As a result of the defeat of the human immunodeficiency virus by the individual’s immune system, a slowly progressive AIDS disease develops. As a result, the body becomes very vulnerable to opportunistic infections, as well as neoplasms, which subsequently leads to death. Without specific therapy, the patient dies in about ten days. Antiretroviral drugs significantly prolong life. No HIV vaccine exists. The only way to protect yourself is through 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. In its structure there is:
- shell;
- matrix;
- nucleotide sheath;
- RNA is genomic, it contains a fragment of an integration complex, nucleoproteins and lateral bodies.
With an increase, the nucleus and envelopes of the virus can be considered. The outer membrane consists of the virus's own proteins. These substances form 72 processes. Inside the nucleotide there are two RNA molecules (the genome of the virus), 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, their designation - gag, pol, env, which are characteristic of any retrovirus. They promote the synthesis of virion proteins.
- Six regulatory: tat - enhances reduplication a thousand times, regulates the expression of cellular genes, rev - activates the production of structural proteins of the virus selectively, helps in the later stages of the disease to reduce the synthesis of regulatory proteins, nef - provides balance between the body and the virus, vpr, vpu for HIV -1, vpx for HIV-2. The simultaneous function of nef and tat contributes to a balanced reduction of the virus, which does not lead to the death of a 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, in sweat, semen, blood, vaginal secretions and other body fluids. With direct contact of blood with damaged skin surfaces or mucous membrane, infection occurs. If the blood donor was an HIV carrier, then the healthy individual who received the transfusion will have signs of the disease within three months. Initially, they will be similar to the clinical picture of a common cold and manifest headaches, fever, sore throat, poor appetite. The virus enters the blood from contaminated blood upon contact with an open wound surface. It is important to remember that a healthy dermis is a barrier that prevents infection, that is, infected blood that has fallen on such a surface is not a threat. The likelihood of infection increases with its punctures in case of poor or, in general, lack of sterilization of medical instruments. Basically, this mode of transmission is common among individuals who use drugs and use a single needle.
- Household - quite rare. Infection occurs through the simultaneous use of the following items with the infected: lancets, tools for manicure, piercings, tattoos and other piercing and cutting products.
- From mother to baby. The use of modern medicines significantly reduces the possibility of transmission of the pathogen from a pregnant woman to a child. Treatment should be started as early as possible and regularly monitored by a doctor. Delivery by natural means is not recommended, preferably a cesarean section. Breastfeeding should also be discarded, since the virus is in breast milk in an infected mother.
- Sexual - the most common way. About eighty percent chance of HIV infection in unprotected sex with a sick individual. And it doesn’t matter if there was one or several contacts. The presence of sexually transmitted diseases increases the risk of infection. Chronic diseases and weak immunity provoke the rapid spread of the virus. HIV can be prevented with antiviral agents, which should be taken 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, that is, it is the period from the moment of infection penetration to the body's reaction in the form of antibody production and clinical manifestations.
- II, or primary manifestations. It takes from several days to several months in time. Its different variants are distinguished: 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 years or more. As a result of the production of a huge number of CD4 lymphocytes, the immune response is compensated, and immunodeficiency increases slowly. Persistent generalized 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 infections 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) - detected in ten to twelve years. It is characterized by the development of life-threatening secondary pathologies.
- V or terminal. A fatal outcome occurs as a result of an irreversible course of secondary pathologies despite adequate antiretroviral treatment.
The etiology, pathogenesis and clinic of HIV infection is diverse. All stages of the disease will not necessarily occur with the progression of the pathology. The duration of the course of infection ranges from several months to twenty years. Symptoms of AIDS by which it can be determined without laboratory tests:
- cerebral tocoplasmosis;
- Kaposi's sarcoma;
- herpetic lesions of the mucous membranes and dermis;
- pneumocystis pneumonia;
- extrapulmonary cryptococcosis;
- damage to organs, with the exception of certain organs (liver, spleen), as well as lymph nodes, cytomegalovirus;
- candidiasis of the lungs, bronchi and esophagus mucosa;
- cryptosporidiosis, accompanied by diarrhea for more than a month;
- leukoencephalopathy is multifocal;
- disseminated mycobacteriosis, affecting the cervical and submandibular lymph nodes, dermis and lungs;
- brain lymphoma.
HIV pathogenesis
The following stages are distinguished in development:
- Virusemic early. The virus replicates at different periods and is rather weak. An increase in HIV-infected CD4 T-lymphocytes and a decrease in CD4 + cells are detected. Ten days after infection, it becomes possible to detect p24 antigen in the blood. The maximum concentration of the virus is observed closer to twenty days after infection. At this time, specific antibodies appear in the bloodstream. The location of the primary entry of HIV is important. For example, if small doses of the virus get on the mucous membranes, then this leads to the formation of local immune responses in 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 no signs of the disease can be detected in an HIV-infected person. The body's defense system inhibits the reproduction of the pathogen.
- Antibody production. Neutralizing antibodies directed against gp 41 and gp 120 help to suppress the virus. If they are absent, the development of the disease and death occurs faster.
- Immunosuppression is the next step secreted in the pathogenesis of HIV infection. The activation of cytotoxic lymphocytes is promoted by the use of drugs such as cocaine, concomitant sexually transmitted pathologies and some other viral components. Increased virus replication leads to the second wave of viremia, which is detected about 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:
- The circulating immune complexes Ar + At inhibit the occurrence of immune responses by binding to the T helper CD4 receptor and thereby block 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 with other infections, includes the following warring elements:
- the damaging effect of the pathogen, and quite active;
- body response in the form of a protective reaction.
Unfortunately, the virus wins in this fight.
The basic principles of treatment
It is not possible to completely cure patients infected with the human immunodeficiency virus. All therapy is aimed at slowing down the development and prevention of the disease. It includes the following types of treatment:
- antiretroviral;
- preventive;
- 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 antiretroviral therapy, life expectancy is extended and the period of AIDS development is delayed. To successfully fight the infection you need:
- chemotherapeutic agents directed to 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.
A study of the etiology and pathogenesis of HIV assists in the selection of therapy. In the treatment of using several groups of medicines:
- Nucleoside analogues are 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 fulfill their function and viral particles lose their ability to infect new cells.
The pathogenesis of HIV is considered in pharmacotherapy. The principles of antiretroviral therapy are as follows:
- lifelong treatment;
- use several antiviral drugs at the same time.
The effectiveness of therapy is controlled by laboratory types of research. If necessary, chemotherapy is corrected. Thus, the treatment methods used by practical doctors are as follows:
- antiretroviral drugs;
- pharmacotherapy of pathological conditions that arose against the background of HIV.
In the presence of interruptions or cessation of treatment, the virus begins to re-duplicate, millions of copies appear. All patients are under constant medical supervision.
HIV: etiology, epidemiology, pathogenesis
The causative agent of infection is able to penetrate not only the human, but also the animal organism. 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 radiation, radiation and temperatures up to minus 70 degrees do not have any effect on the virus. Under ordinary conditions in biological fluids and in the blood, it retains its survivability for several days. An individual, regardless of the stage of the infectious process, is a source of infection. The causative agent is isolated from:
- breast milk;
- sperm;
- vaginal secretions;
- bone marrow;
- blood
- cerebrospinal fluid;
- saliva.
Through the above biofluids, infection is also carried out.
The following transmission paths are distinguished:
- parenteral;
- sexual;
- through breast milk;
- trans-acetal.
The risk group should include:
- injecting drug users;
- homosexuals;
- bisexual
- heterosexuals;
- 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 process 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 affects other systems as well as organs. The main target of the virus are macrophages, lymphocytes, microglia cells. In short, the pathogenesis of HIV infection can be characterized as selective cell damage with the occurrence of progressive immunodeficiency. Lymphocytes are considered the main cells responsible for the immune system. The causative agent primarily affects T4 lymphocytes, because their receptor is structurally similar to virus receptors. This phenomenon helps him to 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 before any infection. So, the unusual pathogenesis of HIV infection lies in its progression and slow death of the immune system.
Diagnostic measures
For the diagnosis of AIDS, the Bangui criteria are recommended:
- Weight loss by more than ten percent of the initial, prolonged diarrhea and fever (about a month). Such symptoms are called large.
- Small ones include herpes infection in the stage of progression or dissemination, persistent cough, herpes zoster, generalized dermatitis and causing constant itching, generalized lymphadenopathy.
- The presence of T4 cells in 1 mm 3 is less than 400, i.e., two times less than normal.
Laboratory studies are carried out in several stages:
- using enzyme immunoassay, antibodies to viral proteins are determined;
- positive sera are studied by immunoblotting by detecting antibodies against individual antigens of the virus.
AIDS in brief
This is a progressive disease that results from HIV infection. Several periods are distinguished in the pathogenesis of AIDS, 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 infection, i.e., when immunity functions are preserved, responses develop that are aimed at the production of specific antibodies. They can be found in blood serum after infection after one to three months. With the further development of the disease, the number of lymphocytes decreases significantly, and the virus actively replicates. The body creates favorable conditions for the occurrence of opportunistic infections, the causes of which are 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.
Features of the manifestation 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 has become 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 often observed. In addition, encephalopathy, pneumonia, interstitial lymphoid pneumonia, anemia, pulmonary lymph node hyperplasia, thrombocytopenia are diagnosed. Studying the pathogenesis of HIV in children, doctors identify how the infection develops and what are the mechanisms of its occurrence.
Instead of a conclusion
The main methods of surveillance of HIV infection are focused on the features of epidemiology, a long incubation period and wide areas of infection. The severity of the course of the disease and the adverse social consequences of those infected with this infection make surveillance difficult. Therefore, issues of anonymity and confidentiality are given great importance.
Psychological support and counseling for individuals such as prescribing medications is possible only with their consent. Until now, information on 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 life.