10 Scary Parasites Living Inside Humans. Pray to God You’re Not Infected with N°7!

We all host billions of foreign bodies inside of us. More often than not, those living organisms are beneficial as is the case with the bacteria of our intestinal flora. However, the relationship does not always go both ways.

Sometimes, we’re hosting parasites that only know one thing. And that is how to TAKE!

Here is a list of the 10 most nefarious parasites living inside us:

Filarial Worm



If you get lucky with a filarial worm, you will only get the type that crawls under your skin and leaves you pretty much in peace. If, however, you become the new home of a Brugia malayi (or even Wuchereria bancrofti), lock yourself up because it’s not going to be a pretty sight!

Filarial worms which are transmitted by those damn mosquitoes are known to cause elephantiasis (just think about Elephant man to get an idea of what we’re dealing with here!)

Guinea Worm

The Guinea worm is the cause of Dracunculiasis, a disease that sounds like Dracula just took a bite of you, but the reality is actually even worse! You develop this charming little disease when you drink contaminated water.

After about a year after you’ve ingested the larvae of the worm, you will start feeling an intense burning as the worm starts digging itself a way out! It will then appear in the open air as if to say hi to everyone in the surroundings. You will usually have to wait a few months for the whole f*$!@§ to come out! Just lovely!


Here, we have another nice worm that loves to make a home out of our brain! Once we get infected by this parasite, it will hesitate between our eyes (and causing ocular sparganosis… how considerate of him) or our grey matter, then it will make itself comfortable.

At first, we won’t feel a thing… but as the larva begins to grow, we will feel that something isn’t right. And we couldn’t be more true! After the headaches, we can expect seizures, paralysis, abscesses…  You might even become blind if it chooses to nest in your beautiful eyes. Hum!


What if we told you that there’s a fish in Amazonia that’s even scarier than the piranha? Because if the latter will eat you from the outside, the former will do it not only from inside of you… but from inside your genitals!

While you’re swimming quietly in the river, taking in the beautiful sights, telling yourself how lucky you are to be in such a wonderful place… You will be light years from imagining that there’s a fish trying to enter your urethra at the same time! One thing is for certain, as far as we’re concerned, we’ve crossed this whole region from our future vacations map!

Roundworm (Ascaris lumbricoides)

OK, here is the one you’re most likely to be infested with. The Ascaris lumbricoides is the most common of all worms in humans (some numbers estimate that as much as 1/6th of the population is host to the worm). It doesn’t mean that it’s not nasty, far from it! With severe infections, you can get ulcers, abdominal pain and even worms coming out from where you know!

If I was you, I would run to the doctor and check whether I have it or not… Or maybe you prefer to live with that uncertainty?  Tonight, remember that you might be eating for two…

Chigoe flea

Introducing the Chigoe flea also known as jigger. Even though it’s the smallest reported flea on planet Earth, it’s also the baddest. The female has a bad habit of burrowing into people’s skin to lay eggs. If that wasn’t bad enough already, when those eggs start to develop, you will see the skin blow and then break down.

At that time, it might be a good idea to consult as leaving the flea inside the skin may lead to lifelong deformation. One just doesn’t mess around with the jigger.

Human botfly

This one is the stuff of nightmares. Botflies will come to you and, when you’re not looking, will gently deposit some eggs on your skin. With the heat from your body, the eggs will hatch, unleashing a horde of larvae that will burrow into your skin and attach themselves to your tissues.

Of course, you can get rid of them once they’ve infested you… but do you really want to know how? Let’s just say that it will take a knife and forceps. Good luck with this!


Ah, tapeworms! If we had to choose a parasite to be infested with, this would be our pick. Even though it’s extremely gross as it can reach up to 10 feet in length and colonize your whole intestines, this worm is rather harmless unless you somehow piss it off and it chooses to move upstairs.


This one will make you look pretty, guaranteed! People infected with Leishmania will develop a disease called Leishmaniasis (how original) that will give the impression that your skin has been bitten off by a wolf.

Leishmania is spread by sandflies and can attack not only your skin but also your mucosa and viscera! The main result will be ulcers the size of big golf balls, and nice fevers.


If the Candiru didn’t dissuade you to ever go swimming in a river ever again, the Naegleria fowleri might very well do! While you’re swimming, this amoeba will enter your nose through your nostrils (and the olfactory nerve, to be more precise) and head directly upstairs.

Once it has settled there, the Naegleria will start feeding on your brain to multiply and ensure a rich and fruitful offspring. Usually, that’s where you will lose the sense of the smell as your olfactory bulbs get wolfed down. Don’t worry, pretty soon you will not be able to feel any more pain because you will be dead. It only takes two weeks from infestation to death.