Non-cheerful infectious agent. It has genome (DNA or RNA), but deprived of its own synthesizing apparatus. Capacked reproduction, only hitting the cells of higher-organized creatures. Spinning, damages the cells in which this process takes place.

Each of us faces viruses many times in life. After all, they are caused by most cases of seasonal colds. With the habitual ARVI, the body successfully copes itself - our immunity is steady withstands the blows of infections. But not all viral diseases are so harmless. On the contrary, some of them can lead to serious lesions of tissues and systems, cause severe chronic diseases, cause disability and even death. How to figure out the variety of viruses? How to protect yourself from the most dangerous? And what if the disease has already been discovered? What is antibodies to the virus and which of them appear during the disease?

Viruses man

To date, more than 5 thousand diverse viruses are described, but it is assumed that there are millions of their species. They are detected in all ecosystems and are considered the most numerous biological form. In this case, these infectious agents are able to affect animals and plants, bacteria and even archaeys. Human viruses occupy a special place, because they are caused by the greatest number of diseases. And diseases in their gravity, forecasts and flow are very diverse.

At the same time, it is precisely with viruses that the important condition of evolution is associated - horizontal transfer of genes, in which genetic material is not transmitted not to descendants, but by other types of organisms. In fact, the virus in a large extent provided genetic diversity. For example, studies have shown that a human gene by 6-7% consists of various virus-like elements and their particles.

Virus in men

Man viruses are capable of equally affecting the organisms of children and adults, as well as representatives of both sexes. However, there are such species that are of particular danger to a specific category of population. An example of a dangerous virus in men can be a paramixirus, which causes steam. Most often, the pig passes without special complications, with a noticeable lesion of the salivary and the parole glands. However, the virus in men is of great danger, since more often than in women affects the sex glands, it is capable of 68% of cases to cause orchitis - inflammation of the testicles. And this in turn can cause infertility. Such a complication is characteristic precisely for adults and adolescents, boys up to 6 years old orchit occurs only in 2% of cases. Also, the virus in men can provoke the development of prostatitis.

Paramiksovirus is highly dismissed, transmitted by air-droplet, including in the incubation period, when there are no symptoms of the disease. No specific pig treatment, therefore, the best protection against the disease is vaccination. Parotitis vaccination is included in the calendar of mandatory planned vaccination in many countries.

Women virus

Now special attention is riveted to the human papilloma virus in women, because it has been proven to the connection of its some species with the development of cervical cancer. Total types, according to the World Health Organization, at least 13, are the greatest danger of 16 and 18 type, which are characterized by the highest oncological risk. It is with these two viruses in the body that 70% of all cases of cervical cancer and precancerous states are associated.

At the same time, with timely diagnostics and deletion, the papilloma of such an outcome is possible to avoid. Cancer, as a complication of HPV, is developing with a normal immunite for 15-20 years, so systematic examinations in the gynecologist will help to identify a dangerous virus in women of different ages. It should be said that such a factor as smoking affects the activity of the Papilloma virus - contributes to the reincarnation of deep in malignant neoplasm. Since there is no specific treatment with HPV, the World Health Organization recommends vaccination from types 16 and 18.

A special danger of viruses in women are presented during pregnancy, because, due to a small size, they easily penetrate through the placental barrier. At the same time, the severity of the course of the disease in the mother and the likelihood of fetal damage is not connected. It often happens that hidden or easily transferred viral infections cause serious pathology in the fetus may cause miscarriage.

It should be said that most viruses are danger only if the woman is infected with them during pregnancy. In this case, the mother's body does not have time to develop a sufficient amount of antibodies to protect the fetus, and the virus causes serious lesions.

The early early term of pregnancy is most dangerous, up to 12 weeks, since it is now that embryonic fabrics are formed, which are easiest to be amazed by viruses. In the future, the risk of complications falls.

Viruses transmitted through blood and its components, as well as other biological fluids, are dangerous and directly during the period of childbirth. Since the child can become infected by them, passing through the birthway.

The most dangerous viruses in women during pregnancy:

• Krasnuh virus.

In the first trimester of pregnancy, the likelihood of fetal damage is 80%. After 16 weeks, the risk of lesion is significantly reduced, and most often pathology are manifested only by deafness. In the early deadlines, the virus can cause the fetus defeating bones, ugliness, blindness, heart patterns, brain damage.

• Herpes Virus 1st (WSG-1) and 2nd (WSG-2) types.

It is most dangerous that the second, genital type, which the child can be infected during the passage of the generic pathways. In this case, severe neurological damage is possible, among which encephalitis is most dangerous. In some cases, the herpes virus of the second type can lead to the death of a child. HPV-1 proceeds asymptomatic, most often easily transferred to the fruit and does not cause significant harm to health.

Infection of the mother in early term can lead to the development of the pathologies of the fetus incompatible with life, resulting in miscarriage. In addition, the disease is dangerous not only by the impact of the virus itself, but also by the general intoxication of the body. She, in turn, can cause hypoxia of the fetus, delays in development and other things. That is why WHO recommends pregnant women to make influenza vaccinations, especially in an epidemic dangerous period.

Botkin's disease (hepatitis A) is very often postponed in childhood, so during pregnancy is quite rare. However, if all the same infection occurred, the disease will flow in severe form. Hepatitis B and C can pose a threat to a future child, especially if the woman has become infected during pregnancy. Chronic hepatitis B and with dangerous infection during childbirth. Most often, the hepatitis V virus is so transmitted, and in congenital form it is treated much more difficult and in 90% of cases it goes into a chronic incurable form. Therefore, women planning pregnancy can be recommended vaccination from hepatitis V. If there is a chronic infection, it is worth making a caesarean section. The hepatitis E virus rarely represents a serious danger, but it is during pregnancy that it can lead to severe consequences for the fetus and the woman itself. Including to cause death from renal failure.

Most often, infection occurs in childhood, after which the person is a carrier of the virus, and no symptoms are manifested. Therefore, as a rule, by the time of pregnancy, this virus in women does not represent much danger. In the event that the infection of the cytomegalovirus occurred during the baby tooling, the fetus in 7% of cases can get complications in the form of cerebral palsy, hearing loss, etc.

Human organism produces specific immunity to different viruses faced throughout life. This explains the fact that the child is sick of ARVI (sharp respiratory viral infections) more often than an adult. The frequency of infection with a virus in different ages is the same, however, in an adult, the immune system suppresses an infectious agent before the symptoms manifest. In the domestic pediatrician there is a concept "often a sick child", that is, the one that transfers more than 5 ARVI per year. However, foreign doctors believe that for children under 3 years old, 6 infections per year are the norm. And the child visiting the kindergarten can carry up to 10 cold annually. If ARVI is undergoing without complications, they should not cause anxiety, "Things the famous pediatrician Evgeny Komarovsky also believes.

Also, a number of certain viral infections are characterized for childhood, which are extremely rare in adults. Among them:

• Chickenpox.
• Measles.
• Rubella.
• Parotitis.

At the same time, it should be noted that the children of the first year of life are practically not subject to these diseases, because still in the womb they are obtained through the placenta antibodies to the viruses from the mother's blood.

Despite the fact that the listed infections are most often easily transferred to children, yet there is a risk of developing complications. For example, the corte often leads to pneumonia and is one of the main causes of child mortality, and vapotitis causes inflammation in the genitals. Therefore, all the above virus infections exist effective vaccinations - timely immunization makes it possible to obtain immunity without suffering from the disease.

Virus as a form of life

Also, these non-calving infectious agents are, it is so now there are viruses, there is no main and energy exchange. They cannot synthesize the protein, as other living organisms do, and outside the cells behave like a biopolymer particle, not a microorganism. The virus located outside the cell is called the virion. This is a full-fledged viral particle, which is able to affect the host cell. When infected, the virion is activated, forms a complex "virus cell" and precisely in this state it is capable of multiplying, while transmitting its genetic code to new virions.

Viruses, like other living organisms, are able to evolve through natural selection. It is due to this that some of them, such as the flu virus, are able to constantly cause epidemics, since the generated immunity against new forms does not work.

Virion size - 20-300 nm. Thus, viruses are the lowest infectious agents. For comparison, bacteria on average are of 0.5-5 microns.

As already mentioned, the virus is characterized by the fact that it can multiply and shows activity only inside the living cell. Most of the types of viruses are completely penetrated into the cage, but there are also those that are administered to it only their genome.

The life cycle of this extracellular agent can be divided into several stages:

• Attachment.

Moreover, it is at this stage that the host of the virus owners is determined, because often it is highly specialized microorganisms that are capable of interacting only with certain types of cells. Thus, viruses causing respiratory diseases prefer the cells of the mucous respiratory tract, and HIV is able to interact only with a specific type of human leukocytes.

• Penetration.

At this stage, the virus delivers its genetic material inside the cell, which will continue to be used to create new virions. Viruses are capable of multiplying in different parts of the cell, one for these purposes use cytoplasm, others - core.

• Replication - reproduction of copies of the virus genetic material.

This process is possible only inside the cell.

• The output of virions from the host cell.

In this case, the membrane and the cell wall is damaged, and the cell itself dies. However, in some cases, viruses remain in a cage, without damaging it and multiplying with it. Infected cells can exist long enough, and the disease itself does not make them know, turning into a chronic form. This behavior is characteristic, for example, for herpes virus, papillomavirus and others.

The genome of the virus: DNA-containing and RNA-containing

Depending that in what form a genetic material of viruses is contained, they are taken to divide them on DNA-containing and RNA-containing (Balticimaro classification).

• DNA-containing viruses.

Their replication (reproduction) occurs in the core of the cell, and the process of forming new virions in most cases is fully ensured by the synthetic apparatus of the cell.

• RNA-containing viruses.

A numerous group that is mainly multiplied by cell cytoplasm. Among RNA-containing agents should be said separately about retroviruses that differ from other things that are able to integrate into the DNA of the host cell. These viruses are often distinguished into a separate group for their unique properties of reverse transcription. With the usual replication of the genome, the information moves from DNA to RNA, and retroviruses are capable of making two-chain DNA based on single-chain RNA.

Depending on how active the virus is active and how the genetic material is destroyed for the cell, its impact on it. For example, retroviruses include one of the most dangerous infections - HIV. On the other hand, it is such an embedding in the living cell genome allowed some kind of virus of this type to gain a foothold in DNA - with them scientists associate the species diversity of living organisms, as well as evolutionary processes.

Types of viruses

Viruses, despite the small size and dependence on the cell, still know how to protect the genetic material portable. It is for that, first of all, a virus shell respond. Therefore, sometimes viruses are classified according to their types.

Compared to other infections, the structure of viruses is quite simple:

• Nucleic acid (RNA or DNA).
• Bell shell (capsid).
• Shell (supercupside). Not all types of viruses are found.

Cape virus

The outer shell consists of proteins and performs the protective function of the genetic material. It is capsid that the virion can attach to what types of cells can be attached, the shell also responds and for the initial stages of cell infection - the membrane break and implementation.

The structural unit of the capsid is the capsometer. Being in a cage, the virus by self-assembly reproduces not only genetic material, but also a suitable protein sheath.

Total 4 types of capsises, which are easy to distinguish with form:

• Spiral - the same type capsens surround single-chain DNA or a virus RNA across their length.
• Ikosahedric - capsides with icosahedral symmetry, which sometimes resemble balls. This is the most common type of viruses that can affect animal cells, which means to infect human.
• An oblong - one of the subspecies of the icosahedral capsid, but in this version it is a little stretched along the line of symmetry.
• Complex - includes a spiral and ikosahedral type. It is rare.

Virus shell

Some types of viruses for additional protection surround themselves with another shell formed from the cell membrane. And if the capside is formed inside the cell, the supercapside "captures" the virus, leaving the cell.

The presence of a shell consisting in essence from the material of the material makes a virus less noticeable for the human immune system. So, such vibriions have greater infinity, capable of longer than others like it in the body. Examples of virions with a shell are HIV and influenza virus.

Infection with virus

Signs of the presence of virus in the body are highly dependent on its type. Some infections cause acute course of the disease, pronounced characteristic symptoms. This include the influenza virus, measles, rubella. Others, on the contrary, may not be manifested for many years, while damaging the body. This behaves hepatitis C virus, HIV and other dangerous infections. It is sometimes possible to detect their presence only by specific blood tests.

War infection methods

Since viruses are widespread and able to hit different cells of the human body, all the main ways of transmitting infection are available to them:

• Aerogenic (airborne-drip) - viruses are transferred by air, with coughing, sneezing or even a simple conversation.

This path of transmission is characteristic of all ARVI, including flu, as well as measles, rubella and other infections.

• Alimentary (fecal-oral) is the path of transmission characteristic of virus species that can accumulate in the intestines, excreted with wheel masses, urine, vomiting.

Infection occurs through dirty water, poorly washed food or dirty hands. Examples are hepatitis A and E, polio. Often, the seasonal character is characteristic of such infections - the infection of the virus occurs in warm weather, in the summer.

• Hematogenic (through blood and components) - infection falls through wounds, microcracks on the skin.

Viruses that are transmitted in this way are dangerous when overflowing blood, operational intervention and other medical manipulations, injecting addiction, tattooing and even cosmetic procedures. Often, the infection is capable of penetrating through other biological fluids - saliva, mucus, and so on. Viruses of hepatitis B, C and D, HIV, rabies and others are transmitted through blood.

• Transmissive - transmitted through insect bites and ticks.

Among the most common diseases caused by such viruses are encephalitis and mosquito fever.

• Vertical - the virus is transmitted from the mother to the child during pregnancy or childbirth.

Most diseases with hematogenic transmission can be transmitted in this way. In the first trimester of pregnancy, the danger is rubella, flu, and other diseases.

• Polya - infection occurs when unprotected sexual contact.

The transmission path is also characteristic of viruses transmitted through blood and components. According to WHO, four viral infections are most often transmitted - HIV, herpes, papilloma virus, hepatitis V.

Not all viruses that fall into the human body are able to cause disease. Any alien organism that fell to us is immediately found with the cells of the immune system. And if a person has developed an acquired immunity, the antigens will be destroyed even before the symptoms of the disease have developed. Our immune system gives sustainable protection, often for life, to many viruses - acquired immunity is produced after contact with the virus (disease, vaccination).

Some infections, such as measles, rubella, poliomyelitis, are able to cause epidemics among children and practically not affect the adult population. This is just explained by the presence of acquired immunity. At the same time, if "collective immunity" was provided with vaccination, such viruses will not be able to cause epidemics and in children's teams.

Some species, such as influenza virus, are able to mutate. That is, every season appears a new strain of the virus, to which the population has not been developed immunity. Therefore, it is this infection that is capable of calling annual epidemics and even pandemic - infection of the population of several countries or regions.

Among the most famous pandemics who survived humanity, different flu strains are quite common. This is, first of all, "Spanish" of 1918-1919, which carried 40-50 million lives, and the Asian influenza 1957-1958, during which approximately 70 thousand people died.

Pandemic caused viruses of natural smallpox, which only in the twentieth century was the cause of 300-500 million deaths. Thanks to mass vaccination and revaccination, this virus managed to win - the last case of infection was recorded in 1977.

Serious fears cause human immunodeficiency virus (HIV), which is also equal to the pandemic disease.

Symptoms of virus penetration into the body

Different viruses in the body behave differently, manifest themselves with their symptoms, and sometimes the disease proceeds asymptomatic, no longer letting themselves. For example, hepatitis is often not manifested by external signs, and the disease is detected only in the running stage or accidentally - according to blood tests. Influenza, on the contrary, always flows sharply, with an increase in temperature, general intoxication of the body. For measles and rubella, specific rash on the skin is characteristic.

There are viruses that are successfully suppressed by the immune system, but continue to be in the body. A classic example is a simple herpes, which is infected with life and incurable. However, the disease rarely causes serious inconvenience, manifested only occasionally ulcers on lips, genital organs and mucous membranes.

Many types of human papilloma viruses proceed with poor symptoms, infection does not require treatment and passes itself. However, there are HPVs that form that can be reborn into malignant neoplasms. Therefore, the appearance of any type of papilloma or conglishers is the reason to pass the analysis for viruses, which will help determine the type of infection.

Signs of viral infection

Most often we face viruses causing sharp respiratory diseases. And here it is important to be able to distinguish them from diseases caused by bacteria, since treatment in this case will be very different. ORVI provoke more than 200 species of viruses, among which rinovirus, adenovirus, paragripp and others. However, despite this, the same infection with the virus is manifested by similar symptoms. For ORVI characteristic:

• Low subfebrile temperature (up to 37.5 ° C).
• Rinith and cough with transparent mucus.
• Headaches are possible, general weakness, poor appetite.

Special symptoms are distinguished by flu, which begins always sharply, for several hours, is characterized by a high temperature, as well as the general intoxication of the body - strong malaise, pain, often in muscles and joints. Human viruses causing respiratory diseases are usually active in the body no more than a week. This means that approximately the 3-5th day after the first symptoms of the patient, a significant improvement in the state feels.

In a bacterial infection, there is a strong heat, sore throat and chest, separation becomes greenish, yellow, more dense, blood impurities can be observed. The immune system does not always successfully cope with bacteria, so the improvements in the state in the first week of the disease may not be observed. Bacterial respiratory diseases can give complications on the heart, lungs and other organs, so their treatment needs to begin as quickly as possible.

Determine the virus only in symptoms is extremely difficult. This is especially true of the types of viruses similar to the impact on the body. For example, about 80 human papillomava viruses have been studied. Some of them are quite safe, others lead to the development of cancer. Hepatitis viruses, despite the fact that they affect the same organ, liver, represent a different threat. Hepatitis A often passes without complications, and the virus with, on the contrary, in 55-85%, according to WHO, leads to the development of chronic disease, ending with cancer or cirrhosis of the liver. Therefore, when symptoms are detected or in suspected infection, it is necessary to pass tests that will help accurately determine the type of virus.

Analysis for viruses

Among the tests that are used to identify viruses are most popular.

• Immunoenimative blood test.

It is used to identify antigens and antibodies to them. In this case, there is both qualitative (determination of the presence of a virus) and quantitative (determining the number of virions) analysis. Also, this method will help determine the level of hormones, identify infections in sexually transmitted, allergens, etc.

• Serological blood test.

Used not only to determine infectious disease, but also to establish its stage.

• Polymerase chain reaction (PCR method).

To date, the most accurate method that helps to determine even small fragments of alien genetic material in the blood. Moreover, since this analysis for viruses determine the presence of the causative agent, and not the reaction to it (detection of antibodies), it can be carried out in the incubation period of the disease, when there is no noticeable immune response.

To diagnose viral infections, it is important to determine not only the infection itself, but also its amount in the blood. This is the so-called viral load - the number of specific types of viruses in a certain amount of blood. It is thanks to this indicator that the doctors determine the contagiousness of a person, the stage of the disease, can control the treatment process and check its effectiveness.

After the virus enters the human body, the immune system begins to produce specific immunoglobulins (Ig) - antibodies to a particular type of virus. It is about them that it is often possible to reliably determine the specific disease, the stage of the disease, and even the presence of previously transferred infection.

A person has five classes of antibodies - IgG, IGA, IGM, IGD, IGE. However, two indicators are most often used in the virus analysis:

• IgM - immunoglobulins, which, if infection, are produced first. That is why their presence in the blood speaks of the acute stage of viral infection. Igm is produced throughout the disease, with primary infection or exacerbation. These are quite large immunoglobulins, which, for example, cannot pass through a placental barrier. This is precisely the serious defeat of the fetus by some viruses in the primary infection of a woman during pregnancy.
• IgG - antibodies to the virus that are produced significantly later, in some diseases already at the stage of recovery. These immunoglobulins are able to remain in the blood for the whole life and thus ensure immunity against a particular virus.

Decipher the analyzes on antibodies should thus follow:

• There are no IgM and IgG. No immunity, a person did not come across infection, which means it is possible primary infection. When planning pregnancy, such indicators for certain viruses in women mean a risk group for the development of primary infection. In this case, vaccination is recommended.
• There is no IGM, there is an IGG. In the body developed immunity to a specific virus.
• Igm is present, there is no IgG. There is an acute stage of infection, the virus in the body is for the first time.
• There are IgM and IgG. The end of the disease, or the aggravation of the chronic process. The correct interpretation of such a result of analyzing viruses depends on the number of antibodies and can only be done by a doctor.

Types of viral infections

Viruses, like other antigens, cause an immune response - this is how the body copes with various alien objects and microorganisms. However, some types of viruses are capable of remaining long enough to immune. It is from this that it depends on how long the disease will proceed, whether it will not go into a chronic form, and how harm will be able to apply the body.

Any viral disease begins with an acute stage. However, in some cases, recovery comes after it, and in others, the disease passes into a chronic form. Moreover, many prone to chronic illness are extremely poorly manifested in the acute period. Their symptoms are nonspecific, and sometimes absent completely. On the contrary, those diseases that the immune system successfully suppresses, are characterized by pronounced symptoms.

To acute viral infections that do not go into chronic stage include:

• ARVI, including flu
• Reduha
• Parotitis
• Hepatitis A (Botkin's disease) and E
• Rotavirus infection (intestinal flu)
• Windmill

A persistent immunity is produced to the listed viruses in the human body. Therefore, diseases are transferred only once in life. The exception is only some form of ARVI, in particular, the flu, the virus is actively mutating.

Chronic viral infections

For a considerable number of viruses, a chronic course is characterized. At the same time, in some cases, if the virus is found, then after the acute stage, a person remains lifelong bearer. That is, the infection does not represent danger to human health and life. These viruses include:

• Epstein-Barr virus (in rare cases can cause infectious mononucleosis).
• Some types of human papilloma virus.
• Simple herpes virus 1 and 2nd types.

All these viruses are potentially able to cause sufficiently serious lesions of tissues and systems, but only in the case when immunity is significantly reduced. For example, with AIDS, some autoimmune diseases, as well as when taking certain drugs, in particular, when treating oncological lesions.

Another group of viruses that can remain in the human body for life is danger even for people with a normally functioning immune system. Among the main infections of this kind:

• AIDS virus.

The period of infection and the first stage of the spread of the virus in the body proceeds asymptomatic. However, 2-15 years after infection, a person develops the acquired immunodeficiency syndrome (AIDS). It is the syndrome that causes fatal outcomes among HIV-infected.

• Hepatitis C and V.

Hepatitis C in the acute stage proceeds asymptomatic, and often (up to 85%) goes into a chronic form, which threatens with serious complications in the form of developing cancer or liver cirrhosis. However, today there are drugs that are effectively curing patients. Hepatitis B enters chronic form much less often, no more than 10% of adult cases. In this case, there are no drugs from this virus - chronic hepatitis B is not treated.

• Human papilloma virus with high oncological risk (types 16, 18 and others).

Some Types of HPV are able to provoke the development of malignant tumors, in particular, the person's papilloma virus in women causes 70% of all cases of cervical cancer. The virus in men can also manifest themselves to the formation of the wings of different types, but oncological diseases do not cause.

To date, medicine managed to significantly advance in the treatment of viral infections, but this group of diseases is seriously amenable to therapy. In most cases, effective drugs are simply no, and virus treatment is reduced to symptomatic and supporting therapy.

What if the virus is found

The treatment strategy is determined by what kind of virus detected. For example, if we are talking about ARVI, children's viral diseases (measles, rubella, steaming, children's roseola), effective therapy will withdraw symptoms. And only if they cause substantial discomfort. For example, you can apply:

• Summarizing drops to remove edema in the nasal cavity.
• Antipyretic at high temperatures (from 37.5-38 ° C).
• Non-steroidal anti-inflammatory drugs that have a double action - reduce the temperature and painkulate (ibuprofen, paracetamol, aspirin).

The treatment of the influenza virus does not differ from the scheme described, however, since it is precisely this infection that often causes severe complications, the patient must necessarily be under the supervision of a doctor. One of the most dangerous consequences is viral pneumonia, which develops on the 2-3rd day after the start of the disease and can cause pulmonary swelling, lead to death. Such inflammation of the lungs is treated exclusively in the hospital with the use of specific drugs (oseltamivir and zanamivir).

If a person's papilloma virus has been found, treatment is reduced to supporting therapy and surgical removal of warts and warts.

When hepatitis with in the chronic stage in modern medicine, antiviral direct action preparations are used (PPD). It is these drugs today recommending WHO, as an alternative to Interferon and Ribavirina, with which the disease was treated until recently.

People with HIV are appointed antiretroviral therapy. If the virus is found in the body, it is impossible to completely eliminate it, but due to treatment it is possible to keep under control, and also prevent the spread of the disease.

In exacerbation of herpetic infection, special drugs can be taken, but they are effective only in the first 48 hours after the symptoms manifest. The use of their later inexpedient.

The basis of combating viruses in the body is human immunity. It is he who provides a successful cure from most of the well-known viruses, and others can neutralize, make safe.

The immunity system is quite complicated and multi-stage. It is divided into congenital and acquired immunity. The first provides nonspecific protection, that is, it acts on all alien objects in the same way. Acquired appears after the immune system faces the virus. As a result, specific protection is produced, effective in the case of a specific infection.

At the same time, some viruses in one way or another can resist the protective system and not to cause an immune response. A vivid example is HIV, which affects the cells of the immune system itself, these viruses are successfully isolated from them and block the production of antibodies.

Another example is the neurotropic viruses that affect the nervous system cells, and the immune system simply cannot reach them. Among such infections are rabies and poliomyelitis.

Congenital immunity

Congenital immunity is the body's response to any alien biomaterial, which occurs when the first contact with the infection. The reaction is developing very quickly, however, in contrast to the acquired immunity, this system is worse recognized the type of antigen.

Congenital immunity can be divided into components:

• Cell immunity.

Most ensured by the cells by phagocytes capable of absorbing the virus infected with dying or dead cells. Phagocytosis is an important component and post-infection immunity. In fact, the phagocytes are responsible for the effective purification of the body from alien objects.

• Humonal immunity.

An important protective reaction to viral diseases is the body's ability to produce specific protein - interferon. The affected cell begins to produce it as soon as the virus begins to multiply. Interferon is released from an infected cell and comes into contact with neighboring, healthy. The protein itself does not act on the virus in itself, so infectious agents cannot work against him. However, it is the interferon that can change the unaffected cells in such a way that the synthesis of viral proteins is suppressed in them, their assembly and even the output of the virions. As a result, the cells become immune to the virus, do not give it to multiply and spread through the body.

Acquired immunity

Acquired immunity - the ability to neutralize the antigens, which have already fallen into the body earlier. There are active and passive types of innate immunity. The first is formed after the body faces the virus or bacterium. The second is transmitted to the fetus or baby from the mother. Through the placenta during pregnancy and with breast milk during feeding to the child, the antibodies of the mother's blood are falling. Passive immunity provides protection for several months, active - often for life.

Acquired immunity, as well as congenital, can be divided into:

• Cell immunity.

It is provided by T-lymphocytes (subspecies of leukocytes) - cells that can recognize viral fragments, attack them and destroy.

• Humonal immunity.

The ability of B-lymphocytes to produce antibodies to the virus (immunoglobulins), which neutralize specific antigens, allows you to create specific protection of the body. An important function of humonal immunity - the ability to memorize contact with the antigen. For this, the specific IgG antibodies are produced, which are later able to prevent the development of the disease if the virus infection occurs.

To date, medicine uses a relatively small amount of antiviral drugs with proven efficacy. The entire spectrum of drugs can be divided into two groups:

1. Stimulating human immune system.
2. Driving directly to the detected virus, the so-called direct action preparations.

The first can be called the preparations of a wide range of action, but they often have a number of serious complications. One of these drugs are interferons. The most popular of them is the alpha-2B interferon, which is used in the treatment of chronic forms of hepatitis B and previously applied to the hepatitis C virus. Interferons are sufficiently endured patients, often cause various side effects from the cardiovascular and central nervous system. They also have pyrogenic properties - cause heat.

The second group of antiviral drugs is more efficient and easier to suffer patients. Among them are the most popular medicines that treat:

• Herpes (acyclovir drug).

Suppress symptoms of viral disease, but cannot completely eliminate the virus.

• Flu.

According to the recommendation of WHO, inhibitors of influenza neuraminidase (oseltamivir and zanamivir) are now applied, since their predecessors, Adamants, in most modern flu virus strains have stability. Commercial titles of drugs - Tamiflu and Releza.

• Hepatitis.

Until recently, Ribavirin in the interferon complex was actively used to treat hepatitis C and in the interferon complex. Now hepatitis C (genotype 1B) is treated with the help of new generation medicines. In particular, since 2013, the drug direct action is approved by Simeprovir, which showed high efficiency - 80-91% resistant virological response in different groups, including 60-80% in people with cirrhosis of the liver.

Unfortunately, the drug virus cannot be completely eliminated, but antiretroviral drugs give a sufficiently resistant effect - the stage of remission occurs, and the person becomes unsuccessful for others. For HIV-positive people, antiretroviral therapy should continue all life.

Prevention of viral diseases

Since there are no specific treatment for a variety of viral diseases, but they represent a completely real danger to human health and life, prevention goes to the fore.

Precautions

Many virus infections spread quickly quickly and at the same time are highly disconnected. If we are talking about the viruses transmitted by air-droplet, an effective measure is the introduction of quarantine in pre-school and school institutions. Since the infected child can spread the virus before the symptoms manifest itself, it is so possible to stop infection with a virus of the whole team.

At an epidemic dangerous period, it is advisable to avoid large clusters of people, especially in closed rooms. This will reduce the risk of infection with various ARVI, including influenza.

Prevention of viruses transmitted by fecal-oral pathway (for example, Botkin and Poliomyelitis Diseases) - Hand washing, boiling water and the use of only proven water supply sources, thorough washing fruits and vegetables.

The greatest danger is viruses transmitted through blood and other biological fluids. Infectness risk factors for them:

• Injection addiction.
• Cosmetology procedures and tattoos using non-disabled tools.
• Use of personal hygiene products of an infected person - manicure scissors, toothbrush, razor and more.
• Unprotected sexual contacts.
• Operational intervention, blood transfusion.

A person who falls into a risk group for infection with such diseases should be sure to pass tests on antibodies to viruses, first of all, HIV, hepatitis C and B. Deliver blood after 4-5 weeks after the intended infection.

Any precautions do not give 100% warranty of virus protection. To date, the most reasonable way to prevent viral infections is vaccination.

Pharmacists have developed vaccinations that are effective in relation to more than 30 different viruses. Among them:

• Measles.
• Rubella.
• Parotitis.
• Chickenpox.
• Flu.
• Polio.
• Hepatitis B.
• Hepatitis A.
• Human papilloma virus 16 and 18 types.

It was using the mass vaccination that two virus of natural smallpox could be defeated, which caused epidemics and resulted in fatal outcomes and disability.

Since 1988, WHO in partnership with a number of public and private health sectors launched a global poliomyelitis elimination initiative. To date, it is precisely with the help of mass immunization that a virus infection is 99% managed to reduce. As of 2016, poliomyelitis is an endemic disease (that is, such that does not go beyond the country's framework) in total in two countries - Afghanistan and Pakistan.

This material is used in vaccines:

• Live, but weakened microorganisms.
• Inactivated - killed viruses.
• Acellylar - purified material, for example, proteins or other parts of the antigen.
• Synthetic components.

In order to reduce the risk of developing complications, vaccination for some viruses takes place in several stages - first inactivated material, and then alive.

Some vaccines give immunity for life - resistant antibodies to the virus are produced. Others require revaccination - repeated vaccination at a certain time.

Viruses and diseases

Human viruses cause various gravity and the flow of the disease. With some of them, most of the residents of the Earth are facing, others are rare. In this section, we collected the most famous viruses.

Adenovirus

Adenovirus was opened in 1953, then it was possible to detect it after surgery on almonds and adenoids. Today, the science knows about 50-80 subspecies of this virus, and they all cause similar diseases. It is the adenovirus that is a frequent cause of the development of sharp respiratory viral infections, as well as in some cases can lead to intestinal diseases in children. Infection of the virus leads to the affix of the cells of the mucous membranes of the upper respiratory tract, almonds, eyes, bronchi.

• Transmission path.

Air-drip (more than 90% of cases), fecal-oral.

• Symptoms of the virus.

The disease begins with high temperatures, which can rise to 38 ° C. There is general intoxication - chills, muscle pain, joints, whiskeys, weakness. There is a redness of the throat and inflammation of the mucous membrane, as well as rhinitis. With eye damage - redness of the mucous membranes, itching, thread.

• Possible complications.

It is rarely manifested, a bacterial infection can join, which will cause pneumonia, otitis, sinusitis.

• Treatment.

Symptomatic, permissible use of vitamins, antihistamine.

• Forecast.

Favorable, in the absence of concomitant diseases and immunodeficiency, the disease itself passes.

The influenza virus is perhaps the most famous of all infections that cause the respiratory tract. It is really different from other ORVI and symptoms, and on possible complications.

It is the influenza that often causes epidemics and a pandemic, as the virus constantly mutters. At the same time, some strains are capable of leading enough severe diseases, often with a fatal outcome. Even in the absence of serious pandemics, according to WHO, in the world dies from 250 thousand to 500 thousand people.

• Transmission path.

Air-drip, the virus can also be maintained on the surfaces and hands of an infected person.

• Symptoms of the virus.

It always begins sharply - the temperature increases (sometimes up to 39 ° C), the cough and rhinitis begins, the general state is worse. The flu virus causes severe intoxication of the body, which manifests itself in pains, general weakness, drowsiness, loss of appetite.

• Possible complications.

The flu more often than other ORVI leads to complications, most of which are associated with the addition of bacterial infection - pneumonia, bronchitis, otitis, sinusitis and other diseases. Inxication leads to the exacerbation of chronic diseases, including cardiovascular, diabetes, asthma. The flu may also cause viral complications that will manifest on the 2-3rd day after the first symptoms. These are the most dangerous effects of the disease, as they can lead to edema of the lungs, the development of encephalitis and meningitis. There is a temporary loss of hearing or smell.

• Treatment.

During the normal course of the disease, the detected virus does not need specific treatment. In the development of viral complications, especially pneumonia, drugs oseltamivir and zanamivir are used, the administration of interferon is possible.

• Forecast.

The greatest danger of influenza is for people after 65 years, as well as those who have concomitant diseases - diabetes, heart disease and lungs. It is among these categories that the virus most often leads to fatal outcomes. Also infection with the influenza virus can be dangerous for pregnant and children. Therefore, for people from risk groups, WHO recommends the annual vaccination.

The wind oil (wind turbine) causes the Herpes Herpes Virus from the extensive family of herpesviruses. This disease is characteristic of young children who suffered her person gets immunity to the virus for life. In this case, the susceptibility of the body is 100%. Therefore, if the person contacts the person without acquired immunity, it is accurately infected. In adult age, the windmill can be transferred heavier, and if the primary infection occurred in a pregnant woman - to cause serious fetus damage (however, a maximum of 2% of cases).

• Transmission path.

Air-drip, while the virus is able to move with air current at a distance of up to 20 m.

• Symptoms of the virus.

The main distinguishing feature of the windmill is a specific bubble rash, which spreads throughout the body, occurs on the mucous membranes. After the first symptoms, new bubbles are formed by another 2-5 days, in rare cases up to 9 days. They will be saczy and itch. The beginning of the disease is accompanied by a high temperature, it takes particularly hard in adults.

• Possible complications.

In childhood, the windmill is carried out fairly easily, the infection itself passes without specific treatment. Special attention should be paid to rash, because if it combed to comb on the skin, a scar can form. Also, blades and an ulcers arising in their place may be an entrance for a bacterial skin infection.

• Treatment.

Specific treatment does not exist, with windmill treatment is symptomatic, in particular, the prevention of skin infection is carried out. Now against the virus has developed an effective vaccine that provides lifelong immunity.

• Forecast.

Favorable.

Simple herpes virus

Simple herpes virus is two types. The first type most often causes ulcers on lips and mucous points. The second is the lesion of the genital organs. A man who infected herpes virus remains his carrier for life. This infection cannot be cured, however, with a normal immunich, it can proceed asymptomatic. HPV refers to neurotropic viruses, that is, after infection, it moves into nervous cells and remains unattainable for the immune system there.

VSV-2 is the greatest danger, since, according to WHO, increases the risk of infection with the human immunodeficiency virus 3 times.

• Transmission path.

WSG-1 is transmitted through oral contact, with saliva, during the exacerbation of infection. HPV-2 is transmitted by sex and vertical path.

• Symptoms of the virus.

HPV-1 is manifested from time to the formation of ulcers on lips and mucous membranes. The frequency of such rash depends on the immunity of a person, in some cases the carrier can not manifest a virus at all. WSV-2 also often proceeds asymptomatic, sometimes manifested by rash in the form of bubbles on the genitals and in the anal area.

• Possible complications.

The greatest danger of the 2nd type virus in women is during pregnancy, because it can cause fetal contamination and subsequent pathologies from the central nervous system and other organs.

• Treatment.

In the exacerbation of an infected person, the use of antiherpetic drugs, such as acyclovir, can be recommended.

• Forecast.

In the absence of immunodeficiency, this infection does not lead to serious health disorders.

Papilloma viruses group combines more than 100 species of various extracellular agents. Despite the fact that they cause diseases similar to symptoms - neoplasms on the skin are manifested - the severity of the disease depends on the type of infection, as well as the immune system of an infected person.

Human papilloma virus

Human papilloma viruses (HPV) are one of the most common infections in the world that can cause various lesions. Most species are safe, after infection, they are manifested by light symptoms and later undergo without treatment. According to WHO, 90% is fully cured within 2 years after infection.

However, the human papilloma virus is under special control and is studied in detail. This is due to the fact that today has been proven - at least 13 types of human papilloma virus are capable of causing cancer. First of all, the danger represents 16 and 18 types.

• Transmission path.

Contact (through the skin with a neoplasm), gender (for genital forms of the virus).

• Symptoms of the virus.

After infection on the skin or mucous membranes, papillomas, condylomas and various warts are formed. Depending on the type of HPV, they look different and arise in different parts of the body. For example, for some types (1, 2, 4), the defeat of the stop, the mouth mucoster attacks the viruses 13 and 32 of the type. Condylomes on the genital organs occur under the influence of 6, 11, 16, 18 and other types.

• Possible complications.

The most dangerous complication is the rebirth of papilloma in a malignant tumor.

• Treatment.

Specific therapy does not exist. Viruses or pass themselves, or remain for life. People with severe symptoms recommended surgical removal of warts, kondil and papillom.

• Forecast.

In general, favorable. Even the types of HPV with a high oncological risk can be controlled. The key in the successful suppression of human papillomas virus in women and men is timely diagnosis, which involves blood tests on antibodies.

Women's papilloma virus

The connection of some types of human papilloma virus in women with the development of cervical cancer are proved. According to WHO, 16 and 18, type causes 70% of all cases of development of this oncological disease.

At the same time, the rebirth of the neoplasm goes on average 15-20 years, if a woman has no problems with immunity. For HIV-infected, this gap can be 5 years. Local treatment can help prevent the development of infection, and for this requires timely diagnosis. That is why women are encouraged annually to visit the gynecologist annually and test analyzes for papilloma viruses.

On the genitals, two types of Condyl are developing - pointed and flat. The first most often provoke the types of virus 6 and 11. They are well noticeable, are formed on the external genital organs, while rarely lead to cancer. Flat are provoked by viruses 16 and 18 types. They are on the interior genitals, are worse noticeable and have a high oncological risk.

Today, 16 and 18 HPVs have developed vaccines that WHO recommends applying at the age of 9-13 years. In the US and some European countries, these vaccinations are included in the vaccination calendar.

Among all inflammation of the liver of virus nature, the virus nature is most often found. Hepatitis - A, B, C, D, and E. are distinguished. They differ in the method of transmission, the flow of illness and the forecast.

Hepatitis A and E

Viruses of this group differ from the rest of the fact that they are not able to cause a chronic disease. Once the suffering disease in the overwhelming majority gives lifelong immunity. Therefore, Botkin's disease is characteristic of children's age.

• Transmission path.

Alimentary (fecal-oral), most often through polluted water.

• Symptoms of the virus.

Hepatitis A and E is manifested by nausea, vomiting, pain in the liver, increasing temperature, loss of appetite. Also characterized by the darkening of urine and the whiffness of the carts. The disease includes the jaundice period, in which, due to the increase in the level of bilirubin in the blood, the yellow shade acquires the skin, mucous, nail plates and eye sclers.

• Possible complications.

These liver inflammation is dangerous for people with immunodeficiency, as well as during pregnancy. In the case of infection with a virus during pregnancy, hepatitis A is transferred much more difficult, and hepatitis E can cause serious pathology of the fetus and in some cases the death of the mother.

• Treatment.

No specific treatment of hepatitis A and E viruses. The main therapy is supporting funds, as well as compliance with the medical diet. From hepatitis A developed vaccine.

• Forecast.

Favorable. Hepatitis A and E viruses do not cause chronic diseases. The infection takes place without treatment after a few weeks or months. In the future, the liver is able to fully recover.

Hepatitis B, C, D

Hepatitis B, C and D represent a greater health hazard. They are prone to chronic, especially the type C, which leads to chronic disease in 55-85% of cases. Hepatitis D virus is a special danger. This is a satellite virus, that is, such that shows activity only in the presence of Virus V. It is he that significantly takes the course of the disease. And in some cases, coinfection leads to acute liver failure and fatal outcome in the acute period of the disease.

• Transmission path.

Hematogenic (through blood), sex, vertical. Especially infectious hepatitis B, which is sometimes called serum.

• Symptoms.

Hepatitis B passes acutely with severe symptoms of liver damage - intoxication, nausea, loss of appetite, white feces, darkening of urine, jaundice. Hepatitis C in the acute stage in the overwhelming majority of cases proceeds asymptomatic. Moreover, it can remain invisible in chronic form. A person is guessing about the disease only at the critical stages of a cirrhosis or liver cancer.

• Possible complications.

Both diseases are able to move into chronic infections. It is most often happening in the case of the hepatitis C virus C. Chronization of hepatitis B depends on the age of the patient. For example, in infants, the likelihood of such a flow is 80-90%, and for adults - less than 5%. Chronic hepatitis is dangerous irreversible lesions of the liver - cirrhosis, cancer, acute liver failure.

• Treatment.

Hepatitis B is treated in the acute period, in the chronic form of specific therapy does not exist - lifelong supporting drugs are prescribed. However, against the virus in exists an effective vaccine, which is used since 1982. Modern pharmacological developments made it possible to increase the percentage of the effectiveness of the treatment of chronic hepatitis from up to 90%. Now for this disease, direct action antiviral drugs are applied, which are accepted for 12 weeks.

• Forecast.

Chronic hepatitis C is able to cause serious liver damage for 20 years after infection, in some cases - 5-7 years. The risk of cirrhosis is 15-30%. Hepatitis B is already dangerous in the acute period if the virus D is also present in the blood, the chronic form of hepatitis B can also cause serious liver damage.

Human immunodeficiency virus (HIV)

HIV today is considered one of the most dangerous infections around the world. It is common everywhere, as of 2014 in the world there were approximately 37 million infected people. HIV is a pandemic disease, which is different from other things that amazes the immune system itself. The virus is most dangerous in the final stage of the development of the disease - with the syndrome of the acquired immunodeficiency (AIDS). It is with such a diagnosis that other infections may be activated, a tendency to form malignant tumors, any minor disease gives serious complications. It is a strong downgrade of immunity and is the cause of death from HIV.

• Transmission path.

Hematogenic, sex.

• Symptoms.

The development of AIDS proceeds asymptomatic. After the manifestations of low immunity occur, in particular, viruses are activated, which in a healthy person practically do not show themselves. For example, the Epstein-Barr virus, cytomegalovirus. Other viruses (cortex, rubella, influenza,) lead to serious damage and development of pathologies.

• Possible complications.

Related to infections that have a person. In immunodeficiency, the risk of complications for any disease sometimes reaches 100%. Even some light infections can lead to a fatal outcome.

• Treatment.

HIV can not be cured completely. If a person has become infected, the infection will remain for his life. However, effective antiretroviral therapy has been developed, which should continue all life. Thanks to these drugs, HIV can be kept under control, prevent AIDS development. The viral load decreases so much that a person who receives treatment ceases to be contagious.

• Forecast.

With a timely treatment, HIV positive people are able to live a full life. Without treatment, AIDS is developing within 2-15 years and leads to the death of the patient.

Cytomegalovirus infection is often remembered in the context of diseases dangerous during pregnancy. It is for the fetus that this virus from the herpesviruses family may pose a serious threat. However, it happens only if the woman is infected in the period of having a child. This happens quite rarely, because the majority of the population faces the virus in childhood.

• Transmission path.

Through biological fluids - saliva, urine, sperm, selection, and also through breast milk.

• Symptoms of the virus.

People without immunodeficiency even in the acute period flows asymptomatic. The fetus can develop various pathologies, in particular deafness. Primary infection with cytomegalovirus during pregnancy can lead to miscarriage.

• Possible complications.

Extremely rarely and only for risk groups.

• Treatment.

A vaccine has been developed against cytomegalovirus, which may be necessary for people with immunodeficiency, pregnant women without immunomized to the virus.

• Forecast.

Favorable.

Freshness virus

The rabies virus belongs to neurotropic, that is, such that can affect nervous cells. Being in the nervous system, it becomes unattainable for the cells of the immune system, since the immune response acts only within the bloodstream. That is why infection with rabies without treatment leads to a fatal outcome.

• Transmission path.

Through bites and saliva of infected animals. Most frequently transmitted from dogs.

• Symptoms of the virus.

After an incubation period, which lasts an average of 1-3 months, an insignificant increase in temperature appears, pain in the place of bite, insomnia. Later, convulsions, light and hydrogen, hallucinations, feeling of fear, aggression appear. The disease is ends with palsy muscles and respiratory disorders.

• Possible complications.

If symptoms appeared, the rabies lead to death.

• Treatment.

Immediately after a bite or possible contact with mad animals, it is necessary to start vaccination. The treatment of rabies virus is aware of post-exposure prevention (PEP).

• Forecast.

With timely vaccination favorable.

Poliomyelitis affects mostly children up to 5 years. In most cases, it does not cause serious health effects, however, 1 out of 200 infected virus leads to severe paralymps. In 5-10% of patients with complications, paralysis of respiratory muscles also occurs, which leads to death.

Now poliomyelitis is almost defeated by vaccination. This disease remained like endemic in two countries - Pakistan and Afghanistan.

Viruses (biology decrypts the meaning of this term so) - extracellular agents that can be reproduced only with the help of living cells. And they are able to affect not only people, plants and animals, but also bacteria. Bacteria viruses are called bacteriophages. Not so long ago, species that affect each other were discovered. They are called Satellite Viruses.

General characteristics

Viruses are a very numerous biological form, as they exist in each ecosystem on planet Earth. Their study is engaged in such science as virology - section of microbiology.

Each viral particle has several components:

Genetic data (RNA or DNA);

Capsid (protein shell) - performs a protective function;

Viruses have a sufficiently diverse shape, ranging from the simplest spiral and ending with ikosahedral. Standard dimensions are about one hundredth of the size of a small bacterium. However, most of the copies are so small that they are not even visible under a light microscope.

Distributed in several ways: viruses living in plants are moved by insects feeding on herbal juices; Animals viruses transfer bloodsowing insects. Y is transmitted by a large number of ways: air-drip or sexually, as well as by transfusion of blood.

Origin

Nowadays, there are three hypotheses of origin of viruses.

Briefly about viruses (according to the biology of these organisms, our knowledge base, unfortunately, is far from perfection) you can read in this article. Each of the above theories listed above has its own minuses and unproved hypotheses.

Viruses as a form of life

There are two definitions of the life of viruses. According to the first, extracellular agents are a complex of organic molecules. The second definition reports that viruses are a special form of life.

Viruses (biology implies the emergence of many new types of viruses) are characterized as organisms on the border of the living. They look like living cells in that they have their own unique set of genes and evolve based on the method of natural selection. They can also multiply, creating their own copies. Since viruses do not scientists do not consider them like live matter.

In order to synthesize its own molecules, extracellular agents need a host cell. The absence of its own metabolism does not allow them to multiply without assistance.

Classification of viruses in Baltimar

What are viruses, biology describes in sufficient detail. David Baltimore (Nobel Prize laureate) has developed its classification of viruses, which still enjoys success. This classification is based on methods for the formation of mRNA.

Viruses should form mRNA from their own genomes. This process is necessary to replicate its own nucleic acid and the formation of proteins.

The classification of viruses (biology takes into account their origin), according to Baltimar, it looks like this:

DNA DNA viruses without RNA stage. These include mimiviruses and herpeviruses.

Single-chain DNA with positive polarity (parvoviruses).

Double RNA (rotaviruses).

Single-chain RNA positive polarity. Representatives: Flaviviruses, Piracornaviruses.

Single-chain Double or negative polarity RNA molecule. Examples: Fingerlings, OrtorticsSovars.

Single-chain positive RNA, as well as the presence of DNA synthesis on the RNA matrix (HIV).

Two-chain DNA, and the presence of DNA synthesis on the RNA matrix (hepatitis B).

Life period

Examples of viruses in biology meet almost every step. But all the life cycle proceeds almost equally. Without having a cellular structure, they cannot be multiplied by the method of division. Therefore, they use materials inside the cell of their host. Thus, they reproduce a large number of copies of themselves.

The cycle of the virus consists of several stages that are interconnected.

At the first stage, the virus is attached, that is, forms a specific connection between its proteins and receptors of the host cell. Next, you need to penetrate the cell itself and transfer it its genetic material. Some species are also transferred also proteins. After that, the capside loss occurs, and genomic nucleic acid is released.

Diseases of man

Each virus has a certain mechanism of action on its master. This process includes cell lysis, which leads to their death. U when moving a large number of cells, the entire body begins to function well. In many cases, viruses may not harm human health. In medicine it is called latency. An example of such a virus is herpes. Some latent species are able to benefit. Sometimes their presence causes an immune response against bacterial pathogens.

Some infections can be chronic or lifelong. That is, the virus develops, despite the protective functions of the body.

Epidemia

The horizontal transmission is the most common type of virus spread among humanity.

The rate of transmission of the virus depends on several factors: population density, the number of people with poor immunity, as well as on the quality of medicine and weather conditions.

Protection of the body

Types of viruses in biology, which can affect human health, innumerable. The very first protective reaction is congenital immunity. It consists of special mechanisms that give nonspecific protection. This type of immunity is not able to ensure reliable and long defense.

When the vertebrate appears acquired immunity, special antibodies are produced, which join the virus and make it safe.

However, not against all existing viruses is formed by the acquired immunity. For example, HIV constantly changes the amino acid sequence, so it leaves the immune system.

Treatment and prevention

Viruses in biology are a very common phenomenon, so scientists have brought special vaccines containing "murderous substances" for viruses themselves. The most common and effective method of struggle is vaccination, which creates immunity to infections, as well as antiviral drugs that are able to selectively inhibit viruses replication.

Viruses and bacteria Biology describes mainly as harmful inhabitants of the human body. Currently, with the help of vaccination, you can overcome more than thirty viruses settled in the human body, and even more in the body of animals.

Prevention measures against viral diseases should be carried out on time and efficiently. For this, humanity should lead a healthy lifestyle and try to increase immunity in all possible ways. The state should arrange quarantines in time and provide good medical care.

Viruses plants

Artificial viruses

The ability to create viruses in artificial conditions may have a lot of consequences. The virus cannot fully measure until the body sensitive to it is.

Viruses are a weapon

Viruses and biosphere

At the moment, extracellular agents can "boast" the largest number of individuals and species living on the planet Earth. They perform an important function, adjusting the number of populations of living organisms. Very often they form symbiosis animals. For example, the nucleus of some OS contains the components of viral origin. However, their main role in the existence of the biosphere is life in the sea and the ocean.

In one teaspoon of the sea salt contains approximately a million viruses. Their main goal is regulation of life in aquatic ecosystems. Most of them are absolutely harmless to flora and fauna

But this is not all positive qualities. Viruses regulate the photosynthesis process, therefore increase the percentage of oxygen in the atmosphere.

Recently, we received a letter from Vladivostok, complete despair, in which the whole family starting from the grandmother and ending with small nasty and bones for several months almost no hospitals due to the intestinal infection caused by viruses. No nifuroxesisides, enterosgels, smects, regions and other drugs, including droppers, do not solve problems. Strong vomiting, high temperature, muscle and headaches, inflammation of nasopharynses, tear, light-friendly, cramps, heart pains, rapid pulse, weakness, drowsiness, diarrhea all this literally pursues and do not let go of this family for a long time. We became for these people literally the last hope, especially when their far relative from Moscow with similar symptoms was cured for one month. People were amazed by the fact that "living herbs" managed to cope with the virus!

However, in recent years, the tendencies of new diseases have been clearly traced, or the "old" diseases change so much that it is necessary to thoroughly improve and modernize their recipe and treatment regimens, for example, as in the case of MRSA, a resistant golden staphylococcus. The article offered to your attention may give an answer about the reasons for the emergence of new diseases and viruses.

In mid-April 2009, samples of viruses from two children from California, suffering from influenza, arrived at the Center for the Control and Prevention of Diseases in Atlanta (USA) for further research. Doctors seemed to "something" that did not knit with normal ideas about those particular strains of influenza, which they already knew and had. After careful study and observation, a virus was discovered, which had a unique genetic code other than any known human flu virus. It was a completely new discovery for science.

But at the same time, this event marked the beginning of the 2009 swine flu pandemic. The virus, which, possibly, began to inflict people, first in Mexico, spread around the world, infecting millions of people and killing thousands. Pandemic ended by the end of August 2010.

A new H1N1 strain, the flu virus, participating in 1918, the Spanish influenza pandemic, as a result of which killed from 30 to 50 million people around the world, more than died during the First World War, or 2.7-5, 3% of the population of the Earth.

Hospitals emergency medical care during the influenza epidemic 1918.

The appearance of the new H1N1 in 2009 was a kind of reminder to people, which, despite the progress in the treatment of infectious diseases in recent decades, the impending shadow of deadly pandemics is preserved.

Each appearance of another mysterious virus is concerned about the concern and concerns of scientists: somehow in 2002

People on the street are masks from behind the outbreak of swine flu.

Torso (atypical pneumonia) in the Chinese province Guangdong, or in 2009 swine flu infected many people in Mexico and spread around the world, or more recently - 2012 Mers-Cov (Middle East respiratory syndrome - viral respiratory infection, which arose around Arabian Peninsula and killed half of those people who infected her; because of this, as well as against the background of the growth of death, the Minister of Health of Saudi Arabia was resigned).

This 3-D model illustrates a common influenza virus (there are various types). Seasonal, respiratory infections, influenza is responsible for three or five million cases of severe illness and approximately 250,000 to 500,000 deaths, according to the World Health Organization.

Each time, when the next mysterious virus appears, the same questions come to the role of researchers: this is exactly the virus that will cause the next pandemic? Will humanity be able to stop him?

But now, to already existing challenges, new threatening trends are added. These are the newest Demographic Projections of the UN, according to which the population in the world will reach 9.6 billion people by the middle of the century, and 11 billion by 2100.

Eleven billion people. Such a number of people under the preliminary assessment of the United Nations can live on earth by the end of this century. This is 4 billion people more than live today. This is a stunning amount compared to only 2.5 billion people who lived in 1950. These 11 billion people will leave a huge "imprint" on Earth: they all need to eat, they must have enough drinking water; All formed waste of their livelihoods can potentially contribute to the spread of diseases; They may affect the already changing climate of the planet and many species of animals and plants of the Earth.

A huge number of people, their interaction with animals and various ecosystems, an increase in international trade and travel, all these factors will change the life of humanity, which is constantly faced with the problems of prevention and struggle from epidemics. And this is not a book theory. In fact, the unprecedented growth of the human population in the second half of the last century - the growing from 2.5 billion to 6 billion - caused changes, including those related to the emergence of new infections. Researchers have established a connection between the pandemic risk and the density of the population.

Studying outbreaks of epidemics from the mid-20th century, scientists found that the rate of occurrence of diseases caused by pathogenic microorganisms with new ones for a person is in no way associated with progress in the methods of diagnosis and observation, which only fix the dynamics of new and new diseases.

In the Center for Control and Prevention of Diseases (CDC), the scientist conducts measuring the number of H7N9 virus, which was grown and collected in the CDC laboratory.

So, between 1940 and 2004, more than 300 new infectious diseases were "recorded".

Some of these diseases were caused by the pathogen, which was present in different species, and then, in humans - for example, the West Nile virus, Coronavirus SARS and HIV.

Coronavirus, family of viruses, to which ORVI belongs, are a group of viruses that have a crown, like (crown), if you look at the appearance under an electron microscope.

Others were caused by new pathogens, which developed, reducing the affordable drugs, exacerbating or making it almost impossible to treat such diseases such as tuberculosis with multiple drug-resistant forms and malaria.

Some pathogenic microorganisms, such as bacteria that cause Lyme disease, not being new to humans, but their frequency increased sharply, perhaps due to the changes that the newly arrived people moved from the environment where animals lived, the owners of these pathogens.

Scientists are confident that every year more and more diseases will occur. One of them even joked, saying that if for most people it is something incomprehensible and abstract, then for specialists and researchers it is also completely new and unknown.

Diseases of the future are already waiting for us in nature.

When scientists analyzed the characteristics of emerging diseases, they found some similarities between them. All known emerging diseases were associated with a sudden increase in the population, new human activity in the environment and a high variety of wildlife in an area where the pathogen arose. Researchers found that about two thirds of new diseases were transferred to a person from animals.

More than 70% of these diseases are known as zoonous infections (that is, infectious diseases affecting not only people, but also some types of animals, from which a person is infected. A person is infected with sick animals either with close contact with them, either by using them Food their meat, milk, as well as products prepared from this milk. In some cases, infection, for example, a Siberian ulcer, can be transmitted to a healthy person through objects made of skin, bristles and sick animal wool). For example, the Nipa virus, which causes the inflammation of the brain and first appeared in 1999 in Prac, Malaysia, or Coronavirus SARs, when both hosts of the virus infected by farmers were volatile mice.

If people do not often come into contact with wildlife, such pathogens are theoretically should not be a big danger to people. But pathogens can attack a person, at first infecting other animals, because people are in contact, for example, with downer pigs. Animals serve as a middle link in this chain of diseases, however, they should have been in places that the growing population began to take away from wildlife, or where people were very rare, if they were ever solved ever to lead their activities in such areas.

Scientists argue that every region of wildlife carries a whole bunch of microbes, about most of whom nothing is known to us. Locking the road through a new section of the rainforest, creating pig farms there, people come into contact with these pathogens.

The number of wildlife causative agents and capable of infecting people increased over time and especially over the past decade of the 20th century. Such pathogens were responsible for more than half of the new infectious diseases, which unexpectedly arose during this period of time.

The contacts of a person with different types of wild animals, during which new viruses take place, may increase in the future, since the population is growing and people are looking for places to live and build settlements in areas of residence, including close to wildlife.

Prediction of the future.

When the first HIV / AIDS case was discovered in 1981, the next pandemic began in essence, which continues to this day. HIV, as believed, arose in chimpanzees, infected 60 million people and took about 30 million lives.

Over the years, if there was complacency, and thought that infectious diseases were defeated, it was already a story.

Summacy, which was present in the years before HIV largely no longer exist. Scientists are constantly in search of the following pathogen, which can cause an epidemic. One of the viruses, which as expected scientists were H5N1, the strain of the influenza virus, which was circulating among birds and killed them. Resources devoted to the preparation and fight against pandemic of bird flu in humans were transferred and began to be applied to pandemic of swine flu in 2009.

Another anxious influenza virus in the observation list is H7N9, bird flu, first discovered in China in 2013. He infected a number of people who came into contact with infected birds.

How viruses are constantly changing how they mutate, what makes it easy to spread among people?

Under the electron microscope, the influenza virus during copying itself. Viral nucleoproteins (blue) incapsulation of flu genome (green). Polymerase flu virus (orange) reads and copies genome.

In fact, these are the most difficult questions for scientists to find answers not only as viruses living in animals become capable of infecting people, but also what makes them in a position to move from person to man.

The H5N1 virus, as scientists suggest, must pass four mutations, before being able to transmit through the air among mammals.

Despite the attempts of careful study of H5N1 and H7N9 viruses, scientists still do not know how people are infected. The mechanism of infection is usually beginning to explore when the virus has already spread among people.

Scientists have discovered that in some parts of the world, new viruses have great chances to "show" themselves. Tropical Africa, Latin America and Asia with their greater biodiversity and the rapid development of human interaction with the environment, contribute to the revitalization of viruses that immediately penetrate the human body. And then, they will be able to travel to any point of the globe.

Epidemics can grow faster and cost more.

Today, travelers are able to overcome distances in a few hours from places to which in the past, had to get several months. But this is good not only for a person, but also for microbes. Patients travelers can be carriers and deliver pathogens to the destination, before they even understand that they are sick. In the future, population growth and rapid development of tourism, and this is confirmed by elementary mathematical calculations, will be invariably related: where there will be more tourists, there will be an emergence and growth of epidemics.

The appearance of atypical pneumonia in 2002 in China clearly demonstrated a picture of how the virus can travel if his carrier is a person uses modern movement communications: the virus quickly spread throughout the world for several weeks, infecting more than 8,000 people and kills about 800 before What measures have been taken - the restrictions on trips and quarantine affected are taken under control and introduced victims.

The traveler virus can cause economic damage related to the treatment of diseases and the fight against the epidemic. The Torso virus cost billions of dollars by reducing international trips from 50 to 70 percent, and affected business in several sectors. The growth of Chinese GDP decreased by 2% of the item in one quarter and at halfrship in annual growth, according to the World Bank and the estimates of the Chinese government.

Is humanity ready to look into the future?

Migration of the population in the world from small rural areas to densely populated cities may also affect the spread of pathogens. By 2050, 85 percent of people in developed countries in the world and 54 percent of the so-called developing countries are expected to leave rural areas for the sake of cities.

From the global point of view of combating diseases, urbanization can have some positive moments. However, this is only if it is possible to form an effective surveillance system and early warning. When the population concentrations in cities require a stronger public health sector, as people in crowded cities are often more vulnerable to infectious diseases.

Scientists believe that a reliable public health system is needed in response to population growth, urbanization, population aging and increasing the number of travel, expanding the interaction between people and animals, which lead to the emergence of new diseases.

Optimism can give except that "huge progress", which was achieved in reducing the amount of time required to make a vaccine from swine flu. Two months have not passed after the swine flu has become a pandemic of 2009, and vaccines have been developed and launched their mass production.

Unfortunately, people currently have a false sense of safety and are quite careless. After all, although it is possible to eliminate some diseases, but the truth is that most of the new diseases simply are waiting for their time and some letters in which people turn to us with requests for help, because the standard treatment schemes cease to act only confirm it.

Disputes of biologists about what viruses are living is a creature or a dead substance, they still go. Encyclopedic dictionaries frankly recognize: Currently, science does not understand the nature of these creatures, does not know how they appeared from.

Scientists still converge on the fact that viruses are a special form of matter. You can consider them alive as if it allows that they contain organic molecules that they have their own genome, and they can multiply. However, they are able to live and multiply only inside a foreign organism, someone else's cell. Outside it is just dead inert crystals, a bunch of molecules.

Human immunodeficiency virus (HIV)

To date, about two thousand species of viruses are open. It is assumed. That this is only a very small part of them. Viruses constantly mutate, from somewhere there are new types of their varieties. Sometimes causeing deadly diseases such as cow's rabies, avian influenza, Ebola, AIDS and others fever.

These ruthless killers of cells seem so alien to everything that many researchers studying their researchers quite seriously claim: viruses appeared to Earth from far space. Their actions are really similar to episodes from horror films about the attack of representatives of extraterrestrial civilization. The monstrous species of dwarf dug into a gigantic,

it is not a suspect cage, dissolves its shell and screws into it "spring-sized DNA. This squeezes "sets the cell its own program, thus changing its entire work. The unfortunate affected cell forgets about its original duties and starts to stamp with the resulting matrix and new and new viruses carrying the death of neighboring cells.

Representatives of one of the varieties of viruses - bacteriophages (bacterial eaters) - even externally looked like a space module created for landing on a foreign planet for the purpose of taking samples of soil. Bacteriophage produces peculiar "support racks", which is attached to the sacrifice, and then stones his bob.
Food viruses are not needed. They do not consume and do not assimilate it. As scientists recognize, viruses are more similar to primitive mechanisms, which pursue a single goal: to look for live cells and integrate into them. But by whom, when and what is your task for them? Specialists are not solved even think about this issue.

Viruses originated in space

In 2008, Dr. Geological and Mineralogical Sciences S. Zhmur proposed his own hypothesis of life on earth. In his opinion, the main ancestor of all the lives were not cells, and not even bacteria, but viruses that originated in the near-free space about five billion years ago.

After the outbreak of some supernovae, the huge masses of the starry substance were thrown into the space, from which a gas-pepped cloud was subsequently formed, and then the planet of the solar system. The high temperature of this substance contributed to the formation of cyanides in it - chemical elements, which are the basis for creating the simplest hydrocarbons. The next stage consisted in the appearance on the basis of hydrocarbons of protein-enzymes and protein-peptides, which were then led to the synthesis of nucleic acid molecules. And this, in turn, made it possible to form RNA and DNA, "creating" to protect against the harmful external influences of the peptide shell. So the structure appeared, which is nothing but a virus familiar to us.

Flu Virus A / H1N1

It turns out that five billion years ago a gas-pepped cloud of the future solar system was not just dead matter, but a substance saturated with the simplest viruses (let's remember the traces of microorganisms in the lunar soil and meteorites of four and a half billion years old!). Subsequently, land and other planets were formed from it, in which embryos of life in the form of viruses were already initially kept.

The further evolution of viruses on Earth was due to water, which penetrated them through the peptide shell. Some species of viruses were swolled, they were formed by protoplasm, their genetic apparatus became complicated. All this led to division and. Ultimately, - the appearance of a full-fledged bacteria cell, which posted the beginning of life on the planet.

S. Zhmur does not exclude the possibility of more ancient origin of viruses. They were able to arise in the substance formed immediately after a large explosion. So, the age of these microscopic creatures is almost equal to the age of the universe. That is, it turns out, in space everywhere there is a single living substance that can give rise to life on any suitable heavenly body for it.

Some researchers go even further, believing that viruses are artificially created by someone biorobot, which billions of years ago fell to the ground with organic embryos. The goal of biorobot viruses was to serve these embryos. Russian scientist M. Daryanenko believes that biorobot viruses were called upon

ensure the necessary course of evolution, connecting in a certain sequence with cells of living organisms and introducing the necessary DNA programs in them. But for millions of years of their activities, something has failed, and viruses from the servants of the cells turned into their killers. It is possible that biorobot viruses decided: life on earth did not follow the scenario, which is prescribed by the program. And the experiment must be collapsed, clearing the planet for new experiments.

Virus Miimi-alternating elevation link?

The question of the origin of viruses from the point of view of most scientists is still not paramount. The main thing is to understand what viruses are, how to coexist with them, how to deal. We learned about the viruses relatively recently - only 100 years ago, and really learned to work with them only in the middle of the past century.

Not so long ago, biologists believed that they were finally found in the structure of viruses and the mechanism of their action. But the insight occurred in 1992, when in Amebe caught in the water of a single industrial reservoir in England, they found an amazing one, nothing like an object. In a diameter, it is larger than known viruses 40 times, but the bacterium is not. Biologists recognized him with a virus, calling Mimi - because of his mimicry, or masking under the bacterium.

Personal form of life

Man is about two million years. The age of viruses, for all the estimates, is calculated billions of years. Moreover, in the "canned" state, they may indefinitely long. In fact, viruses are immortal. Deciphering our genome has shown that it is full of remnants of ancient viruses. They occupy almost 10% of the human genome. For what these remnants are present there - is still unknown. Similar questions Science began to discuss only in the most recent years.

"Human civilization for his history knew such diseases caused by viruses who carried millions of lives," says Robert Shoope, director of the Yale virus laboratory. - sometimes it seemed that humanity stands on the verge of complete destruction. But every time everything accounted for more or less safely. Viruses retreat. Does this happen? Or so it was programmed from the very beginning, from the moment of the appearance of life on earth? "

Secrets of the twentieth century number 34 2011

1.2 Signs of viruses

To disguise the virus, its actions for infection of other programs and damage can be performed, but when performing any conditions. After the virus executes the actions you need, it transmits the management of the program in which it is located, and its work is no longer different from the work unrelated. All virus actions can be performed quickly and without issuing any messages, so the user often does not notice that the computer works with "oddities". The signs of the virus may include:

Slowdown in computer;

The inability to load the operating system;

Frequent "hangs" and malfunctions in the computer;

Termination of work or incorrect work of previously successfully functioning programs;

Increase the number of files on the disk;

Changing file sizes;

Periodic appearance on the monitor screen of inappropriate system messages;

Reducing the amount of free RAM;

Noticeable increase in the time of access to the hard disk;

Changing the date and time of file creation;

Destruction of the file structure (disappearance of files, distorting directories, etc.);

Safety of the drive light bulb when it

no appeal.

It should be noted that these symptoms are not necessarily caused by computer viruses, they may be a consequence of other reasons, so the computer should be periodically diagnosed.

1.3 Classification of viruses

Famous software viruses can be classified according to the following features:

¨ Habitat

¨ Method of habitat infection

¨ exposure

¨ Features of the algorithm

Depending on the habitat, viruses can be divided into:

¨ network

¨ File

¨ loading

¨ File boot.

Network viruses apply to various computer networks.

File viruses are implemented mainly in the executable modules, i.e. in files having the extensions of COM and EXE. They can be embedded in other file types, but are usually recorded in such files, they never receive control and, therefore, lose the ability to reproduce.

Boot viruses are embedded in the boot sector of the disk (boot sector) or in the sector containing the Master Boot Record.

File-loading viruses infect both files and boot sectors of the disks.

By a method of infection, viruses are divided into:

¨ Residents

¨ non-resident.

A resident virus when infected (infection) of the computer leaves its residency in RAM, which then intercepts the access of the operating system to the infection objects (files, boot sectors, etc.) and is introduced into them. Resident viruses are in memory and are active up to shutdown or restarting the computer.

Non-resident viruses do not infect computer memory and are active limited time.

According to the degree of impact, viruses can be divided into the following types:

¨ Non-hazardous, not interfering with the computer, but reduce the amount of free RAM and memory on disks, the actions of such viruses are manifested in any graphic or sound effects

¨ Hazardous viruses that can lead to various violations in computer

¨ Very dangerous, the impact of which can lead to loss of programs, the destruction of data, erasing information in the system areas of the disk.

1.4 Basic measures to protect against viruses

In order not to subject the computer to infection with viruses and ensure reliable storage of information on disks, the following rules must be followed:

¨ equip the computer with modern antivirus programs, such as NOD32, Doctor Web, and constantly update their versions

¨ Before reading with diskettes of information recorded on other computers, always check these floppy disks for viruses, launching antivirus programs

¨ When transferring to a computer files, it is archived to check them immediately after unzipping on the hard disk, limiting the scan area only by newly recorded files

¨ Periodically verify the presence of viruses of computer hard drives, running anti-virus programs for testing files, memory and system regions of disks with a diskette-protected diskette, after downloading the operating system with a system diskette protected from recording

¨ Always protect the floppy disks when working on other computers, if information is not recorded on them.

¨ Be sure to make archival copies on the discrets of valuable information

¨ Do not leave a drive in your pocket a diskette when you turn on or reboot the operating system to exclude computer infection with loading viruses

¨ Use anti-virus programs for input control of all executable files obtained from computer networks.