess and hope that it is wrong...
 

Contributed by:  Bill Sullivan, Ph.D.
Follow Bill on Twitter.

Legendre, M., Lartigue, A., Bertaux, L., Jeudy, S., Bartoli, J., Lescot, M., Alempic, J., Ramus, C., Bruley, C., Labadie, K., Shmakova, L., Rivkina, E., Couté, Y., Abergel, C., & Claverie, J. (2015). In-depth study of , a new 30,000-y-old giant virus infecting Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1510795112

 

Legendre, M., Bartoli, J., Shmakova, L., Jeudy, S., Labadie, K., Adrait, A., Lescot, M., Poirot, O., Bertaux, L., Bruley, C., Coute, Y., Rivkina, E., Abergel, C., & Claverie, J. (2014). Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology Proceedings of the National Academy of Sciences, 111 (11), 4274-4279 DOI: 10.1073/pnas.1320670111