Types of viruses. What viruses are there in a person?

Viruses can cause a variety of diseases depending on the type of infection and the characteristics of the infected tissues. What are viruses in humans? There are a huge number of them, and throughout their lives people in one way or another contact most of the causative agents of the infection. The diseases they cause vary from relatively easily tolerable to deadly. More often in the world there are viruses leading to colds, flu, intestinal infections and hepatitis.

Viruses and common cold

The common cold (as in the everyday life is called infectious diseases, such as influenza, SARS, laryngitis, pharyngitis) remains one of the most common human ailments. Only in the US every year about 1 billion cases of SARS are registered. Viral infection of the nasal mucosa leads to a runny nose, lacrimation, sore throat and sneezing. The course of the disease lasts from one to two weeks. According to statistics, more than 200 of the known strains can lead to colds. What kinds of viruses are the most frequent pathogens of ARVI? These are various rhinoviruses, adenovirus, coronavirus, Coxsackie virus, echovirus, enterovirus, orthomixovirus, paramyxovirus and respiratory syncytial virus.

Influenza virus

Influenza causes three types of microorganisms. Types A and B lead to seasonal infections, characteristic of the period beginning with late autumn and ending in early spring. Infections of the type C virus are less typical and most often cause the disease in mild form. The most common flu symptoms include body aches, fever, fatigue, headache, sore throat, dry cough and nasal congestion. Vaccinations against influenza are a means of protection against a viral infection of types A and B.

Intestinal Viruses

What viruses are in the digestive system and what are their characteristics? Microorganisms of this type penetrate into the tissues of the stomach and intestines, causing viral gastroenteritis. Common symptoms for the disease include abdominal pain, colic, diarrhea, nausea, and vomiting. In young children, including infants, the cause of gastroenteritis is often rotavirus. This infection manifests itself in the form of increased body temperature, vomiting and watery diarrhea. Norovirus is no less common pathogen of infectious diseases, affecting both children and adults. However, in younger patients, almost always the symptom of a disease is prevalent, like diarrhea, while for adults, vomiting is more common. Other known intestinal viruses include adenovirus, sapovirus and astrovirus strains.

Hepatitis viruses

Pathogens of infection of this variety affect the liver, initiating inflammatory processes. Science knows five different viruses that lead to hepatitis; They got names based on the letters of the Latin alphabet from A to E. If you are interested in what kind of hepatitis viruses are in developed countries, then according to statistical studies, types A, B and C prevail in countries with developed infrastructure and medicine. Hepatitis A virus penetrates In the body when digesting food or water contaminated with feces. He calls one brief episode of hepatitis. Strains of type B can cause acute or chronic infection of the liver. Microorganisms are found in the blood and semen. The most frequent cases of hepatitis B infection include sexual acts, the sharing of the same syringes with the use of drugs, the transmission of infection from mother to child during pregnancy and childbirth. The type C virus spreads through contact with the patient's blood. Multiple use of syringes by different people when using drugs is the most frequent way of transmission of infection. Hepatitis C, as a rule, acquires a chronic form, but adequate treatment in many cases allows to facilitate the course of the disease.

Other viruses

What are the viruses in humans besides the above? If you print a complete list of names, you will have to publish several volumes of the list. Moreover: every year, scientists discover new types, hitherto unknown. Some strains are very rare, but they represent a great danger because of their potential mortality. This, for example, Ebola or rabies viruses. Other microorganisms are quite common and are the root cause of a huge number of diseases. Those who are interested in what kinds of viruses a person has, just open any popular medical guide. So, a clear example of a common type of infection are herpesviruses that cause simple (blister) herpes on the lips, herpes genital organs, infectious mononucleosis, chicken pox, shingles and many other ailments. Human papillomavirus causes not only the appearance of ordinary warts on the skin, but also the development of cervical cancer.

What viruses do people have recently? Infections of the newest types - HIV, acute respiratory syndrome (atypical pneumonia) and Middle Eastern respiratory syndrome (coronavirus MERS) - remain a serious problem, as today there is no really effective treatment of these diseases.

Diagnostics

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

Variants of diagnostic tests for a viral infection

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

• Blood tests to check for antibodies to viruses or to detect directly antigens;
• Cultivation of blood components, bodily fluids and other materials taken from the affected area;
• Spinal puncture for the analysis of cerebrospinal fluid;
• Polymerase chain reaction technique to create multiple copies of viral genetic material for faster and more accurate identification of the virus;
• Magnetic resonance imaging to detect the inflammatory process in the temporal lobes of the brain.

Symptoms

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

• Increased body temperature;
• muscle pain;
• cough;
• Sneezing;
• Coryza;
• chills;
• Diarrhea;
• Vomiting;
• Skin rash;
• Feeling of weakness.

The more severe symptoms are manifested as follows:

• Stiff neck;
• dehydration;
• Convulsions;
• Paralysis of the limbs;
• Loss of orientation in space;
• back pain;
• Loss of sensitivity;
• Disruption of the bladder and intestines;
• Drowsiness, which can go into coma or death.

Infection: viral or bacterial?

What are viruses in humans? Names are unlikely to say anything to the layman, but one should distinguish between viral and bacterial infections.

Infections of both types are the causes of deterioration of well-being and development of various diseases. However, there is a difference between them. Viral infection, as its name says, begins with the impact on the body of the virus - the smallest intracellular agent, which is even smaller than the bacterium. In addition, it is in a protective shell, which means it is more difficult to destroy. The virus penetrates into the living cell and builds its genome into its genetic apparatus. Such pathogens of infections are non-cellular particles and need foreign cells for reproduction. If you are wondering what are the viruses, the names that you find in this article are likely to indicate to you the main areas of infection with the infection. This nose, throat and upper respiratory tract. Strains of viruses can cause both ordinary colds and AIDS.

To initiate a bacterial infection, a pathogenic bacterium must be accessed through the body through contaminated water, cuts on the skin, or contact with an infected person or contaminated objects. One of the fundamental differences between the two types of infections is that bacteria can enter the body through contact with inanimate objects, including door handles and table surfaces, and viruses do not. Another difference is the nature of the microorganism: the bacterium is a cell and multiplies by division, while the virus dies without a carrier host. Most often, bacteria enter the body through the respiratory tract or gastrointestinal tract. Some bacterial infections are contagious (as, for example, acute pharyngitis - strep throat).

The cause of the viral infection

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

Reduced immunity allows the virus to quickly attach itself to accessible cells. Weak immunity also promotes the reproduction of the virus, until the body's defense system can cope with the parasite.