Tuberculosis was diagnosed by finding the bacterium Mycobacterium tuberculosis in the clinical specimens taken from the patient. While other investigations may strongly suggest tuberculosis as a diagnosis, they can not be sure.
Complete medical evaluation for tuberculosis (TB) should include medical history, physical examination, chest X-ray examination and microbiology (from sputum or some other appropriate samples). It may also include tuberculin skin tests, other scans and X-rays, surgical biopsy.
Video Tuberculosis diagnosis
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Medical history includes getting pulmonary tuberculosis symptoms: prolonged and prolonged cough for three weeks or more, chest pain, and haemoptysis. Systemic symptoms include low grade remittance fever, chills, night sweats, loss of appetite, weight loss, fatigue, and sputum production that starts out mucus but turns purulent. Other parts of the medical history include previous TB exposures, infections or diseases and medical conditions that increase the risk for TB disease such as HIV infection. Depending on the type of patient population surveyed, at least 20%, or as many as 75% of pulmonary tuberculosis cases may be asymptomatic.
Tuberculosis should be suspected when diseases such as pneumonia have lasted more than three weeks, or when respiratory diseases in healthy individuals do not respond to ordinary antibiotics.
Maps Tuberculosis diagnosis
Physical exam
Physical examination is performed to assess the general health of the patient. This can not be used to confirm or exclude TB. However, certain findings indicate the presence of TB. For example, blood in sputum, significant weight loss and night sweats may be caused by TB.
Microbiology studies
The exact diagnosis of tuberculosis can only be done by breeding the Mycobacterium tuberculosis organism from the specimens taken from the patient (most often sputum, but may also include pus, CSF, biopsied tissue, etc.). Diagnoses made other than by culture can only be classified as "probable" or "alleged". For diagnoses that exclude the possibility of tuberculosis infection, most protocols require that two separate cultures both test negative.
Sputum
Sputum and culture preparations should be made for acid-resistant bacilli if the patient produces sputum. The preferred method for this is fluorescence microscopy (auramin-rhodamin staining), which is more sensitive than conventional Ziehl-Neelsen staining. In cases where there is no spontaneous sputum production, the sample may be induced, usually by inhalation of salts or salts containing nebulose with a bronchodilator solution. A comparative study found that inducing three phlegm samples was more sensitive compared to three gastric washes.
Alternative sampling
In patients unable to produce sputum samples, common alternative sample sources for diagnosing pulmonary TB include gastric leaching, swab larynx, bronchoscopy (with bronchoalveolar lavage, bronchial washing, and/or transbronchial biopsy), and fine needle aspiration (transtrakeal or transbronkial). In some cases, more invasive techniques are required, including tissue biopsy during mediastinoscopy or thoracoscopy.
PCR
Other mycobacteria are also quickly acidic. If a positive smear test, PCR or gene probe can differentiate M. tuberculosis from other mycobacteria. Even if the sputum is smear negative, tuberculosis should be considered and excreted only after negative culture. M, m, d./D
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Many types of cultures are available. Traditionally, cultures have used LÃÆ'¶wenstein-Jensen (LJ), Kirchner, or Middlebrook media (7H9, 7H10, and 7H11). AFB cultures can differentiate different forms of mycobacteria, although the outcome of this can take four to eight weeks for conclusive answers. Faster new automated systems include MB/BBS, BACTEC 9000, VersaTREK, and Mycobacterial Growth Indicator Tube (MGIT). Microscopic Observations The Vulnerability of Drug Observations may be a faster and more accurate method.
Radiography
Chest X-ray and CT
In active pulmonary TB, infiltrates or consolidations and/or cavities are often seen in the upper lung with or without mediastinal or hilus lymphadenopathy or pleural effusion (TB pleuritis). However, lesions can appear anywhere in the lungs. In dispersed TB, the pattern of many small nodules throughout the lung area is common - the so-called miliary TB. In HIV and people with other immunosuppression, any disorder may show TB or chest X-rays may even appear completely normal.
Chronic thoracic abnormalities may lead to conjecture, but not always diagnostic, TB. However, thoracic radiography may be used to rule out the possibility of pulmonary TB in someone who has a positive reaction to the tuberculin skin test and no symptoms of the disease.
Cavitation or consolidation of the upper lobe apex of the lung or tree buds may be seen on chest X-rays of affected patients. Tree-in-bud marks may appear on CT CT in some patients affected by tuberculosis, but are not specific to tuberculosis.
FDG PET/CT
FDG PET/CT may play some useful roles in patients with confirmed or suspected TB. These roles include the detection of active TB lesions, assessment of disease activity, differentiation between active and latent disease, assessment of disease level (stage), monitoring of response to treatment, and identification of potential biopsy targets.
Abreugraphy
The variant of X-Ray chest, abreugraphy (from the name of the discoverer, Dr. Manuel Dias de Abreu) ​​is a small radiographic image, also called miniature mass radiography (MMR) or mini-chest radiography. Although the resolution is limited (not allowing the diagnosis of lung cancer, for example) it is quite accurate for the diagnosis of tuberculosis.
Much cheaper than traditional X-Ray, the MMR was quickly adopted and widely used in several countries, in the 1950s. For example, in Brazil and in Japan, tuberculosis prevention legislation came into force, requiring ca. 60% of the population underwent MMR screening.
This procedure is not favored, as the incidence of tuberculosis decreases dramatically, but is still used in certain situations, such as screening of prisoners and immigration applicants.
Immunological test
ALS Assay
Antibodies from Lymphocyte Secretion or Antibody in Lymphocyte Supernatant or ALS Assay are immunological tests to detect active diseases such as tuberculosis, cholera, typhoid etc. Recently, the ALS assay nods the scientific community because it is rapidly used for the diagnosis of tuberculosis. This principle is based on the secretion of antibodies from in vivo active B plasma cells found in the blood circulation for a short period of time in response to TB antigens during active TB infection rather than latent TB infection.
Transdermal Patch
A similar approach to the ALS test. The transdermal patch is the recommended method for detecting active M. tuberculosis circulating in the patient's blood vessels. These skin patches contain antibodies that recognize secreted bacterial proteins, MPB-64 passing through the blood capillaries of the skin that create an immunologic response. If the patch detects this secreted bacterial protein, the surrounding skin will be flushed.
Tuberculin skin test
Two tests are available: Mantoux and Heaf tests.
Mantoux skin test
Mantoux skin test is used in the United States and authorized by the American Thoracic Society and Centers for Disease Control and Prevention (CDC).
If a person has had a positive tuberculin skin test history, other skin tests are not necessary.
Heaf test
The Heaf test was used in England until 2005, and rated on a four-point scale. Mantoux test is now used.
The Mantoux test is equivalent to a positive level performed with 10 TU (0.1 ml 100 TU/ml, 1: 1000)
- 0-4Ã, mm induration (Heaf 0 to 1)
- 5-14 mm inductors (Heaf 2)
- More than 15mm induration (Heaf 3 to 5)
tuberculin reaction CDC classification
Induration (palpable lifting of the hardened skin area) of more than 5-15 mm (depending on one's risk factor) to 10 Mantoux units is considered a positive result, indicating TB infection.
- 5 mm or more positive
- HIV-positive people
- Recent contacts from the TB case
- People with nodular or fibrotic changes in CXR are consistent with old TBs being cured
- Patients with organ transplants and other immunosuppressive patients
- 10 mm or more positive
- Last arrival (less than 5 years) from countries with high prevalence
- Injecting drug users
- Citizens and employees from high-risk joint arrangements (for example, prisons, nursing homes, hospitals, homeless shelters, etc.)
- Mycobacteriology lab personnel
- People with clinical conditions that place them at high risk (eg, diabetes, prolonged corticosteroid therapy, leukemia, end-stage renal disease, chronic malabsorption syndrome, low weight, etc.)
- Children less than 4 years old, or adult children and adolescents exposed to adults in high-risk categories
- 15 mm or more positive
- People without known TB risk factors
- (Note: Targeted skin testing programs may only be performed among high-risk groups)
Conversion of tuberculin test is defined as an increase of 10 mm or more in a 2-year period, regardless of age.
BCG vaccine and tuberculin skin test
There is disagreement about the use of the Mantoux test on people who have been immunized with BCG. The US recommendation is that in managing and interpreting the Mantoux test, previous BCG vaccination should be ignored; UK recommendation is interferon-? tests should be used to help interpret the positive tuberculin test; also, the UK does not recommend serial tuberculin skin tests in people who already have BCG (a key part of US strategy). In their guidelines on the use of QuantiFERON Gold, the US Centers for Disease Control and Prevention states that while Quantiferon Gold is not affected by BCG inoculation tuberculin test can be affected. In general, the US approach tends to generate more false positives and more unnecessary treatments with potentially toxic drugs; The British approach is equally sensitive in theory and must also be more specific, because of the use of interferon-? test.
Based on US recommendations, the diagnosis and treatment of latent tuberculosis infection (LTBI) is considered for every person vaccinated with BCG whose skin test is 10 mm or more, if any of these conditions exist:
- Interact with others with infectious TB
- Born or have lived in a high TB ​​prevalence country
- Continuously exposed to populations where TB prevalence is high.
already reviewed in detail.
Adenosine deaminase
In 2007, a systematic review of adenosine deaminase by the NHS Health Assessment Program concluded "There is no evidence to support the use of the ADA test for the diagnosis of pulmonary TB, but there is ample evidence to support its use in pleural fluid samples for the diagnosis of pleural TB, very high, and slightly lower for TB meningitis.In pleural TB and TB meningitis, ADA tests have a higher sensitivity than other tests. "
Nucleic acid amplification test (NAAT)
NAATs for TB are heterogeneous test groups using polymerase chain reaction (PCR) or trans-mediated (TMA) amplification or other forms of nucleic acid amplification methods to detect mycobacterial nucleic acid. These tests vary where the sequence of nucleic acids they detect and vary in accuracy. In the 2000s decade, the two most commonly commercially available tests were direct mycobacterium tuberculosis (MTD, Gen-Probe) and Amplicor (Roche Diagnostics) direct tests. In 2007, NAAT's systematic review by the NHS Health Technology Assessment Program concluded that "the accuracy of the NAAT test is far superior when applied to respiratory samples compared to other specimens.Although the results are not statistically significant, AMTD tests appear to perform better than other commercial tests which is available today. "
An observational study before-after 2007 found that the use of MTD tests reduces improper tuberculosis therapy. This study found the accuracy of the MTD test as follows:
Overall
- 92% sensitivity
- 99% specificity
Discard positive patients
- 99% sensitivity
- 98% specificity
BTA patient is negative
- 62% sensitivity
- 99% specificity
In 2010 the Xpert MTB/RIF test, another NAAT for TB, became commercially available and, as the CDC said in 2015, it began "revolutionizing TB control by contributing to the rapid diagnosis of TB disease and drug resistance. detect Mycobacterium tuberculosis complex (MTBC) and resistance to rifampicin (RIF) in less than 2 hours For comparison, standard culture may take 2 to 6 weeks for MTBC to grow and conventional drug resistance tests can add 3 weeks to go. "
Complete blood count
Although the number of complete blood cells has never been diagnostic, normocytic anemia and lymphopenia are common. Neutrophilia is rare [iron deficiency anemia can develop with isoniazid treatment]. Urea and electrolytes are usually normal, although hypocalcaemia and hyponatremia may occur in TB meningoencephalitis due to SIADH. In advanced disease, hypoalbuminemia, hyperproteinemia, and hyperglobulinemia may be present.
The level of erythrocyte sedimentation usually increases.
Interferon-? release the test
Interferon-? (Interferon-gamma) release test (IGRAs) is a relatively new test for tuberculosis. IGRAs are based on the antibacterial antibody Mycobacterium tuberculosis capability for the initial 6-pass antigen target (ESAT-6) and culture filtrate protein 10 (CFP-10) to stimulate interferon-gamma host production. Because these antigens are present in only a few non-TB or non-TB mycobacteria in the BCG vaccine strain, they are considered more specific than tuberculin skin tests.
The QuantiFERON-Gold In-Tube and T-SPOT.TB blood tests use this antigen to detect people with tuberculosis. Lymphocytes from patients' blood are incubated with antigens. These tests are called interferon? test and unequal. If the patient has been exposed to tuberculosis before, T lymphocytes produce interferon? in response. The QuantiFERON-TB Gold In-Tube uses the ELISA format to detect the entire production of interferon blood ?. The difference between the tests is that QuantiFERON-TB Gold quantifies the amount of total interferon? when intact blood was exposed to antigen (ESAT-6, CFP-10 and TB 7.7 (p4)), while the Guidelines for FDA use approved QuantiFERON-TB Gold released by CDC in December 2005. In October 2007, the FDA granted approval from QuantiFERON -TB Gold In Tube for use in the United States.
Immunospot tests associated with enzyme (ELISPOT) are other blood tests available in the UK that can replace the skin test for diagnosis. T-SPOT.TB, a type of ELISPOT test, calculates the amount of activated T lymphocytes secreting interferon?
To diagnose latent TB , three systematic IGRA reviews concluded the test noted an excellent specificity for the test to distinguish latent TB from previous vaccinations.
According to a study from Korea, where there is a high LTBI prevalence, QuantiFERON-TB Gold and T-SPOT.TB have good sensitivity but reduce specificity for diagnosing active TB because their ability to detect latent tuberculosis. In a recently published meta-analysis, with data from both developed and developing countries, QuantiFERON-TB Gold In Tube has a sensitivity collected for 81% active TB and 99.2% specificity, whereas T-SPOT.TB has a sensitivity collected from 87.5% and specificity 86.3%. In head-to-head comparison, IGRA sensitivity exceeds TST. However, several subsequent studies have reported higher TST sensitivity than for IGRA in patients with active TB; one large study reported 90% sensitivity for TST and only 81% for the QuantiFERON-TB Gold test.
A study at Stanford University confirms that the addition of an immune booster can make IGRA more reliable in terms of separating the positives of negative individuals. A study from the University of Southampton shows that variations in ambient temperature can have a profound effect on IGRA performance. A recently published study from the same group also provides evidence that immunosuppressive agents significantly interfere with IGRA performance, raising concerns about their reliability in immunosuppressive patients. Although, IGRA replaces the TST in most clinical settings but variability becomes a concern when reading the results
Tuberculosis detection using trained mice
The international nonprofit organization APOPO has worked with Sokoine University of Agriculture in Tanzania to train African giant rats ( Cricetomys ansorgei ) to detect tuberculosis "scents". A new study shows that "rats improve detection of pediatric tuberculosis by 67.6%" and that training these creatures can help address current challenges associated with the diagnosis of this disease in children.
Tuberculosis classification system used in the US
The current clinical classification system for TB (Grades 0 to 5) is based on the pathogenesis of the disease.
U.S. Citizenship and Immigration Services have additional TB classification (Class A, B1, or B2) for immigrants and refugees developed by the Centers for Disease Control and Prevention (CDC). The
References
Jarvis J, Gao Y, de Graaf H, Hughes S, Allan RN, Williams A, Marshall B, Elkington P, Faust SN, Tebruegge M (2015). "Suhu lingkungan berdampak pada kinerja tes In-Tube QuantiFERON-TB Emas". J Infect . 71 : 276-80. doi: 10.1016/j.jinf.2015.04.004. PMID 25869537. CS1 maint: Banyak nama: daftar pengarang (tautan) .
Catatan
- Pemeriksaan Kesehatan Orang Asing (Pengungsi dan Imigran) - Divisi Global Migrasi dan Karantina, CDC (situs web).
- Target Tuberkulin Testing dan Perawatan Infeksi Tuberkulosis Laten 2000 ATS/CDC (fulltext, format PDF) (Pembaruan 2001-2003).
- Lalvani A (November 2003). "Mengalami infeksi laten: jalan menuju kontrol TB yang lebih baik". Thorax . 58 (11): 916-8. doi: 10.1136/thorax.58.11.916. PMCÂ 1746498 . PMID 14586040.
- Diagnostik Nema V. Tuberkulosis: Tantangan dan peluang. Lung India 2012; 29: 259-66.
Tautan eksternal
- Diagnosis Molekuler Universitas Washington, Divisi Mikrobiologi | Deteksi berbasis PCR dalam sampel jaringan langsung
- Diagnostik Medis Oxford Immunotec | Zona Pendidikan dan Pembelajaran TB
- Alat pengetik Spoligo (Solusi Bio Ocimum) untuk mendeteksi TB
Source of the article : Wikipedia
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