Types of computer viruses. Dangerous viruses in the world

Viruses can cause a wide variety of diseases, depending on the type of infection and the characteristics of the infected tissue. What types of viruses do humans have? There are a huge number of them, and throughout their lives people come into contact with most infectious agents in one way or another. The diseases they cause range from relatively mild to deadly. The most common viruses in the world are colds, flu, and hepatitis.

Viruses and colds

The common cold (as the common cold is called influenza, ARVI, laryngitis, pharyngitis) remains one of the most common human ailments. In the United States alone, about a billion cases of acute respiratory viral infection are registered every year. A viral infection of the lining of the nasal passages leads to a runny nose, watery eyes, sore throat and sneezing. The course of the disease lasts from one to two weeks. According to statistics, more than 200 of the known strains can cause a cold. What types of viruses are the most common causative agents of ARVI? These are various rhinoviruses, adenovirus, coronavirus, Coxsackie virus, echovirus, enterovirus, orthomyxovirus, paramyxovirus and

Influenza virus

Influenza is caused by three types of microorganisms. Types A and B lead to seasonal infections, characteristic of the period starting with late autumn and ending in early spring. Type C virus infections are less common and most often cause mild illness. The most common flu symptoms include body aches, fever, feeling tired, headache, sore throat, dry cough and nasal congestion. Flu vaccinations protect against types A and B viral infections.

Enteric viruses

What viruses are in digestive system and what are they characteristic features? Microorganisms of this type penetrate the tissues of the stomach and intestines, causing viral gastroenteritis. Common symptoms of the disease include abdominal pain, colic, diarrhea, nausea and vomiting. In young children, including infants, gastroenteritis is often caused by rotavirus. This infection manifests itself in the form of fever, vomiting and watery diarrhea. Norovirus is an equally common causative agent of infectious diseases that affects both children and adults. However, in patients younger age almost always the predominant symptom of the disease is diarrhea, while incessant vomiting is more typical for adults. Other known enteric viruses include adenovirus, sapovirus, and astrovirus strains.

Hepatitis viruses

Infectious agents of this type infect the liver, initiating inflammatory processes. Science knows five different viruses that cause hepatitis; they are named based on the letters of the Latin alphabet from A to E. If you are interested in what types of hepatitis B viruses are developed countries, then, according to statistical studies, in countries with developed infrastructure and medicine, types A, B and C predominate. The hepatitis A virus enters the body through the digestion of food or water contaminated with feces. It causes one brief episode of hepatitis. Type B strains can cause acute or chronic liver infection. Microorganisms are found in blood and semen. The most common cases of hepatitis B infection include sexual intercourse, sharing the same syringes when using drugs, and transmission of the infection from mother to child during pregnancy and childbirth. Type C virus spreads through contact with the blood of a sick person. Reusable syringes different people drug use is the most common method of transmission of infection. Hepatitis C usually develops chronic form However, adequate treatment in many cases can alleviate the course of the disease.

Other viruses

What viruses do humans have besides the ones listed above? If you print full list names, several volumes of the list will have to be published. Moreover: every year scientists discover new types, hitherto unknown. Some strains are very rare, but represent great danger due to their potential lethality. These are, for example, the Ebola or rabies viruses. Other microorganisms are quite common and are the root cause of a huge number of diseases. For those who are interested in what types of viruses a person has, just open any popular medical reference book. So, a clear example A common type of infection are herpes viruses that cause herpes simplex on the lips, genital herpes, infectious mononucleosis, chicken pox, herpes zoster and many other ailments. The human papillomavirus causes not only the appearance of common warts on the skin, but also the development of cervical cancer.

What viruses do people have in Lately? Infections the latest types- HIV, acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS coronavirus) remain a serious problem, since today there is no truly effective treatment for these diseases.

Diagnostics

Diagnosis of a viral infection is mainly based on a primary medical examination and analysis of the medical history. For example, a disease such as influenza is fairly easy to recognize, and most people are familiar with its manifestations. Detection of some other infections, however, may require additional diagnostic tests.

Diagnostic testing options for viral infection

Since the answer to the question of what viruses a person has involves thousands of answers, sometimes it is not enough to simply examine the patient and study his medical history. In such cases, doctors will order one or more of the following tests:

• blood tests to check for antibodies to viruses or to detect antigens directly;
• culturing blood components, bodily fluids, and other materials collected from the affected area;
• spinal tap to analyze cerebrospinal fluid;
• polymerase technique chain reaction to create multiple copies of viral genetic material for faster and more accurate identification of the virus;
• magnetic resonance imaging to detect inflammatory process in the temporal lobes of the brain.

Symptoms

What types of viruses do humans have? The list is incredibly extensive, but the symptoms of many infections can be systematized in order to compile a single list. Thus, signs of infection with the virus may include:

• increased body temperature;
• muscle pain;
• cough;
• sneezing;
• runny nose;
• chills;
• diarrhea;
• vomiting;
• skin rash;
• feeling of weakness.

More severe symptoms include:

• neck stiffness;
• dehydration;
• convulsions;
• paralysis of limbs;
• loss of orientation in space;
• back pain;
• loss of sensation;
• bladder and bowel dysfunction;
• drowsiness, which may progress to coma or death.

Infection: viral or bacterial?

What types of viruses do humans have? The names are unlikely to say anything to a non-specialist, but one should distinguish between viral and bacterial infections.

Infections of both types cause deterioration in health and the development of various diseases. However, there is a difference between them. A viral infection, as its name suggests, begins with the impact of a virus on the body - a tiny intracellular agent even smaller in size than a bacterium. In addition, it is in a protective shell, which means it is more difficult to destroy. The virus penetrates a living cell and integrates its genome into its genetic apparatus. Such infectious agents are non-cellular particles and require foreign cells to reproduce. If you are wondering what types of viruses there are, the names you will find in this article will most likely point you to the main sites of infection. These are the nose, throat and upper respiratory tract. Viral strains can cause both the common cold and AIDS.

To initiate a bacterial infection, the pathogenic bacterium must gain entry into the body through contaminated water, cuts on the skin, or contact with an infected person or contaminated objects. One of the fundamental differences between the two types of infections is that bacteria can enter the body through contact with inanimate objects, including doorknobs and table tops, while viruses cannot. Another difference is that nature is a cell and reproduces by division, while the virus dies without a host carrier. Most often, bacteria enter the body through the respiratory tract or gastrointestinal tract. Some bacterial infections are contagious (such as strep throat).

Cause of viral infection

The question of what viruses a person has is especially acute because the cells of the human body are susceptible to them. When exposed to viral particles, the immune system tries to destroy the source of danger and remove foreign strains from the body.

Viruses live while they fight and die from inaction. They are very picky about food, living “on loan” from the cells of animals, plants and even bacteria. Viruses mainly bring harm and very rarely benefit, so to speak, benefit through harm. The kingdom of viruses was discovered relatively recently: 100 years ago. In 1892, the Russian scientist D.I. Ivanovsky described the unusual properties of tobacco pathogens (tobacco mosaic), which passed through bacterial filters.

For more information about viruses, what they are, how they develop, how they harm a person and what consequences they can lead to, watch the video from I. I. Pavlusenko:

A few years later, F. Leffler and P. Frosch discovered that the causative agent of foot-and-mouth disease (disease livestock) also pass through bacterial filters. And in 1917 F. d'Herrel discovered bacteriophage - virus, infecting bacteria. This is how viruses of plants, animals and microorganisms were discovered.

These three events marked the beginning new science— virology, the study of non-cellular life forms.

Viruses very small, they cannot be seen, however, today they are one of the most studied objects, as they cause some of the most common and dangerous diseases in humans and beyond.

It is now recognized that viruses are causative agents of cancer, leukemia and other malignant tumors. Therefore, solving the problems of oncology now depends on knowledge of the nature of cancer pathogens and the mechanisms of carcinogenic (tumor-producing) transformations of normal cells.

Viruses are everywhere where there is life. From the moment of our birth, they accompany us every second of life.

Most known diseases Medicine is caused by viruses. But they also infect animals, plants and even bacteria. This fact makes it clear that protection against viruses and their destruction is the main task medicine and humanity.

Viruses are transmitted:

• through insects and ticks
• through the plants into which they are implanted
• through people: coughing or sneezing;
• upon contact with contaminated food
• fecal-oral route
• sexually
• transfusion of contaminated blood

Infection occurs through the introduction of a virus into a cell. Most often, such a cell dies under the influence of viral proteins, but sometimes it mutates and begins to behave erratically. Different viruses behave differently and cause different diseases.

The most common human viral diseases:

• colds, flu, acute respiratory syndrome;
• , trophic fever;
• , Epstein-Barr virus, infectious mononucleosis;
• , herpes zoster;
• AIDS;
• oncoviruses can lead to cancer of the skin, liver, cervix, penis and leukemia. Some viruses can lead to different types of lymphoma and carcinoma. Read the article on.

It is impossible to name any specific symptoms viral diseases person, because if you look at the list of diseases, it is easy to understand that they will have completely different symptoms. Although common feature Still, it may be lethargy, irritability, fatigue. This is enough to immediately begin prevention, even if it is just a cold.

Prevention and treatment of viral diseases

We are given vaccines against some viruses in infancy, which create immunity to infections. Having suffered from certain diseases in childhood, we also become immune to other diseases.

There are people who live their whole lives and practically never get sick. And there are those who get sick at the slightest contact with these small creatures. This only says one thing: yours.

Be healthy!

Influenza is not such a serious disease, but many millions of people get sick with it every year, and periodically pandemics (widespread epidemics) occur and claim many lives.

In 1886 and 1887, influenza was registered in Russia; In the summer of 1889, pathogen activity increased in Bukhara, and later that year the infection spread to other regions of Russia and Western Europe. Thus began the influenza pandemic of 1889-1890. During the second and third epidemics, the number of deaths progressively increased. The most ominous feature of this epidemic was that it apparently gave impetus to some kind of process, and now the flu is with us, or, as the epidemiologist Greenwood wrote, “we are not able to regain lost ground.”

In 1918, after the end of the First World War, an unprecedented influenza pandemic, called the “Spanish flu,” broke out.

In a year and a half, the pandemic has spread to all countries, affecting more than a billion people. The disease was extremely difficult: about 25 million people died - more than from injuries on all fronts of the First World War in four years.

Never later did influenza cause such a high mortality rate: the mortality rate was low during all subsequent epidemics and pandemics, although the percentage of deaths from influenza is low, the mass nature of the disease leads to the fact that during each major influenza epidemic, thousands of patients die from it, especially the elderly and children. It has been noted that during epidemics the mortality rate from diseases of the lungs, heart and blood vessels increases sharply.

Influenza remains the “king” of epidemics. No disease can reach hundreds of millions of people in a short time, and more than a billion people get sick with the flu during a pandemic! This was the case not only during the memorable pandemic of 1918, but relatively recently - in 1957, when the “Asian” flu pandemic broke out, and in 1968, when the “Hong Kong” flu appeared. There are several types of influenza virus known - A, B, C, etc.; under the influence of factors external environment their number may increase. Due to the fact that immunity to influenza is short-term and specific, repeated illness is possible in one season. According to statistics, an average of 20-35% of the population suffers from influenza every year.

The source of infection is a sick person; Patients with a mild form of the virus are the most dangerous as spreaders of the virus, since they do not isolate themselves in a timely manner - they go to work, use public transport, and visit places of entertainment.

The infection is transmitted from a sick person to a healthy person by airborne droplets when talking, sneezing, coughing or through household items.

Smallpox is one of the oldest diseases. A description of smallpox was found in the Egyptian papyrus of Amenophis I, compiled 4000 BC. Smallpox lesions were preserved on the skin of a mummy buried in Egypt 3000 BC. The mention of smallpox, which the Chinese called “poison from the mother’s breast,” is contained in the oldest Chinese source - the treatise “Cheu-Cheufa” (1120 BC). The first classical description of smallpox was given by the Arab physician Rhazes.

Smallpox was in the past the most common and most dangerous disease. Its destructive power was not inferior to the power of the plague.

The first mention of smallpox in Russia dates back to the 4th century. In 1610, the infection was brought to Siberia, where a third of the local population died out. People fled to the forests of the tundra and mountains, displayed idols, burned scars on their faces like pockmarks in order to deceive this evil spirit, - everything was in vain, nothing could stop the ruthless killer.

However, attempts to protect against smallpox are as ancient as smallpox itself. They were based on the observation that people who once had smallpox did not get sick again.

The first vaccination against smallpox in Russia was carried out in a solemn ceremony by Moscow University professor Efrem Mukhin in 1801. A child from an orphanage in Moscow was vaccinated with smallpox using the Jenner method and in honor of this was given the surname Vaccinov.

April 10, 1919 V.I. Lenin signed a decree on compulsory smallpox vaccination, which marked the beginning of mass vaccinations.

Poliomyelitis is a viral disease that affects the gray matter of the central nervous system. The causative agent of polio is a small virus that does not have an outer shell and contains RNA. The polio virus affects the limbs, that is, it changes the shape of the bones. Characteristic bone changes were found during excavations in Greenland on skeletons dating back to 500-600 BC. The incidence of polio has a number of characteristic features. Poliomyelitis is spread by intestinal diseases. With high levels of sanitation, children do not become infected at an early age, but become infected later. Poliomyelitis seems to mature, and in adults the disease is much more severe. An effective method of combating this disease is the live polio vaccine. The use of the polyvaccine made it possible to effectively extinguish outbreaks of infection, and the incidence rate sharply decreased. However, vaccination with a live vaccine does not mean eliminating the killer virus, but only replacing it with an artificial laboratory strain that is safe for humans.

Rabies - infection, transmitted to humans from a sick animal through a bite or contact with the saliva of a sick animal, most often a dog. One of the main signs of developing rabies is hydrophobia, when the patient has difficulty swallowing liquids and develops convulsions when trying to drink water. The rabies virus contains RNA, packaged in a nucleocapsid of helical symmetry, covered with a shell, and when multiplying in brain cells, it forms specific inclusions, according to some researchers, “viral graveyards” called Babes-Negri bodies. The disease is incurable.

Tumor viruses - Over the years since the fact of the occurrence of viral sarcomas in chickens was first established, numerous researchers have different types Oncogenic viruses belonging to two groups were discovered in vertebrates: DNA-containing and retroviruses. Oncogenic DNA viruses include pacovaviruses, adecoviruses, and herpesviruses. Of the RNA viruses, only retroviruses cause tumors.

The range of tumors caused by oncogenic viruses is unusually wide. Although the polyoma virus primarily causes tumors of the salivary glands, its very name indicates that it can cause many other tumors. Retroviruses cause mainly leukemia and sarcomas, which often cause tumors of the breast and a number of other organs. Although cancer is a disease of the whole organism, an essentially similar phenomenon, called transformation, is also observed in cell cultures. Such systems are used as models for studying oncogenic viruses. The ability to transform cells in vitro underlies methods for the quantitative determination of many oncogenic viruses. The same systems are also used for comparative studies of the physiology of normal and tumor cells.

Viruses and human malignant tumors - One of the arguments against the role of viruses in the occurrence of most malignant tumors in humans is the fact that in the vast majority of cases, malignant tumors are not contagious, whereas in viral etiology person-to-person transmission can be expected. If, however, we assume that activation of heritable viruses by exogenous factors plays a role in the occurrence of tumors, then we should expect that facts of hereditary predisposition to malignant tumors will be revealed. Such a predisposition to the development of some tumors has indeed been discovered, but various explanations can be found for this. Despite 10 years of intensive work directed by special government programs, the connection between human malignancies and viruses still remains problematic. Presented in highest degree It is strange that oncogenic viruses, which play such an obvious role in the occurrence of tumors in a wide variety of animals, should for some reason “bypass” humans.

AIDS - Acquired Immune Deficiency Syndrome - is a new infectious disease that experts recognize as the first truly global epidemic in the known history of mankind. Neither the plague, nor smallpox, nor cholera are precedents, since AIDS is decidedly unlike any of these and other known human diseases. The plague claimed tens of thousands of lives in the regions where the epidemic broke out, but never covered the entire planet at once. In addition, some people, having been ill, survived, acquired immunity and took on the work of caring for the sick and restoring the damaged economy. AIDS is not a rare disease that affects a few people by chance. Leading experts currently define AIDS as a “global health crisis”, as the first truly earthly and unprecedented epidemic of an infectious disease, which still, after the first decade of the epidemic, is not controlled by medicine and every infected person dies from it.

By 1991, AIDS was registered in all countries of the world except Albania. In the most developed country in the world - the United States - already at that time one out of every 100-200 people was infected, every 13 seconds another US resident was infected, and by the end of 1991, AIDS in this country had become third in mortality, overtaking cancer. So far, AIDS forces one to recognize itself as a fatal disease in 100% of cases.

The first people with AIDS were identified in 1981. During the past first decade, the spread of the pathogen virus occurred primarily among certain population groups, which were called risk groups. These are drug addicts, prostitutes, homosexuals, patients with congenital hemophilia (since the life of the latter depends on the systematic administration of drugs and donor blood).

However, by the end of the first decade of the epidemic, WHO had accumulated material indicating that the AIDS virus had spread beyond the named risk groups. He entered the general population.

The second decade of the pandemic began in 1992. It is expected that it will be significantly heavier than the first one. In Africa, for example, in the next 7-10 years, 25% of agricultural farms will be left without work force due to extinction from AIDS alone.

AIDS is one of the most important and tragic problems that arose before humanity at the end of the 20th century. The causative agent of AIDS, the human immunodeficiency virus (HIV), is a retrovirus. Retroviruses owe their name to an unusual enzyme - reverse transcriptase (retrovertase), which is encoded in their genome and allows the synthesis of DNA on an RNA template. Thus, HIV is capable of producing DNA copies of its genome in host cells, such as “helper” T-4 lymphocytes. Viral DNA is included in the genome of lymphocytes, where its presence creates conditions for the development of chronic infection. Even theoretical approaches to solving such a problem as cleaning the genetic apparatus of human cells from foreign (in particular, viral) information are still unknown. Without solving this problem, there will be no complete victory over AIDS.

Although it is now clear that the human immunodeficiency virus (HIV) is the cause of acquired immunodeficiency syndrome (AIDS) and related diseases, the origin of the virus remains a mystery. There is strong serological evidence that the infection appeared on the west and east coasts of the United States in the mid-1970s. However, cases of AIDS-associated diseases known in central Africa indicate that the infection may have appeared there even earlier (50-70 years). Be that as it may, it has not yet been possible to satisfactorily explain where this infection came from. Several human and monkey retroviruses have been discovered using modern cell culture techniques. Like other RNA viruses, they are potentially variable; therefore, they are quite likely to have such changes in the host spectrum and virulence that could explain the emergence of a new pathogen (there are several hypotheses: 1) the impact of unfavorable factors on a pre-existing virus environmental factors; 2) bacteriological weapons; 3) mutation of the virus as a result of radiation exposure from uranium deposits in the supposed homeland of the infectious pathogen - Zambia and Zaire).

There is an opinion that animals, plants and humans predominate in numbers on planet Earth. But this is actually not the case. There are countless microorganisms (microbes) in the world. And viruses are among the most dangerous. They can cause various diseases in humans and animals. Below is a list of the ten most dangerous biological viruses for humans.

Hantaviruses are a genus of viruses that are transmitted to humans through contact with rodents or their waste products. Hantaviruses cause various diseases, belonging to such groups of diseases as “hemorrhagic fever with renal syndrome” (mortality on average 12%) and “hantavirus cardiopulmonary syndrome” (mortality up to 36%). The first major outbreak of disease caused by hantaviruses, known as Korean hemorrhagic fever, occurred during Korean War(1950–1953). Then more than 3,000 American and Korean soldiers felt the effects of a then unknown virus that caused internal bleeding and renal dysfunction. Interestingly, this particular virus is considered probable cause the outbreak of an epidemic in the 16th century that exterminated the Aztec people.

Influenza virus is a virus that causes an acute infectious disease of the respiratory tract in humans. Currently, there are more than 2 thousand of its variants, classified into three serotypes A, B, C. The group of viruses from serotype A, divided into strains (H1N1, H2N2, H3N2, etc.) is the most dangerous for humans and can lead to epidemics and pandemics. Every year, between 250 and 500 thousand people worldwide die from seasonal influenza epidemics (most of them children under 2 years of age and elderly people over 65 years of age).

Marburg virus is a dangerous human virus first described in 1967 during small outbreaks in the German cities of Marburg and Frankfurt. In humans, it causes Marburg hemorrhagic fever (mortality rate 23-50%), which is transmitted through blood, feces, saliva and vomit. A natural reservoir for this virus Serve sick people, probably rodents and some species of monkeys. Symptoms on early stages include fever, headache and muscle pain. In the later stages - jaundice, pancreatitis, weight loss, delirium and neuropsychiatric symptoms, bleeding, hypovolemic shock and multiple organ failure, most often the liver. Marburg fever is one of the top ten deadly diseases transmitted from animals.

Sixth on the list of the most dangerous human viruses is Rotavirus, a group of viruses that are the most common cause of acute diarrhea in infants and young children. Transmitted by the fecal-oral route. The disease is usually easy to treat, but kills more than 450,000 children under five worldwide each year, most of whom live in underdeveloped countries.

Ebola virus is a genus of virus that causes Ebola hemorrhagic fever. It was first discovered in 1976 during an outbreak of the disease in the Ebola River basin (hence the name of the virus) in Zaire, DR Congo. It is transmitted through direct contact with the blood, secretions, other fluids and organs of an infected person. Ebola fever is characterized by a sudden increase in body temperature, severe general weakness, muscle pain, headaches, and sore throat. Often accompanied by vomiting, diarrhea, rash, impaired renal and liver function, and in some cases internal and external bleeding. According to the US Centers for Disease Control, in 2015, 30,939 people were infected with Ebola, of whom 12,910 (42%) died.

Dengue virus is one of the most dangerous biological viruses for humans, causing dengue fever, in severe cases, which has a mortality rate of about 50%. The disease is characterized by fever, intoxication, myalgia, arthralgia, rash and swollen lymph nodes. Found mainly in the countries of South and South-East Asia, Africa, Oceania and the Caribbean, where about 50 million people are infected annually. The carriers of the virus are sick people, monkeys, mosquitoes and the bats.

Smallpox virus is a complex virus, the causative agent of a highly contagious disease of the same name that affects only humans. This is one of the oldest diseases, the symptoms of which are chills, pain in the sacrum and lower back, rapid increase in body temperature, dizziness, headache, vomit. On the second day, a rash appears, which eventually turns into purulent blisters. In the 20th century, this virus claimed the lives of 300–500 million people. About US$298 million was spent on the smallpox campaign from 1967 to 1979 (equivalent to US$1.2 billion in 2010). Fortunately, the last one famous case infection was recorded on October 26, 1977 in the Somali city of Marka.

The rabies virus is a dangerous virus that causes rabies in humans and warm-blooded animals, which causes specific damage to the central nervous system. This disease is transmitted through saliva from the bite of an infected animal. Accompanied by an increase in temperature to 37.2–37.3, bad sleep, patients become aggressive, violent, hallucinations, delirium, a feeling of fear appear, soon paralysis of the eye muscles, lower extremities, paralytic respiratory disorders and death occurs. The first signs of the disease appear late, when destructive processes have already occurred in the brain (swelling, hemorrhage, degradation of nerve cells), which makes treatment almost impossible. To date, only three cases of human recovery without vaccination have been recorded; all others ended in death.

Lassa virus is a deadly virus that is the causative agent of Lassa fever in humans and primates. The disease was first discovered in 1969 in the Nigerian city of Lassa. It is characterized by a severe course, damage to the respiratory system, kidneys, central nervous system, myocarditis and hemorrhagic syndrome. It is found mainly in countries West Africa, especially in Sierra Leone, the Republic of Guinea, Nigeria and Liberia, where the annual incidence ranges from 300,000 to 500,000 cases, of which 5 thousand lead to the death of the patient. The natural reservoir of Lassa fever is polymammated rats.

Human immunodeficiency virus (HIV) is the most dangerous human virus, the causative agent of HIV infection/AIDS, which is transmitted through direct contact of mucous membranes or blood with bodily fluid of the patient. During HIV infection, the same person develops new strains (varieties) of the virus, which are mutants, completely different in reproduction speed, capable of initiating and killing certain types of cells. Without medical intervention average duration The lifespan of a person infected with the immunodeficiency virus is 9–11 years. According to 2011 data, 60 million people have become infected with HIV throughout the world, of which 25 million have died, and 35 million continue to live with the virus.

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Over the course of a lifetime, a person can get sick from so many different diseases and viruses that by old age he may not remember them all. Some diseases occur quickly and unnoticed, but others can be crippling. And to the question of which virus is the most dangerous, several dozen can be named.

What is a virus?

Translated from Latin, “virus” means “poison”. It is a cell-free organism that reproduces and lives only in the cells of living beings. Any virus consists of a protein shell containing DNA and RNA molecules.

Scientists know more than a hundred viruses that differ in shape and habitat. They mutate without problems and adapt to the characteristics of the organisms into which they have invaded. For viruses, life outside the cell does not exist. Microorganisms can cause many different diseases: measles, chickenpox, hepatitis, herpes, rabies, cancer, AIDS.

How do viruses spread?

All viruses that exist in nature can be divided into anthropotic (live in the human body) and zooanthropotic (live in the body of animals). You can pick up one or another virus in several ways.

1. Through food (contaminated food, water).
2. Through blood ( surgical intervention, transfusion, from mother to fetus, sexual contact, through the bites of infected insects or animals).
3. By airborne droplets (through the respiratory tract).
4. Contact and household (through hygiene items).

Almost all viruses have their certain places locations. Thus, hepatitis B and C enter the liver; chickenpox spreads across the skin; The staphylococcus virus can “at its own taste” infect the intestines, throat, heart and other vital organs. All viral infections are accompanied by individual symptoms and can affect the body in different ways. Each has its own specific therapy.

The most dangerous viruses in the world

Our life is very unpredictable. Successful, healthy and strong man Tomorrow you can become practically disabled; it is enough to be infected with the most terrible and incurable disease - AIDS. For many people, just the word itself causes horror and trembling.

So, the 10 most dangerous viruses:

1. Human acquired immunodeficiency syndrome. It was opened in the early 80s of the twentieth century. The immunodeficiency virus affects immune system person, completely depriving him protective functions. So, people can die from a simple runny nose or a scratch on the arm. The disease is incurable.
2. In second place in the category “Most dangerous viruses“There is a relatively new disease - spongiform encephalopathy, as a result of which the human brain is affected and dementia occurs. The disease is incurable. Death occurs within two years.
3. Rabies. Death can occur as early as five days after infection. The rabies virus is at the heart of hundreds of zombie films.
4. African fever. A tropical infection that is accompanied by high temperature, muscle pain and hemorrhages. Some types of this fever are incurable and result in death.
5. Plague is an infection that in the 14th century killed everyone it came across. A third of Europe died from this disease. In our time, the treatment for plague is the Haffkine vaccine, discovered at the beginning of the last century.
6. Anthrax. It is found in both humans and animals. Infection spores can persist in the soil for many years; they are very tenacious and can even withstand boiling. Without treatment, 90% of the disease is fatal.
7. Cholera. A disease with a mortality rate of 85%. Transmitted through household contact. Causes vomiting, dehydration, diarrhea and cramps. Nowadays, a vaccine against this disease is actively used.
8. Meningococcal infection. Affects the upper respiratory tract, nasopharynx. Inflammations end in hemorrhages. The infection can penetrate the brain. May be fatal.
9. Tularemia. The fever is similar to typhoid fever.
10. Malaria, African trypanosomiasis, tuberculosis, pneumonia and some others.

This list is not all of the most dangerous viruses in the world. This is only a small part known to mankind.

Animal viruses dangerous to humans

Viruses that infect animals also pose a significant danger to humans. Infections enter the human body along with food - milk, meat, eggs. They are capable of developing severe, sometimes incurable diseases, and occur in people with complications.

Top most dangerous viruses that are transmitted from animals.

• Brucellosis.
• Tularemia.
• Toxoplasmosis.
• Rabies.
• Ringworm.
• Helminths.
• Trichinosis.
• Ancroceliosis.

Basic precautions can protect you from illness.

1. Personal hygiene.
2. High quality food processing.
3. Vaccination of animals.
4. Correct behavior with domestic and wild animals.

The most dangerous sexually transmitted human viruses

A person may not be sufficiently aware of the presence of infections and diseases in his body. for a long time. Thus, sexually transmitted infections can often occur without any symptoms. As a result, in the absence of a regular partner, the number of infected people may increase.

1. AIDS is the first on the list of deadly infections. The virus can persist in the body for years and make itself felt after 7-10 years.
2. Gonorrhea.
3. Trichomonosis.
4. Chlamydia.
5. Syphilis.
6. Genital herpes.
7. Human papillomavirus.

All of the listed infections, except AIDS, are curable, but they leave their mark, affecting the internal organs and pelvic organs. One of the most terrible consequences is infertility.

You can protect yourself from such ailments with the help of a high-quality condom that has a valid expiration date. Anti-venereal drugs used in the first hours after sexual intercourse help with some sores. They treat the mucous membranes of the genital organs, and the chance of infection is reduced several times.

And, of course, the best prevention is a regular sexual partner. It should be remembered that the most dangerous human viruses are not only those that end in death, but also all known viruses, because any treatment can be both expensive and lengthy.

The impact of viruses on human health

Getting into the body, viral infection can occur in two forms - acute and chronic. Often the disease develops covertly, when a person is unaware of it and becomes a carrier (herpes, AIDS).

There are many different ways of transmitting viruses, so you need to always be on guard. Having had one or another illness once, the body can develop immunity (chickenpox, Botkin's disease). Diseases often recur and return accompanied by serious complications. Sometimes vaccination can help alleviate the infection or avoid it altogether.

The most terrible consequence of viruses is defeat internal organs, nervous system and brain, mucous membranes. Some infections can provoke cancer, and the most dangerous viruses in the world often end in death.

Prevention of viral diseases

Of course, it is much safer and cheaper for people to carry out timely prevention of viruses. This way you can avoid not only expensive treatment and health complications, but also save lives.

1. So, the best prevention is personal hygiene. You should always wash your hands before eating and after going outside.
2. You should only eat well-processed food, and be sure to wash vegetables and fruits. Products must be purchased in specialized stores.
3. Strengthening the immune system should become a rule for every person.
4. More positive - less stress!
5. Infected people are indicated for quarantine and hospitalization.
6. Don't forget about vaccination. Vaccinations are given against many diseases in childhood; there is no need to refuse them.
7. Healthy lifestyle, proper nutrition and vitamins.
8. Safe sex - some of the most dangerous viruses are transmitted through sexual contact.

Viruses that are best to get over in childhood

Viruses are one of the ancient forms of life on the planet. More than a thousand are known. Some exist quietly next to us, but some can cause serious damage to human health. Among all infections, there are some that are better to get over in childhood. Children's diseases are the most dangerous viruses for adults, especially for pregnant women.

What children tolerate easily can cause complications for an adult. Pregnant women pose special group risk, because the infection can affect not only the mother’s body, but also intrauterine life. Infections suffered during pregnancy cause serious defects and abnormalities of the fetus.

Top diseases that are best to get in childhood:

1. Measles (consequences for adults - encephalitis, meningitis).
2. Mumps (can cause mumps, infertility, brain diseases).
3. Chickenpox, rubella (especially dangerous for expectant mothers. They cause cataracts, heart defects, and brain enlargement in the fetus).
4. Polio. Your child must be vaccinated against this disease. When the disease appears in an adult, it almost always ends wheelchair or death.

Equipment also suffers from viruses

A virus is a microorganism with its own DNA that can live and reproduce only in another organism. A computer virus is no different from an ordinary one. It is a specially written program that infiltrates and attacks other programs and files.

A computer virus can erase absolutely any file on its own. There are several signs of infection:

• The program is not working.
• The program is not working correctly.
• Extraneous information appears on the screen.
• The files cannot be opened or read.
• The operating system does not load.
• There are more files on the disk, but less memory.

It is impossible to say for sure which is the most dangerous virus on a computer, because each of them harms files and programs.

Common five computer viruses:

• "Friday the 13th" (Jerusalem) - deletes all programs.
• "Cascade of falling letters."
• “Melissa” - an email arrives in the mail “The document that was requested...”.
• “Letter of confession” or “letter of happiness.” An email with a declaration of love.
• Nimda - creates administrator rights on the computer.

All viruses are created by experienced programmers for the purpose of hacking and personal gain. However, for every poison there is an antidote. The most dangerous computer viruses must be “treated” with antivirus programs or by formatting the hard drive.

For the purpose of prevention, you should use only licensed programs, visit only trusted sites and use “clean” media.

Conclusion

During his life, a person suffers a huge number of all kinds of ailments and viruses. To some, he develops lifelong immunity, and some can return again. Proper nutrition, personal hygiene and good immunity will help protect yourself from various diseases. Some of the most dangerous viruses come to humans from animals (rabies, anthrax, salmonellosis), so it’s worth taking care of them too. For example, vaccinating animals reduces the risk of getting an infection several times.