False positive tuberculin test

False-positive tuberculin skin tests: what is the absolute

Type of tuberculin test did not modify these results. In 18 studies involving 1,169,105 subjects, the absolute prevalence of false-positive TST from NTM cross-reactivity ranged from 0.1% to 2.3% in different regions. Conclusions: The effect on TST of BCG received in infancy is minimal, especially > or =10 years after vaccination. BCG received after infancy produces more frequent, more persistent and larger TST reactions Retest and use clinical judgment, experts advise. Most of the positive results in routine tuberculosis screening of health care workers are false positives. That statistical artifact is creating headaches for employee health professionals as they try to find the best TB testing method and struggle with unexpected results A false-positive tuberculin test result. The tuberculin test can be helpful in the diagnosis of Mycobacterium tuberculosis infection. A recent CMAJ article mentions that false-positive test results can occur in those who have received BCG (bacille Calmette-Guérin) vaccination in childhood 1 but that positive reactions usually wane over time A TB blood test is the preferred method of testing for people who have received the BCG vaccine in order to prevent false-positive reactions. TB blood tests are also called interferon-gamma release assays or IGRAs False positive tuberculosis test. A 36-year-old member asked: Could you tell me what happens if a tuberculosis test shows positive? Dr. Heidi Fowler answered. Psychiatry 25 years experience + PPD: If you have a + PPD then you will be screened to determine if you have TB infection or TB disease. The physician will obtain a medical history, physi..

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However, even use of the preferred skin test technique (intradermal injection of purified protein derivative via the Mantoux method) can lead to either false positive or false negative results. Interpretation of a Mantoux test can be influenced by cross reactions with other mycobacteria, intertester variation, host-response variation, and. High rates of false-positive results on the tuberculin skin test (TST) have been reported among patients treated with methotrexate, regardless of bacillus Calmette-Guerin vaccination status, according to the results of a prospective, single-center cohort study recently published in Seminars in Arthritis and Rheumatism

False positives plague TB screening of health care workers

False-positive tuberculin test in Behçet's syndrome. Kaplinsky N, Movshovits M, Frankel O. In a patient with active Behçet's syndrome, every needle puncture produces a pustule. We report herein a patient with Behçet's syndrome that presented as uveitis and erythema nodosum and developed later to the full blown picture of the disease The positive results were deemed false, based on retesting to the point of reversion to negative. The results from all the cellular immunity tests for Mycobacterium tuberculosis infection (i.e., the skin test with either of two tuberculin solutions and the two commercial IGRA methods) are influenced by biological factors and technical problems with the tests Geronimo's vet has suggested the recent positives may be false positives caused by the tuberculin used in earlier tests. Mr Eustice claimed this wasn't true because the Enferplex tests detect bovine TB protein itself, not antibodies. However, Dr Watt, told us: He [Mr Eustice] was wrong on that Type of tuberculin test did not modify these results. In 18 studies involving 1169105 subjects, the absolute prevalence of false-positive TST from NTM cross-reactivity ranged from 0.1% to 2.3% in different regions. CONCLUSIONS: The effect on TST of BCG received in infancy is minimal, especially ≥10 years after vaccination

Diagnosis for tuberculosis(1)

False-Positive and False-Negative Results You may end up getting a false positive TB skin test if you have received a bacillus Calmette-Guerin (BCG) vaccine in the past. While BCG is not given in the United States because it is not that effective, it is still in use in other countries The Mantoux test or Mendel-Mantoux test is a tool for screening for tuberculosis and for tuberculosis diagnosis. It is one of the major tuberculin skin tests used around the world, largely replacing multiple-puncture tests such as the tine test. The Heaf test, a form of tine test, was used until 2005 in the UK, when it was replaced by the Mantoux test. The Mantoux test is endorsed by the American Thoracic Society and Centers for Disease Control and Prevention. It was also used in the USSR. Low positive values (0.35-1.0 IU/mL) may not repeat as positive in some patient populations; some authorities recommend that the patient be retested to confirm low positive tests. My calculated value of 1.06 (TB antigen tube value minus the Nil tube value) can show a 52% reversion rate. Copy link to clipboard. Bookmark Even so, these mycobacteria can trigger false positive reactions to bovine tuberculin in the skin test. That is why in the UK we also use avian tuberculin alongside bovine tuberculin, since the cross-reactions ('lumps') triggered by these environmental mycobacteria tend to be larger at the avian than the bovine injection site during skin.

A false-positive tuberculin test result CMA

Mantoux Test doesn't distinguish between an active and a latent infection. If positive reaction occurs, additional tests such as sputum smear, culture and chest X-rays etc are necessary to establish a diagnosis of an active TB infection. Several factors can lead to false-positive or false-negative skin test reactions. False Positive Reaction Occasionally, a person infected with or exposed to other Mycobacterium species, for example Mycobacterium kansasii, will give a false-positive Mantoux tuberculin skin test result for tuberculosis. Positive results must be followed up by other tests such as chest X-rays to look for signs of active tuberculosis disease

Although accurate identification of Mycobacterium tuberculosis is the gold standard for tuberculosis (TB) diagnosis, there have been several reports of false-positive results. After identifying a sudden increase in extensively drug-resistant TB, false-positive mycobacterial culture tests were suspected, and we contacted the supranational reference center for molecular typing These false-positive results accumulated under conditions of standard clinical practice, resulting in unacceptably high false-positive rates. Conclusions that accumulation of false-positive results is mathematically predictable further supports discontinuing the use of the QuantiFERON-TB test in low-risk populations

Your GP may suggest having a test when you register as a patient. Mantoux test The Mantoux test is a widely used test for latent TB. It involves injecting a small amount of a substance called PPD tuberculin into the skin of your forearm. It's also called the tuberculin skin test (TST) Adult patients with rheumatic diseases were evaluated with a TST and two IGRAs for LTBI screening. We compared TST and IGRA results in patients treated and not treated with methotrexate and analyzed for factors associated with positive TST results. Conclusions: Our data suggest false-positive TST results associated with methotrexate therapy. Thus, we recommend against using the TST for LTBI screening in patients receiving methotrexate and the preferential use of IGRAs in such patients

Despite suggestions to the contrary, the chances of a false positive using the Enferflex test - the test requested by the owner in August 2017 and has been promoted by the British Alpaca Society.. These tests require only one office visit. A blood test might be useful if you're at high risk of TB infection but have a negative response to the skin test, or if you've recently received the BCG vaccine. Imaging tests. If you've had a positive skin test, your doctor is likely to order a chest X-ray or a CT scan False-positive and false-negative results People who received a bacillus Calmette-Guérin (BCG) vaccine against TB may have a false-positive reaction to the PPD test

How common is a false positive TB test? Type of tuberculin test did not modify these results. In 18 studies involving 1,169,105 subjects, the absolute prevalence of false-positive TST from NTM cross-reactivity ranged from 0.1% to 2.3% in different regions Type of tuberculin test did not modify these results. In 18 studies involving 1,169,105 subjects, the absolute prevalence of false-positive TST from NTM cross-reactivity ranged from 0.1% to 2.3% in different regions. Conclusions The effect on TST of BCG received in infancy is minimal, especially > or =10 years after vaccination Clusters of unexpected positive tuberculin skin test results have been previously reported, often in groups of low-risk persons tested with Aplisol that, on subsequent testing with Tubersol, were. An experience at our institution with false-positive tuberculin skin test (TST) results among a group of health care workers, which was associated with the use of Aplisol, contradicts these conclusions

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False-positive tuberculin skin tests: What is the absolute effect of BCG and non-tuberculous mycobacteria? December 2006 The International Journal of Tuberculosis and Lung Disease 10(11):1192-20 A marked increase in tuberculin skin test (TST) conversions among health care workers (HCWs) at the Grady Health System, Georgia, USA that began in mid-September 1999 was investigated. In the three 6-month periods before September 1999, baseline conversion rates were: 4 (0.09%) of 4670 HCWs tested between January and June 1998; 8 (0.2%) of 4363 tested between July and December 1998; and 5 (0.1. The major test advantage over tuberculin skin test (TST) is that BCG vaccinations and environmental mycobacteria may react with TST but are likely to have false positive QFT-G tests, albeit it can occur up to 9% of the time in foreign born subjects in the U.S. Therefore, the use of QFT-G alone for the detection of latent MTB. Although the focus of this review will be false-positive cultures for Mycobacterium tuberculosis, false-positive results can occur in the examination of acid-fast stained smears [2, 3], with nucleic acid amplification tests for tuberculosis , and in cultures for nontuberculous mycobacteria This is a retrospective analysis of repeating positive QFT assays as a strategy to identify false-positive results in HIV-infected patients at low risk for tuberculosis. The incidence of tuberculosis and the proportion of individuals coinfected with human immunodeficiency virus (HIV) in the United States is falling [ 1 ]

False positive tuberculosis test Answers from Doctors

False positive tuberculosis skin test results

False-Positive PPD Reactions Sometimes people who are not infected with M. tuberculosis will have a positive reaction to the PPD tuberculin skin test.This is called a false-positive reaction. two most common reasons for false positive PPD reactions are:- • infection with nontuberculous mycobacteria (mycobacteria other than M. tuberculosis. We found an unexpectedly high rate of positive tuberculin skin tests (TST) results in patients receiving methotrexate for rheumatic diseases, which are likely related to false-positive TST results. This association has a dose\x96response relationship and is independent of the effect of bacillus Calmette-Guerin vaccination and other relevant. • Both false-negative (negative results in people truly infected with M. tuberculosis) and false-positive (positive results in people not infected with M. tuberculosis) results may occur • They have issues with test-retest reliability, so if the same person is tested on more than one occasion, a different result may be obtaine

People who were born outside the United States who have had a vaccine called BCG may have a false-positive test result. Risks There is a very small risk for severe redness and swelling of the arm in people who have had a previous positive PPD test and who have the test again 49 years experience Infectious Disease. Not false +: Usually the TB skin test remains positive for a lifetime but does not reflect active infection necessarily at all. Send thanks to the doctor. 90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more Pathergy as a Cause of False-positive Tuberculin Skin Test Download Letters to the Editor The Pediatric Infectious Disease Journal • Volume 31, Number 1, January 2012 Ku80 autoantigen as a cellular coreceptor for ease (BD) according to the International mia.1 We report the first case of bacteremia in human parvovirus B19 infection Lines show the cumulative proportion of healthcare workers expected to test false-positive for latent tuberculosis infection (LTBI) if tested serially with QuantiFERON-TB on an annual basis, using.

Thus, inoculation of three PPD skin tests over a 21 month period in 44 initially ELISPOT negative individuals did not induce any false positive ELISPOT results. Time course of development of positive Mantoux results in the three participants who became tuberculin skin test (TST) positive as a result of repeated skin testing. These results show. Until the early 2000s, the tuberculin skin test was the standard for screening for latent tuberculosis infection. [] However, the test has limitations, including precise intradermal administration, the need for a follow-up visit to interpret the results, specific criteria for interpretation of the results, and the possibility of false-positive results with Bacillus Calmette-Guerin vaccination. ANSWER: Bacille Calmette-Guerin is a common cause of false positive tuberculosis tests. BCG is a vaccine strain of bacteria similar to tuberculosis that many countries use to reduce the risk of. Testing positive: This indicates that the body has been infected with the TB bacteria.An infection makes an individual extra sensitive to the tuberculin injection, which causes the test site to.

Answer • Bacille Calmette-Guerin is a common cause of false positive tuberculosis tests. BCG is a vaccine strain of bacteria similar to tuberculosis that many countries use to reduce the risk of. ATS and CDC recommend tuberculin testing in high-risk groups and generally discourage such testing in those at low risk to maximize use of resources and minimize false-positive results. ATS, CDC, and IDSA recommend tuberculin testing in the following high-risk individuals or groups Farhat M, Greenaway C, Pai M, Menzies D. False-positive tuberculin skin tests: what is the absolute effect of BCG and non-tuberculous mycobacteria? Int J Tuberc Lung Dis 2006; 10:1192. von Reyn CF, Horsburgh CR, Olivier KN, et al. Skin test reactions to Mycobacterium tuberculosis purified protein derivative and Mycobacterium avium sensitin. The tuberculin skin test. The TST - or Mantoux test - assesses inflammation in the dermis following intradermal injection of tuberculin protein. The test needs to be read 48-72 hours after administration. The diameter of induration gives a semiquantitative assessment of the likelihood of LTBI Ninety-four studies were evaluated - 67 for pulmonary tuberculosis (TB in the lungs) and 27 for extrapulmonary tuberculosis (TB elsewhere in other organs). Overwhelming evidence showed that the blood tests produced an unacceptable level of wrong results - false-positives or false-negatives - relative to tests endorsed by WHO. Problems of.

False-Positive Tuberculin Skin Test Results Linked to

  1. es if someone has developed an immune response to the bacterium that causes tuberculosis ().; Blood tests for TB are also available, and health care professionals may use them in place of the PPD skin test. The skin test is the preferred test in children under 5 years of age
  2. istration of Tuberculin. Faulty.
  3. The Mantoux tuberculin skin test is often used to screen people at high risk for TB. Those who have been previously immunized with the Bacille Calmette-Guerin vaccine may have a false-positive test result. The test may be falsely negative in those with sarcoidosis, Hodgkin's lymphoma, malnutrition, and most notably, active tuberculosis

False-negative reactions to the comparative intradermal tuberculin test for bovine tuberculosis (aPPD) equal to or greater than 4 mm (bPPD - aPPD) are considered positive for tuberculosis (Brasil 2016). However, cross-reactions with environmental mycobacteria can sensitize animals, leading to positive results on the intradermal test even in. Tuberculosis is a serious infection, usually located in the lungs, but possibly anywhere in the body. However, it is also possible that the positive test is the result of underlying TB-like germs that do not have the disease-causing potential of Mycobacterium tuberculosis (MTb), the agent of TB disease In 2010, the Canadian Tuberculosis Committee issued an updated Advisory Committee Statement on IGRAs, Footnote 4 which recommended the use of IGRA as a confirmatory test when false-negative or false-positive TST results are suspected. The following new recommendations will supersede the previous ACS

If positive tuberculosis skin test results occur, the first test ordered is usually a chest X-ray. An X-ray can determine if infiltrates or lesions are present in the lungs, which may indicate active TB. A symptom checklist will also usually be reviewed to determine if signs of TB, such as weight loss, coughing up blood, fever, and night sweats. The test detects the antibodies, not the antigen. That aside, it appears highly unlikely that earlier tests gave Geronimo any false positives. Dr Watt says: The work hasn't been done in alpacas specifically to show that bovine TB tests don't induce a positive test, but there's two reasons against that theory Defra's bovine tuberculosis test involves more than just a blood test; it requires an injection of tuberculin as a primer 10 to 30 days before the test, Dr. Broadbent said

Dear Air-borne, TB or not TB: that is the question! A person who tests positive for tuberculosis (TB) has likely been exposed (at some point in their lives) to either Mycobacterium tuberculosis (the organism that causes infectious TB) or protein from the bacterium. So yes, once exposed, a person will always have a positive test that reflects the history of that exposure A: A tuberculin test is a skin test done to check the presence of cell mediated immunity of an individual towards the tuberculoprotein (PPD). A positive test only indicates that the person has been exposed to Mycobacterium tuberculosis in the past and has developed cell mediated immunity. It is not a test to diagnose active tuberculosis

A false-positive tuberculin test result

A measurement of more than 5 mm could be considered a positive result. Inform your patient if the test is positive or negative. A positive skin test. If a patient has a positive test result, you may need to: investigate further to rule out a false positive; do more tests to find out if the patient has active tuberculosis disease; You may also. Mantoux test. This is a type of tuberculin skin test where tuberculin is injected intradermally. The skin is inspected for signs of a local skin reaction (induration) after 2-3 days, and the test is considered positive at an induration of 5 mm or more, regardless of previous BCG vaccination history Nonspecific reaction to skin test w/o active tuberculosis; False positive purified protein derivative; Mantoux: positive; Tuberculin skin test false positive; Tuberculin skin test positive; nonspecific reaction to cell mediated immunity measurement of gamma interferon antigen response without active tuberculosis (R76.12); Abnormal result of. Dear M.P.A.: Bacille Calmette-Guerin is a common cause of false positive tuberculosis tests. BCG is a vaccine strain of bacteria similar to tuberculosis that many countries use to reduce the risk.

False positive purified protein derivative; Mantoux: positive; Tuberculin skin test false positive; Tuberculin skin test positive; ICD-10-CM R76.11 is grouped within Diagnostic Related Group(s) (MS-DRG v 38.0): 177 Respiratory infections and inflammations with mcc; 178 Respiratory infections and inflammations with c A Veterinary Laboratories Agency report 12 reports that between 1st Jan 2005 and 30th Jun 2009, out of 26,363,877 cattle tests, tests using the Weybridge tuberculin found on average that 497 animals tested positive in every 100,000 tests whereas the Lelystad tuberculin only found 391. 12 The ratio given by 497 to 391 closely matches the ratio 0.

Recent articles describe the usefulness of PCR in diagnosing active tuberculosis.1,2 As amplification of mycobacterial DNA by PCR is increasingly used as a routine method, we would like to emphasise that this test should be applied with great caution in clinical medicine. In certain situations the uncritical interpretation of PCR results might even be harmful to the patient Tuberculosis Testing: False Positives. describes eight outbreaks of false-positive TB tests between 1983 and 2005. The study was led by U.S. Army Major James Mancuso, M.D., of the Uniformed. Tuberculin skin test for tuberculosis. May 11, 2016 Mantoux tuberculin test (tst) is the standard method causes of these false positive reactions include, but are not limited 6 Oct 2015 tuberculosis a serious infection caused by mycobacterium bacteria. TB tuberculin skin tests positive false skin tb prevalent in u

Background Repeat tuberculin skin tests may be false positive due to boosting of waned immunity to past mycobacterial exposure. We evaluated whether an ELISPOT test could identify tuberculosis (TB) contacts with boosting of immunity to non-tuberculous mycobacterial exposure. Methodology/Principal Findings We conducted tuberculin and ELISPOT tests in 1665 TB contacts: 799 were tuberculin test. Pathergy as a Cause of False-positive Tuberculin Skin Test. Pastore, Serena MD; Naviglio, Samuele MD; Ventura, Alessandro MD. The Pediatric Infectious Disease Journal: January 2012 - Volume 31 - Issue 1 - p 104. doi: 10.1097/INF.0b013e31823627ad. Letters. Free. Author. In Western countries, IGRAs have largely replaced the classic tuberculin skin test for diagnosing latent tuberculosis, but interpreting results can be challenging ‡—Performing a confirmatory test following an initial positive result is based on the evidence that false-positive results are common among persons who are unlikely to be infected with. The TB skin test which being determined if being positive or negative is dependent upon the volume of the lump surrounding the injection place. Based on CDC, it can be considered as a positive reaction for anybody if the lump is over 15mm, in this case, blisters are usually thought to be a sign of a positive test

presupposes a decision to treat if the test is positive. • There are two accepted tests for identification of LTBI: the tuberculin skin test (TST) and the interferon gamma release assay (IGRA). • When interpreting a positive TST, it is important to consider much more than simply the size of the reaction A false positive can occur if: The healthcare professional either carried out the test incorrectly or misread the results. Someone has an infection with a different strain of the bacteria No test is perfect. Let's say for example, the real-world false positive rate is 4% for SARS-CoV-2 RT-PCR testing. For every 100,000 people who test negative and truly don't have the infection. A positive tuberculosis skin test indicates that the patient has active tuberculosis. true or false. false. Mycoplasma pneumoniae causes atypical pneumonia, also known as walking pneumonia. true or false False positives are test results that inaccurately indicate that a particular condition is present when it does not. In testing for COVID-19, RT-PCR tests are considered to be the gold standard in.

What Does a Positive TB Skin Test Look Like

TB Tests: Types of Tuberculosis Tests and Result

  1. ation
  2. imal, especially > or =10 years after vaccination
  3. tested since false positive reactions are common. Currently, the tuberculin skin test (TST) performed by the Mantoux method using purified protein derivative (PPD) is the most commonly used test to diagnose LTBI. A TST is not necessary for individuals with a reliable history of, or a previously documented positive TST result
  4. Of the 239 positive tests found after the pre-employment tests were removed, 54 (22.6%) were deemed to be false positives, giving a positive predictive value of 77.4%. An important caveat to these numbers is that there was a selection bias in who was investigated for the possibility of a false positive result
  5. In some persons who are infected with M. tuberculosis, the ability to react to tuberculin may wane over time. When given a TST years after infection, these persons may have a false-negative reaction. However, the TST may stimulate the immune system, causing a positive, or boosted reaction to subsequent tests. Giving a secon

Tuberculin Skin Test or Blood Assay ---Results: Positive 1. What does a positive tuberculosis (TB) test mean? A positive reaction means that the person has TB germs somewhere in the body. The person may have latent TB infection, but not necessarily the disease. 2. How can a person be infected and not have TB disease need to ever have another TB test, as once the TB skin test is positive, it is positive for life. When you complete a course of treatment with INH for LTBI, Health Services will provide you with a card/letter which documents your past history of a positive TB skin test or postive TB blood test, and your treat-ment Macdonald said she believes the test results returned a false positive because Geronimo had been given a tuberculin vaccine before testing, which led to antibodies in his system. Before Geronimo.

The test used on Geronimo is highly specific, it is validated, it is reliable and the risk of a false positive is extremely low, commented prime minister Boris Johnson's official. False positive or false negative tuberculin skin test reactions may occur in some individuals. (See Interpretation of the Test) False positive tuberculin reaction tests occur in individuals who have been infected with other mycobacteria, including vaccination with BCG. Not all infected persons will have a delayed hypersensitivity reaction to a tuberculin test Tuberculin skin test has been used as an indicator of latent tuberculosis in patients with Rheumatoid Arthritis (RA) before administration of biologicals. Effect of Disease modifying antirheumatic drugs (DMARDs) and steroids on the result of tuberculin skin test (TST) may have important implications in interpretation of results of this test. >Objectives</i> Erythema and redness of skin are not indicative of a positive test result. Storage. Store at 2°C to 8°C (36°F to 46°F); do not freeze. Protect from light. Opened vials should be discarded after 30 days. Drug Interactions. Vaccines (Live): May diminish the diagnostic effect of Tuberculin Tests

Is this positive? (TB skin test) - Glow Community

However, the specificity of lateral flow tests is very high - around 99 per cent - meaning if you test positive it is very likely that result is true, and that false positives are very rare The precise underlying mechanisms responsible for false positive reactions are largely unknown, although variations in the types and potency of tuberculin used, and the criteria used for interpretation of the test results can directly affect sensitivity and specificity of the test [8, 16]

False-positive tuberculin test in Behçet's syndrome

  1. December 12, 2011 — In populations with low prevalence of tuberculosis (TB), the majority of positive results obtained with the 3 commercially available diagnostic tests are likely to be false.
  2. C. Nucleic acid amplification test D. Chest X-ray ~24 hours/1day: A. Sputum smear for acid-fast bacilli F. Interferon gamma release assay (IGRA) 48-72 hours/2-3 days: E. Tuberculin skin test Few Weeks: LONGEST E. Tuberculin skin test (GOLD STANDARD
  3. ACT Health has confirmed 11 people initially tested positive to COVID-19 in the ACT on Wednesday, but all of them have since returned negative results. ACT Health said the results were recorded at.
  4. PPD (Tuberculin Skin Test) •Tuberculin injected subcutaneously •Delayed hypersensitivity reaction •Must be read 48 to 72 hours later •Requires two visits •Measure induration (not erythema) •Positive test is induration >5 to 15 mm depending on population www.mayomedicallaboratories.co
  5. Ms Macdonald believes the first test came back with a false positive because he had been injected with tuberculin as part of skin tests conducted just before he left New Zealand
  6. Tuberculosis is one of the leading causes of morbidity and mortality worldwide [1]. Rapid identification of contagious tuberculosis patients and effective treatment are necessary to prevent the spread of Mycobacterium tuberculosis , the causative bacterium of the disease. Although interferon-γ release assays (IGRAs) have been developed for the diagnosis of latent infection with M.
Tuberculosis (TB) uveitis - iritisMantoux test - Wikipedia

Interpreting False Positive Tuberculosis Tests in

  1. Tuberculin Skin Test. Tuberculosis (TB) is an illness caused by a bacterial infection. Most people infected with TB have no sign of the disease as the bacteria are 'sleeping' or dormant. This is called TB infection (latent TB). Some people with latent TB will develop TB disease (active TB)
  2. Why it's unlikely Geronimo the alpaca's TB test gave a
  3. Positive TB Skin Test Result: What Does It Mean? New
Tuberculosis Test - PPD Skin Test, Blood Test, How It WorkPPT - Screening for Tuberculosis Infection PowerPointMantoux