In our country Manta put test to all children years are more senior: many young mothers and fathers since own childhood remember small “button“ on a hand. Why this test is necessary what it can tell about and what to help to?
Tuberculosis and its manifestations
Test to Mant (its other names - test of the Tuberculine test, tuberkulinovy test, a tuberkulinodiagnostika, tuberculin skin - test, PPD test) represents an immunoassay on existence in an organism of a tuberculosis infection.
Tuberculosis is the chronic bacterial infection causing the greatest number of death around the world. The causative agent of a disease, a tuberculosis mikobakteriya (Koch`s stick, Koch`s bacillus), extends vozdushno - a drop way - during the sneezing, cough, conversation. Originally dangerous bacillus affects lungs, however infections can be subject and other bodies. At the majority infected never tuberculosis develops. It happens only at people to the weakened immune system (especially HIV - infected) when the bacillus breaks all protective barriers of an organism, breeds and causes actively current disease.
Infectious are only those patients at whom tuberculosis is in an active stage. However the patients receiving adequate treatment against tuberculosis for at least 2 weeks are not dangerous any more.
At an active stage of a disease the following signs can be observed:
a severe cough lasting 3 weeks and more (when tuberculosis is localized in lungs);
breast pain, cough with allocation of a phlegm and, perhaps, blood;
weakness or fatigue;
loss of weight and appetite;
fever, heat and night sweating;
transfer of a disease of another (is possible
at localization of tuberculosis in lungs);
infected with tuberculosis bacteria, but not to hurt or not to be infectious. It is called “a latent tuberculosis infection“.
of People with a latent tuberculosis infection:
has no symptoms;
does not feel ill;
the disease among other people cannot extend
has normal results of radiological inspection of a thorax and dab of a phlegm.
When transition from a latent infection to an active phase of an illness comes, the person gets sick and at damage of lungs becomes infectious.
As the test “works“?
Reaction to Mant is a reaction of an organism to intracutaneous introduction of a tuberkulin. In the place of introduction of a preparation on skin there is a specific inflammation caused by a congestion T - lymphocytes - the specific blood cells responsible for cellular immunity. The essence of reaction is that parts of mikobakteriya as if attract to themselves lymphocytes from the blood vessels of skin lying nearby. Those lymphocytes react to introduction of a tuberkulin that “are already familiar“ with a tuberculosis mikobakteriya. If “meeting“ with the causative agent of a disease took place, then such lymphocytes there will be more, an inflammation - more intensively, and reaction to the test will be positive.
If to speak simply, reaction of an organism on tuberkulin is one of kinds of an allergy. Let`s make a reservation at once: positive reaction to Mant is not the absolute proof of infection with tuberculosis. For an exception or confirmation of this diagnosis it is required to conduct a number of other researches: exception of connection with vaccination of BTsZh; thorax fluorography; microbiological crops of a phlegm; IFA (the immunofermental analysis) which reveals antibodies to tuberculosis; PCR (polimerazny chain reaction), revealing the causative agent of tuberculosis, etc. Often, in total with positive result of test to Mant, these additional methods of diagnostics help to pass a final decision on the diagnosis.
a number of the diseases which are unambiguous contraindications for test statement to Mant Exists. Treat them:
sharp and chronic infectious and somatic diseases in an aggravation stage (test to Mant is put in 1 month after disappearance of all symptoms of an illness or right after quarantine removal);
allergic states in an aggravation stage;
Immunity after preventive inoculations can also influence sensitivity to a tuberkulin therefore Mant needs to plan test before carrying out any inoculations. And if to your child test is already delivered to Mant, then it is possible to impart him - in the absence of contraindications right after an assessment of results of test. If test to Mant is made not to inoculations, and after them, then the tuberkulinodiagnostika has to be carried out not earlier than in 4 weeks after the carried-out inoculation.
Carrying out procedure
In our country test Manta is carried out by
once a year, irrespective of results of the previous test, since age of 12 months. To children 1 years are younger test to Mant is not put as the result will be doubtful or inexact, in connection with age features of development of immune system: reaction can be lozhnootritsatelny.
Test to Mant is put in a sitting position by the special tuberkulinovy syringe vnutrikozhno (in an average third of an internal surface of a forearm). After introduction of a tuberkulin the specific vybukhaniye of the top layer of skin better known as “button“ is formed.
“Button“ cannot smear
with brilliant green, peroxide or cream. It is strictly forbidden to allow its contact with water and other liquids: it can affect appearance of skin in the place of introduction of a tuberkulin and distort results of test. It is impossible to stick a wound with an adhesive plaster also: under it skin can sweat. Parents have to keep the kid from combing of “button“ in order to avoid an additional allergization. The wrong care of the place of introduction of a tuberkulin can affect result of test.
From history In 1882. the microbiologist Robert Koch opened a way of coloring which allowed it to see, identify and describe the causative agent of tuberculosis - a tuberculosis mikobakteriya, or Koch`s stick. For it in 1905 Koch got the Nobel Prize. In 1890 Koch invented vodno - the glyceric extract from mikobakteriya under the name “tuberkulin“ which is initially offered for treatment of tuberculosis, but was inefficient. Nevertheless, this important opening. Austrian Clemens Pirke in 1907 found out that at repeated contact of the patient with a tubercular anti-gene (tuberkuliny) allergic reaction is shown. Pirke suggested to put tuberkulin on povrezhdennuyuskalpely skin for diagnosis of tuberculosis (Pirke`s reaction), and a bit later the French doctor Charles Mantou began to enter tuberkulin vnutrikozhno. Widely applied still tuberkulinovy skin test, or reaction to Mant was so invented. Test in modification to Mant is applied in Russia since 1965.
the Assessment of results
On 2 - 3 - y day after introduction of a tuberkulin is formed by
specific consolidation of skin - a so-called papule. By sight it is the towering, a little reddened roundish site of skin. The papule differs from surrounding skin in the consistence: it more dense at the expense of a cellular infiltration around the place of introduction of a tuberkulin.
In 72 hours by a transparent ruler (that the maximum diameter of infiltrate was visible) is measured and register cross (in relation to a hand axis) the infiltrate size in millimeters. At the same time only the amount of consolidation is measured - reddening around consolidation is not a sign of immunity to tuberculosis or infected.
Reaction can be:
negative - lack of infiltrate (consolidation), hyperaemia (reddening) or existence of ukolochny reaction (0 - 1 mm);
doubtful - infiltrate (papule) of 2 - 4 mm in size or hyperaemia of any size without consolidation;
positive - the expressed infiltrate, a papule with a diameter of 5 mm and more. Such reaction can be slabopolozhitelny ( infiltrate of 5 - 9 mm); average intensity - of 10 - 14 mm; expressed − 15 - 16 mm or giperergichesky (too strongly expressed). Giperergicheskoy at children and teenagers is considered reaction with a diameter of infiltrate of 17 mm and more, adults have 21 mm and more, and also vezikulonekrotichesky reaction with formation of gnoynichok and necrosis.
False positive reaction. needs Separately to tell about false positive reaction to Mant - those cases when the patient is not infected with Koch`s stick, but at the same time test shows to Mant positive result. One of the most frequent reasons of such reaction is infection with not tubercular mikobakteriya. The allergic frustration which are available for the patient and recently postponed any infectious disease can be other reasons. There are no ways of reliable differentiation of reaction to tubercular and not tubercular mikobakteriya now (a native habitat not tubercular mikobakteriya - the soil and water; these bacteria cause diseases of skin, lungs, joints which manifestations are similar to tuberculosis). However the following factors can demonstrate tubercular infection:
giperergichesky (infiltrate of 17 mm and more) or the expressed reaction;
the long period which passed from the moment of vaccination of BTsZh (more than 7 years);
recent stay in the region with the increased circulation of tuberculosis (socially unsuccessful countries or regions of the country with big population density at a low standard of living);
the contact with the carrier of a tubercular stick taking place;
existence in a family of the patient of the relatives who were ill or infected with tuberculosis.
Venue. If the kid attends kindergarten or a day nursery, then test Manta is carried out in a procedural office of child care facility. As a rule, it is a planned mass tuberkulinodiagnostika on which terms of carrying out parents are notified in advance. If the child does not visit organized collective, then test is carried out in a procedural office of local children`s policlinic with the subsequent control of the local pediatrician.
terminology Questions . It is necessary to explain two terms which parents can face. First of all, it is so-called “bend“ of test to Mant - change (increase) of result of test (diameter of a papule) in comparison with last year`s result. Criteria of a bend are:
the first emergence of positive reaction (a papule of 5 mm and more) after negative or doubtful; strengthening of the previous reaction to 6 mm and more;
giperergichesky reaction (more than 17 mm), irrespective of prescription of vaccination;
reaction more than 12 mm later 3 - 4 years after vaccination of BTsZh.
a transparent ruler measure by
In 72 hours the amount of consolidation.
the bend forces the doctor to think of the infection which happened within the last year. For example, if the result of test for each of the last 3 years was 12 mm, and for the fourth year the result of 17 mm was received, then with high probability it is possible to speak about the happened infection. It is natural that at the same time it is necessary to exclude all influencing factors: an allergy to components of a tuberkulin, an allergy to other substances, recently postponed infection, the fact of recent vaccination by BTsZh or other vaccine, etc. In this case further joint action of the doctor and parents is complex inspection of the child for a diagnosis exception “tuberculosis“.
Busterny effect of test to Mant - effect of strengthening (from the English word boost - “strengthening“), i.e. increases in diameter of a papule at frequent (is more often than once a year) test statement (it is possible at suspicion on mass infection, contact with the tubercular patient etc.) . The effect is connected with increase in sensitivity of lymphocytes to a tuberkulin. The Busterny effect has also a reverse side: the people infected with a tubercular stick over the years lose ability to react on tuberkulin, and eventually the result of test becomes lozhnootritsatelny. At children this effect is expressed less, than at adults, however test statement to Mant more often than once a year is undesirable.
Illness or result of vaccination? It is extremely necessary to be able to differentiate positive result of tuberkulinovy test owing to vaccine-challenged immunity and manifestation of infection with tuberculosis. To distinguish one from another, it is necessary to know:
the size of a vaccine-challenged skin hem after immunization of BTsZh;
time, a past from the moment of vaccination or a revaccination;
results of the previous tests and current size of a papule.
the Hem which remained after vaccination of BTsZh is on the left shoulder, on border of the top and average third. As a rule, it has rounded shape, its sizes fluctuate from 2 to 10 mm, the average size - of 4 - 6 mm. communication between the size of a scar and duration of vaccine-challenged immunity Exists. So, at the size of a scar of 5 - 8 mm immunity duration at most of children makes of 5 - 7 years, and with a diameter of a hem of 2 - 4 mm - 3 - 4 years. Lack of a hem if in the first 2 years of life the result of test makes Manta 10 mm, speaks well for infection.
Besides, the important sign allowing to distinguish vaccine-challenged immunity from infection is pigmentation existence (brownish coloring of the place where there was a papule) later 1 - 2 weeks after test statement to Mant. The papule appearing after vaccination usually has no accurate contours, it is pale - pink and does not leave pigmentation. The post-infectious papule is more intensively painted, has accurate contours and leaves the pigmentation remaining about 2 weeks. The following signs testify to primary infection with a tubercular mikobakteriya:
for the first time revealed, after doubtful and negative reactions, the size of a papule of 5 mm and more;
increase in result in comparison with last year`s on 6 mm if it was the positive and caused by vaccination BTsZh;
resistant (throughout of 3 - 5 years) (hranyayushchayasya reaction with infiltrate of 10 mm and more;
giperergichesky reaction, irrespective of vaccination terms;
infiltrate more than 12 m in size and more later 3 - 4 years from the moment of vaccination;
the contributing factors: existence in a family being ill (or ill) tuberculosis, extra family contact with tubinfitsirovanny, stay in the endemic region, the low socioeconomic status, low education level of parents.
in case of suspicion on infection the child or the teenager immediately goes for consultation to the phthisiatrician.
If to your doctor did not manage to be determined by
, the positive result of test is connected with vaccination or infection, the pre-trial detention about not clear etiology of positive result of test becomes, and in 6 months test is put repeatedly. If at repeated test the result is again positive or will increase, then without additional researches the conclusion about infection becomes. At reduction of the size of a papule the conclusion about the vaccine-challenged nature of positive result of the previous test is drawn.
If the result is positive
In case test Manta showed to
positive result and all influencing factors are excluded: vaccination BTsZh and other vaccines, a recent infection, an allergy to components of a tuberkulin, - that for specification of the diagnosis conduct additional examinations. It is thorax fluorography, microbiological crops of a phlegm, inspection of members of families.
Children and teenagers with for the first time the tuberculosis revealed by infection have the increased risk of development of clinically expressed tuberculosis: it is considered that at 7 - 10% of such children primary tuberculosis with all inherent symptomatology can develop. Therefore such children are subject to supervision in an antitubercular clinic within a year. Within 3 months he carries out chemoprophylaxis by an isoniazid. On the end of this period the child is given under supervision of the local pediatrician as “infected more than one year“. If a year later at the child signs of strengthening of sensitivity to a tuberkulin and giperergichesky reaction do not come to light, then it is observed by the pediatrician in accordance with general practice. At such children the result of annual test to Mant is carefully traced. Strengthening of reaction to 6 mm also more speaks about activation of an infection.
the Children infected more than one year with giperergichesky reaction on tuberkulin and increase in reaction to 6 mm are also more observed by
in a tubdispanser. He also carries out chemoprophylaxis within 3 months. If the result of test is positive, but the previous test was carried out not one, but two and more than a year ago, the child is considered “infected with an unspecified limitation period“. In this case carrying out repeated test in 6 months is recommended. By results of the second test the issue of need of supervision for a tubdispanser and chemoprophylaxis is resolved.
Important differences test Statement to Mant is often connected by
with carrying out vaccination of BTsZh, and at times parents even confuse these concepts. Attention: BTsZh vaccine (unlike many other vaccines), though is capable to prevent at children to 80% of severe forms of the Infection, is not a control device of a tuberculosis infection as does not prevent infection. Prevention of tuberculosis is based first of all on early identification of the people infected with a tubercular stick and their adequate treatment. Vaccine of BTsZh (Kalmet`s bacillus - Gerena; Bacillus Calmette - Guerin) is the tuberculosis vaccine prepared from a strain of the weakened live cow tubercular bacillus, Mycobacterium bovis which lost virulence for the person, being specially grown up in the artificial environment. Bacilli keep rather strong antigennost (ability to cause formation of the immune answer) to give to a vaccine due efficiency in prevention of tuberculosis. The standard calendar of introduction of BTsZh looks as follows: the first introduction of a vaccine is carried out in maternity hospital, to first 3 - 7 days of life (in the absence of contraindications); further - in 7 years (with preliminary control of test to Mant and provided that it is negative) and in 14 years (also with test control to Mant before vaccination) - that who did not take root in 7 years. In settlements where the epidemiological situation on tuberculosis is unsuccessful, the revaccination is carried out to 6 - 7, 11 - 12 and of 16 - 17 years. of BTsZh healthy faces only with negative reaction on tuberkulin are subject to the Revaccination (repeated introduction to appropriate terms).