As a result of the defeat of the human immunodeficiency virus in the immune system of the individual, the slowly progressive disease AIDS develops. As a result, the body becomes very vulnerable to infections of the opportunistic type, as well as neoplasms, which subsequently leads to death. Without specific therapy, the patient dies in about ten days. Significantly prolong the life of antiretroviral agents. There is no vaccine for HIV. The only way to protect yourself is to take preventive measures to reduce the risk of infection to a minimum. The article will discuss HIV treatment, etiology, pathogenesis, epidemiology, diagnosis and clinic.
Etiology
The causative agent of this infection is the HIV-1 virus of the retrovirus family, a subfamily of lentiviruses, i.e. slow viruses. It has in its structure:
- shell;
- matrix;
- shellnucleotide;
- RNA is genomic, it includes a fragment of the integration complex, nucleoproteins and lateral bodies.
When you zoom in, you can see the core and shells of the virus. The outer membrane is made up of the virus' own proteins. These substances form 72 processes. Inside the nucleotide there are two RNA molecules (viral genome), protein and enzymes: RNase, protease, transcriptase. The structure of the HIV genome is similar to other retroviruses, it consists of the following genes:
- Three structural ones, their designation is gag, pol, env, which are typical for any retrovirus. They promote the synthesis of virion proteins.
- Six regulatory ones: tat - enhances reduplication by a thousand times, regulates the expression of cellular genes, rev - selectively activates the production of structural proteins of the virus, in the later stages of the disease they help to reduce the synthesis of regulatory proteins, nef - ensures balance between the body and the virus, vpr, vpu for HIV-1, vpx for HIV-2. Simultaneous function of nef and tat contributes to the weighted reduplication of the virus, which does not lead to the death of the cell infected with the virus.
Epidemiology
The development of the disease depends not only on the etiology and pathogenesis of HIV infection, epidemiology is also important. There are several ways of transmission of the human immunodeficiency virus:
- Through the blood. In a sick individual, the virus is found in saliva, sweat, semen, blood, vaginal secretions, and other body fluids. With direct contact of blood with damaged skin surfaces or mucous membranes,infection. If the blood donor was a carrier of HIV, then a he althy individual to whom it was transfused will show signs of the disease within three months. Initially, they will be similar to the clinical picture of the common cold and will be manifested by headaches, fever, sore throat, and poor appetite. The virus from infected blood enters the blood upon contact with an open wound surface. It is important to remember that a he althy dermis is a barrier that does not allow infection to pass through, that is, infected blood that has fallen on such a surface is not a threat. The likelihood of infection increases when it is punctured in case of poor or, in general, lack of sterilization of medical instruments. This mode of transmission is mostly common among individuals who use narcotic drugs and use the same needle.
- Household - quite rare. Infection occurs through the simultaneous use of the following items with the infected: lancets, tools for manicure, piercing, tattoos and other piercing and cutting products.
- From mother to baby. The use of modern medicines significantly reduces the possibility of transmitting the pathogen from a pregnant woman to a child. Treatment should be started as early as possible and regularly monitored by a doctor. Vaginal delivery is not recommended, caesarean section is preferred. Breastfeeding should also be avoided, as an infected mother has the virus in her breast milk.
- Sexual - the most common way. About eighty percent chance of contracting HIV through unprotected sex with a sick personindividual. And it does not matter if there was one contact or several. The presence of sexually transmitted diseases increases the risk of infection. Chronic diseases and weak immunity provoke the rapid spread of the virus. You can prevent HIV infection by using antiviral drugs, which should be started immediately after sexual contact. The course of prevention is about 28 days.
Clinical picture
The development of the disease is determined by both etiological and pathogenetic factors, i.e. etiology and pathogenesis. The HIV clinic depends on the stage of the disease:
- I, or incubation. Its duration is from three weeks to three months, i.e., this is the interval from the moment the infection enters to the reaction of the body in the form of antibody production and clinical manifestations.
- II, or primary manifestations. It takes from several days to several months. There are different variants of it: asymptomatic - only antibodies are produced; acute infection without secondary diseases - it is characterized by fever, pharyngitis, diarrhea, rashes on the mucous membranes and dermis, lymphadenopathy, aseptic meningitis, as well as a decrease in the number of CD4 lymphocytes; acute infection with a secondary disease - against the background of immunodeficiency, mild herpetic lesions, candidiasis are observed. The number of CD4 lymphocytes is significantly reduced.
- III, or subclinical. Its duration is from two to twenty or more years. As a result of the production of a huge number of CD4 lymphocytes, the immune response is compensated, the immunodeficiency grows slowly. Persistentgeneralized lymphadenopathy is the main clinical picture of this stage.
- IV, or secondary diseases. Against the background of a significant immunodeficiency state, oncological and opportunistic infectious diseases develop. The following substages are distinguished: IV (A) - occurs six to ten years after the onset of infection and is characterized by viral and fungal lesions of the skin, mucous membranes, and upper respiratory tract. IV (B) - develops in seven to ten years. The peripheral nervous system, internal organs are attacked, the individual loses weight, fever appears. IV (B) - comes to light in ten - twelve years. It is characterized by the development of life-threatening secondary pathologies.
- V or terminal. Death occurs as a result of the irreversible course of secondary pathologies despite adequate antiretroviral treatment.
Etiology, pathogenesis and clinic of HIV infection is diverse. All stages of the disease will not necessarily manifest with the progression of the pathology. The duration of the course of infection ranges from several months to twenty years. Symptoms of AIDS that can be identified without laboratory tests:
- brain tocoplasmosis;
- Kaposi's sarcoma;
- herpetic lesions of mucous membranes and dermis;
- pneumocystis pneumonia;
- cryptococcosis extrapulmonary;
- damage to organs, with the exception of some organs (liver, spleen), as well as lymph nodes, by cytomegalovirus;
- candidiasis of the lungs,bronchi and esophageal mucosa;
- cryptosporidiosis with diarrhea for more than a month;
- multifocal leukoencephalopathy;
- disseminated mycobacteriosis affecting cervical and submandibular lymph nodes, dermis and lungs;
- cerebral lymphoma.
Pathogenesis of HIV infection
The following stages are distinguished in development:
- Virosemic early. The virus replicates at different periods and rather weakly. There is an increase in HIV-infected CD4 T-lymphocytes and a decrease in CD4+ cells. Ten days after infection, it becomes possible to detect the p24 antigen in the blood. The maximum concentration of the virus is observed closer to the twentieth day after infection. At this time, specific antibodies appear in the bloodstream. The location of the initial entry of HIV is of great importance. For example, if small doses of the virus get on the mucous membranes, this leads to the formation of local immune responses during subsequent attacks of the pathogen.
- Asymptomatic. A distinctive feature in the pathogenesis of HIV is its rather long period (about ten to fifteen years), during which it is possible not to reveal signs of the disease in an HIV-infected person. The protective system of the body inhibits the reproduction of the pathogen.
- Antibody production. Neutralizing antibodies directed against gp 41 and gp 120 help suppress the virus. In their absence, the development of the disease and death occurs faster.
- Immunosuppression is the next stage identified in the pathogenesis of HIV infection. Activationscytotoxic lymphocytes contributes to the use of drugs such as cocaine, concomitant sexually transmitted pathologies and some other viral components. Increased viral replication leads to a second wave of viremia, which is detected approximately fourteen months before the onset of clinical manifestations of AIDS. During this period, the level of antibodies decreases. Contribute to the reduction of T-lymphocytes cytomegalovirus, the body's immune response, the formation of syncytia, infection of progenitor cells. In addition, in the pathogenesis of HIV, the development of immunosuppression is influenced by:
- Circulating immune complexes Ar+At inhibit the occurrence of immune responses by binding to the CD4 receptor of T-helper cells and thereby blocking their activation.
- Reducing the number of T-helpers helps to reduce the activity of other cells of the individual's immune system.
In short, the pathogenesis of HIV, as in other infections, includes the following opposing elements:
- damaging action of the pathogen, and quite active;
- The body's response in the form of a defensive reaction.
In this fight, unfortunately, the virus wins.
Basic principles of treatment
Definitively cure patients infected with the human immunodeficiency virus, it is not possible. All ongoing therapy is aimed at slowing down the development and preventing the disease. It includes the following treatments:
- antiretroviral;
- prophylactic;
- anti-opportunistic;
- pathogenetic, information for which is collected as a result of studying the etiology and pathogenesis of HIV infection.
With the help of antiretroviral or ARV therapy, life expectancy is extended and the period of development of AIDS is delayed. To successfully fight the infection you need:
- chemotherapeutic agents directed at the pathogen;
- pharmacotherapy of parasitic, bacterial, opportunistic, fungal, protozoal infectious conditions;
- oncology treatment;
- drug correction of syndromes inherent in HIV infection, as well as immunodeficiency.
Studying the etiology and pathogenesis of HIV helps in the selection of therapy. Several groups of medicines are used in the treatment:
- Nucleoside analogues - drugs that block the reproduction of viruses.
- Non-nucleoside reverse transcriptase inhibitors - stop replication.
- HIV protease inhibitors - as a result of their action, proteolytic enzymes cannot perform their function and viral particles lose their ability to infect new cells.
HIV pathogenesis is taken into account in pharmacotherapy. The principles of antiretroviral therapy are as follows:
- treatment for life;
- using multiple antivirals at the same time.
The effectiveness of therapy is controlled by laboratory types of research. If necessary, chemotherapy is adjusted. Thus, the methods of treatmentused by practitioners are as follows:
- taking antiretrovirals;
- pharmacotherapy of pathological conditions that have arisen on the background of HIV.
If there are interruptions or termination of treatment, the reduplication of the virus begins again, millions of copies of it appear. All patients are under constant medical supervision.
HIV: etiology, epidemiology, pathogenesis
The causative agent of infection is able to penetrate not only into the human, but also into the animal body. The subfamily of lentiviruses, to which HIV belongs, are slow viruses, it is thanks to them that the disease acquires a protracted and chronic course. The causative agent in the external environment is unstable and dies within thirty minutes at a temperature of 56 degrees. Chemical disinfectants also have a detrimental effect on it. However, ultraviolet irradiation, radiation and temperatures up to minus 70 degrees do not have any effect on the virus. Under normal conditions, in biological fluids and in the blood, it retains its vitality for several days. An individual, regardless of the stage of the infectious process, is the source of infection. The causative agent is isolated from:
- mother's milk;
- sperm;
- secret vagina;
- bone marrow;
- blood;
- liquor;
- saliva.
Through the above biofluids, infection is carried out.
The following transmission paths are distinguished:
- parenteral;
- sexual;
- through mother's milk;
- transplacental.
The risk group should include:
- injecting drug users;
- homosexuals;
- bisexual;
- heterosexual;
- recipients of blood, as well as its components and transplanted tissues and organs;
- hemophilia patients.
The etiology and pathogenesis of HIV infection are closely related. The development of pathology is influenced not only by the conditions and causes of its occurrence, but also by pathogenetic factors that arise in the course of the disease. The virus is able to enter the body of an individual only through the mucous membranes and the dermis, which is damaged. The immune system suffers the most from it, although it also affects other systems, as well as organs. The main target of the virus are macrophages, lymphocytes, microglial cells. Briefly, the pathogenesis of HIV infection can be characterized as selective cell damage with the onset of progressive immunodeficiency. Lymphocytes are considered the main cells responsible for immunity. The causative agent mainly affects T4 lymphocytes, due to the fact that their receptor has a structural similarity to the receptors of the virus. This phenomenon helps it penetrate into T4 lymphocytes, as a result of such an invasion, the virus actively multiplies, and blood cells die. When their number is reduced by more than two times, the immune system becomes unable to cope with a viral attack, and the individual becomes powerless against any infection. So, the unusual pathogenesis of HIV infection lies in itsprogression and slow death of the immune system.
Diagnostic measures
Bangi criteria recommended for AIDS diagnosis:
- Decrease in body weight by more than ten percent of the original, prolonged diarrhea and fever (about a month). Such signs are called large.
- Small include herpes infection in the stage of progression or dissemination, persistent cough, herpes zoster, generalized dermatitis and constant itching, generalized lymphadenopathy.
- Presence in 1 mm3 T4 cells less than 400, i.e. half the norm.
Laboratory studies are carried out in several stages:
- using enzyme immunoassay, antibodies to viral proteins are determined;
- positive sera are studied by immunoblotting to detect antibodies against individual antigens of the virus.
AIDS in brief
This is a progressive disease that results from HIV infection. In the pathogenesis of AIDS, several periods are distinguished, the clinical manifestations of which depend on the type of pathogen, the amount of virus, and the method of infection. In the initial stage of the infection, i.e., when the immune functions are preserved, responses develop that are aimed at the production of specific antibodies. They can be detected in the blood serum after infection in one to three months. With the further development of the disease, the number of lymphocytes decreases significantly, and the virus actively replicates. Created in the bodyfavorable conditions for the occurrence of opportunistic infections caused by bacteria, helminths, viruses, fungi, as well as the development of autoimmune processes and tumors of a malignant nature. In addition to the immune system, the central system is also affected. All violations are irreversible and lead to the death of the individual.
Peculiarities of HIV symptoms in children
HIV in babies born to infected mothers is characterized by rapid progression. If the child is more than a year old, and he became infected, then the course and development of the disease proceeds slowly. Therefore, it is important to study the etiology and pathogenesis. The clinic of HIV infection in the younger generation is characterized by a delay in physical and psychomotor development. In babies, bacterial recurrent infections are quite common. In addition, encephalopathy, interstitial lymphoid pneumonia, anemia, hyperplasia of the pulmonary lymph nodes, and thrombocytopenia are diagnosed. By studying the pathogenesis of HIV in children, doctors reveal how the infection develops and what are the mechanisms of its occurrence.
Instead of a conclusion
The main methods of surveillance for HIV infection are focused on the peculiarities of epidemiology, long incubation period and wide areas of infection. The severity of the disease and the adverse social consequences of those infected with this infection make surveillance difficult. Therefore, the issues of anonymity and confidentiality are of great importance.
Psychological support and counseling for individuals such as appointmentmedicines, only with their consent. Up to now, information about the etiology, pathogenesis and clinic of HIV infection has been studied and collected. Treatment of individuals infected with the virus can significantly improve and extend their lives.
