The animal kingdom is full of terrifying and
deadly parasites. While there aren’t any that will eat their
way out of a human’s chest - unlike those a certain sci-fi movie makes us afraid of
- there are no shortage of parasitic animals that would love nothing more than to feed
on you. These are the thirteen most painful parasites
that infect humans. #13. Tapeworms One of the most common parasites, tapeworms
usually make their way inside the human body as hitchikers alongside your lunch or dinner. These tiny, ribbon-like worms lurk inside
the flesh of animals, commonly fish, beef, or pork. When you unwittingly consume them, these creatures
don’t get digested - they set up camp in the digestive tract and can live there for
a long time. Their long bodies have hooks or suckers that
embed themselves in the intestine, and they then get all the energy they need to live
by absorbing part of your food. But they don’t stay invisible for long. People who are infected with tapeworms soon
report symptoms including nausea, vomiting, digestive issues, unexplained weight loss,
and signs of malnutrition including dizziness. While most people eventually expel their tapeworm
through their digestive tract - which can be a disgusting sight in the bathroom - they
can survive for up to twenty-five years. And when ingested as eggs or larvae, the tapeworm
can reproduce in the body. Larvae can turn into cysts that migrate through
the body - even in the brain, where they can potentially cause serious illness or even
death. This parasite is often invisible - but the
next makes itself very well known. #12. Bedbugs These little insects are the scourge of anyone
who has stayed in a hotel. Tiny bloodsucking insects that are notoriously
hard to find and eliminate, they spread in high-density areas and can hide in mattress
seams or wall cracks. When they attach to a person, their bites
cause a host of skin issues that become impossible to ignore. Skin rashes, blisters, and constant itchiness
become a part of regular life until the bedbugs are eliminated, and more severe cases can
result in fatigue and fever. While the insects aren’t known to spread
serious diseases - unlike other pesky bloodsucking insects - one of their biggest threats is
causing allergic reactions. And while many exterminators will promise
to get rid of a bedbug infestation, these little buggers can live up to seventy days
without feeding and reproduce fast - making them likely to be unwelcome guests for a long
time. These next parasites make their presence known
in a very unpleasant way. #11. Pinworms Roundworms are a common species of parasitic
worm that lays eggs in the body, but many of them don’t pose a serious danger to humans. That’s not to say you don’t want to avoid
them - especially the pinworm, a small worm that spreads via its eggs. It can be picked up via contact with the hands
and then getting swallowed - and then it goes where the sun doesn’t shine. The pinworm likes to lay its eggs around the
anus, and this causes a host of uncomfortable symptoms for the unlucky humans. Pinworm hosts report itching around the anus,
painful bowel movements, and difficulty sleeping due to the constant annoyance. Fortunately, it can be treated with a number
of medications - but the worms spread so quickly that doctors recommend everyone who lives
with the infected take the medicines. This parasite is so common that it’s estimated
that twenty percent of children in the United States will get infected. Some roundworms, though, can cause much more
serious infections. #10. Filarial Worms Everyone knows mosquitos are annoying, but
some can carry something far more dangerous. These pesky bloodsuckers are hosts to tiny
roundworms that can cause a whole host of diseases. Mosquitos are a common transmitter of plague,
and the World Health Organization estimates more than 120 million people may have an infection
of filarial worms. While many of them don’t cause any symptoms
at all, they have the nasty effect of clogging lymphatic vessels in some cases. Another variety affects the eyes. These worms can usually be treated with antiparasitic
medications, but if left untreated they can cause serious ailments. They’re one of the world’s leading causes
of blindness, and in severe cases can cause elephantiasis syndrome - a disorder that causes
extreme swelling due to the inability of the lymph glands to drain, mostly affecting the
legs. The next parasitic worm has more aggressive
tastes. #9. Hookworm The Hookworm is a species of roundworm that
is common in many countries around the world - especially those without access to clean
water. Its larvae infects people both orally and
through the skin, at which points it sets up camp inside the human digestive tract for
a feast. Pretty similar to other parasitic worms - except
the hookworm doesn’t want your food. It wants your blood. These worms latch onto the intestinal tract
and start acting like a vampire, causing major health issues for the unfortunate host. If left untreated, it can cause abdominal
pain, nausea, diarrhea, and most seriously anemia that can result in weakness and other
serious health conditions. This worm kills up to 60,000 people a year. The good news is, it’s vulnerable to many
anti-parasitic medications, but it’s hard to detect before it reaches maturity. But it’s not the most deadly parasitic worm. #8. Whipworm The whipworm is a soil-based parasite that
infects over half a billion people worldwide, and is mostly spread by contaminated soil
and often eaten through fruits and vegetables. The eggs hatch and take up residence in the
large intestine. While many cases are asymptomatic, those who
have heavy infections can find themselves seriously sick. Not only do these worms wreak havoc on the
digestive tract, but it can trigger more serious illnesses like appendicitis that require emergency
surgery. Its most dangerous effect, though, may be
on children. Kids who are infected can suffer delayed growth
and cognitive impairment, as well as suffering from nutritional ailments. Experts estimate this worm kills upwards of
sixty thousand people a year, but like other parasitic worms, it can be killed off with
antiparasitic medication. But the biggest challenge of battling these
worms is preventing infections and treating people before they progress to serious cases. One worm makes its presence known with a name
that says “terror”. #7. Dracunculus Medinensis, or the Guinea Worm Translated as “little dragon of the Mediterranean”,
the proper name of the Guinea Worm gives away that this worm is a killer. The female worms are among the largest worms
that can infect humans, growing to up to thirty-one inches in length - longer than many snakes
as they slither around in the human gut. It’s not surprising that they can cause
excruciating pain. They infect people through contaminated drinking
water and are most common in rural areas of Africa and tropical regions like southwest
Asia and India. Once embedded in the human body, the effects
can be deadly. These worms cause a secondary disease as the
female worm tries to emerge from the body through the skin. The chemicals she releases can cause infections,
nausea, blisters, and itching. But if she fails to emerge and gets stuck
in the body, the worm can cause arthritis, paralysis, or severe swelling from the infection
and resulting immune response. To treat this, doctors look for a blister
where the worm is going to emerge and then use warm water to lure the worm out. They then slowly pull it out and wrap it around
a stick. It can take several days to remove a full-sized
guinea worm, followed by treatment with antibiotics and bandages. These next parasites don’t wait for you
to consume them. #6. Blood Fluke Everyone is scared of leeches, those predatory
worms that latch onto your skin in water and start sucking your blood. But the Blood Fluke takes that nasty MO to
the next level. After spending part of their life in a snail
host, they lurk in water and enter the skin of humans and proceed to feed on their blood. They can live for decades, and can remain
asymptomatic for years. But when things go bad, they go VERY Bad. When they cause a series of infections called
schistosomiasis, they can affect almost every part of the body. Their most serious symptom is swelling, which
can cause long-term damage to glands and can even cause liver failure if left untreated. While the parasite can be treated with the
same antiparasitic medications useful against other worms, these parasites are particularly
common in Africa and are estimated to cause up to two hundred thousand deaths a year - making
the blood fluke one of the deadliest parasites worldwide. The next parasite is much more visible - and
much more painful. #5. Jiggers. Any dog or cat owner probably knows how annoying
fleas are - constantly jumping everywhere and biting. But that’s nothing compared to the sand
flea, also known as the jigger. These fleas are common in Central and South
America and have arrived in sub-Saharan Africa, and they have an parasitic tactic that can
make every step miserable. The smallest known flea, they lurk in sand
and attach to people as they burrow head-first into the skin, usually on the foot. This causes swelling and lesions as the female
swells up with eggs. This is just the beginning of the problem. It’s common for victims of jiggers to have
dozens or even hundreds of them embedded in their feet. As the fleas die off, this can cause infections
that result in pain, scabbing, dead skin, and permanent deformation of the toes. As pulling the fleas out can cause their bodies
to tear and leave parts behind, jigger infestations are treated by a doctor to carefully remove
any trace of the attached flea and disinfect the area - which can be a lengthy process. The next parasite also makes itself way too
welcome in the human body. #4. The Human Bot Fly Flies usually do little more than buzz around
you, making that annoying sound. But dermatobia hominis, or the human botfly,
has a particularly invasive method of reproduction. Its eggs are carried by other insects like
mosquitoes which bite humans, transferring the eggs into the open wound. They hatch there, and the larva wedges itself
in the human skin, growing there and creating a visible grub sticking out of the skin. Disgusting - but not dangerous...usually. The biggest danger the human botfly poses
is infection, because when you see a grub sticking out of your skin, what’s the first
thing you do? You try to pull it out. That’s a mistake, because while the body
breaks off and the grub dies, the head and jaws attaching it to the body stay in place. That becomes a vector for potentially deadly
infections. The best way to safely remove a botfly larvae
without medication or professional help? To suffocate it with a coating of petroleum
jelly. After a day, it can be removed with tweezers. It makes sense that Australia would have deadly
parasites - and the next one adds a killer kick to a common pest. #3. Australian Paralysis Tick Ticks are common parasites, jumping from animal
to human and sucking blood. While they’re usually easy to remove with
tweezers because they stay on the outside of the body, their main threat is as a vector
for deadly diseases - including the potentially lethal Lyme Disease. But one tick down under poses a bigger threat
- one that can kill quickly. Not only can it cause allergic reactions,
but it secretes a toxin that can cause neuromuscular function to fail. Within eight to twelve hours of injection,
paralysis can set in and even cause respiratory failure if it is allowed to progress. While these reactions aren’t common, with
only about twenty fatalities reported in Australia, this tick is one of Australia’s most feared
animals. And in the land of the bird-eating spiders,
that’s saying something. The penultimate parasite is invisible - and
deadly. #2. Brain-Eating Amoeba Not a true amoeba but a tiny shapeshifting
organism, this microscopic bacteria-eater lives in bodies of warm freshwater. That means that it can be lurking anywhere
people want to take a dip - rivers, lakes, wells, or even swimming pools that aren’t
treated with enough chlorine. While it doesn’t function like other parasites
and feed on humans long-term, this organism has one major impact on humans - it causes
a rare, but almost invariably fatal brain infection that can kill a healthy person in
days. And it has shown up in the happiest place
on Earth. One of the earliest cases that brought this
parasite to the public's attention was when a young boy died of the infection after swimming
at Disney’s River Country waterpark. The parasite enters through the nasal cavity,
usually when swimming but also occasionally through rinsing out the sinuses. It travels to the brain, where it changes
up its usual diet of bacteria and starts eating the brain’s astrocytes and neurons. Symptoms appear after an average of five days
- and by then, it’s already too late. While this parasite can’t be spread between
humans, it soon results in headache, nausea, a stiff neck, decreasing brain function, seizures,
and eventually death. But no parasite causes as much death as our
#1. #1. Malaria Plasmoidium When you think about the deadly disease malaria,
you probably think about mosquitos. These biting pests do spread disease - but
the actual cause of malaria is a single-celled parasite called Plasmodium. These protozoans enter the body through the
mosquito’s saliva, and they infect red blood cells. The cells swell and burst, infecting the bloodstream
- thus spreading to mosquitoes when they bite a host containing the virus. This makes it one of the fastest-spreading
parasitic infections in the world, affecting up to 600 million people a year. And things can get bad for the unfortunate
victims. Malaria starts with simple symptoms including
fever and chills, but some cases evolve into something deadly. Vomiting and severe sweating turn to anemia,
seizures, and possible damage to the body’s vital organs and bloodstream. This can cause the victims to slip into a
coma, suffer serious neurological issues, and potentially die. Several hundred thousand people die of malaria
each year, most in the global south, and while no vaccine is available, treatments are available
to lessen the severity of symptoms. The challenge is to outrace this fast-spreading
parasite, which spreads as quickly as the mosquito flies. For more on a tiny organism that caused mass
chaos, watch “Why Spanish Flu Killed Over 50 Million People - Deadliest Plague in Modern
History”, or check out “13 Most Dangerous Animals in History” for some larger predators.
