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Test 4th generation HIV timing and accuracy

Modern problems of mankind can be called a disease that affects the immune system – HIV. It affects the immune system, which defines its complete dysfunction. The applied treatment methods do not allow to kill the virus that is aimed only at reducing the degree of manifestation of symptoms. It is quite important to detect the problem and time to start the treatment, as the virus develops gradually and cause the development of other serious diseases. Despite the fact that the problem has been known for the past several decades, truly effective method of virus detection no. Today the most often used test of the 4th generation, which allows to determine antibodies to the virus. Note that the 4th generation is represented by several test types, each effective in certain circumstances. Let us consider tests for HIV 4th generation: features of, the timing and results.

Test 4 pokoleniya na vich sroki i tochnost

Why it is important to test

There are several reasons why the recommended time to test:

  1. Immediately after infection a person becomes a peddler of infection. Be aware that the virus is transmitted through blood, sexual contact. Time to learn about the illness the person can protect others, so as the disease is not cured result in a significant deterioration in the quality of life, with death from diseases, developing on the background of immunodeficiency.
  2. The sooner you start treatment, the greater the likelihood that it will be effective. HIV develops in the body gradually, clearly there are several stages, each characterized by certain symptoms.

Of course, even when an early diagnosis is also impossible to cure the disease under consideration, but if you start treatment immediately after exposure can reduce the probability of transfer of infection from one stage to another in a short time. The 4th generation test for HIV is the deadlines are quite tight, which allows to promptly diagnose and start treatment in the case of obtaining a positive result.

What are the generation of tests for HIV infection?

Over the years, have created several types of tests, with each year their accuracy is increased significantly reduces the time required to obtain results. Consider the following blood tests:

  1. Methods of 1st and 2nd generation can not be called effective because of their disabilities. Attention should be paid to the fact that the tests of the first generation can be held only to determine the presence of antibodies to HIV. Also such a study, which called ELISA, can be used only to determine the virus that causes AIDS.
  2. The second generation is somewhat different from the first. The difference is that the second method allows the capture antibodies to HIV-1 and HIV-2.
  3. The third type of research is conducted in recent times more often than the first two. This is due to the fact that the third generation test allows you to identify Ig6 and IgM antibodies. The accuracy is quite large, the probability of errors is significantly reduced.
  4. Modern method of determination of the virus can be called a test for HIV 4th generation. The research of the past generation are held for the reason that it is possible to detect the antigen P24. Note that the system of IFA involves the use of a virus that treated with ultrasound.

The above points should be taken into account when considering what tests are done today to identify the virus in the body. When considering what is the accuracy of each test note that the last type is most accurate and fast, held recently in all the clinics that spetsializiruyutsya on the diagnosis of HIV infection.

The accuracy and sensitivity of the 4th generation

An important point is the fact how accurate the result of ongoing research. Many argue that to obtain accurate results it is recommended to conduct the test 4 th generation. It allows you to determine antibodies and antigens of the virus that allows us to deliver a more accurate result.

The special features of this test include the following points:

  1. Despite the high accuracy test of the 4th generation,to obtain the result of diagnosis is possible only after the passage of 60 days after infection. This period is selected based on the fact that within a month you can get false negative results: every body has its own characteristics, the virus manifests itself depending on what condition is the immune system if there are other hidden infections or chronic illness.
  2. Antibodies can be detected only after the fact, as determined by RNA in the blood of the infected, what is the method of PCR. You should consider the point that RNA even the most modern methods can only be revealed through 30 days after infection. In less time to identify the problem impossible.
  3. Note that the accuracy of the study depends on how many negative results obtained during the test.
  4. The present study shows that of 100 people who are infected before the virus, the sensitivity is 100%.

Note, however, that the exact test can be used only for the production of a positive or negative result. Other methods allow to obtain more information in order to provide more effective treatment. Note, however, that the accuracy, which has a 4th generation test does not allow to obtain 100% result.

What are the differences between 3rd and 4th generation tests?

As previously noted, quite often the tests of the 4th generation, which allow to obtain a positive or negative result. Therefore, consider whether there are differences between 3rd and 4th generation tests. Just note that the generations are, and they are quite substantial.

The main differences include the following points:

  1. As a rule, the 3rd generation of studies allows to determine antibodies against the virus in question. It antibodies quite often used during most of the test concentrations indicates the presence of problems. But only the number of antibodies does not indicate the type of problem and degree of its manifestation.
  2. Should pay attention to the fact that the 3rd generation does not allow the diagnosis at an early stage of the disease. Therefore, in order to make a diagnosis as early as possible, which will reduce the probability of infection of sexual partners, should be exactly the 4th generation tests. Note that the fourth type of test, even at the early conduction allows to give the most accurate result.
  3. Quite often PCR and investigation of the 4th generation of bind, since their results are similar in terms of accuracy in conducting research at an early stage.
  4. Note that at the legislative level permitted the use of the 4th generation. Quite often this test is known as AGATE.
  5. There is a certain method of determining the effectiveness of the test 3-th and 4-th generation. In a test of the latter type it is possible to obtain a result that indicates the amount of RNA of HIV infection.

In many medical centers that conduct research on blood for determination of HIV infection, conduct the test 4 th generation. The system involves the use of sophisticated software in one group can handle about 250 samples, which significantly reduces the cost of the test.

What is the test?

Modern methods of research allow to determine the almost exact date for when an infection has taken place. However, you should consider the point that such study is possible only after many months or even years after infection.

Quite often when conducting such research the main result consider receiving a positive or negative result. Only after a positive conduct additional studies that provide more detailed information about the infection.

The accuracy of modern methods of testing depends on what time after infection samples were taken. As shown by ongoing research, antibodies are produced to 3-4 week from the time of infection. Thus the test of the 4th generation can detect a single antibody as early as 7 days, but high precision in this case it is impossible to say. Officially, the specialists established a period of 6-12 weeks, in which occurs the formation of antibodies and the virus begins to show itself.

Our surveys indicate that the highest probability of infection between 3-6 weeks after infection. But this does not mean that the infection will not happen another time.

Determining the type of infection

You should consider the moment that this type of test allows to identify rare subtypes of HIV.

Few even of those infected know that there are several subspecies of the pathogen. The test of the 4th generation, you can identify the virus subtypes and M. is Quite rare virus subgroups of P and N, but they can also be detected by ELISA.

Modern research methods allow to distinguish between HIV-1 and HIV-2. Current studies indicate the following moments:

  1. As a rule, the group N is found in 9 instances from one group.
  2. The group P is found in a single instance from one group.

Quite important is the fact that HIV-2 is revealed much later. This is due to the development of the virus in the body.The group of the causative agent only determines the peculiarities of detection of the virus.

The fourth generation test can be characterized by the fact that it is carried out to determine the antigen. Other methods of research do not reveal it that can be quite important. The HIV antigen P24 can detect much earlier than other antibodies. The P24 antigen over a long time increases the production of antibodies.

Test 4 th generation a is also called "antigen-antibody". As previously noted, to detect the pathogen only after 7 days of infection, but a General guide is approximately 14 days or 1 month.

The scheme of the test

Having dealt with the features of the test, pay attention to how he conducted the test. Scheme of test the following:

  1. As you sample a small amount of blood from the cubital vein. We will note that earlier in this stage quite often, mistakes: must use only sterile containers and tools while collecting the sample, further blood should be located in the insulated tank to eliminate the possibility of changing its composition and influence the environment.
  2. All people are advised to contact the medical centre for the test only after 14 days after infection. If the test will be carried out earlier, a very large probability of obtaining a false positive result.
  3. It is recommended to follow the recommendations for preparation for the test. Some foods can change the composition of the blood and affect the test results. Many doctors say that before the collection of blood should not take medications because they cause a change in the result. Analyses it is recommended to take only in the morning, in the afternoon is not recommended to conduct the test, as used food, drinks can cause distortion of results. After a few hours you can learn about when the results will be obtained.
  4. You should consider the point that is initially carried out only IFA. When you receive a positive result should also test for PCR and HIV infection. Repeated studies are carried out for the reason that the probability of obtaining a false result when you run a test of the 4th generation is 1%.
  5. When you receive a positive result is assigned to a certain treatment and research to detect hidden infections and chronic diseases. However, the final result can only be obtained in six months. During this period, it is possible to conduct a full examination in order to diagnose the development problems.
  6. In that case, if the survey six months later, also is in doubt, conduct additional test in about 1-2 weeks.
  7. In some cases, the doctor decides that he obtained a false positive result. But most often is false negative. Getting a false-negative result is due to the fact that the tests are conducted in the early stages. If the test was done in less than 90 days after the alleged infection, there should be an additional study.
  8. The type of ongoing research can the patient choose. The testing is free and anonymous in many medical centers.

When considering the peculiarities of conducting researches note the time that the forced blood draw is unacceptable in all countries. However, some professions include conducting blood tests for diagnosis. An example is the fact that the staff of medical institutions should periodically test the blood to eliminate the possibility of infection of patients under certain circumstances.

The implementation of mandatory testing

Documents which are of international importance, provide information that is not permitted to force the donation of blood for determination of HIV infection. However, there are some cases which require mandatory testing. It is obligatory to carry out tests for detection of HIV infection in the case of organ donation, biological liquids.

Even just a few years ago common means of transmission is the donation. The infection is rarely determined immediately after the course. With the donation:

  1. Studies are being conducted to determine HIV-1 and HIV-2, and the DNA of the virus under consideration. Note that in this case necessarily is a combo test, which reduces the likelihood of errors.
  2. After passing the specified period is re-collection of blood and its validation. Only then you can become a donor.
  3. Then be kept for quarantine for 6 months. Note that in this period all infected regardless of the immune system and the presence of chronic diseases, there is a manifestation of DNA and antibodies to the virus.
  4. Even if you have received a positive result again is a binary test of venous blood. If you have received repeated and positive result, then again start the tests in a reference laboratory. In the case that was again a positive result is obtained, then the study is no longer held, as no doubt the result will be.

Except for the above point also note that the tests are conducted anonymously regardlesscitizenship and other things. Also, the rules define that all people who are serving sentences in prison, are tested on a mandatory basis. Perhaps, this case is practically the only one forced to blood test for determining HIV infection.

The stage of the disease and characteristics of symptoms

Treatment and study of blood depends on what stage the disease is. HIV infection causes AIDS which is a complete defeat of the immune system.

It is possible to allocate following stages of progression of HIV infection:

  1. The primary stage of infection has certain symptoms: insignificant increase in body temperature, chills, swollen lymph nodes and many other symptoms. Symptoms can occur in varying degrees, in some cases, they are completely absent. So often people do not pay attention to the manifestation of symptoms. As a rule, if symptoms persist, you can do the test of the 4th generation, which will have a sufficiently high accuracy.
  2. The second stage of development of the virus has no bright symptoms. With proper treatment it can last for several years and even decades. At this stage the outcome of the studies with 100% confidence. In the second phase, the immune system loses its function, so the body can fight off infections and bacteria.
  3. The third stage is called AIDS. It can be characterized by the fact that there is immunodeficiency which means the body is not protected against other infections and bacteria. However, even the most common infection becomes the reason why the disease develops in its most complex form. As a rule, before the onset of the third stage of the disease already diagnosed. Up to this stage takes several years and even decades. Most often the diagnosis is made accidentally when carrying out biochemical analysis of blood. In the blood with the active behaviour of the virus there are certain elements that indicate the problem. Example would be the increase in red blood cells.

If you carry out treatment in the first stage, it is possible to increase the quality of life and its duration. Why it is important to identify the virus at an early stage, when the lesion of the immune system may not pass. Test 4 th generation allows to exclude the possibility of false positive or false negative result in the early stage of diagnosis.

In conclusion, we note that the infection before the pathogen can not be called a sentence. Modern methods of treatment can significantly extend the life and increase its comfort. It is important to diagnose at an early stage of development, as treatment presented a mild pathogen. If you hold a cupping at the initial stage of development of the virus, the damage the immune system will be insignificant.