Let’s Talk About Brain Parasites

by Kristy Tye

Haven’t you ever feared the possibility of contracting a brain parasite and facing a slow, terrible death? Me too! I promise to make this not as disgusting as it could be, so read on my paranoid friends.


(from cliche on Flickr)

Let’s start with the one you’re most likely to already have. Toxoplasmosis.

Toxoplasmosis is a parasite carried by your fuzzy kitten friends and transmitted to humans via their teeny adowable cat turds which ends up being pretty easy since you’re scooping their poop so often. How do cats get it? Likely, through murdering and eating a rodent. Yya know, your cat’s ideal Friday night.

The actual amount of people who already have Toxoplasmosis is debated, but seems to be around 11-22% in the US (and possibly a whopping 75% in El Salvador). Thankfully, it’s not normally fatal unless the host has AIDS, is pregnant, or otherwise has an compromised immune system.

Then, how would you know you had it? Upon infection, it’s possible you’ll have flu-like symptoms for the better part of a month and enlarged lymph nodes for a couple more months- then it’s likely to go into a latent phase with no symptoms. What will stick with you is a fairly undetectable increased risk-taking personality (for example, you’ll be more likely to be in a car accident!) and you’re more prone to be considered OCD or diagnosed with Parkinson’s or Alzheimer’s among other mood disorders.


(from digitalart on Flickr)

Moving right along, here’s one that’s about 99% assured to kill you if you’re infected: Naegleria fowleri. These guys (aka the “brain-eating amoeba”) live in fresh water and poorly-kept chlorinated pools. If you use a neti pot, boiling drinking water (or just using distilled) is no joke, because the closer you get one of these guys to your brain, the more likely an infection can be and the nose is their primary gateway.

How likely are you to contract these lil guys? Not very- there have only been 31 cases between 2003-2012 in the US, three of them were from nasal irrigation- AS. I. SAID. But most of the others happen in the southern, costal states.

What will happen if you become infected? It’ll be blessedly quick. Within five days you’ll show symptoms, and within five more, you’ll be dead. Since the amoebas are actively dining on your brain, you’ll get headaches, fever and nausea at first, then it’ll progress to hallucinations, seizures and general confusion/lack of awareness.


(from sunshinecoast_bc on Flickr)

I’ll save you a heart attack: you probably won’t find Taenia solium (aka the pork tapeworm) in bacon. In fact, you don’t even need to eat pork at all to contract this one.

When pigs eat a tapeworm egg, it grows in their stomach and then launches larval cysts through the stomach lining that hooks into the pig’s muscle. Humans get the intestinal version from eating undercooked pork (and thus, the larval cysts), but the brain parasite version comes from inhaling the tapeworm eggs from a human carrier which is an interruption in the whole process. The tapeworm eggs think they’re in a pig stomach and send larval cysts through the lining which ends up in our bloodstream, eventually going up into the brain. When it gets up there, the host will develop headaches and seizures, but it’s not necessarily going to kill you, which is actually fairly kind!

How likely are you to get a pork tapeworm? The intestinal version: pretty easily, cook that meat, fools. The brain parasite is a lot less prevalent in the US, but that’s thanks to the in large part to the CDC. Thanks, CDC!


(from gregoryrallen on Flickr)

Lest dog owners feel smug, there is indeed a parasite found primarily in dogs’ fur. It’s called Toxocara canis, otherwise known as dog roundworm, and yes- it sure does sound like something your disgusting best friend had when you first got him.

Transmission to humans is pretty easy, the eggs end up within a dog’s fur, and simply petting the dog will get all those eggs rustin'. There are two basic infections in humans- inhaling the egg, which will end up hatching and migrating to your liver or brain causing pneumonia-like symptoms, fever, coughing, etc. The other way is when the egg goes straight into your EYE, DEAR GOD. It hatches and latches onto the back of your eye causing a litany of disgusting issues ending most probably in vision loss, let’s never speak again of this.

How likely are you to get it? It’s nearly impossible to actually catch so long as you’re keeping yourself and your dogs clean and not, like, rubbing your face in every homeless, mangey dog, which is a solid tip regardless.

So, do you feel more informed now? Ever had a parasite yourself? Or just fear that you have one now? Tell me all the disgusting details in the comments!