Why you need to get tested
Tuberculosis is a very complex and serious disease that cannot be cured in a week. More than 30% of the world's population suffers from this disease, and treatment requires the strongest medications. Treatment periods can vary from six months to one year depending on the severity of the disease.
The bacillus was discovered by scientist Robert Koch, and the method of combating it, the Mantoux test, was invented by the French doctor Charles Mantoux.
Why is the bacillus so dangerous? It is very easily transmitted from a sick person to a healthy person through airborne droplets or household objects. Moreover, the tuberculosis bacillus can remain on the surfaces of objects for a long time and not die. Without treatment, the disease can affect all human organs. Such people do not live long, six years at most. In order to prevent the spread of tuberculosis, Mantoux vaccination or other blood tests are performed.
Many people are interested in what types of blood tests are there and how are they taken? How can an ordinary person determine whether he has tuberculosis or not? Any person should have a minimum of knowledge about blood tests for tubercle bacilli. It is not difficult to understand and does not require medical qualifications.
Diaskin test as an alternative to Mantoux: contraindications and side effects
With the Diaskin skin test, exaggeratedly strong reactions are less common than with Mantoux. However, as with any other tuberculin diagnosis, there are contraindications.
At the time of injection, the child should not have:
- acute allergic conditions;
- infectious diseases in the period of exacerbation;
- skin diseases for at least two weeks;
- protein allergies.
The test is contraindicated for rheumatism, bronchial asthma, or if the child suffered a severe infectious disease less than a month ago. Staying in a group where quarantine has been declared for any disease will also be a contraindication.
Did you know? In order for the study to show an objective result, it is not combined with vaccinations. After any vaccination, at least a month must pass before testing the child for the tuberculosis pathogen.
Side effects of the test occur in very rare cases and in this case the test is also a better alternative than Mantoux. Of the possible consequences, only general poor health and a slight increase in temperature were noted.
Features of the Mantoux test
The Mantoux test is a vaccine that is injected under the skin. Mantoux contains a small dose of the drug tuberculin and the reaction is similar to an allergy. At the site of tuberculin injection, redness and a button are formed, the size of which determines the presence of Koch's bacillus in the body. If the reaction is positive, this does not mean that the person is sick. The sample itself does not provide a 100% guarantee of the presence of bacteria, and additional types of diagnostics will be required.
If the button does not exceed 1 mm, then the person has not encountered Koch’s wand. If the body is infected with Koch's bacillus, the reaction will be pronounced. However, the result may be affected by allergies or skin diseases, which will lead to a false conclusion. The result of a button diameter of 4 mm and redness should be especially alarming. This indicates a strong immune system capable of fighting the virus. In such situations, a blood test for tuberculosis is prescribed instead of Mantoux. Other research methods are currently being introduced.
The Ministry of Health allowed children to have a blood test instead of the Mantoux test
Novosibirsk experts spoke about the incidence of tuberculosis among children and adolescents
The Ministry of Health has provided parents with the opportunity to choose a method for diagnosing tuberculosis for their child. Among the testing options, the results of which are required to be accepted in a preschool institution, are the Mantoux test, the Diaskin test and the T-test, performed using a blood test.
This information is published on the website of the Ministry of Health. It is reported that new recommendations for testing for tuberculosis have been adopted by the All-Russian Society of Phthisiologists.
“The results of each of these tests will be considered sufficient for admission of the child to a preschool institution,”
– says the Ministry of Health.
Earlier, at a press conference dedicated to the Day against Tuberculosis, Novosibirsk experts spoke about the prevalence of this infection among children in the Novosibirsk region, and also recalled the importance of timely diagnosis.
As noted by Zhanna Shakuro, head of the children's department of the branch of the State Budgetary Healthcare Institution NSO NOPTD "Anti-tuberculosis dispensary No. 6", the incidence of tuberculosis among children in the Novosibirsk region is decreasing, although not at such a rapid pace as among the adult population.
According to her, the bulk of the sick are children of preschool age. However, only about 13% of patients are children from disadvantaged families.
“To date, we have no relapses after treatment in children and adolescents. And the earlier the tuberculosis process is detected at an early stage, the more effective its treatment and the more favorable the prognosis for this patient.”
, - said the expert.
Tatyana Kolpakova, head of the clinical department of the Federal State Budgetary Institution "Novosibirsk Research Institute of Tuberculosis" of the Russian Ministry of Health, recalled that, according to current legislation, every child upon admission to school or a preschool institution must be examined for tuberculosis. The main diagnostic method remains tuberculin diagnostics (or Mantoux test), Diaskintest, computed tomography and x-ray examination are used as additional methods.
The Mantoux test is performed on children under 18 years of age, and Diaskintest on adolescents from 15 to 18 years of age. At the same time, Tatyana Kolpakova clarified that these are not interchangeable techniques: the main diagnostic method remains the Mantoux reaction, other procedures can be performed as additional ones.
The expert also added that there are no absolute contraindications against the Mantoux reaction.
“Now a problem is emerging when specialized specialists prescribe a medical exemption from tuberculin diagnostics, which is currently illegal, they violate the legislation of the Russian Federation”
, she warned.
However, the child’s parents have the right to refuse tuberculin diagnostics, and in this case, X-rays become the most reliable alternative.
“But an X-ray examination already shows the tuberculosis process itself in the child’s body; we cannot see the moment when the child is infected, that is, when tuberculosis bacteria entered him from the outside.”
,” explained Tatyana Kolpakova.
According to her, the advantage of the Mantoux reaction is that this method allows you to track infection and prescribe preventive treatment that will prevent the development of the tuberculosis process.
“Parents often tell us: “I know that my child is healthy.” But knowing does not mean being healthy. To really know that your child is healthy, you need to undergo an examination,”
– the specialist reminded.
After the press conference, information appeared about the expansion of tuberculosis diagnostic methods through the T-test (T-SPOT), performed using a blood test. The proposal to give parents a choice in this matter was initiated by the Commissioner for Children's Rights under the President of the Russian Federation, Anna Kuznetsova.
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Other research methods
In addition to the Mantoux test, there are other types of tests:
- bronchoscopy;
- sputum analysis;
- enzyme immunoassay test ELISA;
- PCR or polymerase chain reaction means obtaining a copy of DNA enzymes;
- biochemical research;
- complete blood count;
- quantiFERON-TB Gold - quantinferon test;
- IGRA.
Currently, another test has been introduced in Russia, it is called Diaskintest and has many advantages. One of them is that there is no contact with blood, but they help to dislocate the Koch bacillus.
Of the listed assays, QuantiFERON-TB Gold and IGRA are rarely seen in audits. They represent screenings and indicate the presence of antibodies. In Russia, such methods are practically not used.
Sometimes Mantoux can be replaced with the Quantiferon test for children who are allergic to Mantoux. But if a disease is detected, additional checks cannot be avoided. However, the Quantiferon test does not determine which type of disease is incubating or active.
The quantiferon method is similar to the Interferon Gamma Release Assays (or IGRA) test. It correctly indicates the presence of bacteria in the body.
If necessary, a biochemical blood test is prescribed to check protein levels. If tuberculosis is passive, then the protein will be normal. If it is acute, then cholesterol, urea and lysozyme increase.
To diagnose the extrapulmonary type of tuberculosis, additional tests of saliva and urine, semen and sweat will be needed.
What is the name of the test that replaces Mantoux?
The Mantoux reaction, also known as the Pirquet test, is carried out using an intradermal or cutaneous test to detect tuberculin.
The reason for this is more than serious - in our country there is an increase in the number of tuberculosis patients. For every hundred thousand people, eighty are diagnosed with this serious illness.
Despite the fact that medicine has long learned to fight this terrible disease, the mortality rate from it is still quite high. The key to successful treatment of any disease is its early detection. It is for this purpose that examinations are carried out from early childhood.
However, few people know that this method also has disadvantages. The fact is that the Mantoux test is positive not only in sick people, but also in healthy people who have been vaccinated against tuberculosis at one time. It should be taken into account that today, due to mass vaccination, most children are vaccinated - accordingly, the result of the reaction will be positive . And for allergy sufferers, this method poses a threat.
Alternative
Therefore, the question of alternative research naturally arose. These include:
- blood analysis ;
- Diaskintest;
- quantiferon test;
- polymerase chain reaction.
They are resorted to in cases where the Mantoux reaction is suspicious (it turns out to be more than 6 mm ), or the person is referred to a tuberculosis clinic . They make it possible to identify those who are actually sick with tuberculosis, without capturing those who have been vaccinated.
Photo 1. If the Mantoux test is positive, they resort to other testing methods to confirm the diagnosis.
Blood tests ELISA and PCR
Enzyme-linked immunosorbent test (ELISA) of blood is a quick and convenient method and is done frequently, replacing Mantoux. In this study, blood is taken from a vein. This is a completely acceptable option, however, it cannot answer the question of what stage the disease is at. This procedure helps to detect only the presence of antibodies. Currently, ELISA is considered not very reliable.
A PCR blood test is to obtain a copy of the DNA enzymes of the tuberculosis bacilli. Such research is more effective. This is a modern method that allows you to identify Koch's wand. The basis is to search for the DNA of the bacillus.
Blood testing is more consistent with plausibility. The advantage of this analysis is the short time period of five hours. This diagnosis has proven itself positively, is more often used in blood tests and is based on the detection of tuberculosis through a chain reaction.
In addition, it allows you to show the number of bacilli, and this is not carried out by enzyme immunoassay. If it is necessary to urgently perform an analysis and identify the source of infection, then this particular analysis is used. We can say that such a study is more effective and has correct results compared to other analyzes. However, it does not show the local focus of the disease. Additional checks will be necessary: an x-ray and a urine test.
Additional diagnostic methods
Is it possible to use PCR instead of Mantoux?
Due to its high information content, this test is indicated for people with an increased risk of infection. However, such sensitivity of the analysis sometimes causes false positive test results. The essence of the method is based on the detection of sections of mycobacterial DNA in the patient’s blood, which allows us to judge the form of tuberculosis and the generalization of the process. The method has no age restrictions, the results of the study can be obtained already on the first day. Its disadvantages are that it detects, among other things, dead Koch bacilli, which does not allow diagnosing a relapse of tuberculosis.
Diagnosis using the quantiferon test
It can be considered as an analogue of Diaskintest; it allows you to find out whether the child has an immune response to mycobacteria. The test requires blood sampling from the child - it is performed in 3 test tubes using antigen proteins. The test is highly accurate and allows you to detect even latent forms of tuberculosis.
General blood test
In some situations, a general blood test is taken at the initial stages of the disease. If the Mantoux test is positive, then a general blood test can be done. With tuberculosis, changes occur in the composition of the blood. Such an analysis really helps to find out about the presence of the disease at a later stage. In the initial stages of the disease, the blood does not change, so there is no point in donating it.
General analysis and what they pay attention to. The fundamental indicator is ESR and it varies depending on age. In children it is up to 10 mm/h, in adults up to 30 mm/h. In patients with tuberculosis it reaches up to 50 mm/h. Also an indicator of infection is the growth of eosinophils, an increase in the number of leukocytes and a decrease in the level of hemoglobin and lymphocytes.
Decoding the results
The test is interpreted by the attending physician. The result can be positive or negative. If no bacteria are found in the blood, the result is considered negative. In this case, the suspicion of the presence of the disease is removed. If bacteria causing the disease are found, the result is considered positive.
This result indicates that the patient may be suffering from tuberculosis. The ELISA result may be positive when detecting AMG immunoglobulin. This suggests that infection is possible. In this case, there may be no symptoms and the presence of an active stage of the disease.
A negative result occurs when the doctor was unable to detect immunoglobulins. If a person is sick, then a general analysis will show an increase in the erythrocyte sedimentation rate of ESR by more than 50 units. With the disease, the eosinophil count will increase. Thus, it can be noted that blood testing is a more accurate procedure than the Mantoux reaction.
Who needs to donate blood for tuberculosis
It is necessary to donate blood to people who fall into a dangerous group. These are doctors, prison workers, homeless shelters, anti-social individuals, drug addicts and alcoholics, AIDS patients and those who have reduced immunity, and who have undergone chemotherapy. Sick people who have open tuberculosis are dangerous. People who have been in contact with a sick person should also get tested.
It is advisable to donate blood for infection to citizens who have visited places with a high degree of infection: India and China, South Africa and Pakistan, Nigeria and Indonesia.
Blood is donated on an empty stomach. Before this, it is contraindicated to consume alcohol and medications, which may affect the conclusion.
People with permanent bronchitis or frequent pneumonia may be referred for an X-ray. The dangerous group includes patients with diabetes mellitus, permanent adrenal insufficiency, stomach ulcers, as well as those who have undergone surgery to remove an ulcer.
The tests do not require special preparation. The only thing the doctor can tell you is what to exclude from food or medications before diagnosing.
Only pulmonologists decide what additional tests need to be taken, because one blood test may not be enough.
In addition to fluorography, patients are given a lateral X-ray. Expensive, but the most accurate would be computer or magnetic and resonance imaging.
Mantoux test
The Mantoux test is a popular diagnostic method in the modern world for infection with tuberculosis agents.
The procedure for carrying out a preventive measure is simple: the substance tuberculin is injected under the child’s skin using an injection. After the injection, a papule appears on the skin, the size and condition of which serves as a criterion for assessing the state of human health.
A measuring ruler is used to evaluate the results.
There are some indications for performing the Mantoux reaction:
- if the baby was vaccinated with BCG in the first week after birth, the first diagnosis is carried out at the age of one year;
- then every year the Mantoux reaction is carried out with a change in the injection site (either in the right or in the left hand);
- A child undergoes the Mantoux test every year until he reaches fourteen years of age.
A diagnostic test is not carried out if the child has a number of contraindications.
Factors prohibiting the use of the test include:
- Atopic dermatitis.
- Diagnosed epilepsy.
- A severe allergic reaction in a child.
- Acute form of chronic diseases.
The Mantoux test remains the most commonly used test for tuberculosis, but its effectiveness is questionable.
Often, after BCG, the test result shows a false positive value, therefore, when detecting tuberculosis in this way, it is necessary to undergo a number of other diagnostic measures.
Which method should I choose for my child instead of Mantoux?
Before entering a preschool or school, tuberculosis must be excluded for absolutely every child in accordance with current legislation. The main method of screening diagnostics has been and remains tuberculin diagnostics.
The federal clinical recommendations of the Russian Society of Phthisiologists clearly define the algorithm for the management of children entering (attending) educational institutions in case of refusal of immunodiagnostics. According to the requirements of sanitary and epidemiological rules 3.1.2.3114-13 “Prevention of tuberculosis”, children who have not undergone tuberculin diagnostics are admitted to a children's educational organization if they have a phthisiatrician's conclusion about the absence of the disease.
It should be remembered about the danger of tuberculosis in children, as well as the fact that a completely safe and absolutely reliable method for diagnosing it has not yet been invented. That is why the child must be examined for tuberculosis, and the choice of method remains with the parents.
Why hasn't Mantoux been completely replaced by this modern test?
Because he also has shortcomings. If tuberculin quite often gives false positive results, then diaskintest is dangerous due to false negative ones:
1. This test is not sensitive against M. bovis, the causative agent of bovine tuberculosis. Which can also cause disease in humans in 5-15% of cases of all forms of the disease. And also against atypical mycobacteria, with indolent infections. In different sources, information regarding the causative agent of bovine tuberculosis and the sensitivity of Diaskintest to it differs. From order 109 it follows that the test is sensitive to the presence of virulent M.bovis in the body. And from the instructions for the drug - the Vidal reference book - it follows that the test is sensitive only to Mycobacterium tuberculosis - the causative agent of human tuberculosis. Although the typical pathogen of human tuberculosis is the leading cause of the disease, other mycobacterium tuberculosis pathogenic for humans should not be missed when diagnosing the disease. Therefore, an X-ray examination is carried out for children with a turn according to the Mantoux results and a negative diaskintest.
2. Diaskintest may be negative in the early stages of infection. And in the early stages of development of the tuberculosis process. Therefore, with a Mantoux turn and a negative diaskintest, it is recommended to repeat the latter after 2 months.
3. A false negative result may occur in patients with severe forms of tuberculosis in the decay stage. And in patients with immunodeficiency conditions (HIV, immunosuppressive therapy, etc.), against the background of other severe chronic diseases.
Therefore, not all phthisiatricians are optimistic about this drug as a replacement for Mantoux for mass tuberculin diagnostics.
It can be performed simultaneously with Mantoux on different hands, or after it. The interval between them does not matter, since both are skin tests, not vaccinations. At the same time, if, based on the Mantoux results, a turn is set, then a negative result of the diaskintest does not remove this diagnosis. In this case, a negative result indicates that the child’s body is currently successfully coping with the pathogen that came from outside and no additional treatment is required. But a positive result is an indication for prescribing preventive treatment with isoniazid.
Last changes
Since 2020, Diaskintest began to be used in children from eight to seventeen years old inclusive, instead of Mantoux, for mass diagnosis of tuberculosis in schoolchildren, in accordance with the Order of the Ministry of Health of the Russian Federation dated December 29, 2014. No. 951 and the methodological recommendations approved therein for improving the diagnosis and treatment of respiratory tuberculosis.
In children under 7 years of age, the Mantoux test is used to be able to track immunity after BCG and select children for BCG revaccination.
Currently, Diaskintest is considered an alternative to Mantoux. That is, if the parents refused Mantoux, but gave the child a Diaskintest and it is negative, the child is admitted to the preschool.
