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Top 10 Most Horrific Parasite Infections

[WARNING: content will be disturbing to most.] Most of us (thankfully) never have had to experience any of these parasites. Though there are people who are at risk everyday and have to go through these horrid symptoms and even risk death if infected, or more so, infested.


Taeniasis (Tapeworm)

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Taeniasis is a tapeworm infection. Tapeworm infestation does not usually cause any symptoms. Infection is generally recognized when the infected person passes segments of proglottids in the stool, especially if the segment is moving. Mmm sounds like fun! Not. People acquire tapeworms by eating undercooked meat or freshwater fish that contain tapeworm cysts. Tapeworms in the intestine usually cause no symptoms but may cause abdominal discomfort, diarrhea, and loss of appetite. Though however if they are in the brain, larval cysts cause various symptoms, such as headaches, seizures, and confusion. [JFrater: Given the choice of a picture of the worm itself, and the picture above, it was a no-brainer.]


Bot Fly Larva


Only one bot fly species attacks humans, the Dermatobia hominis. Eggs are deposited in animal skin directly, or the larvae drop from the egg: the body heat of the animal induces hatching upon contact. Infestation can be caused by larvae burrowing into the skin of the host animal. They do not kill the host animal, and thus are true parasites (though some species of rodent-infesting botflies do consume the host’s testes/ovaries). You can cause them to suffocate by placing smoke over your wound or tape where they then try to come to the surface and you can then extract these pests. The disgusting video clip above shows an extraction from a human head.


Ascaris infection


Ascariasis is the most common human worm infection. Infection occurs worldwide and is most common in tropical and subtropical areas where sanitation and hygiene are poor. Children are infected more often than adults. In the United States, infection is rare, but most common in rural areas of the southeast. Anesthesia appears to agitate the worms and when there is infection of adults in the lungs they can exit the mouth and nose. The normal life cycle of ascaris is to migrate to the lungs for the larval stage and grow to an adult in the intestines, but sometimes the adults reside in the lungs. Ascaris eggs are found in human feces. After feces contaminates the soil, the eggs become infectious after a few weeks. Infection occurs when a person accidentally ingests infectious Ascaris eggs. Once in the stomach, immature worms hatch from the eggs. The larvae are carried through the lungs and then to the throat where they are swallowed. Once swallowed, they reach the intestines and develop into adult worms. Adult female worms lay eggs that are then passed in feces; this cycle takes between 2-3 months. I couldn’t imagine that something like that wriggling out of me! If you don’t believe they can come out of the nose and mouth, take a look at this picture [warning: don’t – it is revolting].




Also known as river blindness, this is the world’s second leading infectious cause of blindness. It is caused by Onchocerca volvulus, a nematode that can live for up to fifteen years in the human body. It is transmitted to humans through the bite of a black fly. The worms spread throughout the body, and when they die, they cause intense itching and a strong immune system response that can destroy nearby tissue, such as the eye which causes the blindness.


Lymphatic Filariasis


A parasitic and infectious tropical disease that is caused by thread-like filarial nematode worms. These worms occupy the lymphatic system, including the lymph nodes, and in chronic cases these worms lead to the disease Elephantiasis – as seen above.


Guinea Worms


First swallowed by a water flea, the Guinea worm transforms into a third stage larvae. The flea, ingested by a human being, is consumed by the stomach’s juices and the larvae of the Guinea Worm are released. They remain in the stomach for up to three months. After mating, the male dies and the female bores through the body making her way to the extremities, usually the lower leg or foot, but she can go to any part of the body. Once settled, just under the skin, she begins to grow, by eating the flesh of her carrier, and turns into a three to five foot worm. This worm is about as big around as a piece of spaghetti. While growing, she causes severe pain and cripples the carrier, so that they are not able to move. As the worm matures, a painful blister appears on the skin of the carrier. When the person puts the affected part of the body in water, the blister breaks and hundreds of thousands of tiny first stage larvae are released into the water. The adult female worm then comes slowly out of the body of its carrier through the sore made by the broken blister. It usually takes several weeks for the worm to completely exit the body.


Cutaneous leishmaniasis


A skin infection caused by a single celled parasite that is transmitted by sand fly bites. The sandfly vector is a 2-mm long, hairy fly. These flies are able to pass through the usual netting used for mosquitoes. Sand flies are found around human habitations and breed in specific organic wastes such as feces, manure, rodent burrows, and leaf litter. Cutaneous leishmaniasis manifests as painful sores that could, if infected, lead to death.


Screw-worm fly


An insect parasite of warm-blooded animals. The fly has red eyes and a shiny blue-green body and looks similar to Australian blowflies. Flies lay eggs on the edge of open wounds from scratches, injury, branding, dehorning or castration. Larvae hatch and feed on the underlying flesh causing extensive tissue damage. Left untreated, animals can die from infection and loss of tissue fluid. Its known for the larvae to eat their host from the inside out!


African trypanosomiasis
sleeping sickness


A vector-borne parasitic disease, this disease is transmitted through the bite of an infected tsetse fly. At first they multiply in subcutaneous tissues, blood and lymph. In time, the parasites cross the blood-brain barrier to infect the central nervous system. Tsetse flies are found in Sub-Saharan Africa. Only certain species transmit the disease. They are mainly found in vegetation by rivers and lakes, in gallery-forests and in vast stretches of wooded savannah. When symptoms do emerge, the patient is often already in an advanced disease stage when the central nervous system is affected. The first stage of the disease, known as a haemolymphatic phase, entails bouts of fever, headaches, joint pains and itching. The second stage, known as the neurological phase, begins when the parasite crosses the blood-brain barrier and invades the central nervous system. In general this is when the signs and symptoms of the disease appear: confusion, sensory disturbances and poor coordination. Disturbance of the sleep cycle, which gives the disease its name, is an important feature of the second stage of the disease. Without treatment, sleeping sickness is fatal.


brain-eating amoeba


Don’t drink the water. And while you’re at it, you might not want to take any chances by putting your head in it, either. Naegleria fowleri, a not-so-friendly little amoeba, makes its home in warm fresh water in the American Southwest. That’s not such a problem, but it occasionally also likes to make its home in people’s brains, which is a bit of a problem. Infection with Naegleria causes the disease primary amebic meningoencephalitis (PAM), a brain inflammation, which leads to the destruction of brain tissue. Initial signs and symptoms of PAM start 1 to 14 days after infection. These symptoms include headache, fever, nausea, vomiting, and stiff neck. As the amoeba cause more extensive destruction of brain tissue this leads to confusion, lack of attention to people and surroundings, loss of balance, seizures, and hallucinations. After the onset of symptoms, the disease progresses rapidly and usually results in death within 3 to 7 days.




This is a bonus item courtesy of Top 10 Worst Things in Nature. The Candiru is a small parasitic catfish which is found mostly in the Amazon river where it is the most feared fish – even more so than piranhas. The fish can grow to a maximum length of around six inches. Candiru feed on the blood of their host creatures by swimming into the gills and using razor sharp spines on its head to attach itself. It then chews its way through the host until it reaches a major artery and drinks blood until it is satiated. The fish finds its prey by sniffing the water and this is where it starts to get nasty: the smell of human urine appeals to candirus and they can find their way to a human penis or vagina under the water and enter it. When this happens, the fish attaches itself (causing great pain to the poor human) and it can generally only be removed through surgery. This is a very unpleasant situation to be in – so be warned: don’t pee in the Amazon river.

  • That’s a drag

  • capt funtime

    awesome list for the worse morning ever, cheers for cheering me up……

  • Jacob

    That’s gotta hurt!

  • Phender_Bender

    Tasty! Luckily I have yet to find something that can truly gross me out. #9 and #8 came close though.

  • Al


  • Jonny

    sick list in both meanings of the term!

  • YoungAnabaptistRadical

    Wonderful list! And great pictures! Great job! (I’m being 100% serious).

  • Normally people would say “Good thing I’ve eaten lunch already” or “You just spoiled my appetite”. I on the other hand feel like puking (since I did just ate) and I’m thinking twice whether I should still eat later. “sigh”

  • Snake

    I don’t remember its name, but there is a parasite that can infect the brain and permanently change the personality of its host, surprised that wasn’t on this list.

  • Zuleika

    #8 truly horrified me. This really is a horrific list. Now I’m going to get paranoid about water and stuff. Ick!

  • BravehisTickle

    For doctors, these images are not disturbing at all. My elder brother is a doc and his gargantuan medical books are full of these pics..

  • Jack

    My friend’s girlfriend studied leishmaniasis, and wow, the pictures and stories she used to tell us. Horrifying stuff.

  • Chris

    There’s another parasite I’m trying to think of. It’s on the tip of my tongue. It gets all nutrients from the host and causes nausea, vomiting, swollen abdomen and major mood changes. Symptoms set in shortly after it starts to grow and it is generally transmitted from a male. Oh what’s it called? Hang on, I remember now…

    It’s called a human baby.

  • E. Coli

    Wow 8 in a row of good list comin from Listverse!!

  • Matt

    I’ve been reading from this site for 1 year and am appreciative of all the education I’ve aquired from this site. Thank You.

  • dustofstars

    Ugh…horrifying…where is fresh water in the American southwest? I live in LA…dont want #1!!!!””

  • dustofstars

    What about the cat parasite infecting half the people of the world…toxoplasma gondii…its scarier than everything on this list…really makes you wonder how much of “us” is “us”. If our humanity can be so effected by something like this it makes me ponder the “soul”….but i still believe ( :

  • hannahmondo

    wicked list!

  • I am lucky, as are many of the people o this list, that we live in areas where these sorts of things are unknown. It must be awful to live in a place where these things are common. It seems that no matter how much medical aid is given to places like Africa, these sort of parasites and diseases thrive.
    And @Chris (13), I like to think of babies as more of a cancer than a parasite, but you’re right! And it’s worse than most cause then it forces you to look after it for the next 18-25 years.

  • Si Si

    #8 made my boyfriend throw my phone, the XBOX controller and almost vomit and scream at me! Awesome! This list was disgusting! Thanks!

  • herpderp

    Great, new fuel for people to spam on 4chan.

  • Ny

    Great list with a disgusting theme… :D

  • gav

    You forgot the dreaded “Visiting Relative” a true parasite that can be nearly impossible to get rid of.

  • David

    Snake, what you`re talking about, doesn`t happen to people, it happens to a certain breed of Ant. A Fungus injects itself into the Ants brain, and it changes the Ants behaviour. It then eventually bursts out of the the Ants head like Alien, and then it catches the wind, which then blows it away so it can grow somewhere else. Disgusting.

  • cinnamon

    #8 ascaris looks like a spaghetti…noddles…now i feel hungry…lol! nicole great list i enjoy it very much.

  • archangel

    I have encountered one of these, but will not mention which!!! Haha xP

  • astraya

    There are horrific parasitic infections of the List Universe from time to time.

  • Kerschti

    i’m not going to be able to sleep now!

    thanks, by the way

  • Kemutologist

    DISGUSTING! But still an awesome list.

  • Wrichik

    @Si Si (20):

    “#8 made my boyfriend throw my phone, the XBOX controller and almost vomit and scream at me!”

    Really ??? Your bf had pasta coming out of his behind and you’re surprised he was screaming ?

  • khatzeye

    UGH!!! Completely and utterly grotesque! I LOVED IT!! Awesome job.

  • Wrichik

    The swollen lymph node on the woman’s lamp in #6 looks just like a little girl wearing pink slippers.

  • Kay

    Wow. I’ve got only about 3 hours till my first day of exams. Hopfully the memory of these will not distract me. But I’m still hungry, and I have to wait about an hour till I get up.

  • mandy

    eww good list but I hate the pictures :S

  • Si Si

    @Wrichik): LOLOL! No! At the sight of the picture! I showed him the picture when I was looking and I guess he did not know what to expect so he got pretty upset. Oh well.

  • shadydeathrow

    Grose list but still educative, although i have to cancel my trip to amazon(having a big catfish drinking blood from my d!(k isn’t exactly my idea of enjoying vacations!)

  • strwrz

    david you so knew that from david attenboroughs life in the undergrowth but its not just ants the fungus affects most insects

  • oouchan

    Awesome (yet gross) list, nicolewishes. I was particuarly grossed out by number 4. *shudder* I have seen the video on the fly before during a biology class so I knew what to expect on that one.
    Truly disgusting stuff. :P

  • Swifty66

    Facinating yet repulsive. My kind of list

  • Winston

    Too American

  • NickNamed

    More evidence to back up my long-standing mistrust of the natural world.

  • Firefly

    I’m not usually squeamish, especially when it’s only a picture, but I think the very strong antibiotics and the picture for no. 8 have done it for me. Think I’ll go throw up now :(


    Didn’t even bother looking or reading. Went straight to the bottom and put in my comments–YUCK! Didn’t even like the title of the list.

  • Anonymous

    Size really doesn’t matter when talking about these parasites. I’d rather have 2 rhinos charging at me than have one of the parasites in this list…uhhh wait that doesn’t sound good either.

  • Firefly

    Oooooooh I really did get sick. But I think it was the antibiotics.

  • chingpower

    great list. could these parasites be cultivated? might be of better use like for example put some in a cake or any apology gift, you will give to your mortal enemy. haha. of course he/she would be suspicious and your apology gift would end up in a thrash bin, but still, the possibility. XD

  • robneiderman

    Wow! If I can eat breakfast while reading this list, I can eat through anything!

  • Sarah

    Great list..but a bit disgusting though.

  • mathilda2

    What a disgusting list! I feel like things are crawling all over me right now. Great job! It was very nicely written as well.

    Excuse while I go bathe in boiling water now…

  • msgsudz

    I’m suddenly craving Italian…

  • agginym

    @Si Si (20): well…he sounds like a giant pussy

  • wondersquid

    I love a good parasite list! Thank you.

  • steeveedee

    Marylou Welch. That woman drained my savings and wouldn’t leave me alone. Now SHE was a real parasite.

  • CandJ

    my skin’s still crawling :P
    I really feel for those folks who have to risk these awfull parasites daily.
    interesting list.

  • beckyh101

    I didn’t think it would be THAT horrific. Urgh number 8, I don’t think i’ll ever get that imagine outta my head.
    On the brighter side…
    Great list :)

  • beckyh101

    * image :P

  • zigra

    Good list, although I would say that mucocutaneous leishmaniasis trumps cutaneous leishmaniasis any day. Instead of just skin lesions, the mucosal lining of the nose and mouth are eaten away.

    Once a person with sleeping sickness reaches the second stage the treatment needed to kill the parasite becomes worse as well. About 10% of patients die of the treatment itself.

    As a parasitologist I really appreciate this list – good job!

  • plasmatwa2

    Its times like this I’m glad the Las Plagas from Resident Evil isn’t real… Though number 8 sure reminds me of the tentacles.

  • zigra

    @9 Snake: you may be thinking of Toxoplasma. When this infects mice, it depresses the center of the mouses brain that makes it cautious around cats. So a Toxo-infected mouse is more curious and therefore more likely to be eaten by a cat and pass on the parasite. But overall I wouldn’t call it more horrifying than anything on this list – the immune response of an immunocompetent person has no problem keeping Toxo under wraps. It’s only when a person gets immunosuppressed by HIV or chemo or something like that that Toxo becomes a problem.

  • General Tits Von Chodehoffen

    Possibly the most disgusting thing that could happen

  • undaunted warrior

    Great informative list, judging by the above comments very few knew about this topic or should I say see it in photos.

    Well done.

  • Liah

    wow.. should have waited until later in the day for this one.. ;)

  • CRC3

    This list, for the first time in my entire life, make me feel sad for living in a tropical area. :(

  • Katie

    Gross list, really enjoyed it! I like how you write too.

  • Groogle

    Probably been mentioned before but i don’t think theres a confirmed case of a candiru going up anyones penis.

  • Julia

    For those of you who are interested in parasites, I would recommend Scott Westerfields “Peeps”. And what about Malaria, which I think is a kind of parasite. But it maybe wasn’t disguesting enough.

  • QDV

    Brings back some wonderful memories of working in a veterinary clinic. Mange looks worse in its outward manifestation on the host, but one look at it under a microscope tells you “I don’t want it.” The real fun ones were advanced cases of canine heartworm, where it looked like a family-style Italian dinner when you cracked open Rover’s chest to take a look at the diseased (and no longer functional) heart.

    Lunch time!

  • DrEvo82

    @Si Si (35): Your boyfriend plays XBox too much and sounds like a real bitch. Get a new one at once!

  • Wael

    Out of all the lists about death, ways of torture, corpses, etc.. This, is by far the most DISTURBING list for me. Thanks =D

  • YoungAnabaptistRadical

    @zigra (59): Snake is right that the full name of the parasite is toxoplasma gondii.
    That being said, I agree with you, but I would like to add something. Pregnant women can pass it along through the placenta to their unborn children, leading to birth defects or even spontaneous abortion. It is for that reason that pregnant women are told not to handle cat litter.

  • mom424

    Great list. Glad I live here; the only parasites I’ve come into contact with are ring worm (one of the kids got it, probably from traipsing in the woods through coon shit), and swimmers itch (contracted by me via duck shit in the Moira River). Both easily eradicated by oral medication. Swimmers itch left a nifty raised road map on my extremities btw….tunnels for the larvae, I believe.

    @zigra (59): Unless you’re pregnant zigra. Toxoplasmosis causes birth defects in the fetus – one of the bonuses of being preggers – didn’t have to change the cat litter for 9 months.

  • Grasshopperking

    Ugh. #8 was just terrible. I come on here to read a list and I get an eyeful of pasta crawling out of an ass… great.

    Interesting list though. Keep ’em comin!

  • deeeziner

    Nature will ALWAYS find a way to succeed…..uggghh.

    Makes the idea of traveling to the far corners of the Earth a lot less compelling to me.

    Brita has a campaign of commercials in my area showing their efforts to help far rural people use purification systems for drinking water. This list sure does show that clean water is more than just a question of mud or no mud.

  • El the erf

    Is las plagas a parasite too? But then it is so cool…

  • bearded_defender

    hmmok, im eating…

    maybe ill read this later.

  • puke

    OMG these pictures is SOOOOO disgusting I can’t even read the description.

  • Miss_Info

    Tapeworms are an excellent way to lose swallow a pill infested with tapeworm larvae. Some South American doctors say its totally safe.

  • rudeboi

    Why not just exterminate every animal that is of no use to humankind? The misery creatures like this cause would no longer exist and the world would be a better (and roomier) place.

    A bit radical i know, but just thought i should throw it out there.

  • zigra

    Just to clarify: If you are already infected with Toxo and have antibodies against Toxo, you won’t pass it on to your fetus. It isn’t like HIV in that respect. Toxoplasma is only harmful to the fetus of pregnant women if the mother gets infected for the first time during her pregnancy. Since most people who are infected don’t know that they are infected, all pregnant women are told to avoid cat feces.

  • Mrs. Antichrist

    Awesome list. #1 was used in an episode of House, although their portrayal of it wasn’t exactly accurate.

    @Miss_Info (77): Until you suffer the symptoms brought on by lack of proper nutrients, which can range from feeling tired and sick to brain damage, coma and death… or you end up with a tapeworm in your brain, and suffer permanent brain damage.

  • Mrs. Antichrist

    Also, I wanted to add… a very large percentage of children, even in developed countries, will contract pinworms at some point. The infection is basically harmless, and usually only causes itching around the anus if any symptoms at all, but it’s still a bit gross to think about. There is some research showing that they can contribute to appendicitis (they were considered by the doctor who performed my appendectomy when I was ten to be the likely cause of the inflammation), but it’s not proven.

  • Angelina

    Now, this is my kind of list! Good job! :D

  • GiantFlyingRobo

    To JFrater,
    Please don’t EVER publish a follow-up to this list. Ever.
    From, GFR
    P.S. I hate you.

  • Hikari

    Naegleria and Candiru are big fears of mine.

  • ChaoticPython

    Wah. Dx I didn’t click on the link on number 8; could someone give me a heads up about it? Is it that horrible?

  • superbloop

    Neat list…

  • GiantFlyingRobo

    @ChaoticPython (85): Why would you want to know?

  • bassbait

    I don’t know why, but the giant tapeworm coming out of the dude’s butt reminded me of Spaghetti and made me hungry. I’m not joking, I seriously am hungry after this list. Honestly though, I was hungry before so anything resembling food will make me hungry.

  • Miss_Info

    @ChaoticPython (85): Just click it.

  • Iakhovas

    @mom424 (71):
    Ha Ha, I got stuck doing that shitty job for most of last year for the same reason. Was glad when my g/f finally had the baby so I could ditch that job. Cat shit smells worse than any other shit I have ever encountered in my life. Horrid stuff!

  • granadog

    “‘Disturbing to most’? Well, Listverse, I am not most pe– OH GOD”

  • nicoleredz3

    Boiling/ bottled water drinking for me, strictly, from now on… Uggghh… These pics weren’t that bad. But, beware everyone. Anything can happen to anyone… You never know when you would find yourself in a river in Brazil or Arica…

  • Angelique

    Pics #10 & #8 are just sick, but I liked it!

  • Jubbs

    I was too grossed out by #3 to finish the list… and I did click on the picture you said not to click on…

    Of course, the first picture of the goat pooping out a tape worm was a good warning of what was to come…

  • trfan

    This is why I don’t watch that show Monsters Inside Me, it’s too disturbing, especially for someone who’s a bit of a hypochondriac.

  • hunter

    After seeing all those pictures of worms coming out of asses, I could only think of one thing – worm burgers! yummmmm!

  • Lee06

    Worst listverse list ever….. mostly because of #8!!!!!!!!!

  • Dani

    wow…this list made me sad, not because of the parasites, but the fact that people would refer to human babies as parasites and cancers… remember how you got here? Twisted…

  • Um, yuk…just yuk.

  • gr8flddfn

    well im glad i ate b4 reading this list, good job!

  • Diogenes

    girfren: what’s that worm in your eye?

    boifren: oh i’m just hungover n blood shot.

    girfren: no baby, thats a loa loa worm.

    see here:

    yup thats right, the eye worm is fo-real-to.

  • karolina

    I was like “I know I shouldn’t be seeing this” but still did. Even when the picture didn’t load properly I still clicked on it to see it .Now I am positively going to have nightmares.

  • allie80

    Holy hell, this list was nasty.

  • DoomSai

    I could only read two entries and see two photos.

    This is more disturbing than gore pics.

  • Nicolewishes

    Hah wow I’m super surprised my list was published! It was the first one I have ever written and I love the feedback! Awee Thanks!

  • Pyderz

    ARRRRR Man, some of them photos are discusting lol! Didnt even want to read causes and symptons part.

    Nasty list.

  • Prototype23

    One Word…….. GROSS !!! Thats discusting # 8 is just horrific and if i ever found out i had 1 of those things i would shoot myself.

  • ladyval

    Oh gee, thanks, thanks a lot. Now I am not only freaked out but grossed out as well. And don’t you know that telling someone not to look makes them look. Well interesting list.

  • Luv4Tahoe

    Nice list! I like the really disturbing ones.

  • ThetaSigma

    You know, in regards to the tapeworm how exactly are “abdominal discomfort, diarrhea, and loss of appetite” not symptoms?

  • Courtney

    I have to point out an error that is in this list. I’m a vet tech student, so I have the glorious job of sifting through animal poop to determine whether or not they have an infestation…The correct term for the parasite is Ascarid, and it refers to a wide variety of parasites, all of which cause some type of worm. Ascariasis correctly refers to the infestation itself.

  • Courtney

    Another thing that I forgot to mention. It’s also very common for tapeworms to crawl out of the host while they are under anesthesia. Since tapeworms are sometimes missed while doing a fecal floatation, they’re only discovered when you realize what’s crawling out of the animal’s bum :)

  • FierceGrace

    disturbing… very very disturbing. :(

  • macph

    METAL list! \m/

  • Flock O’Seagulls

    Reminds me of a classic Three Stooges routine:

    Moe: “What’ll you have?”
    Larry: “Burnt toast and a rotten egg.”
    Moe: “Burnt toast and a rotten egg?!”
    Larry: “Yeah, I’ve got a tapeworm and it’s good enough for him!”

  • Robert

    holy crap

  • ten’s my first time to comment (and i didn’t even finish reading the whole list)..i was totally shaken by’s just scary..

  • Mabel


    I knew about the candiru. Freaky stuff!

  • GiantFlyingRobo

    @nicoleredz3 (92): “These pics weren’t that bad.”? There’s something worse than crapping out a spaghetti monster?

  • ZibbyYamala

    eeeeeeew, what a nightmare! i feel for these people.

  • Jay

    OMG these pictures are not what I needed to see. I think 8 will haunt me for the rest of my life.

    Interesting list though!

  • Tequila Sunrise

    Dude, that “revolting” link in number 8 was not that bad, compared to that first pic of a huge mass of worms being shat out.

    As for the rest of the list, f’ing gross.

  • lp

    David Sedaris actually wrote a hilarious story about one of these infestations…

  • @lp (123): David Sedaris could write a hilarious story about a penis removal which became infected by the baddest of these bad boys!
    He’s just a funny guy.

  • G

    I hate those fucking worms… I seriously do…
    Ascaris lumbricoides is another reason to hate pediatrics… Yuk. About a year ago a baby died in my country because his parents didn’t give him his medication and he choked on the bloody worms. The case was well known because they parents filed a lawsuit against the hospital.
    We have dermatobia over here as well, as well as the tapeworms… I’m glad I’m a vegetarian.
    Oh, and, rudeboi, if there was a way to exterminate these things, I’m sure it would have been done already. It’s too difficult. I’d be the first one to support that initiative, though… No more plucking out worms out of people. Bliss.

  • labaria

    I have seen people infected by #4 and it is not a nice sight. It leaves permanent scars that are hideous to look at: usually on the face. In South America it mostly common to catch this parasite in the undisturbed parts of the jungle.

  • Sunny


  • Jason

    Oh wow, I’ve actually had #4, on several places all around my arms. The open wounds it creates are extremely itchy and the infection is quite difficult to remedy. I went through two boxes of bandages, a tube of polysporin, this other first aid cream stuff and I still have red blotchy scars where the wounds were. I don’t know how I got them but I wouldn’t wish that horror on anyone.

  • missdizzy1

    EWWWWWWWWWW!!! They are ALL nasty!! As are the pics to go with the list….. Yuk!!! Number 8 is going to give me nightmares!!!

  • nicoleredz3

    @ GiantFlyingRobo (119) Yeah, there are worst things than crapping out a spaghetti monster! You’re right! Lol! These pics were terrible… :-/ Sorry, I’m schizophrenic…

  • Sunny

    AAAHHHHHHHH!!!!!!!! This list is so scary. At first all the pics didn’t load but now I have seen a few and they are horribly scary. I don’t think I will be able to go to the washroom. :(
    Number 8 I didn’t even look at it properly. It’s tooooooo disgusting

  • This pretty much sums up the list: :'(

  • CourtneyKaboom

    GODAMNIT! that's nasty! but still a spiffy list :D

  • A.I.

    Infestation routes varies depending on the species, but intestinal worms are very often transmitted through the fecal-oral route:

    “The fecal-oral route, or alternatively, the oral-fecal route or orofecal route is a route of transmission of diseases, in which they are passed when fecal particles from one host are introduced into the oral cavity of another potential host.

    There are usually intermediate steps, sometimes many of them. Among the more common causes are:

    * water that has come in contact with feces and is then inadequately treated before drinking;
    * food that has been handled with feces present;
    * poor sewage treatment along with disease vectors like houseflies;
    * poor or absent cleaning after handling feces or anything that has been in contact with it;
    * sexual fetishes that involve feces, known collectively as coprophilia (its eating is known as coprophagia).

    Some of the diseases that can be passed via the fecal-oral route include:

    * Giardiasis[1]
    * Hepatitis A[2]
    * Hepatitis E[3]
    * Rotavirus
    * Shigellosis (bacillary dysentery)[4]
    * Typhoid fever[5]
    * Vibrio parahaemolyticus infections[6]
    * Enteroviruses, including poliomyelitis
    * Cholera
    * Clostridium difficile
    * Cryptosporidiosis
    * Ascariasis

    Transmission of Helicobacter pylori by oral-fecal route has been demonstrated in murine models[7].”


    This is why you should always wash your hands with soap and warm water after using the bathroom, and before handling food. Intestinal bugs can be transmitted to other people.

    @mom424 (71) Many common intestinal worms like ascaris, and flatworms (taenias, the fish tapeworm which infests freshwater fish) are undetected in developed countries because the symptoms are usually very common, so patients may not think go to the doctor, or the doctor may not think to check for parasites, unless the person has gone to a developing country.

    Which means you can have worms and not be aware of it. If you were harboring one or several ascaris, you would probably be asymptomatic, except you might sometimes have diarrhea and abdominal pain, but how many people in developed countries think about the possibility of parasites when their tummy hurts?

  • A.I.

    Some of the commenter seem to believe parasites have been eradicated in developed countries, but this is far from true!

    A very high proportion of children get pinworms, and this species, like tapeworms and ascaris, can be transmitted to entire families through the oral-fecal route .

    Tapeworms and ascaris are not rare either.

    Botfly is rarer, but can still be found in parts of the United Sates. Guinea worms used to be endemic in parts of Southern Europe and were eradicated only because marshes were filled.

  • A.I.

    About ascaris (number 8):

    “Roundworm Detection:

    The roundworm ascaris lumbricoides is the most common worm infection worldwide. It is more concentrated in warm, moist climates (southeastern U.S.) and on swine farms or where pig feces are used as fertilizer. Humans acquire it by swallowing eggs from contaminated soil, water, fruits or vegetables and in children through the fecal-oral route. Clinically, it causes coughing and difficulty breathing that subsides only to be followed by abdominal discomfort / pain. A common finding is malnutrition, especially in children. Microscopic egg detection is elusive because the time required from egg ingestion to shedding in stool is 2-3 months. The saliva based SIgA test enhances detection of this worm. ”


    “The eggs of these worms are found in insufficiently treated sewage-fertilizer and in soils where they embryonate (i.e., larvae develop in fertilized eggs). The eggs may contaminate crops grown in soil or fertilized with sewage that has received nonlethal treatment; humans are infected when such produce is consumed raw. Infected foodhandlers may contaminate a wide variety of foods. (Source: FDA Bad Bug Book) ”


  • A.I.

    Now, there are many developing countries where raw human feces are used as fertilizer on crops, or fed to pigs, and where sewage is usually not retreated.

    That’s why travelers to 3rd world countries are advised against eating uncooked vegetables, like salads.

    While in developed countries, sewage sludge (most waste treatment stations don’t get rid of all eggs), and pigs feces are commonly used as fertilizer in developed countries, so you can catch ascaris and the pork taenia from produce grown in developed countries with pig feces or unsuficently treated sewage!

    You can catch parasites from pets too (cats and dogs), which is why it’s very important to deworm pets often, because if they have parasites, they will shed eggs with their feces, and contaminate the surroundings, which can spread the parasites to other animals and humans too. Ascaris eggs can stay viable for years in soil, so a single pet can contaminate an entire area for a long time.

  • A.I.

    Now, there are many developing countries where raw human feces are used as fertilizer on crops, or fed to pigs, and where sewage is usually not retreated.

    That’s why travelers to 3rd world countries are advised against eating uncooked vegetables, like salads.

    While in developed countries, sewage sludge (most waste treatment stations don’t get rid of all eggs), and pigs feces are commonly used as fertilizer in developed countries, so you can catch ascaris and the pork taenia from produce grown in developed countries with pig feces or insufficiently treated sewage!

    You can catch parasites from pets too (cats and dogs), which is why it’s very important to deworm pets often, because if they have parasites, they will shed eggs with their feces, and contaminate the surroundings, which can spread the parasites to other animals and humans too. Ascaris eggs can stay viable for years in soil, so a single pet can contaminate an entire area for a long time.

  • hmmm…….

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    I’m never going to move to a more temperate clima, as most of these horrible creature live in such places.

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  • peter8172

    An irony on the Bonus fish called the Candiru. I watched an episode of “A Thousand Ways To Die” on the SPIKE Network where a tourist was hiking in an Amazonian Rain Forest. He had to urinate and waded into the water of the Amazon until he was up to his stomach in water. Well, he zipped his fly down, whipped it out (underwater) and the Candiru picked up on the scent of his urine. The Candiru bit off his you know what and he screamed bloody murder. So when he was bleeding, who else joined the feeding frenzy, a large school of Pirahna. He was gone in less than 3 minutes.

    • segues

      Impossible, peter. The Candiru is tiny, it doesn’t bite anything off, it is so small, slender, it literally swims up the urethra. The fins on the fishes sides have backward facing spikes, so once it swims up it can’t be pulled out without shredding the inside of the urethra.
      Some claim this fish is the most feared in the entire Amazon region, and the fear stems from the fact that it has a knack for finding open orifices and working its way inside. Once inside another organism, the Candiru feeds on its host’s blood, becoming increasingly swollen. The Candiru is the star of an urban legend — which turns out to be true — of a man who was urinating in the Amazon River when a 6-inch Candiru swam up his urine stream into his penis. The fish remained there for days, until a surgeon was able to remove it.
      btw, there is a Jeffrey Miller in the records of the Amazon. He is a professor of environmental science who has written a paper, presented at a seminar, concerning the effects of burning the rainforest.

  • peter8172

    @ seques. Thank You for correcting and I made a false start. But the way that the narrator of “A Thousand Ways To Die, described this fish was in the shape of a pencil. There is another list on here about the deadliest creatures on earth and one of them was the Poison Dart Frog. Apparently if you find a live one and lick the back of it, its sends you on a drug trip and lasts for up to 12 hours. These 2 saps took an airplane ride just to get to Peru. When they found what they were looking for, they both started licking away at it. What they didn’t know was that the frog bit them on their tongue. Their “trip” went on as usual, but inevitably they suffered a slow and painful death

    • That Poison Dart Frog is both beautiful and scary! I can’t imagine wanting to get high so badly I’d lick the back of a frog…YIKES!!

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  • Jaezebel

    I know I’m 2 years late with my comment, but was just trawling back through old lists. LOVE Listverse btw. Longtime reader.

    @Snake you could be thinking of rat lung-worm (Angiostrongylus cantonensis). Transmitted through contact with snails & slugs or their slime, often through unwashed veggies. The larvae can then travel to the brain and cause permanent nerve/brain damage and even death. There has been publicity in Australia over a guy eating a slug for a dare and ending up with severe brain damage.
    It has been reported in the following countries: American Samoa, Australia, Hong Kong, Bombay, Fiji, India, Honshu, Kyushu, New Britain, Okinawa, Ryukyu Islands, Western Samoa, China, Polynesia, New Caledonia, the Philippines, Cambodia, Guam, Hawaii, Java, Thailand, Sarawak, Vietnam, Rarotonga, Saipan, Sumatra, Taiwan, Tahiti, Melanesia, Micronesia, Cuba, Egypt, Louisiana, Madagascar, Nigeria, New Orleans, Vanuatu and Puerto Rico. (Source. Wikipedia)

    @Mom424 Even though it sounds like it ring worm is not a worm or parasite, it’s a fungal infection. So is swimmers itch.

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  • mich

    Candiru sounds horrible

  • Ridolfi

    I believe I have now permanently lost my appetite. The picture with the worms coming out of the kid’s butt, ERRRGGGH! And again, ERRRGGGH!

  • Barbara Saunders

    A teeny tiny flea entered into my eye about a year and a half ago, now I see worms looking like strings of pearls and some are little tiny eggs, and some are just straight and skinny. I have been to about five eye Doctors and none of them can see what I see in my eye, thy keep telling me they are floaters when I know and can see that it is worms and flea lava. What do I do I do not want to loose my eye site.

  • grace

    # 8 is terrifying…

  • concep

    Im gonna have nightmares o~o