HIV 1 2 antigen antibodies what. Methods for diagnosing HIV infection
The primary stage (screening) of HIV testing.
Attention! When passing the AT and AG test for HIV 1/2 for the primary screening study in accordance with the legislation of the Russian Federation It is mandatory to provide the following data and documents:
1) For residents of Moscow and the Moscow region
- Full Name
- Day, month and year of birth
- Registration Information
- Passport
- Full Name
- Day, month and year of birth
- Registration Information
- Passport
You can take the test anonymously: in this case, the patient is registered as anonymous with an individual order number (clause 2, article 8 of the Federal Law of the Russian Federation No. 38-FZ), with the obligatory indication of the year of birth and place of residence (subject of the Russian Federation).
Draw your attention to!
That the results of the primary (screening) study are only the results of a laboratory test and are not the result of an examination or a conclusion about the presence or absence of HIV infection. Based on the results of the screening study, you should contact the municipal AIDS center to conduct a voluntary examination for the presence of HIV.
The results of an HIV test, regardless of their outcome, are issued only if the patient personally contacts the laboratory department. When examining minors (under 14 years of age) - to the legal representative specified in the order.
Results are issued upon presentation of a contract, estimate and identification document of the patient himself or the patient’s representative specified in the order.
Research results are not communicated by phone or email.
With this test, test serum/plasma samples can be simultaneously tested for the presence of HIV type 1 and 2 antigen and HIV type 1 and 2 antibodies.
The human immunodeficiency virus belongs to the family of RNA-containing retroviruses and the subfamily of lentiviruses, i.e. viruses of slow infections. HIV is genetically and antigenically heterogeneous; according to its structure, it is divided into types 1 and 2. When introduced into human cells, the virus forms a DNA section in their genome, which subsequently forms new HIV in unlimited quantities. Viral antigens appear on the surface of damaged cells. The response to their appearance on the part of the immune system is the formation of specific antibodies to the virus of the first or second type. Over the past three years, the number of HIV-infected persons officially registered in Russia has been growing exponentially. The rapid spread of HIV infection in the country may become uncontrollable. Therefore, one of the main tasks at present is the use of more advanced methods of its diagnosis, ensuring the identification of infected individuals at the earliest stages of infection. These methods include laboratory serological tests that determine both the protein structures of the virus and specific antibodies to the virus.
Indications for the purpose of the study
1. Enlarged lymph nodes in more than two areas;2. Leukopenia with lymphopenia;
3. Night sweats;
4. Sudden weight loss of unknown cause;
5. Diarrhea for more than three weeks of unknown cause;
6. Fever of unknown cause;
7. Planning pregnancy;
8. Preoperative preparation, hospitalization;
9. Identification of the following infections or combinations thereof: tuberculosis, manifest toxoplasmosis, often recurrent herpesvirus infection, candidiasis of internal organs, repeated herpes zoster neuralgia caused by mycoplasmas, pneumocystis or legionella pneumonia;
10. Kaposi's sarcoma at a young age;
11. Casual sex.
Preparing for the study
It is recommended to donate blood in the morning between 8 and 11 o'clock, on an empty stomach (at least 8 hours must pass between the last meal and blood drawing, you can drink water as usual), on the eve of the study - a light dinner with limited intake of fatty foods.1-2 hours before donating blood, refrain from smoking, do not drink juice, tea, coffee, you can drink still water. Avoid physical stress (running, quickly climbing stairs), emotional excitement. It is recommended to rest and calm down 15 minutes before donating blood.
Diagnosis of the immunodeficiency virus is made in various ways. However, ultra-sensitive test systems have recently gained the most popularity. With their help, it is possible to identify this disease at the earliest stages. For this purpose, HIV antigen is used, the presence of which in the body is guaranteed to indicate an unpleasant and dangerous diagnosis. Several different studies are used to detect it.
Why is the HIV 1, 2 antigen-antibody reaction the most reliable indicator of the presence of the immunodeficiency virus?
Testing for the immunodeficiency virus in public medical institutions is free. But it is done in two stages if necessary. Initially, HIV hypertension is not tested. The first analysis for the presence or absence of this disease is aimed at identifying antibodies. This is ELISA testing. Enzyme immunoassay allows you to identify people who are guaranteed not to be sick with the immunodeficiency virus (if the test was carried out according to all the rules).
And also conditionally infected. Why conditional? The fact is that antibodies to HIV 1.2, unlike antigens to this virus, are secreted in the body for other reasons. What exactly are we talking about? First of all, this is possible with diseases of the immune system. If there are problems with this vital system, the body produces antibodies as a defense, which are determined by enzyme immunoassay, just like those that appear with this dangerous disease. If the ELISA result is positive, the patient is referred for additional research, which is based on identifying the reaction of AG - AT type 1.2. Immunoblotting is most often used in clinics. This is the most common type of test for detecting the immunodeficiency virus. With its help, antigen and antibodies to HIV 1 and 2 are not only detected, but also tested for the strength of the reaction.
What is p24 antigen to HIV?
Before talking about what methods can be used to detect HIV hiv ag antigen, it is necessary to explain what it is. Scientists have long been able to find out that AG, which is marked in test forms and in laboratories with the p24 marking, is the capsid of a retrovirus. In simple terms, it is a protein of the immunodeficiency virus. Determining the HIV antigen is impossible without detecting antibodies of the first and second types. After all, Ags are tightly bound to antibodies. They are formed in the body as an immune response to the appearance of antibodies, which, in turn, are a kind of “interveners” aimed at destroying the immune system and producing dangerous biological material.
AT and AG to HIV types 1 and 2 are detected in reaction with each other. The former act as foreign molecules in the human body. The latter serve as a kind of developers of proteins or polysaccharides. In the case of immunodeficiency virus, Ags cause an immune response. Accordingly, in medicine and science related to the study of this disease, they are classified as immunogens.
P24 antigen HIV types 1 and 2 are detected only through a comprehensive study of biological material. Most often, venous blood is used for analysis. In some cases, sperm or secretory fluid secreted by the female genital organs is suitable for this. A combined HIV antigen test is performed in three known ways. What specific studies are we talking about? These are immunoblotting, combo test (hiv combo HIV) and chemiluminescence immunoassay. Each of them should be discussed separately.
Immune blotting: antibodies and antigens to HIV 1 and 2
As mentioned above, immunoblotting is one of the most common tests that detect HIV antigen. How is it produced? Initially, blood is taken from a vein from the patient. The examination is performed on an empty stomach. Thirty to forty minutes before this, the patient is not recommended to smoke. The essence of the study is that if a person has immunodeficiency virus type 1 or 2 in the body, the antigen-antibody reaction is persistent and inseparable. The biological material of the test subject is first digested in a special reagent, then placed on a strip, which, as a rule, is a blister with polystyrene cells. As a result of adding special reagents, the laboratory technician first finds out whether this reaction will occur, and then, using repeated blood washings, draws conclusions about how persistent it is. This allows you to understand whether there is an immunodeficiency virus in the body, which in the future is the most important factor in making a diagnosis.
The HIV AG-AT test, performed through immunoblotting, is recommended to be taken no earlier than four to five weeks after the suspected infection. Despite the fact that this test is a fourth generation system, it is not super sensitive and has an error of several percent (two to three).
Ultrasensitive analysis: hiv duo HIV (combo) antibodies type 1, 2
The HIV (hiv) ag - ab (AG-AT) combo test, unlike immunoblotting, is ultrasensitive. Medical experts say that its use is advisable as early as two weeks after the suspected infection. It is aimed at studying specific antibodies, which are a kind of immune response of the human body to such an invader as the immunodeficiency virus, as well as p24 antigen. Hiv duo HIV antibodies type 1 and 2 are also aimed at identifying antibodies to this dangerous disease. With its help, it is possible not only to detect them in the blood, but also to determine the type of disease.
The HIV combo antigen test is a combination test. It is also used to check the antigen-antibody reaction, which indicates the presence of a terrible disease in the body.
Chemiluminescent immunoassay: hiv 1,2 combo HIV AT-AG IHLA
The IHLA test for HIV at-ag is also ultrasensitive. This study is based on a unique AG-AT reaction. The specificity of the method is about ninety-two percent, while its reliability is from ninety-eight to ninety-nine. From this we can conclude that such an analysis has an error, but it is relatively small. And if necessary, it can easily be covered by repeated checking. This analysis is used already two or three weeks after the suspected infection.
This combo test for HIV is aimed at examining venous blood, in the case of checking for the presence of the immunodeficiency virus in the body. When identifying other diseases and pathologies, urine or secretory fluid is used, which is released from the genitals. AT and AG to the immunodeficiency virus in case of ICHPA are also checked for reaction. For this purpose, special reagents and strips with cells are used. The study, carried out in several stages, allows you to quickly and accurately establish or refute a diagnosis.
All of the above methods for diagnosing the immunodeficiency virus through a persistent AT-AG reaction are effective. They differ only in the permissible research time frame. It is up to the doctor to decide which specific method to use.
Description
Preparation
Indications
Interpretation of results
Description
Determination method Enzyme-linked immunosorbent assay (ELISA).
Material under study Blood serum
Home visit available
Combined detection of antibodies to HIV types 1 and 2 and HIV p24 antigen, qualitative test.
Attention. In case of positive and questionable reactions, the period for issuing results can be extended to 10 working days. HIV (human immunodeficiency virus), which causes AIDS (acquired immunodeficiency syndrome), belongs to the family of retroviruses. It is transmitted from person to person through the use of contaminated needles and syringes for intravenous drug administration or therapeutic procedures, during sexual contact, both heterosexual and homosexual. Transmission of the virus can occur through transfusion of infected blood and its products, donation of organs or seminal fluid, and among medical workers - through injury from contaminated needles or instruments. HIV infection is possible through transmission from an infected mother to a child (vertical route), although modern methods of prevention using antiretroviral therapy, if all recommendations are followed, can reduce this risk to a minimum.
The process of interaction of a virus with a cell includes a number of stages: binding of the virus to the cell, releasing it from the envelope, penetration into the cytoplasm, synthesis of DNA using viral RNA, integration of viral DNA into the genome of the host cell. After this, the latent stage of infection begins. In this state, proviral DNA can exist for some time without showing activity and without affecting the life of the host cell. While there is no expression of viral proteins, there is no immune response to the virus. Antibodies to HIV, which characterize the body’s immune response, appear after the activation of viral DNA and the beginning of active reproduction of the virus. The duration of the latent period depends on a number of factors, including the individual genetic characteristics of the organism.
Antibodies to HIV may appear starting from the second week after infection; their content increases within 2-4 weeks and remains for many years. In 90-95% of infected people they appear in the first three months after infection, in 5-9% - in the period from three to six months, in 0.5-1% - at a later date.
In the first weeks of infection, even before the appearance of antibodies to the virus (i.e., before seroconversion), the presence of HIV antigens, including its p24 capsid protein, can be detected in serum or plasma samples. Later, after seroconversion, it usually becomes undetectable.
4th generation combined test systems, which include the HIV Ag/Ab Combo test (Architect, Abbott), detect both antibodies to HIV types 1 and 2 and HIV p24 antigen, which allows for early detection of infection. The special characteristics of the screening test used in the INVITRO laboratory to detect HIV infection include the high specificity of the study (> 99.5%); The assay is 100% sensitive to antibodies characteristic of the period of seroconversion, and the sensitivity of the test to the p24 antigen is about 18 pg/ml.
The procedure for conducting a laboratory examination for HIV is strictly regulated by orders of the Ministry of Health of the Russian Federation and includes the stage of a screening (selection) study of the presence of antibodies to HIV using enzyme-linked immunosorbent assay (ELISA) methods approved for use, and the stage of a verification (confirmation) more detailed study in the laboratory of the city AIDS center. It should be noted that even the best screening ELISA systems do not guarantee 100% specificity, that is, there is some probability of obtaining nonspecific, false-positive results associated with the characteristics of the patient’s blood serum. Therefore, a positive result of a screening ELISA examination may not be confirmed in confirmatory tests, after which the patient will be given a negative or indeterminate result. If the result of the confirmatory study is uncertain, testing should be repeated over time after 2-3 weeks.
Laboratory diagnosis of HIV infection in children born to HIV-infected mothers has its own characteristics. Maternal antibodies to HIV (IgG class) can circulate in their blood for up to 18 months from the moment of birth. The absence of antibodies to HIV in newborns does not mean that the virus has not penetrated the placental barrier. Children of HIV-infected mothers are subject to laboratory diagnostic examination within 36 months after birth.
Preparation
No special preparation required. It is recommended that blood be taken no earlier than 4 hours after the last meal. General recommendations for preparing for research can be found. It is advisable to conduct a test to detect antigen and antibodies to HIV no earlier than two weeks after possible infection, with a repeat test after three and six weeks in case of a negative result. Applications for research at INVITRO LLC are filled out using a passport or a document replacing it (migration card, temporary registration at the place of residence, military personnel ID, certificate from the passport office in case of loss of a passport, registration card from a hotel). The presented document must necessarily contain information about temporary or permanent registration in the Russian Federation and a photograph. In the absence of a passport (a document replacing it), the patient has the right to fill out an anonymous application for the donation of biomaterial. During an anonymous examination, an application and a sample of biomaterial received from the client, a number is assigned that is known only to the patient and the medical staff who placed the order. ! The results of studies performed anonymously cannot be submitted for hospitalization, professional examinations and are not subject to registration in the ORUIB.
Indications for use
- Enlarged lymph nodes in more than two areas.
- Leukopenia with lymphopenia.
- Night sweats.
- Sudden weight loss of unknown cause.
- Diarrhea for more than three weeks of unknown cause.
- Fever of unknown cause.
- Pregnancy planning.
- Preoperative preparation, hospitalization.
- Detection of the following infections or combinations thereof: tuberculosis, manifest toxoplasmosis, often recurrent herpesvirus infection, candidiasis of internal organs, repeated herpes zoster neuralgia, pneumonia caused by mycoplasmas, pneumocystis or legionella.
- Kaposi's sarcoma at a young age.
- Casual sexual contacts.
Interpretation of results
Interpretation of research results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. The doctor makes an accurate diagnosis using both the results of this examination and the necessary information from other sources: medical history, results of other examinations, etc.
Units of measurement in the Independent Laboratory INVITRO: qualitative test.
Form of presentation of results: in the absence of antibodies to HIV 1 and 2 and p24 antigen, the answer is “negative”.
If antibodies to HIV or an antigen are detected in a screening enzyme-linked immunosorbent test, a serum sample is sent for confirmation by immunoblotting to the city AIDS center, which verifies positive and indeterminate results.
Positive result:
- HIV infection;
- false positive result requiring repeated or additional studies *);
- the study is not informative in children under 18 months born from HIV-infected mothers.
*The specificity of the screening test system Antibodies to HIV 1 and 2 and HIV antigen 1 and 2 (HIV Ag/Ab Combo, Abbott), according to estimates provided by the reagent manufacturer, is about 99.6% in both the general population and the group patients with potential interferences (infections HBV, HCV, Rubella, HAV, EBV, HNLV-I, HTLV-II, E. coli, Chl. trach., etc., autoimmune pathologies (including rheumatoid arthritis, the presence of antinuclear antibodies), pregnancy, elevated levels of IgG, IgM, monoclonal gammopathies, hemodialysis, multiple blood transfusions).
Negative result.
Diagnosis of the immunodeficiency virus is made by several methods. If necessary, it is carried out in several stages. It begins with an enzyme immunoassay. It is produced in clinics and free laboratories. Based on the results of this study, the patient is referred for additional diagnostics. Test results fit on one page, but their interpretation may not always be clear to the patient. Antibodies to HIV were not detected or detected. What does it mean? How to understand the result of an immunodeficiency virus test?
What does it mean that no HIV antibodies were detected or the result is negative?
The first test for which a patient with suspected immunodeficiency virus is sent is ELISA testing. This test can detect antibodies to the immunodeficiency virus. What does it mean that antibodies to HIV have not been detected is a question that interests many. When people receive a form with a negative result, they often do not receive an answer to the main question. The question is whether this diagnosis can be safely dismissed or is there still a threat of infection? If antibodies to HIV are not detected, what does this mean? In most cases, a negative result means that the person is healthy. It is important to comply with certain verification conditions. What exactly are we talking about? Blood should be donated on an empty stomach. And it is important to carry out the verification procedure within the time frame established by medical specialists after the suspected infection. “Antibodies to HIV are negative” - this is what may appear on the test result form if you take it a few days or weeks after the suspected infection. Antibodies to HIV will not be detected until seroconversion occurs in the patient's body. Only after their number reaches a certain limit, the enzyme immunoassay will be able to show them. In some cases, the patients themselves are the first to undergo immunoblotting rather than ELISA testing. As a rule, such an analysis is performed in paid clinics. Budget medicine uses it to confirm or refute ELISA results. Antigens and antibodies to HIV were not detected - this may be the wording of the immunoblotting result. It means that the immunodeficiency virus is absent in the body. However, only if the verification conditions have been met. We are talking primarily about the timing of AIDS testing.
If the form with the test results contains the following wording: HIV 1.2 antigen, negative antibodies, it means that the immunodeficiency virus is also absent. The numbers in this formulation mean that a qualitative analysis was carried out. That is, the patient was checked not only for the presence or absence of the virus, but also its type was checked. If antigens and antibodies to HIV 1.2 are negative, then the person is healthy and has nothing to fear.
Positive antibodies to HIV: what does it mean?
If antibodies and antigens to HIV are not detected, there is nothing to worry about. What awaits a person with a positive test result? It is worth noting that the presence of antibodies to the immunodeficiency virus in the blood serum is not yet a diagnosis. An enzyme immunoassay aimed at identifying them is not enough to make a diagnosis. After all, there are various pathologies, as well as conditions of the body, in which the production of antibodies to the immunodeficiency virus begins in the blood. We are talking about problems with the kidneys (some diseases are in the terminal stage), the immune system or the thyroid gland. If there are no antibodies to HIV, this does not mean that there are no problems with the above organs and systems of the human body. Everything is individual and depends on the physiology and condition of a particular person.
HIV antigen is negative, antibodies are positive, what does this mean? This means that a diagnosis such as human immunodeficiency virus was not established. It should be clarified here that with the help of enzyme immunoassay, healthy and doubtful patients are identified. And if the antibodies detected by ELISA do not react with the artificial protein of the immunodeficiency virus, then the person is healthy.
There are no antibodies to HIV, the antigen is positive, what does this mean and does this happen? It is immediately worth noting that this development of events is possible, especially if the AT test showed a negative result, and symptoms of early manifestations of the immunodeficiency virus are present in a person. In this case, the doctor may suspect a laboratory or administrative error and refer the patient to a more sensitive and accurate test - immunoblotting. It is worth noting that such situations are extremely rare. In most cases, there is no need to double-check the results of the enzyme immunoassay. It is extremely important to comply with the terms and conditions of the inspection.
Attention! In case of positive and questionable reactions, the period for issuing results can be extended to 10 working days.
Antibodies to HIV types 1, 2, p 24 antigen - the study of specific antibodies that arise in the body in response to infection with human immunodeficiency virus (HIV) types 1, 2 and the p 24 antigen of the human immunodeficiency virus.
HIV(human immunodeficiency virus) is a virus of the retrovirus family (a slow-replicating virus) that infects cells of the human immune system (CD4, T-helper cells) and causes acquired immunodeficiency syndrome.
The incubation period is usually 3–6 weeks. In rare cases, antibodies to HIV begin to be detected only several months or more after infection. Their concentration levels may decrease markedly in the terminal period of the disease. In rare cases, antibodies to HIV infection may disappear for a long time.
Antigen p 24 HIV 1.2 type detected in blood serum indicates an early stage of the disease. During the first few weeks after infection, the amount of virus and p 24 antigen in the blood increases rapidly. As soon as antibodies to HIV 1 and 2 begin to be produced, the level of the p 24 antigen begins to decrease.
Determination of the p 24 antigen allows diagnosing HIV infection in the early stages of infection, before the production of antibodies.
Simultaneous detection of antibodies to the HIV-1.2 virus and the p 24 virus antigen increases the diagnostic value of the study.
This analysis allows you to detect antibodies to HIV-1,2, as well as HIV-1,2 p 24 antigen. The analysis allows you to diagnose HIV infection in the early stages.
Ways of transmission of infection:
- sexual;
- during blood transfusion;
- from an infected mother to a newborn.
HIV infection- long-term and severe disease, which is accompanied by damage to the cells of the human immune system; Effective treatment methods and means of specific prevention (vaccines) have not yet been developed against it.
The source of the immunodeficiency virus is humans. The virus in humans can be isolated from seminal fluid, cervical secretions, lymphocytes, blood plasma, cerebrospinal fluid, tears, saliva, urine and breast milk, but the concentration of the virus in them is different. The highest concentration of the virus is contained in the following biological media: semen, blood, cervical secretions.
The ways in which the virus can be transmitted from an infected person to an uninfected person are limited.
Routes of transmission of HIV infection
There are 3 ways to transmit the immunodeficiency virus:
- Sexual route is the most common. Infection occurs through unprotected sexual contact, with the virus entering the body through the mucous membranes. Wounds on the mucous membrane, ulcers, inflammations increase the likelihood of infection. People who suffer from sexually transmitted infections have a 2 to 5 times higher risk of becoming infected through contact with an infected person. For transmission of the virus, not only the degree of intimacy of contact is important, but also the amount of the pathogen. During unprotected sex, the likelihood of a woman becoming infected by a man is approximately three times higher, since more of the virus enters her body, and the woman has a much larger surface area through which the virus can enter the body (vaginal mucosa). The risk of infection is highest with anal sex and least with oral sex.
- Contact with the blood of an infected person: a) when using shared needles, syringes, utensils for preparing drugs, unsterile medical instruments; b) administration of drugs in the preparation of which blood is used; c) use, transfusion of infected donor blood and drugs made from it (the risk is extremely low, since all donors, as well as blood, are carefully checked).
- From an HIV-infected mother (vertical route) to the fetus during pregnancy, during passage through the birth canal, and during breastfeeding.
AIDS - terminal stage of HIV infection
AIDS does not develop overnight. In most people with antibodies to the immunodeficiency virus, clinical signs of AIDS may not appear for 2 to 10 years or more, and with successful treatment this period increases significantly. This is because it takes quite a long time for the number of CD4 T cells to decline to a level at which the immune system weakens.
The virus also infects other types of cells, including cells of the central nervous system and red and white blood cells, in which the virus appears to lie dormant for a long time before it begins to actively reproduce. Factors influencing the progression of the disease are varied: genetic characteristics, strain of the virus, psychological state of the patient, living conditions and others.
The course of the disease and the duration of the stages also depend on whether the person receives treatment, and if “yes,” then what drugs.
4 stages of HIV infection
- The incubation period (“window period”) is the time from the moment of infection until the appearance of antibodies (protective proteins of the immune system) to the virus in the human blood. During this period, the infection does not manifest itself in any way, all tests are negative, but the person is already contagious. The incubation period can last up to 3 months (average 25 days).
- Stage of primary manifestations. Lasts on average 2-3 weeks and is characterized by a sharp increase in the amount of virus in the blood. This condition is called “seroconversion disease,” since at this time antibodies to the virus appear in the blood in quantities sufficient to be detected during testing. This period does not manifest itself in any way for most people, but 20–30% may experience flu-like symptoms: fever, swollen lymph nodes, headache, sore throat, malaise, fatigue and muscle pain. This condition resolves after 2–4 weeks without any treatment.
- Asymptomatic period. It occurs after the end of the primary manifestations of the infection and lasts for an average of 10 years if left untreated. During this period, the immune system fights the virus in the human body: the number of viral particles gradually increases and immunity decreases. By the end of this stage, infected individuals experience enlarged lymph nodes, night sweats, general malaise, and the first manifestations of opportunistic infections that occur in humans appear, with a severely weakened immune system. These infections are caused by microorganisms that surround us and do not cause infections in healthy people. A weakened immune system can also lead to the development of other diseases, such as cancer.
- AIDS is the last stage of this disease and is characterized by the appearance of a number of diseases due to a weakening of the body's immune system. Typically, patients have very low CD4 T counts; one or more severe opportunistic infections (Pneumocystis pneumonia, severe fungal infection, tuberculosis, etc.), which cause death if left untreated; oncological diseases; encephalopathy (brain damage accompanied by the development of dementia).
Diagnosis of HIV infection is a complex process based on data from laboratory, clinical and epidemiological examinations, with laboratory blood testing playing a major role in making the diagnosis.
The main method of laboratory diagnosis is the detection of antibodies to the virus using enzyme immunoassay.
The procedure for conducting laboratory testing for the presence of human immunodeficiency virus antigens and antibodies to this virus is strictly regulated by orders of the Ministry of Health of the Russian Federation and includes:
- stage of screening (selection) study using enzyme immunoassay (ELISA) methods approved for use;
- stage of verification (confirming) study using the immunoblot method in the laboratory of the city AIDS center.
Laboratory diagnosis of the presence of the immunodeficiency virus in children born from mothers infected with this virus has its own characteristics. Maternal antibodies to the virus (class Ig G) can circulate in the blood of children up to 15 months from birth. The absence of antibodies to the virus in newborns does not mean that it has not penetrated the placental barrier. Children of mothers infected with the immunodeficiency virus are subject to laboratory diagnostic examination within 36 months after birth.
Until a positive result is obtained in the immunoblot and if the test result is negative, the person is considered healthy and anti-epidemic measures are not carried out with him.
The material for testing for antibodies to the immunodeficiency virus is venous blood, which should preferably be donated on an empty stomach.
Of course, testing for the presence of the virus is a voluntary matter for each person. Tests for carriage of the immunodeficiency virus cannot be prescribed forcibly, without the consent of the patient. But you also need to understand that the sooner the correct diagnosis is made, the greater the chance of living a long and fulfilling life, even if you are a carrier.
Indications:
- swollen lymph nodes in more than two areas;
- leukopenia with lymphopenia;
- night sweats;
- sudden weight loss of unknown cause;
- diarrhea for more than three weeks of unknown cause;
- fever of unknown cause;
- pregnancy planning;
- preoperative preparation, hospitalization;
- identification of the following infections or their combinations: tuberculosis, manifest toxoplasmosis, often recurrent herpes viral infection, candidiasis of internal organs, repeated neuralgia herpes zoster, pneumonia caused by mycoplasmas, pneumocystis or legionella;
- Kaposi's sarcoma at a young age;
- casual sex.
It is recommended to donate blood in the morning, between 8 am and 12 pm. Blood is drawn on an empty stomach or after 4–6 hours of fasting. It is allowed to drink water without gas and sugar. On the eve of the examination, food overload should be avoided.
Rules for registration for HIV:
Applications for research at DNAOM are completed using a passport or a document replacing it (migration card, temporary registration at the place of residence, military personnel ID, certificate from the passport office in case of loss of a passport, registration card from a hotel). The presented document must necessarily contain information about temporary or permanent registration in the Russian Federation and a photograph. In the absence of a passport (a document replacing it), the patient has the right to fill out an anonymous application for the donation of biomaterial. During an anonymous examination, an application and a sample of biomaterial received from the client, a number is assigned that is known only to the patient and the medical staff who placed the order.
The results of studies performed anonymously cannot be submitted for hospitalization, professional examinations and are not subject to registration in the ORUIB.
Interpretation of results
The test for antibodies to HIV 1/2 is qualitative. If there are no antibodies, the answer is “negative”. If antibodies to HIV are detected, the test is repeated in another series. If a positive result in the enzyme-linked immunosorbent test is repeated, the sample is sent for testing using the confirmatory immunoblot method, which is the “gold standard” in diagnosing HIV.
Positive result:
- HIV infection;
- false positive result requiring repeated or additional studies*;
- the study is not informative in children under 18 months born from HIV-infected mothers.
Negative result:
- not infected (diagnostic deadlines for analysis have been met);
- seronegative version of the infection (antibodies are produced late);
- terminal stage of AIDS (the formation of antibodies to HIV is impaired);
- the study is not informative (diagnostic deadlines are not met).