Where it lives: in West and Central Africa, in particular – in the Congo, Gabon, Chad, Sudan, South Sudan, the Central African Republic, Cameroon, Nigeria and northern Angola.
Let’s start right away with something as appetizing as possible. Loa-loa is a nematode worm up to 70 mm long and 0.5 mm thick. This parasite lives in the subcutaneous adipose tissue of its hosts, and is also very fond of the eye protein. Loa-loa also parasitizes in the bodies of baboons, monkeys and some rodents. It is carried by horseflies with bites.
The worm forms around itself specific edema and tumors on the carrier’s skin – sometimes they reach the size of a chicken egg. It also causes severe conjunctivitis .
If the loa loa is large enough, you can see how it moves and wriggles in the eye.
The worm is removed both surgically and with special anthelmintic preparations. And remember that if you do not rush to take medications and go to the doctor, loa-loa can live up to 17 years in the human body.
Prevention: Do not live in the rainforests of West or Central Africa. Well, or at least not visit them during the rainy season, when horseflies and mangrove flies are especially rampant. Do not burn fires, because these insects are attracted to smoke.
2. Negleria Fowler
Where it lives: In dirty warm waters around the world, especially in hot springs and reservoirs near power plants and factories. Negleria fowlera was first discovered in Australia, then came to the United States, as well as to Belgium, England, New Zealand, India and Mexico.
This parasitic protozoan also bears the telling name “brain-eating amoeba”. The unicellular enters the body through the nose along with water when bathing. Then it, moving along the olfactory nerves, enters directly into the brain, where it begins to actively multiply, populating all its departments.
About a week after infection, a person experiences symptoms such as fever, headache, and nausea, and it becomes difficult for them to move their head. As the infection progresses, inattention, incoordination, seizures, and hallucinations develop. It ends in coma and death.
This disease is called primary amoebic meningoencephalitis, or non-gleriasis.
The disease is almost always fatal. About seven cases are known around the world when the infected survived and healed without neurological damage – why this is so is still unclear. There are drugs for Fowler’s negleria, but they mostly only slow down the course of the infection.
Prevention: Do not swim in dirty water. And if you still really want to, first put on a scuba gear and an insulated mask with air supply from a cylinder.
Where it lives: Around the world, where the meat of pigs or predatory animals is consumed, especially in China, 10,000 people are infected there every year, of which about 200 die.
Trichinella are roundworms that parasitize the muscles of predatory animals. They mainly prefer omnivorous pigs, as well as foxes, wolves, bears, skunks, raccoons, rats and other small mammals.
Infection with trichinella is fatal and is called trichinosis. People get it by eating infected meat, most often pork , but sometimes some exotic like bear meat.
For example, the famous Swedish polar explorer Salomon André became infected and died in 1897 after tasting a polar bear.
Once in the human body with food , males and females of Trichinella begin to multiply in the small intestine. After fertilization, the former die, and the latter produce larvae – this process can last up to 6 weeks in a row.
Young individuals penetrate through the intestinal mucosa into the blood vessels and spread throughout the body. They settle in the muscles, forming calcified capsules around them, and live there for many years, causing fever, chills, coughing, severe pain throughout the body, in the head, muscles and joints.
If the parasite enters the central nervous system, respiratory tract, or vital organs like the heart , it will gradually kill the host.
Naturally, surgically cutting out all the worms, given that they can fill up to 15 thousand per 1 kilogram of muscle tissue, is basically impossible. The reproduction and growth of larvae is suppressed with special preparations, but there is still no complete treatment for trichinosis.
Prevention: Eat meat from pigs that have been kept in clean pens with concrete floors and not free range. Cook it thoroughly at a temperature of at least 74 °C. Do not eat wild animals without thoroughly testing them for worms.
Where they live: all over the world, except for the polar latitudes.
Even those flies that periodically fly to you from the veranda can reward you with many unpleasant diseases – for example, diphtheria and tuberculosis. In addition, they carry eggs of various worms and cysts of parasitic protozoa. And that’s not to mention those tropical tse-tse cuties who can infect with sleeping sickness.
But on our long-suffering planet, there are also much more severe flies that simply amaze the imagination with their disgusting ways to procreate.
So, different types of gadflies are able to lay eggs under human skin so that the larvae feed on the tissues of the host. In adulthood, these guys do not have a mouth apparatus. They fatten up in their youth, crawling under the epidermis and in the mucous membranes of their victims, creating terrible tumors resembling large eels.
And sometimes, when the owner accidentally swallows the eggs of gadflies, they can grow in his intestines and in other internal organs, where they will be carried by the bloodstream. At times, the larvae destroy tissue down to the bone, causing extreme pain, necrosis, and gangrene .
In addition to gadflies, wolfart flies are engaged in such bullying – these generally can lay hundreds and a half eggs at a time on the mucous membranes of the victim. For example, in the nose and mouth.
Prevention. Cleanliness and careful hygiene will reduce the likelihood of infestation with fly larvae to almost zero. Install mosquito nets and insect curtains in living areas, use fly traps, and do not leave food unattended in the open air. If you go to nature in places where gadflies are found, wear tight clothing.
Where it lives: around the world, where their owners wander.
There are more than 6,000 species of these parasites, and they affect almost all vertebrates. The most famous of them that live in humans are pork and bovine tapeworm, tapeworm, echinococcus and alveolococcus. The latter got its name because it parasitizes in the lungs.
Basically, tapeworms settle in the intestines: they are fixed there with their hooks and suckers on the head and grow a long body – a real egg factory. The size of these disgusting creatures is impressive.
The same bull tapeworm, parasitizing in a person, can grow up to 20 meters, and the whale tapeworm – these, fortunately, do not contact people – can reach up to 40.
Most tapeworms are made up of segments, like links in a chain. Their segments periodically fall off the tail, going on a free journey to spread eggs and larvae along with feces.
In addition, worms are hermaphrodites , which fertilize themselves, so even a single individual can reproduce extremely efficiently. For example, a bovine tapeworm produces 600 million eggs per year, and for a lifetime (18–20 years) – under 11 billion.
If you think that there can be nothing worse than a twenty-meter monster that sticks to the inner wall of the intestine and feeds on its contents, then you are mistaken.
If the larva of the worm with the bloodstream does not get into the intestines, but somewhere else – into the muscles, skin, eyes, heart, brain – it will quickly realize that there is nothing to catch. And eventually pupate, creating a cyst. The calculation is simple: when the host dies, someone will eat it, and then the worm will enter the stomach of the next host.
Especially severe tapeworms, such as echinococci, can form cysts the size of a baby’s head, in which many individuals live at once. Having settled in the brain, lung, liver and kidneys, they are quite capable of completely destroying the affected organ and causing necrosis with a fatal result for the carrier.
Parasites that have entered the intestines are successfully treated with anthelmintic drugs, but cysts have to be fought with surgical methods. And there, how lucky: the parasite is quite capable of not showing itself for years, until the cyst grows to an indecent size.
Prevention: cleanliness. Wash your hands with soap before eating. Refrain from eating in places with poor sanitation and visiting countries with poor food hygiene standards .
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