Serological markers of infections: deciphering a laboratory puzzle. Why is a serological blood test taken? What does a serological blood test show?

Nowadays, there are quite a lot of tests that we have to take in life. In this article we will consider such a type of analysis as a serology blood test. This analysis is carried out in order to answer the question of whether a person has any infectious diseases and whether everything is in order with his health. Infectious diseases can also be transmitted sexually, and it is precisely such diseases that can be determined by a serological blood test.

What is a serological blood test?

A serological blood test is a test that can show the presence of infectious, viral and microbial diseases.

Basically, this analysis is based on identifying foreign bodies, namely bad bacteria, infections and other organisms that can cause diseases in humans.

Probably, many people know that when a foreign body, bacteria, or other infection enters the human body, the body actively begins to secrete specific antibodies, which subsequently release protein. It is this protein that helps fight foreign microorganisms. But sometimes our body needs help, because it is a protein that fights to heal and cleanse the body, and a serological blood test allows doctors to determine what disease needs to be treated and how to choose an effective treatment method.

How is a serological blood test performed?

A serological blood test is carried out using two methods.
The first method involves the process of introducing serum into the human blood itself, so that an antibody reaction subsequently occurs, and find out how many pathological cells there are in the body.

This method is provided to determine the disease itself, what it threatens and to choose the appropriate treatment tactics.

The second method prefers the process of introducing specific antibodies from human blood into serum. This method is used only in individual cases, when the disease has already been determined, but medical specialists simply need to find out the number of antibodies.

What features should be taken into account when taking a serological blood test?

The fact is that such products can significantly affect the composition of the blood; everything we eat can deposit sediment in our blood, and it is because of this that we need to adhere to a 3-day diet in order for the body to cleanse itself a little before the analysis.

Under no circumstances should you take a blood test for serology when it contains alcohol, as you can not only spoil the diagnosis, but also earn yourself a bad reputation.
You need to donate blood on an empty stomach, because while your stomach is empty, only leukocytes, red blood cells, platelets, protein and antibodies will be visible in the blood. Thus, the analysis will show a more accurate answer.
It is also worth donating biological material (blood) so that specialists from the medical field can easily establish the correct diagnosis, see how antibodies interact with antigens, and ultimately prescribe correct and effective treatment.
For smokers, it is also worth remembering that 2 days before donating blood, you need to refrain from tobacco, as it is also visible in the blood.
The mental and emotional state is also very important, since this is also a factor that affects a person’s well-being and condition. In stressful situations, the blood test will most likely not be unsatisfactory.

Norm and deviations in analysis

When medical professionals conduct such tests, the result is very important, since it can show how the body reacts to the serum.

If a person has no antibodies in his blood at all, then this is a very good result that he does not have any disease. But this happens extremely rarely, since our body is a mechanism that constantly fights with something, sometimes with germs, sometimes with viruses, because every day we walk the streets where there are already germs and bacteria in the air.

Typically, such a blood test is carried out 2 times in order to convince oneself of a particular diagnosis.
Under circumstances where a large number of antibodies are detected in a person, this means that a virus or infection is present in the person’s body. In such circumstances, treatment and examination are prescribed immediately.

How to decipher a blood test

A person who has received a certificate about the result of such an analysis may simply not understand anything, since there will be quite a lot of terminology, which may subsequently be incomprehensible to an ordinary person, but the attending physician who sees such conclusions and results will be able to accurately say the result and interpretation of the analysis .

If, however, something is wrong, the doctor must inform this patient, since this is his job.

As mentioned above, such an analysis is mainly carried out to determine the amount of antibodies; in the normalized version, their amount should be equal to zero.

Bottom line

Most often, people think that donating blood is very scary and painful, but it is not so. Still, we all need to donate blood so that a person knows what is in his blood and whether there are any diseases in his body. It is important to remember that any deterioration in your emotional state, stress or fear of something can cause a storm of emotions in you, which will then be directly reflected in the analysis itself. The main thing is not to worry; after all, this is done for health.

Since the discovery of serological markers of infections, this analysis has been fundamental in laboratory research. The purpose of its implementation is to help in recognizing, as well as identifying ailments caused by a violation of the protective functions of the immune system.

Diagnosis of hepatitis, rubella, syphilis, HIV and many other diseases has become available in our time thanks to tests for serological markers of infections. Deciphering research results helps to quickly determine the presence of diseases that are sometimes difficult to detect using conventional methods.

Serological research method: helping the doctor in determining the nature of diseases

The origin of the name “serology” is from Lat. names of serum (serum). The combination with the famous logos means "the doctrine of the serum." Serology means a branch of immunology that studies the specifics of the interaction of serum antibodies with antigens.

The basis of serology is the identification of specific antibodies formed in response to infection with a specific antigen. Based on the presence of certain antibodies in the blood, a conclusion is made about the nature and degree of activity of the infection.

The serological method is used in diagnosis:

• herpes
• cytomegalovirus
• mumps
• atypical pneumonia
• rubella
• chlamydia
• toxoplasmosis
• viral hepatitis B and C

The study is also used in cases where it is necessary to identify the causes of myocarditis.

Serological tests can be used:

1. In case you need to confirm the diagnosis. It is practiced to add the corresponding antigen to the blood serum. The presence of antibodies is proven or disproved by the nature of the response.
2. In cases where nothing is known about the nature of the disease, the species of antigens in the blood is revealed by the addition of antibodies.

To carry out the analysis, the component responsible for clotting (fibrogen) is first removed from the blood.

Thus, the purpose of conducting a serological blood test is:

• Establishing diagnosis. The study is indicated when laboratory confirmation of the presence of a pathogen in the blood serum is required.
• . The analysis will help identify the reaction of the pathogen to various medications.

Metastatic liver disease: required diagnosis and treatment methods

The use of serological analysis is also practiced in the diagnosis of autoimmune diseases. The procedure helps to identify antibodies to body tissues.

Serological markers of hepatitis: interpretation of results

Viral hepatitis is a type of serious infectious disease that can last for quite a long time without showing anything special. The difficulty of timely detection lies in its main danger.

Carrying out an analysis for markers that appear in the blood as a result of the administration of a vaccine or a previous illness makes it possible to detect hepatitis in an early phase, in which it is better treatable.

Types of viral hepatitis

Hepatitis A

This type (so-called jaundice) is quite common. It is transmitted by consuming contaminated food and water. When diagnosing it, an analysis is done for the presence of antibodies:

• Anti-HAV IgM. The existence of early antibodies in the blood indicates the presence of the virus in the body for at least 25-30 days.
• Anti-HAV IgG. Its presence is evidence that the patient has had this form of hepatitis in the past.

Hepatitis B

Transmitted sexually. The virus can also enter the bloodstream when using unsterile instruments. It is widespread and, if detected early, responds well to treatment. Upon recovery, the body becomes infected with the virus for life. Untreated hepatitis B will most likely become chronic, which can lead to complications such as cirrhosis and liver cancer.

When identifying hepatitis B, the following markers are looked for:

• HBsAg. A specific antigen indicating the presence of a disease.
• Anti-HBs. Its appearance indicates the completion of the process.
• Anti-HBc IgG. Its long-term presence in the body indicates the course of the process.
• Anti-HBc IgM. Its detection is a sign of the initial phase of the disease.
• Anti-HBe. Its presence is a sign of a sluggish form of hepatitis.

The most severe form of the disease. It can be treated only in the early stages. The outcome of an untimely detected disease is fatal.

Nasal drops, names of drugs: vasoconstrictor, antibacterial, homeopathic, herbal medicine

Based on the research results, the following markers are identified:

• Anti-HCV. Indicates the presence of a disease.
• Anti-HCV IgM. Allows us to judge a fairly recent infection, which gives grounds for a favorable prognosis.

Hepatitis D

The symptoms are the same as for hepatitis B. Diagnosed by the presence of anti-HDV Ig G, characteristic of hepatitis B, supplemented by anti-HDV Ig M.

Hepatitis E

In general, it is similar to hepatitis A, but is more dangerous for pregnant women. Detected by the presence of anti-HEV lg.

Hepatitis G

Its properties are similar to hepatitis C, but less dangerous.

Markers of intrauterine infections: interpretation of results

– a period when susceptibility to infections becomes quite an acute problem for the body. There is a group of infections that are dangerous for pregnant women, while they pose no threat to other groups of patients. This group is called TORCH infections. The name is formed from the first letters included in the group of names of infections:

• toxoplasmosis
• other infections (syphilis, listeriosis, chlamydia, etc.)
• rubella
• cytomegalovirus infection

Detected IgG antibodies indicate the presence of immunity to the disease. They are not an obstacle to planning a pregnancy.

Detection of IgM is possible only in the acute stage. Pregnancy can be planned only after recovery.

Rubella. Refers to infections transmitted in utero. The transferred disease forms lifelong immunity. The severity of the disease is directly proportional to the age of the patient. The fetus of an infected woman is more likely to develop severe defects. Today it is possible to get vaccinated against rubella, thereby avoiding the possibility of getting sick during pregnancy. After vaccination, IgM titers remain in the blood for some time, so it is better to refrain from planning pregnancy for 3 months.

Before vaccination, you need to do a serological test, after which you can make a decision about vaccination.

Possible results:

• IgM-, IgG-: indicates the absence of antibodies and the need for vaccination.
• IgM-, IgG+: indicates the presence of immunity. No vaccination required.
• IgM+, IgG-: disease in the early stage, period of exacerbation.
• IgM+, IgG+: period of exacerbation.

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The dynamics are monitored by the degree of decrease in IgM and increase in IgG. The disease is dangerous in the acute phase with a positive IgM value.

The appearance of IgM or IgG in the blood, if they were not previously observed in this patient, means the development of the disease. The same verdict can be made with a 4-fold increase in the amount of IgG over two to three weeks. The statute of limitations of the previous examination is also important: antibodies can be present in the blood for 2 years from the onset of the disease. Therefore, the presence of IgM cannot be interpreted as a sign of acute infection. The presence of IgG in decreasing quantities is not considered a disease and does not pose a danger.

If infection occurs in the second or third trimester, the disease is curable.

Safe test: serological testing for allergies

Diagnostic tests for allergies are carried out using the quantitative determination of immunoglobulin E. With this method, allergens bind to antibodies, forming a single complex. The study uses more than 200 allergens.

More thorough studies are carried out when it is necessary to identify the type and severity of the reaction. The advantage of this method is that there is no direct contact of the patient with the allergen. In this case, general and allergen-specific IgE.

In determining the diagnosis, not only laboratory tests are important, but also other data. Only a doctor specializing in this field can compare them and correctly diagnose the presence of the disease. Self-medication based on the interpretation of serological tests cannot be practiced.

Jun 5, 2016 Violetta Doctor

Serological blood analysis is a fundamental research method carried out in order to quickly and reliably identify microbes, infections and viruses in the human body. In addition, thanks to this method, it is possible to determine the entire list of existing diseases that have arisen as a result of decreased immunity.

Through serological analysis, blood taken from the patient is examined for HIV, syphilis and other dangerous ailments. In addition, the study is necessary in case of confirmation of the patient’s blood type and to determine the specificity of proteins.

As noted earlier, the analysis is recommended for diagnosing infectious diseases and establishing the stage of the inflammatory process. Thanks to a serological chemical reaction, it is possible to determine the level of interaction between antigens and antibodies responsible for the result.

This analysis applies:

1. When determining the number of antibodies that fight the causative agent of the disease: during the analysis, blood serum is mixed with the antigen of the causative agent of the disease, after which they look at the reaction that occurs.
2. The opposite situation is that a developing infection is detected due to existing antigens detected by adding antibodies to the blood.
3. In case of blood type determination.

In case of poor blood clotting and in case of hypercoagulation, dangerous consequences associated with cardiac activity can occur.

The need for serological tests increases when the patient is suspected of having sexually transmitted infections and other diseases. The resulting analysis contains information about the presence of antibodies to a given type of bacteria or virus in the blood. These are liver diseases, measles, human immunodeficiency virus, herpes, etc. If antibodies are detected, the doctor makes a conclusion for the patient and determines the further course of therapy. If necessary, additional studies will need to be completed.

The material is collected from the ulnar vein. The analysis is taken on an empty stomach in the morning. However, before taking a biochemical test for hepatitis, all brightly colored vegetables and fruits should be excluded from the daily diet. If confirmation of the results of the completed analysis is required, a secondary examination can be prescribed without special preparation.

Interpretation of serological analysis

This laboratory test is indicated for patients when difficulties arise in the differential diagnosis of various types of infections. In this case, only a serological analysis can determine the type of infectious agent and help the doctor determine the diagnosis of the disease. In addition, the enormous benefit of this technique is reflected in the selection of drug therapy for the patient, because the causative agents of many diseases differ greatly in their sensitivity to the action of antibiotics and other drugs.

Thanks to a serological test, it is possible to easily determine whether a person has a disease that was caused by a latent infection entering the body. Having completed the procedure for collecting material, laboratory assistants decipher the indicators, allowing experienced doctors to fully examine the pathologies that have arisen in the body. If there are no antibodies in the blood, a person does not develop an infectious disease. In this case, the result of the analysis will be positive. But this is a rare case. As a rule, in the presence of symptoms of the disease, serological analysis serves as evidence of the presence of a dangerous pathology. In this case, the process is duplicated. Initially, the presence of small infectious agents in the body is detected. Next, the degree of development of the inflammatory process is identified by the number of antibodies.

The norm for this test is considered to be zero antibody levels. The value will always mean the presence of pathology in the body. In this regard, the patient needs to undergo additional studies to confirm the diagnosis.

Features of serological testing for syphilis, HIV and hepatitis

The test for syphilis involves the detection of proteins responsible for the entry into the human body of the infectious agent - Treponema pallidum. The biological material in this case is blood serum. Before donating blood, you should stop taking heart medications and avoid any alcoholic beverages 4 days before donating blood. It should be noted that infection can only be established after 1.5-2 months from the moment of infection. If a pregnant woman performs this test, she should be prepared for a false positive result.

The following symptoms may be the basis for conducting a serological test for hepatitis:

• unreasonable fatigue and weakness of the body;
• poor appetite or lack thereof;
• vomit;
• changes in the color of urine and feces;
• yellowness of the facial skin.

In addition, diagnosing hepatitis is considered necessary during a medical examination or during examination during pregnancy.

If a person has been tested positive for HIV infection, this does not mean that he is infected with AIDS. If less than 2 months have passed since infection, the presence of antibodies to the immunodeficiency virus in the blood cannot allow us to draw a conclusion indicating the development of the disease. To do this, you need to repeat the procedure. HIV testing is mandatory during pregnancy at the time of the first visit and at 30 weeks of pregnancy.

Enzyme immunoassay blood test

One of the popular types of serological studies is considered to be an enzyme-linked immunosorbent assay, which is carried out to effectively control the number of antigens and antibodies in human blood serum. In addition, using this method it is possible to determine the content of hormones, immunological complexes and other biological components.

When bioorganic substances penetrate human tissue and vital organs, immunity prevents them from affecting health due to antibodies and immunoglobulins. As a result of their influence, an antigen-antibody complex is formed in the body. Only its comprehensive analysis will be an important component of the enzyme immunoassay method.

The main material required to perform the study is the patient’s blood. In some cases, in order to recognize the type of disease or select therapy, cerebrospinal and amniotic fluid is taken for analysis. Enzyme immunoassay blood test as a component of serology is based on a detailed study of blood molecules and immunoglobulins. Their feature is the ability to detect and destroy infectious agents together with a specific antigen.

The advantages of this method include the ability to determine the disease in the early stages of its development, the speed and accuracy of the result, low cost and the elimination of preparation for the study.

There are few disadvantages of the method: it is possible to obtain a false negative result, which requires further re-testing.

Before taking any laboratory test, you must follow the preparation rules. The collection of material must be carried out exclusively in sanitary conditions. In addition, it is necessary to prevent foreign substances from entering the blood. An important condition for every infection test is to donate blood exclusively on an empty stomach. At the same time, the day before the test, it is not recommended to consume fatty and spicy foods, alcoholic beverages and sweet drinks. Additionally, it is necessary to avoid stressful situations and any physical activity. In any case, before deciding to donate blood for testing, you need to undergo a medical examination by your attending physician.

Having heard the patient’s complaints, the doctor will be able to recommend the advisability of taking a serological blood test.

In what cases is a serological blood test used?

Serology is a science that allows us to qualitatively study the properties of human blood serum. This is one of the most important branches of immunology, which pays special attention to the interaction of antigens and antibodies.

There are two main types of serological reaction according to the mode of action:

1. Straight. Also called two-component. This type includes agglutination reactions, as well as passive hemagglutination reactions.
2. Indirect, or three-component. Hemagglutination or neutralization reaction is inhibited.

At the moment, this type of research is actively used for the following purposes:

1. Determination of human blood group.
2. Identification of the number of antibodies that arose as a result of the appearance of an infectious pathogen in the human body. In this case, it is necessary to conduct a comprehensive assessment of the chemical reaction that appeared due to the addition of a special disease antigen to the serum.
3. Determination of an infectious disease by antigens, while antibodies must be added to the blood for the effective manifestation of the antigen.

If any problems occur during the clotting process, then appropriate measures should be taken immediately. Otherwise, inaction can lead to heart attacks, thrombosis or stroke.

Main indications for performing a serological blood test

Today, this technique is actively used to determine the following diseases:

• amoebiasis;
• giardiasis;
• opisthorchiasis;
• syphilis;
• toxocariasis;
• toxoplasmosis;
• trichinosis;
• cysticercosis;
• echinococcosis.

In addition, such studies are used in the following cases:

• examination of a pregnant woman;
• detection of diseases of the cardiovascular system;
• examinations that are necessary in venereology and urology;
• liver studies;
• various examinations before or after operations;
• determination of pathologies in the process of blood clotting;
• phlebeurysm;
• autoimmune diseases;
• identifying effective treatment;
• after completion of appropriate therapy.

Thus, with the help of a serological test of human blood, various types of complex diseases can be identified in a timely manner. This allows you to prescribe an effective treatment plan.

Serological blood test: pros and cons

Each type of examination has its own advantages and disadvantages that are worth considering.

The advantages of the technique include the following aspects:

• reliability of the result;
• affordable price;
• the result is ready in a fairly short time - only a day is needed for complete readiness;
• The method allows for monitoring the quality and effectiveness of the entire treatment.

The main disadvantage is that certain diseases cannot be detected immediately, since there is an incubation period.

How to prepare for the test

This analysis is performed exclusively on an empty stomach. To avoid various mistakes and get the most reliable result, it is recommended to adhere to the following rules:

1. For a few days, it is better to eliminate too fatty and spicy foods from your diet.
2. Try to be less nervous and worried.
3. Minimize consumption of foods containing large amounts of sugar.
4. Limit physical exercise.
5. Avoid alcoholic beverages and nicotine.

Thanks to the above rules, you can get the most reliable result.

Decoding

Immunoblot method

Non-treponemal reactions are assessed in laboratory conditions. If the result is negative, a dash is placed in the column. If sufficiently large flakes were found, the indicator will be from +3 to +4. If medium-sized flakes were detected, the result will indicate +1 and +2.

It is important to remember that infection is detected only after one to two months.

Treponemal tests are more accurate. But the designations are largely the same.

Remember that tests are individual, and only a professional laboratory technician can truly accurately interpret them. You should not engage in self-treatment, since your health can only be entrusted to specialized doctors.

What does a serological blood test show? Diagnostic measures are the most important stage in the treatment of any disease. The success of treatment depends not only on the prescribed drugs, but also largely on how correctly the diagnosis was made.

In addition, diagnosis allows you to prevent complications and concomitant diseases. Using a serological test of the patient's blood, the presence of antibodies and antigens is detected. The study helps to find many diseases, determine their phase and monitor the progress of treatment.

What is serology?

Serology is the branch of immunology that studies the reactions of antigens to antibodies. This branch of medicine deals with the study of blood plasma and its immunological characteristics.

Today, a serological blood test for antibodies is a reliable way to detect human immunodeficiency virus, hepatitis, brucellosis, STDs and other life-threatening diseases. Let's figure out in what cases it is prescribed.

Indications for use

A serological blood test is necessary to identify the causative agent of the disease if it is difficult to make a diagnosis.

To carry out this reaction, antigens of pathogens are introduced into the plasma, and then the ongoing process is studied by a laboratory assistant. Or they carry out the reverse reaction: antibodies are injected into the infected blood to determine the specific identity of the pathogen.

Scope of application

This research is used in various branches of medicine. This reaction identifies specific cells and antibodies produced by the body to fight infections and viruses.

In addition, a person’s blood type is determined using the serological method.

A similar serological blood test is used in gynecology to diagnose sexually transmitted diseases. This method is also used for comprehensive examinations of pregnant women (detection of toxoplasmosis, HIV, syphilis, etc.). Passing this test is mandatory when registering with a antenatal clinic.

In children, a serological reaction is used to confirm the diagnosis of so-called “childhood” diseases (chickenpox, measles, rubella, etc.) if the symptoms do not have pronounced manifestations and it is impossible to identify the disease by analyzing clinical indications.

Detection of sexually transmitted diseases

For venereologists, this testing is truly irreplaceable and allows you to make a diagnosis very accurately.

With a blurred clinical picture, a serological blood test for syphilis, giardiasis, ureaplasmosis, chlamydia, herpes and other diseases can quickly detect the presence of antibodies.

Viral and infectious diseases

Serological analysis is actively used by gastroenterologists, hepatologists and infectious disease specialists to diagnose viral hepatitis.

Deciphering a serological blood test makes it possible to determine the stage of the disease and answer the question of how necessary hospitalization is at the moment. How to prepare properly?

Preparing for the test

Serological blood tests are done in both public and commercial clinics. Preference should be given to a laboratory with modern equipment and qualified personnel.

Biological samples for testing can be saliva and feces, but in most cases the patient's venous blood is used. Blood for a serological test is taken from the cubital vein in a laboratory. Before taking the test, you should consult with your doctor about preparing for this procedure.

To prepare for a serological test, you need to follow a few simple rules.

Blood is donated in a calm state before meals, that is, on an empty stomach. Before this, you should not undergo other tests, such as x-rays, ultrasound, etc.

It is necessary to avoid taking antibacterial and some other drugs several weeks before donating blood. Certain recommendations in this case depend on the disease for which the test is being done. For example, a test for hepatitis involves eliminating fatty foods and alcohol 48 hours before the procedure.

Fluorescence reaction

Among the types of serological reactions there is a fluorescence reaction. This technique uses a reagent that illuminates antibodies in the blood serum.

Setting up a direct serological reaction involves marking specific antibodies with a fluorescent substance. This reaction is the fastest and is carried out in one stage.

Another option for conducting such an analysis is called indirect, or RNIF. It is carried out in two stages. In the first step, antibodies are not labeled with fluorescent tags, and in the second, appropriately labeled antibodies are used to identify antigens and antibodies. The glow occurs only after binding to a specific antibody occurs.

What does a serological blood test show? The result of the entire procedure is assessed by a special device that analyzes the strength of the radiation and reveals the shape and size of the object under study. The causative agents of infectious diseases are detected with a result whose reliability is 90-95%, depending on the type and stage of the pathology.

Linked immunosorbent assay

These types of serological testing use unique, stable reagents. The marked substances seem to stick to the desired antibodies. As a result, we get a qualitative or quantitative result.

If no pronounced markers are found, the result will be considered negative. If the presence of antibodies in biological samples is detected during a qualitative study, then the test result is considered positive. By quantifying cells, the analysis gives a more accurate result.

By analyzing the analysis indicators (for example, the sum of identified cells), the specialist determines whether the disease is at the initial stage, in the acute stage, or whether the chronic form of the pathology has worsened. In order to make a diagnosis, the doctor takes into account not only the data of a serological study, but also the clinical picture of the disease.

Features of this test

Carrying out this analysis is not always able to provide 100% confidence that a certain disease has been detected. It happens that the results may be ambiguous and other procedures are required.

For example, during a test for brucellosis, blood serum is controlled for self-retention without antigen. This significantly increases the reliability of testing. A test for brucellosis can be positive or negative, and may also raise doubts.

If you receive questionable results that do not have an unambiguous interpretation, it is recommended to take the test again. In addition, brucellosis can be detected by blood cultures, bone marrow and cerebrospinal fluid examination.

Pros of serological blood test

Diagnostic techniques using serological reactions are widely used in modern medical practice. This is especially often done when determining viral and infectious pathologies.

The same tests are used during geographic screening and medical examination to prevent the epidemiological spread of infection.

The advantages of the method include:

• High level of confidence.
• Fast reaction and results. The results of the RSC are known within 24 hours. In a special situation, in a hospital setting, the analysis will be ready in a few hours.
• Monitoring the development of the disease and the effectiveness of therapy.
• Low cost and accessibility for patients.

Disadvantages of the method

However, serological studies also have their drawbacks.

These include the fact that when conducting an analysis, the incubation period of the disease should be taken into account in order to obtain a more reliable picture.

For example, determination of herpes simplex type 1 or 2 is possible only 14 days after infection. An analysis for the presence of the immunodeficiency virus is carried out 30 days, 90 days and six months after contact with an infected person.

Of course, the reliability of the results can also be influenced by the human factor: neglect of the rules for preparing for blood sampling or an error made by the laboratory assistant when carrying out the reaction.

According to statistics, an erroneous result can be obtained in 5% of cases. An experienced doctor, when examining a patient, having studied the clinical picture, in most cases can calculate the mistake made.