How dangerous are viral infections? Viral infection in adults: symptoms and treatment

They are completely dependent on cells (bacteria, plant or animal) for reproduction. Viruses have an outer shell of protein and sometimes a lipid and a core of DNA or RNA. For infection to occur, the virus first attaches to a host cell. The viral DNA or RNA then enters the host cell and is separated from the outer envelope (viral cecapsulation) and replicated to the host cell using certain enzymes. Most RNA viruses copy their nucleic acid in the cytoplasm, while most DNA viruses copy it in the nucleus. The host cell typically dies, releasing new viruses that infect other host cells.

The consequences of viral infection vary greatly. Many infections cause acute illness after a short incubation period, and some are asymptomatic or cause minor symptoms that cannot be recognized except in retrospect. In many viral infections under the influence protective forces the body recovers, but some pass into a latent form. In latent infection, the viral RNA or DNA remains in the host cells without causing disease for a long time, sometimes for many years. Most often, infection from person to person occurs during the asymptomatic period with hidden, latent forms of viral infections. Various triggers can cause re-activation of the process, this especially often occurs during immunosuppression.

Common viruses that remain latent are:

Herpes viruses.
Papovaviruses.

Some diseases are caused by reactivation of the virus in the central nervous system after a very long period of latency. These diseases include progressive multifocal leukodystrophy (polyomavirus K), subacute sclerosing panencephalitis (measles virus), and progressive rubella panencephalitis (rubella virus). Spastic pseudosclerosis and bovine spongiform encephalopathy were previously classified as slow viral diseases due to prolonged incubation periods(years), but are now known to be caused by prions; Prions are protein pathogens that are not bacteria, fungi or viruses and that do not contain genetic material.

Several hundred different viruses can infect people. Such viruses are often spread through respiratory and intestinal secretions. Some are transmitted through sexual contact and blood transfusions. Some viruses are transmitted by arthropod vectors. Viruses are distributed throughout the world, but their pathogenicity is limited by innate resistance, resistance, post-vaccination immunity, sanitary and other health system control methods, and prophylactic antiviral drugs.

Zoonotic viruses carry out their biological cycles mainly in animals; humans are secondary or accidental hosts. These viruses exist in certain environment, which is able to maintain their natural cycles that differ from humans (vertebrates, arthropods, or both).

Viruses and cancer. Some viruses are oncogenic and predispose to certain cancers:

Papillomavirus: cervical and anal carcinoma.
Human T-lymphotropic virus 1: certain types of human leukemia and lymphoma.
Epstein-Barr virus: nasopharyngeal carcinoma, Burkitt's lymphoma, Hodgkin's lymphoma and lymphomas in organ transplant recipients and the immunocompromised.
Hepatitis B and C viruses: hepatocellular carcinoma.
Human herpesvirus 8: Kaposi's sarcoma, primary lymphomas and multicentric Castleman disease (lymphoproliferative disease).

Types of viral diseases

Classification of viral infections according to the organ system affected (eg, lung, GI, skin, liver, CNS, mucosal membranes) can be clinically useful, although certain viral diseases (eg, mumps) are difficult to classify.

Respiratory infections. The most common viral infections are probably acute respiratory infections. Respiratory infections are more likely to cause severe symptoms in infants, the elderly, and patients with lung or heart problems.

Gastrointestinal infections. Affected age group First of all, it depends on the virus:

Rotavirus: children.
Norovirus: older children and adults.
Astrovirus: usually infants and young children.
Adenovirus 40 and 41: infants.
Pathogens similar to coronavirus: infants.

Localized epidemics may occur in children, especially during colder times of the year.

The main symptoms are vomiting and diarrhea.

Rotavirus vaccine, which is effective against most pathogenic strains, is part of the recommended childhood vaccination schedule. Hand washing and compliance sanitary rules may help prevent spread.

Exanthematous infections. Some viruses cause only skin lesions (as with molluscum contagiosum and warts); others may cause systemic manifestations or skin lesions on various parts of the body. Transmission typically occurs from person to person; The carrier of alpha viruses is the mosquito.

Liver infections. At least 5 specific viruses (hepatitis viruses A, B, C, D and E) can cause hepatitis; everyone calls certain type hepatitis. The hepatitis D virus can only infect people if there is hepatitis B.

Other viruses can also attack the liver. Common examples are cytomegalovirus, Epstein-Barr virus, and yellow fever virus. Less common examples are echovirus, coxavirus, and the herpes simplex, measles, rubella, and varicella viruses.

Neurological infections. Most cases of encephalitis are caused by viruses. Many of these viruses infect humans through the bites of arthropods, mainly mosquitoes and blood-feeding ticks; these viruses are called arboviruses. For such infections, prevention includes avoiding mosquito (mosquito) and tick bites.

Hemorrhagic fever. Certain viruses cause fever and a tendency to bleed or bleed. Spread by mosquitoes, ticks, or contact with infected animals (e.g. rodents, monkeys, bats) and people.

Infections of the skin or mucous membranes. Some viruses cause lesions of the skin or mucous membranes, which recur and can become chronic. Infections affecting the skin and mucous membranes are the most common type of herpes simplex viral infection. The human papillomavirus causes warts. Transmission by person-to-person contact.

Diseases with multiple lesions various systems and organs. Enteroviruses, which include coxsackieviruses and echoviruses, can cause various multisystem syndromes, as can cytomegaloviruses.

Nonspecific febrile illness. Some viruses cause nonspecific symptoms, including fever, malaise, headaches, and myalgia. Transmission usually occurs through insects or arthropods.

Rift Valley fever rarely progresses to eye lesions, meningoencephalitis, or the hemorrhagic form (which has a 50% mortality rate).

Virus diagnostics

Some viral diseases can be diagnosed clinically by familiar symptoms and syndromes (eg, measles, rubella, roseola infantum, erythema infectiosum, and varicella) or epidemiologically during epidemic outbreaks (eg, influenza). A clear laboratory diagnosis is necessary primarily when specific treatment may be helpful or when the pathogen may be a public health threat (eg, HIV). Typical hospital laboratories can test for individual viruses, but at relatively rare diseases(eg, rabies, Eastern equine encephalitis), materials should be sent to state health laboratories or the Centers for Disease Control and Prevention.

Serological testing in the acute and convalescent phases is sensitive and specific but slow; faster diagnosis can sometimes be made using culture methods, PCR, and sometimes histochemical methods using electron microscopy to detect viral antigens.

Treatment of viruses

Antiviral drugs. Progress in the use of antiviral drugs is rapid. Antiviral chemotherapy can be aimed at different phases of viral replication: to interfere with the process of attachment of the virus particle to the host cell membranes or decapsulation nucleic acids virus, inhibit a cellular receptor or factor necessary for viral replication, block specific virus-encoded enzymes and proteins that are produced in host cells and that are important for viral replication and not for normal host cell metabolism.

Antivirals are most often used therapeutically or prophylactically against herpesviruses (including cytomegalovirus), respiratory viruses, and HIV. However, some drugs are effective for various types viruses.

Interferons. Interferons are substances produced by infected host cells in response to viral or other foreign antigens. There are many different interferons that have numerous

effects such as blocking viral RNA translation and transcription and stopping viral replication without disrupting normal function host cells. Sometimes interferons are attached to polyethylene glycol (pegylated compounds), which gives a slow and prolonged release of interferon.

Viral diseases that can be treated with interferon:

Chronic hepatitis B and C.
Condyloma acuminata.
Hairy cell leukemia.
Kaposi's sarcoma.

Depression and, with large doses, bone marrow suppression are also possible.

Virus prevention

Vaccines. Vaccines work to stimulate the innate immune system. Vaccines used include hepatitis A, hepatitis B, human papillomavirus, influenza, measles, mumps, polio, rabies, rotavirus, rubella, chickenpox and yellow fever. adenovirus and smallpox vaccines are available but are used only in at-risk populations (eg, military recruits).

Immunoglobulins. Immunoglobulins are available for passive immunoprophylaxis in selected situations. They can be used when there is a risk of infection (for example, hepatitis A), after infection (for example, rabies or hepatitis) and to treat a disease (for example, eczema vaccinatum).

Preventive measures. Many viral infections can be prevented with regular preventive measures(which vary depending on the mode of transmission of a given pathogen). Hand washing is important proper preparation food and water treatment, avoiding contact with sick people and practicing safe sex. Regarding infections that are carried by insects (eg mosquitoes, ticks), it is important to protect yourself from contact with them.

Viral diseases affect cells that already have abnormalities, which the pathogen takes advantage of. Modern research They have proven that this only happens when the immune system is severely weakened and is no longer able to fight the threat at the proper level.

Features of viral infections

Types of viral diseases

These pathogens are usually distinguished by genetic characteristics:

DNA – human cold viral diseases, hepatitis B, herpes, papillomatosis, chicken pox, lichen;
RNA – influenza, hepatitis C, HIV, polio, AIDS.

Viral diseases can also be classified according to the mechanism of their effect on the cell:

cytopathic - accumulated particles rupture and kill it;
immune-mediated - the virus integrated into the genome sleeps, and its antigens come to the surface, putting the cell under attack by the immune system, which considers it an aggressor;
peaceful – the antigen is not produced, the latent state persists for a long time, replication starts when favorable conditions are created;
degeneration - the cell mutates into a tumor cell.

How is the virus transmitted?

The viral infection spreads:

Airborne. Respiratory viral infections are transmitted by drawing in particles of mucus splashed during sneezing.
Parenterally. In this case, the disease spreads from mother to child, during medical manipulations, sex.
Through food. Viral diseases come from water or food. Sometimes they lie dormant for a long time, appearing only under external influence.

Why do viral diseases become epidemics?

Many viruses spread quickly and en masse, which provokes epidemics. The reasons for this are the following:

Ease of distribution. Many serious viruses and viral diseases are easily transmitted through droplets of saliva inhaled. In this form, the pathogen can maintain activity for a long time, and therefore is able to find several new carriers.
Reproduction rate. After entering the body, the cells are affected one by one, providing the necessary nutrient medium.
Difficulty in eliminating. It is not always known how to treat a viral infection, this is due to lack of knowledge, the possibility of mutations and difficulties in diagnosis - at the initial stage it is easy to confuse it with other problems.

Symptoms of a viral infection

The course of viral diseases may differ depending on their type, but there are common points.

Fever. Accompanied by a rise in temperature to 38 degrees, only mild forms of ARVI pass without it. If the temperature is higher, this indicates a severe course. It lasts no longer than 2 weeks.
Rash. Viral skin diseases are accompanied by these manifestations. They may appear as macules, roseolas, and vesicles. Characteristic for childhood, in adults, rashes are less common.
Meningitis. Occurs due to enterovirus and is more common in children.
Intoxication– loss of appetite, nausea, headache, weakness and lethargy. These signs viral disease caused by toxins released by the pathogen during activity. The strength of the effect depends on the severity of the disease; it is more difficult for children; adults may not even notice it.
Diarrhea. Characteristic of rotaviruses, the stool is watery and does not contain blood.

Human viral diseases - list

Impossible to name exact number viruses - they are constantly changing, adding to the extensive list. Viral diseases, the list of which is presented below, are the most famous.

Flu and colds. Their signs are: weakness, elevated temperature, sore throat. Antiviral drugs are used, and if bacteria are present, antibiotics are additionally prescribed.
Rubella. The eyes, respiratory tract, cervical lymph nodes and skin are affected. It spreads by airborne droplets and is accompanied by high fever and skin rashes.
Piggy. The respiratory tract is affected, and in rare cases, the testes are affected in men.
Yellow fever. Harmful to the liver and blood vessels.
Measles. Dangerous for children, affects the intestines, respiratory tract and skin.
. It often occurs against the background of other problems.
Polio. Penetrates into the blood through the intestines and breathing; when the brain is damaged, paralysis occurs.
Angina. There are several types, characterized by headache, high temperature, severe sore throat and chills.
Hepatitis. Any variety causes yellowing of the skin, darkening of urine and colorlessness of feces, which indicates a violation of several body functions.
Typhus. Rare in modern world, amazes circulatory system, can lead to thrombosis.
Syphilis. After damage to the genital organs, the pathogen enters the joints and eyes and spreads further. It has no symptoms for a long time, so periodic examinations are important.
Encephalitis. The brain is affected, a cure cannot be guaranteed, and the risk of death is high.

The most dangerous viruses in the world for humans

The list of viruses that pose the greatest danger to our body:

Hantavirus. The pathogen is transmitted from rodents and causes various fevers, the mortality rate of which ranges from 12 to 36%.
Flu. This includes the most dangerous viruses known from the news; different strains can cause a pandemic; severe cases affect the elderly and young children more.
Marburg. Discovered in the second half of the 20th century, it is the cause of hemorrhagic fever. Transmitted from animals and infected people.
. It causes diarrhea, the treatment is simple, but in underdeveloped countries 450 thousand children die from it every year.
Ebola. As of 2015, the mortality rate is 42%, transmitted through contact with the fluids of an infected person. Signs are: a sharp increase in temperature, weakness, muscle and throat pain, rash, diarrhea, vomiting, and possible bleeding.
. Mortality is estimated at 50%, characterized by intoxication, rash, fever, and damage to the lymph nodes. Distributed in Asia, Oceania and Africa.
Smallpox. Known for a long time, it is dangerous only to people. Characterized by a rash, high fever, vomiting and headache. The last case of infection occurred in 1977.
Rabies. Transmitted from warm-blooded animals, it affects the nervous system. Once symptoms appear, treatment success is almost impossible.
Lassa. The pathogen is carried by rats and was first discovered in 1969 in Nigeria. The kidneys and nervous system are affected, myocarditis and hemorrhagic syndrome begin. Treatment is difficult, fever claims up to 5 thousand lives annually.
HIV. Transmitted through contact with the fluids of an infected person. Without treatment, there is a chance to live 9-11 years; its complexity lies in the constant mutation of strains that kill cells.

Fighting viral diseases

The difficulty of the fight lies in the constant change in known pathogens, making the usual treatment of viral diseases ineffective. This makes it necessary to search for new drugs, but modern stage In the development of medicine, most measures are developed quickly, before the epidemic threshold is crossed. The following approaches have been adopted:

etiotropic – preventing the reproduction of the pathogen;
surgical;
immunomodulatory.

Antibiotics for viral infections

During the course of the disease, the immune system is always suppressed; sometimes it needs to be strengthened to destroy the pathogen. In some cases, for a viral disease, antibiotics are additionally prescribed. This is necessary when a bacterial infection occurs, which can only be killed in this way. In case of a pure viral disease, taking these medications will not bring any benefit and will only worsen the condition.

Prevention of viral diseases

Vaccination– effective against a specific pathogen.
Strengthening immunity– prevention of viral infections in this way involves hardening, proper nutrition, support with plant extracts.
Precautions– exclusion of contacts with sick people, exclusion of unprotected casual sex.

Everyone has heard about computer viruses, but few people know anything specific about them. This article will correct this and allow you to feel more confident when accessing the global network. You will learn about what viruses are and how to make sure your computer never gets sick with them, as well as how to cure your PC.

Types of computer viruses

There are viruses created for fun that can make the cursor run around your screen or display some vulgar picture on the screen, but none of this does any harm, only annoyance. Another thing is special programs created for the purpose of stealing money, personal information or its complete destruction.

There is an “almost” official classification that will tell you what viruses there are and, for clarity, separates them:

By affected objects (script, file, boot, viruses that infect source code).

According to the mechanism of infection.

By affected operating systems (UNIX, LINUX, WINDOWS, DOS).

By technologies used by malware (Polymorphic viruses, rootkits, stealth).

According to the language in which the virus was written (low-level, high-level programming languages, scripting languages).

For additional malicious functionality (spyware, backdoors, botnets).

This classification allows us to more or less put everything into categories, but it is far from ideal. Today there are a huge number of unknown viruses created every day and their functionality is constantly changing. Therefore, it will not be possible to create an exact division in this area.

Among the huge number of programs that can infect your PC, there are some that almost every Internet user has heard of, such as:

These are the most famous malware(algorithms) that caused a lot of harm and from which they came up with large number means of protection. However, this is not all that exists and is known today! To complete the article, I will give more full list known malware:

There are a lot of them and this is bad... But we remember from school that action causes reaction in this case too good people created means of protection, let's talk about them. I really recommend watching this one first documentary for general development in this topic:

Computer viruses and protection against them

There are many dangers on the Internet, but we are not afraid of them if we do everything meaningfully and wisely. First, the main points:

Set yourself good antivirus from a well-known company with auto-updates.
Use only proven programs from well-known companies (for good money, of course).
You shouldn’t give everyone your flash drive or portable hard drive.

In most cases, this will last forever. True, additional protective measures will not hurt:

Use the computer only with user rights if you do not know how to properly operate the computer as an administrator.
Do not open and, preferably, do not download files from unknown resources.
Make backup copies of important files in case a virus finds you.

How to cure a virus on your computer

Even if you are not sure about infection, but there are suspicions, then you should not hesitate. First, disconnect your computer from the Internet so that the stolen (if any) data cannot fall into the hands of intruders. Then transfer all important files to external media (flash drive), having first checked the files and the media itself for viruses. After this, run a full scan of your computer for infection using an antivirus program.

After which, even if the scan did not reveal any threats, you should reinstall operating system and check your computer again for infection. In 99 cases out of 100, this is enough to completely restore the computer.

Conclusion

Computer viruses are an annoying problem that can affect anyone. But you shouldn’t be afraid of this and wait for the day when you have to treat your PC, because, most likely, this day will never come. Observe basic rules and you won’t have to waste your nerves and time in the future.

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 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 impaired kidney function. 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 acute illness in humans. infectious disease respiratory tract. 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. The natural reservoir for this virus is sick people, probably rodents and some species of monkeys. Symptoms in the 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 in 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 children. younger age. 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 Southeast 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 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, vomiting. 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.

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, paralysis of the eye muscles soon occurs, lower limbs, paralytic respiratory distress and death. The first signs of the disease appear late, when destructive processes have already occurred in the brain (swelling, hemorrhage, degradation 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, the average life expectancy 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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Of all the organisms existing on the planet, the most large area pathogens, including bacteria, rods and, of course, viruses invisible to the human eye, have coatings and numbers. The latter are causative agents of diseases that differ in symptoms, course and severity.

It is quite difficult to identify the most dangerous virus for humans, since different approaches to analysis must be used. For example, there are pathogens that change the overall mortality rate of a population. Others lead to death in already infected people. Still others kill the host faster than he can spread them to other people. For example, with a mortality rate of up to 3%, the Ebola virus and the Spanish flu pandemic killed more than 100 million people. There is also a historical approach to assessing the harmfulness of the virus. It demonstrates which microorganism has killed the most people throughout human history.

We offer you a list of the 10 most dangerous viruses on the planet, which kill hundreds and thousands every year. human lives. Let's add some statistics and figures, as well as data on the characteristic symptoms of a viral disease of one type or another.

Arboviruses of the family Flaviviridae

These dangerous pathogens cause a specific disease - Dengue fever. The patient is worried about acute pain in the musculoskeletal system (joints, especially knees, spine). The patient also notes hyperthermia, severe fever and fever, nausea and vomiting. An itchy rash often appears on the body. It is known that if the disease becomes severe, it ends in death in half of the cases. You can pick up an arbovirus through an insect bite (tick, mosquito, etc.). Before traveling to an area where the virus is spreading, take care of preventive vaccinations and other personal protection methods.

Influenza virus

In the modern world, the “common cold” does not cause panic in people, as it is easily treatable. Simply put, human immunity is resistant to many strains infectious lesion respiratory tract. But few people know that there are more than 2 thousand variants of the virus in the world, which are classified by serotypes (B, A, C) and strains. Serotype A is life-threatening, as it causes massive epidemics and even pandemics. Every year, up to half a million people (most often preschoolers and the elderly) die from a seasonal outbreak of influenza. A virulent strain of the virus caused the so-called “Spanish flu,” which in 1918 affected about a third of the world’s population, killing about 100 million patients. At the same time most at risk People with strong immune systems were susceptible, which ultimately provoked the so-called “cytokine storm.”

Hepatitis C virus (HCV)

A specific disease can masquerade as other pathologies in its symptoms, so a person may long time not suspecting the presence of a virus in the body. So the disease gradually becomes chronic, which provokes liver failure and, as often happens, fatal outcome. The virus claims about 350 thousand patients annually, and in developing countries. Relentless statistics say that there are 200 million carriers of this dangerous microorganism in the world. Unfortunately, the disease cannot be treated, and an effective vaccine has not been developed. Hepatitis C infection occurs through blood, and the source is often medical and cosmetic instruments, unprotected sexual intercourse, and failure to comply with hygiene rules.

Hepatitis B virus (HBV)

This hepatitis virus leaves the patient a chance for recovery, but in 20-30% of cases it still progresses into a chronic form, causing cirrhosis or liver cancer. The “reaper” claims about 700 thousand human lives per year. Just like the previous type of hepatitis virus, it provokes an asymptomatic disease that slowly attacks the liver over the years. Most often the disease is diagnosed in children. Those who carry the virus may not suffer any consequences but still actively transmit it to others. The virus is characterized by resistance to temperature fluctuations. It is transmitted through drops of blood in everyday life, as well as through injections, instruments, sharp instruments, and sexual intercourse.

Rabies virus

It occurs in warm-blooded animals and is transmitted from them to humans. Causes rapid and irreversible damage to the central nervous system. The virus is transmitted through the saliva of an infected animal during a bite. The temperature rises to low-grade levels, the patient complains of sleep disturbances, notes attacks of aggression and hallucinations, paranoid delusions. This is followed by paralysis of the limbs and eye muscles, respiratory system, which leads to death. Unfortunately, symptoms of the disease appear already at the stage when the virus penetrates the brain and causes degradation of nerve cells. Only a vaccine given as soon as possible after a stray animal bite can save a life.

Rotavirus

It is a group of viruses that are transmitted by the fecal-oral route. Causes attacks of acute diarrhea, dehydration and is observed mainly in young children. Despite the available treatment methods, the disease annually affects about 450 thousand preschool children (mostly residents of underdeveloped countries). Rotavirus is a “dirty hands” disease, so the best prevention is to observe the rules of personal hygiene, especially after visiting public places.

Ebola virus

The microorganism causes hemorrhagic fever. Transmitted through body fluids, infected tissues and blood. Accompanied by a sharp rise in temperature, muscle aches, lethargy, muscle spasms, migraines and sore throat. Nausea and vomiting, indigestion, skin rashes, kidney and liver dysfunction may also occur. In severe form, external and internal hemorrhages are noted. The mortality rate from Ebola in 2015 was 42% of cases.

Variola virus

Surviving patients can be seen from afar - their skin is covered with numerous scars. The first symptoms of “black pox” are high fever and a rash on the body (purulent blisters). Complications include headaches, vertigo, pain in the sacrolumbar region, nausea and vomiting. In the 20th century, the epidemic took about 300-500 million lives. The last case was recorded in 1977. Climate change in recent years may lead to the return of the disease. By the way, the smallpox virus only affects humans.

Virus of the family Flaviviridae

The pathogen is carried by mosquitoes living in areas South America and on the African continent. Once in the body, the virus causes “yellow fever”, which is accompanied by jaundice. Since the 80s, the spread of the disease has been increasing, which is explained by the deterioration of immunity in people and climate change. In severe cases of the disease, the liver cannot cope with its function and death occurs. Tourists visiting the above countries are advised to get vaccinated.

Human immunodeficiency virus

It is considered the most dangerous virus, which is transmitted through body fluids and blood. Most common reasons HIV is spread by unsterilized medical and cosmetic devices, drug addiction (reuse of syringes), and promiscuity. Average duration The life of an infected person without adequate therapy is 9-11 years.

These dangerous microorganisms are constantly near us and threaten our livelihoods. To prevent infection, get vaccinated in a timely manner, observe personal hygiene rules, use barrier methods of protection and avoid contact with infected people.