"Are you out of your mind?": 10 parasites and pathogens that control the human mind

Many people underestimate the effect of bacteria on the body, and they are both "good" and "evil". These microorganisms are not only the causative agents of various infections, but are also able to control the human mind, forcing it to behave in such a way that it is more convenient for them to multiply.

It is about such pathogens that we want to tell you. Be prepared to see in the list both rare and fairly common parasites that you yourself have repeatedly encountered personally.

Bruce's trypanosome is a parasitic single-celled organism that can infect the blood of humans and animals. It has a fairly long life cycle and begins with a tsetse fly biting its prey. After that, the trypanosome enters the lymphatic system and from there gradually passes into the blood.

The most common disease that causes this parasite is sleeping sickness. It manifests itself in the form of two separate stages of symptoms and can affect both animals and people. The first signs are pain in the joints and muscles, fever, dilation of the lymph nodes. At the second stage, changes in the behavior of the infected person are observed: the parasite begins to attack the spine and brain. Eventually, Bruce's trypanosoma can cause lethargy or death.

It is worth noting that most of the bacteria that enter the human body do not aim to kill it at all. A dead "host" will not be able to serve for the spread of the parasite, which means that it will complete its life cycle. Therefore, pathogenic bacteria only weaken the host organism, making it available to other parasites, if necessary for their spread.

Who would have thought that the elementary gut bacteria that most people have probably lived with all their lives could have some effect on the mind. But these microorganisms play an important role in getting rid of such mental disorders as depression or anxiety. Scientists have long linked gut microflora to animal behavior, but recent studies have shown that humans are just as dependent on bacteria.

During the observations, the scientists tried to find out how the bacteria present in the intestine affect the mood of the subjects. With the help of MRI and other equipment, specialists recorded the brain's reaction to the images shown. Previously, the scientists divided into two groups of people whose mental state, according to their assumptions, could depend on bacteria: the organisms of the first were dominated by bacteria of the genus bacteroides, the second had more bacteria-Prevotella.

When images with a bright emotional color appeared on the screen, the brains of the participants in the second group began to work more intensively. Among them, there were also more people with depressive states, anxiety and other negative emotions. Final conclusions have not yet been made, but scientists believe that the mood of humans, like primates, depends on intestinal bacteria.

The parasitic protist Toxoplasma gondii, as a rule, lives in the organisms of representatives of the cat family, but this does not mean that a person has nothing to fear. According to official data, half of the world's population is infected with toxoplasmosis – a disease caused by these parasites.

In most cases, toxoplasmosis is asymptomatic. The body is cured of it on its own, without medical intervention. However, for those who have an immune deficiency, this disease can be dangerous.

Scientists have found that the parasite Toxoplasma gondii affects the behavior of rodents, causing them to become fearless. The subjects lost their sense of danger and took risky actions, for example, almost ran into the clutches of the cats themselves. Experts believe that this way toxoplasma affects a person.

Naegleria fowleri (Latin: Naegleria fowleri) is a single – celled organism from the family Vahlkampfiidae, which is also called the "brain-eating amoeba". You can catch it as a result of contact with water – it is in it that these bacteria live. To do this, you do not even have to go to the lake or go to the pool – there is a chance that the water in your house is also infected. When such a liquid enters a person's nose, the bacteria present in it immediately enter the brain. The first symptoms of infection are headache, vomiting, nausea. Many people mistake the infection for the flu.

In the second stage of the disease, attention distraction, loss of balance, dizziness and even hallucinations may occur. It ends with hemorrhages and necrosis in the gray and white matter of the brain. As a result, a person develops amoebic meningoencephalitis, which, as a rule, leads to death.

Since the discovery of the protozoan Naegleria fowleri (1970), several hundred cases of infection with it and only one case of recovery have been recorded. In 2012, a 5‑month-old baby was cured of amoebic meningoencephalitis in Iran. And although drugs to fight the bacterium exist, they do not always help.

Malaria is a dangerous infectious disease transmitted to humans by the bite of An Anopheles mosquito. Malaria is caused by parasitic protists of the genus Plasmodium, which have an interesting life cycle. The parasites Plasmodium falciparum and Plasmodium vivax spend most of their lives in humans, and the rest in mosquitoes. Therefore, to spread the disease, the female mosquito first bites an infected person and only then-a healthy one, thus transmitting the pathogen to him.

But what is interesting is not even this, but how the parasite Plasmodium affects the mind of an infected person. Once in the body, it forces a person to absorb as much glucose as possible, because it is on it that the pathogens of the disease depend to a greater extent. Even at the stage of stay in the body of mosquitoes, malaria makes them want to get glucose and makes them more voracious. Mosquitoes are drawn to where the strongest smell of nectar is, and when the time comes, they begin to want human blood, which also contains this substance.

Malaria parasites quickly absorb glucose and hormones from the blood, so infected people often experience anemia, vitamin deficiency and a decrease in blood sugar levels. All this leads to the fact that the patient begins to pull on the sweet, and this applies to both people and mosquitoes.

Scientists have already found that the ATCV‑1 virus, which was previously considered exclusively an algophagus (an organism that destroys algae), also has a significant effect on the behavior of mice, causing them cognitive impairment. However, as it turned out, this parasite is dangerous for a person, and acts on his brain in a similar way.

Experts were able to study the long-term process of changes in the human brain that occur under the influence of ATCV-1 and various chemical reactions. It turned out that this virus leads to dullness. Yes, yes, that's why it became known as the "virus of stupidity".

When it comes to diseases that affect a person's consciousness, rabies is immediately remembered. The virus of this disease lives in the saliva of infected people and is usually transmitted through a bite. Once in the body, it affects the brain and spine, and eventually kills its host. But first, the bitten begin to show changes in behavior: they become aggressive, agitated, and arrogant.

The first signs of the disease in people are hallucinations and confusion, which are often accompanied by flu symptoms. After the virus spreads through the body, it is fatal. For all cases of clinical rabies in the United States, only ten patients were saved.

It is noteworthy that one of the consequences of rabies infection is the development of hydrophobia – fear of water. No wonder, because the virus lives in saliva, and water can partially wash it away – this is a vivid example of an evolutionary "arms race" in action.

The bacteria that cause sore throats can also lead to unusual and long-lasting changes in human behavior. This is especially true for children. As a rule, with the help of medical treatment, and sometimes only by the power of immunity, it is possible to destroy all the pathogenic bacteria and avoid the consequences. But there are cases when the pathogen "survives", and then patients begin to manifest obsessive-compulsive disorders.

Doctors call this condition PANDAS (from the English PANDAS, "Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections" – "children's autoimmune neuropsychiatric disorders associated with streptococcal infections") and associate it with pharyngitis. In children, it can manifest itself in the form of mood disorders, for example, fear of germs or fear of separation.

Every day, science learns something new about human behavior, including the effects of various viruses and vaccines. So, experts were able to find out that the flu vaccine, like the disease itself, makes people more sociable. What for? Although this mechanism is not yet fully understood, scientists believe that a sociable "host" is an ideal way to spread the disease among other people, and the virus "understands" this.

Let's return to the topic of intestinal microflora, because the microorganisms living in the gastrointestinal tract, it turns out, can affect not only the mood of a person, but also his addictions. For a reason, some people just love chocolate, and others, on the contrary, do not like it. It is quite possible that in the body of the latter there are intestinal bacteria that "do not like" this sweetness.

Craving or aversion to certain foods is not the most terrible consequences of the presence of these bacteria in the body. Sugar, which a person consumes, nourishes not only him, but also microorganisms. For example, candida-a type of yeast, one of the components of the microflora-grow in the intestine and love to eat sugar. When these micro-fungi become too much, they begin to release chemicals that make a person want to eat something sweet.

In this way, they promote the growth of themselves and affect the host's brain, causing it to have the same addiction to sugar as the bacteria themselves.