How and why a Wasserman blood test is performed. Tests for syphilis: what are they called, how to take them, which is the most reliable? What does a weakly positive reaction to syphilis mean?

Content

Syphilis is a common sexually transmitted disease, if it is not detected in time, the body will suffer serious damage and death is possible. Wasserman reaction - special analysis which should be done if this pathology is suspected, timely diagnosis will help cure the disease immediately positive result. You can become infected with syphilis not only through sexual contact, but also through household items, hygiene products, and bedding.

Methods for diagnosing syphilis

Tests should identify the main causative agent of the disease - treponema pallidum, also known as treponema pallidum. To do this, blood is drawn on an empty stomach for serological analysis. Such a study is considered to be the main type of laboratory diagnostics for detecting syphilis. The most common research methods are:

• blood test for RW (RW) - Wasserman analysis;
• RPGA - reaction passive hemagglutination;
• ELISA – enzyme immunoassay of blood;
• RIF – immunofluorescence reaction;
• RPR – microprecipitation reaction with cardiolipin antigen;
• RIBT – immobilization reaction of Treponema pallidum.

What is the Wasserman reaction

This is a laboratory blood test for syphilis, which is aimed at determining the immunological reaction to the penetration of the pathogen into the body. Characteristic processes begin in the human body during infection. The causative agent of the disease contains the antigen cardiolipin. The patient's blood serum, due to the presence of reagins in it, enters into a complement fixation reaction. The result is a specific complex with this antigen, which RV can detect.

When infected with syphilis, a person will definitely have antibodies to Treponema pallidum in his blood, which is characterized as a physiological response of the immune system. During the test, the drug cardiolipin is added to the collected blood. If the causative agent of syphilis is already in the body, the result will be visible RSC, which binds the introduced antigen and antibodies. In the decoding, the number of “+” signs indicates the intensity of the formation of complexes or “-” in their absence.

Indications for the study

It is recommended to regularly conduct a general blood test in order to promptly identify any abnormalities in the human body; staging the reaction at an early stage can significantly increase the effectiveness of treatment. The following indications exist for donating serum to RW:

1. During medical examinations, medical examinations on a regular basis with employees of trade, medicine, and education.
2. During pregnancy. There is a possibility of infection of the fetus with syphilis in the womb, so it is important to identify the result of the Wasserman test in women who are planning to give birth to a child or are already carrying one. Pathology can cause serious harm to the baby.
3. People who have had long-term contact with pathology at work or at home.
4. If a person suffers from alcoholism or drug addiction.
5. During urgent hospitalization of a patient with signs of syphilis.
6. After intimacy without using a contraceptive with a random person.
7. Anyone wishing to become a blood or sperm donor must be tested.
8. If the pregnancy was terminated unnaturally.
9. The test is carried out during and after serving time in prison.
10. The reason for performing RV is the hospitalization of a patient with enlarged nodes lymphatic system and elevated temperature.

Blood for the Wasserman reaction during pregnancy

This is the initial test that your OB/GYN will ask you to take. A blood test for the Wasserman reaction may be inaccurate because the woman’s condition during this period affects the results. According to statistics, 32% of cases show a false positive result. If there is a “+” in the decoding, it is necessary to undergo differential diagnosis. It is recommended to perform the test once per trimester, regardless of the presence or absence of sexual intercourse. There are no contraindications for RW for pregnant women; this is a standard collection of material.

Preparation

Some tests require specific preparation before taking. Wasserman's analysis will be as reliable as possible if 2 days before the test you do not drink any alcoholic beverages (even low-alcohol ones). It is recommended not to eat fatty foods during this period, so as not to distort the results. You should not take any digitalis preparations while preparing for RV.

How is the procedure performed?

Blood for the Wasserman reaction is carried out only on an empty stomach, this is an important condition. The last meal before collection should be no later than 6 hours. The employee who performs the manipulations sits the client on a chair or places him on a couch. The analysis requires 8-10 ml of blood from the cubital vein. If the study is carried out small child, then the material can be taken from the jugular or cranial vein.

How many days does a blood test for RW take?

There are two stages in conducting material research. Wasserman's rapid test will be ready in 2 hours, but it can only confirm or refute the presence of syphilis antibodies in the patient. To obtain quantitative information on the state of the blood and the concentration of antibodies to treponema, it takes from 1 to 7 days. The duration of analysis and interpretation depends on the laboratory and the number of ongoing tests.

Decoding

A blood test according to Wasserman should only be deciphered by a qualified doctor. The results may indicate not only a negative or positive reaction, but also something in between. Only a specialist will be able to correctly interpret the data and not frighten the patient ahead of time. A typical negative result is indicated by a “-” sign and indicates the undoubted absence of syphilis in the human body.

Positive reaction

When assessing the concentration of antibodies, a positive manifestation may be marked by one, two, three or four pluses. The following symbols may appear in the decoding:

1. “+” and “++” - the result indicates a dubious, weakly positive microreaction. Additional diagnostic tests and examination are necessary. After some time, you can repeat the analysis of August Wasserman, because there is no complete confidence in the absence or presence of syphilis. The reason for this result may be a violation of the preparatory procedures before donating blood.
2. “+++” is a positive reaction. No additional or repeated confirmation is required; the patient has syphilis and must undergo a full examination. Women are prescribed a smear from the vagina or uterus, men donate material from the urethra. This result is rarely erroneous, but clarifying tests may be prescribed if the patient’s symptoms are similar to other diseases.
3. “++++” is the final positive result. High reaction intensity.
4. “++++” is the final positive reaction. The result obtained is 100% reliable and does not require any additional analysis. The diagnosis is syphilis.

False-positive Wasserman reaction

This answer can be absolutely healthy man, this happens for specific reasons. This reaction occurs if the patient has acute or chronic stages of the disease, has recently received vaccinations or has recently received physical injuries. All these conditions lead to the active production of a nonspecific protein in the body, which is called antibodies or immunoglobulin. The RW analysis is aimed at identifying these proteins and recognizing them as syphilitic. This becomes the basis for obtaining a false positive result.

Causes

It was described above why a patient may receive a false positive result when testing for syphilis. Here is a list of conditions that can lead to this:

• myocardial infarction;
• alcoholic, food poisoning;
• acute, chronic liver pathologies, hepatitis D, C, B;
• soft tissue or bone injuries;
• age-related changes in the functioning of the patient’s body;
• tuberculosis;
• autoimmune diseases.

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Attention! The information presented in the article is for informational purposes only. The materials of the article do not call for self-treatment. Only a qualified doctor can make a diagnosis and give treatment recommendations based on the individual characteristics of a particular patient.

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How to take a blood test for the Wasserman reaction - test indications, preparation and interpretation of results

Syphilis is accompanied by numerous symptoms and has a large number of clinical forms. Its recognition is based on a comprehensive clinical and laboratory examination of the patient. General analysis blood for syphilis carries little information, so it is not used to diagnose the disease.

The following materials can be taken for analysis:

• blood from a finger and vein;
• cerebrospinal fluid - cerebrospinal fluid;
• discharge of hard chancre (ulcers);
• areas of regional lymph nodes.

The choice of material and diagnostic method depends on the stage of the disease. We will talk about what tests are taken for syphilis in the next section.

Classification of methods for laboratory diagnosis of disease

IN initial stage You can use the bacterioscopic method, based on identifying the pathogen - Treponema pallidum - under a microscope. In the future, serological tests based on the determination of microbial antigens and antibodies produced by the body in biological material are widely used.

Bacteriological studies are not carried out, since the causative agent of syphilis grows very poorly on nutrient media under artificial conditions.

All methods for detecting treponema, that is, types of tests for syphilis, are divided into two large groups:

1. Direct, which directly detect the microbe itself:

• dark-field microscopy (detection of treponemes on a dark background);
• RIT test – infection of rabbits with the test material;
• polymerase chain reaction (PCR), which detects sections of the genetic material of a microorganism.

2. Indirect (serological), based on the detection of antibodies to the microbe that are produced by the body in response to infection.

Serological tests are divided into two groups

Non-treponemal:

• reaction of complement fixation with cardiolipin antigen (CCk);
• microprecipitation reaction (MPR);
• rapid plasma reagin (RPR) test;
• test with toluidine red.

Treponemal:

• reaction of complement fixation with treponemal antigen (RSCT);
• Treponema immobilization reaction (RTI or RIBT);
• immunofluorescence reaction (RIF);
• passive hemagglutination reaction (RPHA);
• enzyme immunoassay (ELISA);
• immunoblotting.

The methods of these analyzes are quite complex, so we will focus mainly on when they are carried out and how accurate information they provide.

Let’s say right away that the basis for diagnosing syphilis is serological methods. What is the test for syphilis called: in each case, the examination may include different techniques. Below we will talk about them in more detail.

Direct tests

Their detection under a microscope convincingly proves the presence of treponemes. The probability of syphilis reaches 97%. However, microbes can be detected in only 8 out of 10 patients, therefore negative test does not exclude the disease.

Diagnosis is carried out during periods when there is chancre or skin rash. It is in the discharge of these infectious elements that they look for the causative agents of the disease.

A more effective, but at the same time more expensive and complex analysis is the detection of treponemes after pre-treatment with fluorescent antibodies. These are substances that “stick” to microbes and form a “glow” in the microscope field.

The sensitivity of the methods decreases with a long duration of the disease, treatment of ulcers and rashes with antiseptics, and also after treatment.

The biological method for diagnosing RIT is highly specific, but expensive, and the result is obtained only after a long time, when the infected animal has developed the disease. Currently, the method is practically not used, although it is practically the most accurate of all. An excellent blood test for syphilis to detect the genetic material of treponemes is PCR. Its only limitation is the relative high cost of diagnostics.

Serological methods

Non-treponemal tests

RSKk and RMP

The most famous of these tests is the Wasserman reaction. This is a method of rapid diagnosis (express test for syphilis), based on a similar reaction of antibodies from the blood of a sick person to the treponemes themselves and to cardiolipin obtained from bovine heart. As a result of this interaction of antibodies and cardiolipin, flakes are formed.

In Russia this analysis practically not used. It was replaced by the microprecipitation reaction. The disadvantage of the method is its low specificity. A false-positive blood test for syphilis occurs in tuberculosis, blood diseases, systemic lupus erythematosus, during pregnancy, after the birth of a child, during menstrual bleeding and in many other cases. Therefore, with positive RW, more accurate diagnostic methods are used.

After infection, the reaction becomes positive after two months. With secondary syphilis it is positive in almost all patients.

The microprecipitation reaction, which replaced the Wasserman reaction, has a similar mechanism. It is inexpensive, easy to implement, quick to evaluate, but can also give a false positive result. These two tests are used as screening tests.

RMP becomes positive a month after the appearance of chancre. To carry it out, blood from a finger is used.

Can a syphilis test be wrong? Of course yes, especially when using non-treponemal tests.

Causes of acute false-positive samples when using RMP:

• acute infectious diseases;
• pneumonia;
• myocardial infarction;
• stroke;
• injuries and poisoning.

Chronic false-positive results often occur in the following diseases:

• tuberculosis;
• brucellosis;
• leptospirosis;
• sarcoidosis;
• rheumatic diseases;
• Infectious mononucleosis;
• malignant tumors;
• diabetes;
• liver cirrhosis and others.

If controversial tests arise, treponemal serological tests are used to clarify the diagnosis.

RPR and toluidine red test

The rapid plasma reagin test (syphilis rpr test) is another type of reaction with cardiolipin antigen. It is used in the following cases:

• population screening;
• suspicion of syphilis;
• donor examination.

Let us also mention the test with toluidine red. All these methods are used to evaluate the effectiveness of treatment. They are semi-quantitative, that is, they decrease with recovery and increase with relapse of infection.

Negative results of non-treponemal tests most likely indicate that the subject does not have syphilis. Therefore, nontreponemal tests are used to assess cure. The first such analysis should be taken 3 months after completion of the course of treatment.

Treponemal tests

Treponemal tests are based on the use of treponemal antigens, which significantly increases their diagnostic value. They are used in the following situations:

• positive screening test (microprecipitation reaction);
• recognition of false positive screening results;
• suspicion of syphilis;
• diagnosis of latent forms;
• retrospective diagnosis when the patient had previously suffered from the disease.

RIT and RIF

The highest quality (highly sensitive and highly specific) are RIT and RIF. The disadvantages of these methods are complexity, time, and the need for modern equipment and trained personnel. In most cured patients, treponemal tests remain positive for many years and therefore cannot be used as a criterion of cure.

RIF becomes positive two months after infection. If it is negative, the patient is healthy; if it is positive, the probability of illness is high.

RIT is especially often used in case of positive results of bladder cancer to exclude or confirm the disease. It is highly sensitive and allows you to tell with great accuracy whether a patient has syphilis or not. However, the test becomes positive only three months after infection.

Immunoblotting

Immunoblotting is even more sensitive than RIF, but less sensitive than RPGA. It is used infrequently, mainly for the diagnosis of syphilis in newborns.

The listed methods are not suitable for screening, that is, rapid detection of the disease, because they become positive later than the microprecipitation reaction.

ELISA and RPGA

Modern highly informative standardized methods for diagnosing syphilis - ELISA and RPGA. They are inexpensive, quickly installed and tested in large quantities. These tests can be used to confirm the diagnosis.

The RPGA analysis becomes positive with primary seropositive syphilis, that is, with the appearance of chancre (a month after infection). It is especially valuable in diagnosing late and congenital forms of the disease. However, RPGA must be complemented by at least one nontreponemal and one treponemal test for diagnostic accuracy. This triple test is the most reliable test for syphilis. The disadvantage of RPGA is the persistence of a positive reaction for a long time, which does not allow the test to be used as a criterion for cure.

An ELISA test for syphilis becomes positive three weeks after the disease. The disadvantage of ELISA is that it can be false. A false positive reaction occurs with systemic diseases, metabolic disorders, and also in children born to sick mothers.

Flaws serological methods led to the development of the most advanced methods that do not give errors, but are still expensive and rarely used - gas chromatography and mass spectrometry.

Algorithm for diagnosing syphilitic infection at different stages

In the primary seronegative period (up to 2 months after infection), a search for treponema is carried out in a dark field or using fluorescent antibodies.

For primary seropositive, secondary and latent syphilis, RMP and ELISA are used, and RPGA is used as a confirmatory test.

In patients with relapses of secondary syphilis, elements of the rash are examined, trying to isolate treponemes from them for microscopic examination.

In the tertiary period, bladder cancer is negative in a third of patients. ELISA and RPGA are positive, but they may not indicate tertiary syphilis, but a previous disease. A weakly positive test indicates recovery rather than tertiary syphilis.

When making a diagnosis of “congenital syphilis,” the presence of the disease in the mother, the difference in the rates of breast cancer in the mother and child, positive ELISA and RPGA in the newborn, and immunoblotting are taken into account.

Pregnant women must be examined for syphilis, especially those who have already had a stillbirth, an undeveloped pregnancy, or early miscarriages. They carry out RMP, ELISA, RPGA. They are examined for the presence of the disease before terminating pregnancy.

Rules for obtaining a test for syphilis

To get a referral to the laboratory, you need to visit your local physician. If you want to get tested faster, this can be done in a private laboratory without a referral (for example, Invitro laboratories do a test for syphilis quickly and anonymously).

How to get tested for syphilis? Blood is donated in the morning, on an empty stomach. You can only drink clean water.

Preparation: Two days before the test, you need to exclude fatty foods and especially alcohol from your diet.

How is the analysis taken? in the usual way from a finger or ulnar vein.

How long does it take to test for syphilis? The test result is usually ready the next day. The transcript can be taken from a doctor or laboratory.

How long is the analysis valid? For up to three months.

Cerebrospinal fluid analysis

In some cases, a cerebrospinal fluid test is taken to diagnose neurosyphilis.

This examination is prescribed to all patients with latent syphilis if they have signs of pathology nervous system, as well as with latent and late neurosyphilis.

In addition, the analysis is performed on all patients after recovery if they maintain positive serological reactions. We have already written in our article that this phenomenon happens quite often.

A cerebrospinal fluid analysis for syphilis is prescribed and performed only by a doctor.

Cerebrospinal fluid is obtained by puncture between two vertebrae lumbar region. It is collected in 4 ml in two test tubes. Then the puncture site is treated with iodine and covered with a sterile bandage. After the puncture, the patient should lie on his stomach with the foot end of the bed raised for at least 3-4 hours, then he can lie on his side. Bed rest after puncture is indicated for two days.

The cerebrospinal fluid from the first test tube is examined using generally accepted reactions for protein content, cells, and determination of signs of meningitis (inflammation of the meninges).

Cerebrospinal fluid from the second tube is examined for the content of antibodies to treponema using the Wasserman reaction, RMP, RIF and RIBT, which we discussed above.

According to the severity of the disorders, four types of changes in the cerebrospinal fluid are distinguished. By analyzing them, the doctor can conclude about the presence of different forms of damage to the nervous system (vascular neurosyphilis, syphilitic meningitis, meningovascular syphilis, tabes dorsalis, late mesenchymal neurosyphilis), as well as about the recovery of the patient with positive serological tests.

Syphilis is considered a sexually transmitted disease, the main culprit of which is Treponema pallidum. This bacterium can enter the body after sexual contact, or through household contact.

Diagnostic measures aimed at identifying this disease are complex. Test results can be affected by various antibiotics, pregnancy, and other factors that will be described in the article.

When is a test for syphilis prescribed - indications for diagnosis

Some patients, when coming for examination to a gynecologist or andrologist, do not provide objective information about the quality of their sex life.

Perhaps the reason is simple embarrassment, or perhaps it is due to a lack of information in the field of sexually transmitted diseases.

The doctor can refer you for examination even if syphilis does not manifest itself in any way, and the patient is 100% sure that he could not become infected with this disease. The fact is that the pathology in question can be transmitted through household contact, or be asymptomatic.

Testing for syphilis is prescribed if:

• You need to register if you are pregnant.
• The patient wishes to donate blood as a donor.
• There is a prospect of occupying a certain position (military, medical worker, cook, etc.), which requires passing a special medical commission.
• The person is in prison.
• There was sexual intercourse with a patient with syphilis.
• The mother of a newborn baby suffers from syphilis.
• The patient showed signs of this disease. Often these are rashes in the genital area.
• The first analysis confirmed the presence of the disease in question.

Regular blood testing is done if syphilis is present. This is necessary to control the quality of treatment measures.

After therapy, blood is also taken from the patient for research.

How to get tested for syphilis correctly -

For research manipulations they often use blood from a vein. In certain situations, a laboratory technician can take the required sample for diagnosis from a finger or from the spinal cord.

The period from the moment of submission to the receipt of results may vary: from one day to two weeks. Everything will be determined by the type of testing.

When preparing to take a blood test to identify the disease in question, you should adhere to the following recommendations:

• Fatty foods should be excluded from the diet the day before the test. It will provoke opalescence of the blood serum, which will distort the results obtained.
• You should abstain from food for at least 8 hours before testing for syphilis.
• Alcohol and nicotine may interfere with reaction assessment. Experts advise not to drink drinks containing alcohol 24 hours before the test, and you should hold off on cigarettes for at least an hour before the test.
• If the patient is taking antibiotics, this analysis should be carried out at least a week after the end of treatment.

Methods for submitting material for research and deciphering indicators

Nowadays, none of the diagnostic methods of this disease cannot guarantee the accuracy of the information received. In any case, there are errors, and they can reach 10%.

In this regard, they use complex of research methods.

Serological analysis - nonspecific and specific tests

This type of diagnosis is indicated for limited symptoms of the disease or its complete absence.

There are two types of serodiagnosis:

1.Nonspecific tests

They are relevant when you need to test a large group of people for syphilis, but this technique is not suitable when you need to confirm the diagnosis.

Testing is not difficult, but the final assessment must be made by a doctor.

These types of diagnostics include the following tests:

A) Precipitation microreaction (MR)

Such a study is indicative after one month after infection. The examination requires blood pricked from a finger, but sometimes cerebrospinal fluid can be used.

Positive test result ( Antibodies in titer vary from 1:2 to 1:320 ) does not mean that the patient has syphilis: the diagnosis can be definitively confirmed by taking additional tests.

A negative reaction can result from two options:

• The patient does not have syphilis.
• There is syphilis, but at the initial stage of development.

B) Wasserman reaction ( P.B. RW)

The testing material used here is the same as in the analysis described above.

This examination method can provide objective information at least 6 weeks after infection. We can talk about the presence of this venereal pathology if the antibody titers are 1:2 - 1:800.

The results of analyzes for RV are evaluated by the following mathematical signs:

• « — "There is no syphilis.
• « + “or” ++” - a weakly positive reaction is stated.
• « +++ "- positive reaction.
• « ++++ “The patient has a sharply positive reaction to syphilis.

2. Specific tests

There are many different tests for this type of screening that focus on specific antibodies. They do not appear in the blood immediately, but about a month after infection and can remain there for several years (if untreated).

The doctor must reasonably choose one type of analysis or another, know about each of them in detail, navigate the results obtained, and be able to differentiate the diagnosis after receiving an answer.

The most common types of specific tests are:

A) Immunofluorescence reaction (RIF)

Relevant in the very early stages of syphilis, but the optimal period for testing is 6-8 weeks after infection.

The study requires capillary/venous blood.

• Pregnancy, defects connective tissue may cause a false reaction, which is assessed by the sign “ — «.
• Positive results are expressed as pluses (“ + ") from one to four.

B) Passive agglutination reaction (RPGA)

During this test, a small amount of blood is removed from a finger/vein, which is then mixed with red blood cells from a sheep/rooster. If the causative agent of this disease is present in the bloodstream, the microbodies stick together, followed by their sedimentation.

This type of testing is highly sensitive: it can confirm a positive reaction to syphilis long after treatment.

Mononucleosis and errors in the structure of connective tissue can also cause a false positive reaction.

It takes a maximum of 1 hour to receive an answer, and patients can test themselves 4 weeks after infection: for more early stages antibodies will not be produced in sufficient quantities.

You can judge how long the infection remains in the blood by the titers:

• If their value does not exceed 1:320, the infection occurred recently.
• The higher the titers, the longer the treponema remains in the body.

B) Enzyme-linked immunosorbent assay (ELISA)

One of the most reliable methods for diagnosing this disease, which began to be used at the end of the last century.

It is very indicative already 21 days after infection, and a positive result of 98-99% will indicate the presence of syphilis.

ELISA is often used after nonspecific tests, or in combination with some specific tests.

ELISA test by detecting one or another group of antibodies in the blood ( IgA, IgM, IgG) makes it possible to determine the stage of the disease:

• If the blood sample taken containsIgA, but absentIgM,IgG: no more than 14 days have passed since Treponema pallidum entered the body.
• If identifiedIgA,IgM, but noIgG: infection occurred about 28 days ago.
• The presence of all of the above antibodies in the blood indicates that more than a month has passed since infection.
• If the blood reaction to the presenceIgA is negative, andIgM,IgG positive: a huge period of time has passed since the moment of infection or the treatment of the disease was successful.

D) Immobilization reaction of Treponema pallidum (RIBT)

One of the most popular methods for diagnosing syphilis.

There is no point in using it in the early stages of infection, however, after the 12th week, the results of the RIBT test are 99% reliable.

Apply this method diagnostics for suspected neurosyphilis, syphilis internal organs, or in combination with nonspecific tests.

When taking durable antibiotics, the patient must wait at least 25 days after the end of therapy. Water-soluble antibiotics require less time to be eliminated from the body: 7-8 days.

Blood is taken from a vein on an empty stomach, and the results are interpreted as a percentage of immobilization:

• If the level of immobilization does not exceed 20%, the test for syphilis is considered negative.
• If 50% is exceeded, the reaction to this pathology is positive.

In other cases, a repeat study is prescribed.

D) Immunoblotting

One of the latest methods a test that is used when other tests give questionable results.

With this diagnostic procedure, it is possible to detect even a minimal amount of antibodies in the blood: it has almost 100% accuracy.

Not all clinics carry out such testing: it is not cheap.

Laboratory analysis

The cost of the analysis in question is very low, and you can find out the result within 30 minutes.

1. To carry out such a study, a sample is taken from the patient from ulcerative/erosive defects , which are located in the genital area. Microscopic examination of a sample is often carried out in a laboratory.

The affected areas are initially wiped with saline solution. This will help protect the damaged area from harmful microorganisms.

2.Next, using a special loop, irritate the surface several minutes until a white-transparent liquid appears. You should be more careful with this manipulation: it is impossible for blood impurities to get into the sample taken.

3. The extracted liquid is transferred to transparent glass. Sometimes it is mixed with saline solution.

We can talk about a positive reaction when typical treponemes are identified, which will have at least 8 curls. If the result is negative, the procedure is repeated (sometimes several times).

Indicates that a person is infected and is an indication for specific antibacterial therapy. This disease is easily transmitted by contact and other mechanisms and often leads to damage to internal organs.

Types of analyzes

Blood is taken for syphilis if the disease is suspected. Indications for testing are:

• initial examination of the patient;
• identification of a latent form of the disease;
• donor screening;
• performing surgical interventions;
• screening of the population.

The main tasks of laboratory diagnostics are to identify the genome of the causative agent of syphilis (treponema pallidum) and antibodies to them. The following tests may be positive:

Laboratory diagnostics are crucial in making the correct diagnosis.

Positive microscopy results

Microscopic methods are widely used to identify the causative agent of this disease. These include dark-field microscopy, Romanowsky-Giemsa examination, and treponemal silver impregnation. The materials for the study are:

Dark-field microscopy is positive for syphilis. When light is directed onto a slide with a patient’s specimen, pale treponemas begin to glow against a completely dark background. They have a thin, spiral shape and are capable of various types movements (translational, rotational, flexion). Treponemas have several whorls.

For syphilitic infection, analysis using the Romanovsky-Giemsa method is very informative. The preparation is stained with special substances, dried and examined under a microscope. An oil medium is used for this. Positive analysis occurs if microbial cells are visually detected. The pink color allows you to distinguish pale treponema from other spirochetes. Less commonly used in the diagnosis of syphilis is the silver impregnation method, in which the pathogen turns dark brown or black.

Wasserman reaction for syphilis

To establish the disease, the Wasserman reaction is used. Currently, it is rarely performed. In modern laboratories, the RW test has been replaced by the anticardiolipin test. The Wasserman reaction is... The disadvantage of the analysis is its low information content. A false positive result is often observed.

In the primary form of syphilis, RW becomes positive only 6–8 weeks after infection. For research, blood is taken from a vein. The essence of the reaction is that in response to the addition of a special protein to the patient’s blood, a complex is formed and a precipitate is observed. This happens if the material contains Treponema pallidum cardiolipin.

According to the results of the analysis, crosses are given. A false result is often observed if a person has other diseases (lupus erythematosus, tuberculosis). The result may be affected by:

The result in the form of 1 cross is regarded as doubtful. In this case, the hemolysis reaction is weakly expressed. 2 crosses are placed when the destruction of the patient’s red blood cells is partially delayed. This indicates a weakly positive test. 3 crosses indicate a pronounced delay in hemolysis. Wasserman's reaction is considered positive. The answer is possible in the form of 4 crosses. It indicates the presence of a disease.

Results of other studies

When examining large groups of people for syphilis, the RPR test is one of the most informative. It is more accurate than Wasserman's reaction. This study refers to non-treponemal methods, that is, it is aimed at searching for antibodies (immunoglobulins) against lipids of microbial cells or phospholipids of destroyed tissues.

When performing an RPR test, a false positive result is observed in 1–2% of cases. Antibodies in the blood of patients are detected within 7–10 days after the onset of chancre. Over time, the antibody titer decreases and by the 3rd period of the disease a false negative result is possible. Even if 4 crosses are given for syphilis, additional treponemal tests are performed (RIF, ELISA, RPGA, immunoblot and RIBT).

After nonspecific tests, serodiagnosis is performed. The immunofluorescence reaction and enzyme immunoassay are very informative. These reactions become positive in last days asymptomatic (incubation) period. They are informative in diagnosing latent syphilis and identifying false-positive reactions.

People who have recovered from the disease have specific antibodies in their blood throughout their lives. RIF, RPGA and ELISA are not used to determine the effectiveness of antibacterial therapy. Decoding a blood test for syphilis is simple. The result is often presented as crosses or percentages. The “-” sign indicates that the person is not infected with Treponema pallidum. 2 crosses indicate a dubious result. A weakly positive analysis is equivalent to 3 crosses. 4 crosses indicate the presence of Treponema pallidum in the body.

Why are the tests positive?

You need to know the reasons for positive laboratory tests performed when syphilis is suspected. Detection of treponemes or antibodies indicates infection. The main causes of the occurrence and development of the disease:

The reason for positive results for syphilis may be improper patient preparation, the presence of concomitant pathology, and errors during the analysis itself.

What to do for sick people

If Treponema pallidum or immunoglobulins are detected in the patient's body, treatment is required. Additionally, the following studies can be carried out:

• general and biochemical tests blood;
• Analysis of urine;
• MRI or CT;
• radiography;
• examination of mucous membranes and skin;
• cerebrospinal fluid examination.

If the test result is positive for syphilis, the doctor must determine the timing of infection and the period (stage) of the disease. After this, a treatment regimen is selected.

If treponema pallidum is detected, systemic antibiotics (penicillins, macrolides, tetracyclines) are prescribed. The most effective are Doxal, Dixicycline-Acos, Bicillin-5, Benzylpenicillin sodium salt, and Forte.

In the later stages, along with antibiotics, bismuth and iodine preparations, immunostimulants and physiotherapy are indicated. At the end of the course of therapy, control tests are organized. Thus, if syphilis is suspected, treponemal and non-treponemal tests are performed. In addition to the patient himself, his sexual partners should be examined.

The Wasserman reaction, successfully used for diagnosing and monitoring the effectiveness of treatment of syphilis, is widely used in mass examinations of donors, pregnant women, and workers educational institutions, trade and catering.

Wasserman reaction - how to get tested?

This analysis is one of the main serological studies. It is recommended to donate blood for analysis on an empty stomach. This is due to the fact that the use alcoholic drinks and fatty foods may affect the accuracy of the results obtained. Blood is drawn from both a vein and a finger.

Wasserman's false reaction

The Wasserman reaction is based on the production of antibodies by the immune system in the blood serum of a sick person. Antibodies are detected as a result laboratory research antigen - cardiolipin. Positive reaction is considered if antibodies are detected in the blood sample being tested. However, there are frequent cases of the so-called false-positive Wasserman reaction. This is due to the paradoxical reaction of the human immune system when the immune system begins to fight the cells of its own body. It is with this scenario that the same anti-lipid antibodies are tested in the blood as with syphilis.

Causes of false positive Wasserman reaction

According to statistics, such results occur in 0.1-2% of cases of the total number of studies. Possible reasons can be:

• viral infections (hepatitis, intestinal infections, malaria, );
• systemic diseases(lupus erythematosus, dermatomyositis, scleroderma and others);
• cardiac inflammatory diseases;
• pregnancy;
• blood diseases;
• taking alcohol and drugs.

The false-positive Wasserman reaction in some of the listed cases may become negative after a certain long period (a year or more) even without any treatment.

Diagnosis of a false positive reaction Wasserman during pregnancy is a stress factor for a woman preparing for motherhood. To exclude an erroneous diagnosis in such cases, a repeat serological test is recommended, which is carried out 2 weeks after the first. Treatment can be prescribed only after a sharply positive reaction has been re-established.

As a rule, a nonspecific serological reaction in most cases is weakly positive. It should also be taken into account that the detection of a weakly positive Wasserman reaction may also depend on the methodological purity and technique of conducting the study.