HIV is a disease caused by the human immunodeficiency virus, characterized by acquired immunodeficiency syndrome, which contributes to the occurrence of secondary infections and malignancies due to the deep suppression of the protective properties of the body. HIV infection has a variety of course options. The disease can last only a few months or last up to 20 years. The main way to diagnose HIV infection remains the identification of specific antiviral antibodies, as well as viral RNA. Currently, treatment of patients with HIV is carried out with antiretroviral drugs that can reduce the reproduction of the virus.
General information
HIV is a disease caused by the human immunodeficiency virus, characterized by acquired immunodeficiency syndrome, which contributes to the occurrence of secondary infections and malignancies due to the deep suppression of the protective properties of the body. Today, there is a pandemic of HIV infection in the world, the incidence of the world’s population, especially in Eastern European countries, is steadily increasing.
Characteristics
The human immunodeficiency virus is DNA-containing, belongs to the genus Lentivirus of the Retroviridae family. There are two types: HIV-1 is the main causative agent of HIV infection, the cause of the pandemic, the development of AIDS. HIV-2 is a rare type, found mainly in West Africa. HIV is an unstable virus, Quickly dies outside the host’s body, is sensitive to temperature (reduces infectious properties at a temperature of 56 ° C, dies after 10 minutes when heated to 70-80 ° C). It is well preserved in the blood and its preparations prepared for transfusion. The antigenic structure of the virus is highly variable.
The reservoir and source of HIV infection is a person: an AIDS sufferer and a carrier. No natural reservoirs of HIV-1 have been identified, it is believed that wild chimpanzees are the natural host in nature. HIV-2 is carried by African monkeys. Susceptibility to HIV in other animal species has not been noted. The virus is found in high concentrations in blood, semen, vaginal secretions and menstrual secretions. It can be secreted from women’s milk, saliva, lacrimal secretions and cerebrospinal fluid, but these biological fluids pose less epidemiological danger.
The probability of transmission of HIV infection increases in the presence of damage to the skin and mucous membranes (injuries, abrasions, cervical erosion, stomatitis, periodontal disease, etc.) HIV is transmitted using a hemocontact and biocontact mechanism naturally (during sexual contact and vertically: from mother to child) and artificially (mainly implemented with a hemopercutaneous transmission mechanism: for transfusions, parenteral injections of substances, traumatic medical procedures).
The risk of HIV infection with a single contact with a carrier is low, regular sexual contact with an infected person significantly increases it. Vertical transmission of infection from a sick mother to a child is possible both in the prenatal period (through defects of the placental barrier) and during childbirth, when the child comes into contact with the mother’s blood. In rare cases, postnatal transmission with breast milk is recorded. The incidence among children of infected mothers reaches 25-30%.
Parenteral infection occurs during injections with needles contaminated with the blood of HIV-infected persons, with blood transfusions of infected blood, non-sterile medical manipulations (piercing, tattoos, medical and dental procedures performed by instruments without proper treatment). HIV is not transmitted by contact and household means. Human susceptibility to HIV infection is high. The development of AIDS in people over 35 years of age, as a rule, occurs in a shorter period from the moment of infection. In some cases, there is an immunity to HIV, which is associated with specific immunoglobulins A present on the mucous membranes of the genitals.
Pathogenesis
The human immunodeficiency virus, when it enters the blood, is introduced into macrophages, microglia and lymphocytes, which are important in the formation of immune reactions of the body. The virus destroys the ability of immune cells to recognize their antigens as foreign, inhabits the cell and begins reproduction. After the release of the multiplied virus into the blood, the host cell dies, and the viruses are introduced into healthy macrophages. The syndrome develops slowly (over years), undulating.
At first, the body compensates for the mass death of immune cells by producing new ones, over time compensation becomes insufficient, the number of lymphocytes and macrophages in the blood decreases significantly, the immune system is destroyed, the body becomes defenseless both in relation to exogenous infection and to bacteria inhabiting organs and tissues normally (which leads to the development of opportunistic infections). In addition, the mechanism of protection against the reproduction of defective blastocytes – malignant cells is violated.
The colonization of immune cells by the virus often provokes various autoimmune conditions, in particular, neurological disorders are characteristic as a result of autoimmune damage to neurocytes, which can develop even before the immunodeficiency clinic manifests itself.
Classification
There are 5 stages in the clinical course of HIV infection: incubation, primary manifestations, latent, stage of secondary diseases and terminal. The stage of primary manifestations may be asymptomatic, in the form of primary HIV infection, as well as combined with secondary diseases. The fourth stage, depending on the severity, is divided into periods: 4A, 4B, 4B. The periods undergo phases of progression and remission, which differ depending on the anti-retroviral therapy taking place or its absence.
HIV symptoms
Incubation stage (1) – can be from 3 weeks to 3 months, in rare cases it is extended to a year. At this time, the virus is actively multiplying, but there is no immune response to it yet. The incubation period of HIV ends either with the clinic of acute HIV infection, or with the appearance of HIV antibodies in the blood. At this stage, the basis for the diagnosis of HIV infection is the detection of a virus (antigens or DNA particles) in the blood serum.
The stage of primary manifestations (2) is characterized by the manifestation of the body’s reaction to the active replication of the virus in the form of an acute infection clinic and an immune reaction (the production of specific antibodies). The second stage may be asymptomatic, the only sign of developing HIV infection will be a positive serological diagnosis for antibodies to the virus.
The clinical manifestations of the second stage are of the type of acute HIV infection. The onset is acute, observed in 50-90% of patients three months after the moment of infection, often preceding the formation of HIV antibodies. Acute infection without secondary pathologies has a rather diverse course: fever, various polymorphic rashes on the skin and visible mucous membranes, polylymphadenitis, pharyngitis, lienal syndrome, diarrhea may occur.
In 10-15% of patients, acute HIV infection occurs with the addition of secondary diseases, which is associated with a decrease in immunity. These can be sore throats, pneumonia of various genesis, fungal infections, herpes, etc.
Acute HIV infection usually lasts from several days to several months, on average 2-3 weeks, after which in the vast majority of cases it passes into the latent stage.
The latent stage (3) is characterized by a gradual increase in immunodeficiency. The death of immune cells at this stage is compensated by their increased production. At this time, HIV can be diagnosed using serological reactions (antibodies to HIV are present in the blood). A clinical sign may be an increase in several lymph nodes from different, unrelated groups, excluding inguinal lymph nodes. At the same time, there are no other pathological changes from enlarged lymph nodes (soreness, changes in surrounding tissues). The latent stage can last from 2-3 years, up to 20 or more. On average, it lasts 6-7 years.
The stage of secondary diseases (4) is characterized by the occurrence of concomitant (opportunistic) infections of viral, bacterial, fungal, protozoal genesis, malignant formations on the background of pronounced immunodeficiency. Depending on the severity of secondary diseases, there are 3 periods of the course.
- 4A – body weight loss does not exceed 10%, infectious (bacterial, viral and fungal) lesions of the integumentary tissues (skin and mucous membranes) are noted. Performance is reduced.
- 4B – weight loss of more than 10% of the total body weight, prolonged temperature reaction, prolonged diarrhea that has no organic cause is possible, pulmonary tuberculosis may join, infectious diseases recur and progress, localized Kaposi’s sarcoma, hairy leukoplakia is detected.
- 4C – general cachexia is noted, secondary infections acquire generalized forms, candidiasis of the esophagus, respiratory tract, pneumocystis pneumonia, tuberculosis of extrapulmonary forms, disseminated Kaposi’s sarcoma, neurological disorders are noted.
The sub-stages of secondary diseases undergo phases of progression and remission, which differ depending on the anti-retroviral therapy taking place or its absence. In the terminal stage of HIV infection, secondary diseases that have developed in the patient become irreversible, treatment measures lose their effectiveness, and death occurs a few months later.
The course of HIV infection is quite diverse, all stages do not always take place, certain clinical signs may be absent. Depending on the individual clinical course, the duration of the disease can be either several months or 15-20 years.
HIV in children symptoms
HIV in early childhood contributes to the delay of physical and psychomotor development. The recurrence of bacterial infections in children is noted more often than in adults, lymphoid pneumonitis, enlargement of pulmonary lymph nodes, various encephalopathies, anemia are not uncommon. A common cause of infant mortality in HIV infections is hemorrhagic syndrome, which is a consequence of severe thrombocytopenia.
The most frequent clinical manifestation of HIV infection in children is a delay in the pace of psychomotor and physical development. HIV infection received by children from mothers ante- and perinatal proceeds noticeably harder and progresses faster, unlike that in children infected after a year.
Diagnostics
Currently, the main diagnostic method for HIV infection is the detection of antibodies to the virus, produced mainly using the ELISA technique. In case of a positive result, the blood serum is examined using the immune blotting technique. This makes it possible to identify antibodies to specific HIV antigens, which is a sufficient criterion for final diagnosis. The non-detection by blotting of antibodies of a characteristic molecular weight, however, does not exclude HIV. During the incubation period, the immune response to the introduction of the virus has not yet been formed, and in the terminal stage, as a result of severe immunodeficiency, antibodies cease to be produced.
If HIV is suspected and there are no positive results of immune blotting, PCR is an effective method for detecting virus RNA particles. HIV infection diagnosed by serological and virological methods is an indication for dynamic monitoring of the state of the immune status.
HIV treatment
Therapy of HIV-infected persons implies constant monitoring of the immune status of the body, prevention and treatment of emerging secondary infections, control over the development of neoplasms. HIV-infected people often need psychological help and social adaptation. Currently, due to the significant spread and high social significance of the disease on a national and global scale, support and rehabilitation of patients is being carried out, access to social programs that provide patients with medical care that facilitates the course and improves the quality of life of patients is expanding.
To date, the predominant etiotropic treatment is the appointment of drugs that reduce the reproductive abilities of the virus. Antiretroviral drugs include:
- NsITI (nucleoside transcriptase inhibitors) of various groups: zidovudine, stavudine, zalcitabine, didanosine, abacavir, combined drugs;
- NtTI (nucleotide reverse transcriptase inhibitors): nevirapine, efavirenz;
- protease inhibitors: ritonavir, saquinavir, darunavir, nelfinavir and others;
- fusion inhibitors.
When deciding to start antiviral therapy, patients should remember that the use of drugs has been carried out for many years, almost for life. The success of therapy directly depends on strict adherence to the recommendations: timely regular intake of medicines in the required dosages, compliance with the prescribed diet and strict adherence to the regime.
Emerging opportunistic infections are treated in accordance with the rules of effective therapy against the causative agent that caused them (antibacterial, antifungal, antiviral agents). Immunostimulating therapy for HIV infection is not used, because it contributes to its progression, cytostatics prescribed for malignant tumors inhibit immunity.
Treatment of HIV-infected people includes general strengthening and body-supporting drugs (vitamins and biologically active substances) and methods of physiotherapeutic prevention of secondary diseases. Patients suffering from drug addiction are recommended to be treated in appropriate dispensaries. Due to significant psychological discomfort, many patients undergo long-term psychological adaptation.
Forecast
HIV infection is completely incurable, in many cases antiviral therapy gives little result. Today, on average, HIV-infected people live for 11-12 years, but careful therapy and modern therapeutic drugs will significantly lengthen the life span of patients. The main role in containing the developing AIDS is played by the psychological state of the patient and his efforts to comply with the prescribed regime.
Prevention
Currently, the World Health Organization conducts general preventive measures to reduce the incidence of HIV infection in four main areas:
- education on the safety of sexual relations, the distribution of condoms, the treatment of sexually transmitted diseases, and the promotion of a culture of sexual relations;
- control over the manufacture of drugs from donated blood;
- managing the pregnancy of HIV-infected women, providing them with medical care and providing them with chemoprophylaxis (in the last trimester of pregnancy and in childbirth, women receive antiretroviral drugs, which are also prescribed to newborn children for the first three months of life);
- organization of psychological and social assistance and support for HIV-infected citizens, counseling.
Currently, in world practice, special attention is paid to such epidemiologically important factors in relation to the incidence of HIV infection as drug addiction, promiscuous sexual life. As a preventive measure, in many countries, disposable syringes and methadone replacement therapy are distributed free of charge. As a measure to help reduce sexual illiteracy, sexual hygiene training courses are being introduced into the curricula.