HIV INFECTION

A B B D E F G And K L M N O U R C T Y P X C H W E I

HIV infection - an infectious disease that develops as a result of long-term persistence in lymphocytes, macrophages and cells of the nervous tissue of human immunodeficiency virus (HIV) and is characterized by a slowly progressive defect in the immune system, which leads to the patient report cards on secondary lesions, described as Acquired Immunodeficiency Syndrome (AIDS ), or subacute encephalitis.

First HIV in its final stage (AIDS) has been described in 1981 in the USA. After the discovery of the causative agent (1983) and a variety of clinical forms of HIV infection is recognized as an independent nosological form (1988). A retrospective analysis showed that HIV began spreading between 1950 -. 70 years, but remained undetected due to the sporadic nature of the disease. From 1981 to 1989 the number of reported WHO infected individuals, including AIDS patients increased from 300 to 157 000. At present, the disease was registered in almost all countries of the world. Monthly HIV infected in the world 440 thousand. Man. To date, the total number of infected people, according to various estimates, about 40 million people. Ill mostly urban dwellers.

In Russia, HIV infection registered in 1985 As at 24.11.03, in the Russian Federation, there are about 257,120 HIV-positive people, including 7591 children. AIDS patients, there are 812 people in Russia, including 193 children; died from HIV infection to date 3456 people.

Etiology. Pathogen - human immunodeficiency virus belongs to the family of retroviruses. T virus killed at 56 ° C for 30 min, at 70 - 80 ° C - 10 minutes, rapidly inactivated ethanol, ether, acetone, 0.2% sodium hypochlorite and other disinfectants. Currently known two types of HIV-1 and HIV-2, which differ in structure and antigenic characteristics.

Epidemiology. The source of the infectious agent is a person at any stage of infection. The virus is found in significant amounts in the blood, semen, vaginal secretions, breast milk, which determines its transmission path. It is possible through sexual intercourse, blood transfusion, breastfeeding women from child to child and from a woman during pregnancy - from mother to fetus, medical instruments contaminated with infected blood. Transmission of the virus in other ways not registered. Decisive importance for the infection is getting the virus in the bloodstream uninfected person. Reliable data on cases of infection through intact skin not.

The possibility of transmission during sexual intercourse due to traumatization of the skin and mucous membranes partners. The highest degree of trauma during intercourse is carried out through the anus (anal), which causes the most rapid rate of spread of the virus among gay men. In contrast, no cases of transmission among women gomoseksualistok shows that less traumatic sexual practices reduces the risk of infection. Inflammatory processes of genitals (eg, cervical erosion) increases the risk of infection. Oral-genital sex rarely leads to infection. Transmission of the virus by kissing on the mouth is unlikely. The possibility of transmitting the virus through everyday was rejected on the basis of long-term observation of the infected families. When the probability of infection prolonged sexual relationship infected for 3 years 45 - 50% of the cases, men - in 35 - 45%.

Transmission of the virus through transfusion of infected blood causes, according to statistics, to infection in 80 - 100% of the cases. Among the parenteral interventions greatest risk of infection are intravenous injections performed with unsterilized needles and syringes, which were carried out in front of this same procedure for the infected person. The probability of infection injecting drug intravenously, in this embodiment, the transmission is estimated at 30%. Intramuscular and subcutaneous injections and random infected instrument lead to infection in 0.2-1% of cases. Open incised wounds, such as surgical procedures, even less dangerous, as the virus is washed away by blood flow.

Among babies born to infected mothers are infected with 25 - 35%. It is believed that the virus can penetrate the placenta defect and give the child during passage through the birth canal. Feeding infected female child infection causes it to 25 - 35% of cases. Infection of mothers breastfeeding infected children. Infection in children due to the presence of oral bleeding walls associated with candidiasis and breast nipple injuries, leading to the ingress of contaminated blood baby in the mother's bloodstream.

Transmission of the virus in the dental practice, with beauty treatments, hairdressing, although theoretically permissible, but not yet registered. Susceptibility to HIV infection general.

Pathogenesis. The virus has a tropism to a number of cells of the lymphoid series: T-lymphocytes-helpers (T4 cells), macrophages, monocytes. It is also found in brain tissue. Probably the virus infects other cells. Parasitizing virus in T-lymphocytes-helpers is a progressive disorder of their functions in connection with which the restructuring begins immunity. After a long period of time followed by a period of compensatory shifts decompensation, clinically manifested decrease the body's resistance to certain kinds of microorganisms, mainly opportunistic, or the occurrence of certain types of tumors. Brain damage HIV causes a picture of subacute encephalitis deaths.

Clinical presentation and diagnosis. During HIV distinguish 3 stages: I - incubation, II - initial manifestations, III - secondary diseases.

incubation stage lasts from 3 weeks to 3 - 6 months. Stage II begins with enlarged lymph nodes and frequent fever. This may be accompanied by pharyngitis, enlarged liver and spleen, polymorphous skin rash, diarrhea, encephalitis or lymphocytic meningitis. The blood at this time reveals lymphocytosis and neutropenia, lymphopenia sometimes. With the help of virological and serological tests can detect the virus or antigen, and after 2 weeks from the start of acute manifestations - HIV antibodies.

This is followed by lasting from several months to 8-10 years or asymptomatic period develops generalized lymphadenopathy lasting more than 1 month and manifested an increase of two or more lymph nodes in two or more groups. Against this background, it may cause lesions of the nervous system, most often in the form of diffuse subacute encephalitis, clinically characterized by increasing dementia. During this period, antibodies to HIV, the amount of immunoglobulin in the blood increases, reduced the absolute number of T-lymphocytes, a help-ditch and begin to weaken skin and allergic reactions.

The duration of the stage of secondary diseases - from a few months up to 3 - 5 years. It begins with the moment when the first clinically observed disease, show a decrease in immunity. Most often it is oral candidiasis. Perhaps the development of a simple and herpes zoster, pyoderma, furunculosis. These illnesses may be sporadic at first, then - recurrent. There may be fever , unmotivated weight loss. Over time, developing new lesions. When they take a threatening nature, to talk about the development of acquired immunodeficiency syndrome (AIDS) for life. The most common diseases, allowing to state AIDS are pneumocystis pneumonia ; candidiasis of the esophagus, trachea, lung; Cryptococcus defeat of various organs (except the lungs); cryptosporidiosis with diarrhea lasting more than 1 month; Cytomegalovirus organ damage (other than liver, spleen and lymph nodes) in patients older than 1 month; multiple ulcers of the skin and mucous membranes caused by the herpes simplex virus persisting for more than 1 month, as well as herpes bronchitis , tracheitis and pneumonia ; Toxoplasmosis of the brain in patients older than 1 month; lymphoid interstitial pneumonitis or pulmonary lymphoid hyperplasia in children under 13 years; defeat Micobacterium avium or M. kansasii various organs and tissues (except the lungs, skin, cervical or axillary lymph nodes); progressive multifocal leukoencephalopathy; brain lymphoma and Kaposi 's sarcoma in patients younger than 60 years.

Other diseases that may be due to the development of AIDS, sepsis, pneumonia, meningitis, bone and joint damage, abscess, otitis and other inflammatory processes caused by bacteria genera Haemophilus and Streptococcus (including Streptococcus pneumoniae), or other pyogenic bacteria; all extrapulmonary lesions caused by mycobacteria; coccidioidomycosis; histoplasmosis, histoplasmosis except lung and cervical lymph nodes; Kaposi 's sarcoma and lymphoma of the brain, regardless of age; Other lymphoma, immunoblastic sarcoma; generalized forms of salmonellosis. This group of diseases include, and are specific to other periods of HIV infection: subacute encephalitis and exhaustion for no apparent reason.

The clinical picture of HIV infection in young children, especially those born to infected mothers, is characterized by enlarged lymph nodes of all groups, the liver and spleen, constant or recurrent diarrhea, growth retardation, the appearance of fever of unknown origin and frequent viral and bacterial infections.

In the event that any of these syndromes and diseases shows a blood serum test for the presence of antibodies to HIV, which usually appear during the period from 2 weeks to 3 months after infection and persist until death of the patient, although their number may be reduced for a few weeks before the death .

A preliminary study carried out by ELISA; positive serum check more specific by immunoblotting. Isolation of the virus or viral antigen less efficiently and restrictions apply. Studies of immune parameters allow a certain degree of immunity to characterize a defect, but are of minor diagnostic value.

Treatment. Hospitalization for clinical reasons, the insulation is not carried out. The basis of the treatment is 3 groups of drugs: nucleoside analog reverse transcriptase (timizid, Retrovir, Phosphaside, Zerit), non-nucleoside reverse transcriptase inhibitors (hivid, Epivir) and proteinase inhibitors (Invirase, Norvir, Crixivan, varisept), the combined use of which can suppress virus replication . Treatment of secondary diseases is carried out, depending on their etiology and also usually gives a temporary effect. Patients and those with positive serology for HIV are subject to dispensary observation and examined two times a year.

Prognosis without treatment unfavorable. AIDS or subacute encephalitis develop within 10 years half of the infected. Half of AIDS patients die within a year. Only in Kaposi's sarcoma is possible to save the patient's life for more than 2 years after the appearance of threatening symptoms. The use of chemotherapy improves the prognosis.

Prevention. The main method of HIV prevention is the training of the population, from school age, correct sexual behavior: limit the number of sexual partners and condom use. In health care it must be ensured strict compliance with the rules of use and sterilization of syringes, needles and other tools, and the use of syringes, systems for transfusion and other disposable items.

As an anti-epidemic measures carried out mandatory testing of blood donors. Practiced identifying sources of infection by a survey of foreigners coming for more than 3 months; Russian citizens, who have returned from abroad, where they stayed for more than 1 month; pregnant women; patients with sexually transmitted diseases; homosexuals, drug addicts, prostitutes. Also carried out a survey of patients with clinical signs of immunodeficiency. The largest number of people living with HIV is detected on examination of persons who had sexual contact with an infected partner, as well as the anonymous survey and examination as clinically indicated.

Given the high prevalence of HIV infection and hepatitis B, all providers should be like in cases of suspected HIV infection, as well as in their daily work, to perform all manipulation with biological material from a patient in rubber gloves, and with the threat of a spray - in a mask and glasses . Special care is required perform injections and other manipulations that allow accidental injury contaminated with blood tool.

Lack of experience in Russia to train the population safe sex practices amid growing phenomena such as prostitution and drug addiction, does not allow hope for the quick effect of preventive measures. The survey population is only a partial measure, since it is technically impossible to carry out at the same time the entire population of the country, especially since there are cases where antibodies are not found in the infected (for example, during the incubation period).