Journal of Pulmonology and Clinical Research

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Commentary - Journal of Pulmonology and Clinical Research (2022) Volume 5, Issue 5

Screening and Diagnostic tests for tuberculosis

Narasimhan Mathai*

Department of Pulmonary and Critical Care

*Corresponding Author:
Narasimhan Mathai
Department of Pulmonary and Critical Care
University of California San Francisco
United States

Received:29-Aug-2022, Manuscript No. AAJPCR-22-81007; Editor assigned: 30-Aug-2022, PreQC No. AAJPCR-22-81007 (PQ); Reviewed:13-Sep-2022, QC No. AAJPCR-22-81007; Revised:16-Sep-2022, Manuscript No. AAJPCR-22-81007 (R); Published:23-Sep-2022, DOI: 10.35841/aaccr-4.4.117

Citation: Mathai N. Screening and Diagnostic tests for tuberculosis. J Pulmonol Clin Res. 2022;5(5):122

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Mycobacterium tuberculosis is the causative agent of tuberculosis. Whether the goal is to diagnose latent infection or active disease will influence how the tuberculosis test is conducted. It is crucial to pinpoint the illness site if active disease is detected. Prior to doing additional testing, sputum specimens should be examined for mycobacteria. Never declare an illness to be latent until ruling out active disease. Interferon gamma release assays might be helpful in some situations, although tuberculin skin testing is advised for identifying latent infection. In Australia, there are about 1000 new cases of tuberculosis detected each year. The majority of these patients were infected outside of Australia, and current transmission is uncommon and only occurs in tiny clusters.


Illness, Tuberculosis, Mycobacterium, Interferon gamma.


Before recommending immunosuppressive treatments, such as tumour necrosis factor alpha inhibitors, cancer treatment, or transplantation, it is advised to screen for latent tuberculosis. Additionally, tuberculosis testing should be done on patients who have a high risk of tuberculosis reactivation, especially those who have HIV infection. Mycobacterium tuberculosis is the main cause of tuberculosis in humans. Respirable droplets released during forceful expiratory movements like hacking are used to transmit the disease. There are two types of tuberculosis disease: active and latent. Dynamic contamination patients experience symptoms or adverse effects that are successfully mimicked by tubercle bacilli. If this affects the lungs, it may be contagious and often causes symptoms including hacking, chest pain, fatigue, windedness, loss of appetite, fever, and night sweats. Those who have inert contamination have recently been contaminated, yet they show no symptoms of infection and are not contagious [1].

Analysis of TB

The diagnosis of tuberculosis can be assisted by a number of investigations. These include of histology, microbiological tests, tests of the immune system (interferon gamma release assays, tuberculin skin testing, etc.), and medical imaging [2].

Chest radiology

A normal chest X-ray virtually often rules out pulmonary tuberculosis in patients who have no respiratory symptoms. Chest X-rays are useful for spotting tuberculosis pulmonary lesions, but they cannot accurately predict disease activity.


The only reliable way to diagnose active tuberculosis is to identify M. tuberculosis. M. tuberculosis can take up to six weeks or longer to grow in culture, even though it is a sensitive test. No matter the presumed site of the disease, three morning sputa should be collected, unless the chest X-ray is normal and the patient has localised extrapulmonary disease and has no respiratory symptoms.

Tuberculin skin testing

If a 5 mm induration is used to define a positive reaction, the test is particularly sensitive for identifying tuberculosis in healthy individuals. Based on the prevalence of tuberculosis and the degree of non-specific cross-reactivity in the population being tested, bigger indurations are frequently used to define a positive reaction, which can often come at the expense of sensitivity [3].

Methods of diagnosis

The key to early diagnosis of tuberculosis is to consider the possibility that a patient may be infected.

Active tuberculosis

Sputum samples should be tested for mycobacteria if active infection in an adult is suspected, unless the chest X-ray is normal and there are no respiratory symptoms. It's crucial to understand that patients may also have pulmonary tuberculosis, which is what transmits tuberculosis, even if non-pulmonary tuberculosis is suspected in them. Then, in conjunction with an expert, more testing can be performed.

Long-term infection

Clinicians who can rule out active tuberculosis and treat latent tuberculosis are ideally suited to perform screening for latent tuberculosis. Clinicians who are involved in population screening and have experience interpreting tuberculin tests are likely to choose tuberculin skin testing as the preferred test, supplementing it with interferon gamma release assays as needed for specificity [4,5].


Due to the contagious nature of pulmonary tuberculosis, it is crucial to take this risk into account in patients with subacute and chronic infectious syndromes as well as those who have a cough that has lasted longer than two to three weeks. Analysis of three morning sputum samples taken from such a patient will quickly identify those with active transmissible infection if the patient has an abnormal chest X-ray


  1. Nathavitharana RR, Friedland JS A tale of two global emergencies: tuberculosis control efforts can learn from the Ebola outbreak.. Eur Respir J. 2015;46(2):293-6.
  2. Indexed at, Google Scholar, Cross Ref

  3. Lönnroth K, Jaramillo E, Williams BG, et al. Drivers of tuberculosis epidemics: the role of risk factors and social determinants.. Soc Sci Med. 2009;68(12):2240-6.
  4. Indexed at, Google Scholar, Cross Ref

  5. Kyu HH, Maddison ER, Henry NJ, et al.. The global burden of tuberculosis: results from the Global Burden of Disease Study 2015.. Lancet Infect Dis. 2018;18(3):261-84.
  6. Indexed at, Google Scholar, Cross Ref

  7. Kyu HH, Maddison ER, Henry NJ, et al. . Global, regional, and national burden of tuberculosis, 1990–2016: results from the Global Burden of Diseases, Injuries, and Risk Factors 2016 Study. Lancet Infect Dis. 2018;18(12):1329-49.
  8. Indexed at, Google Scholar, Cross Ref

  9. Law S, Piatek AS, Vincent C, et al. Emergence of drug resistance in patients with tuberculosis cared for by the Indian health-care system: a dynamic modelling study.Lancet Pub Hea. 2017;2(1):e47-55.
  10. Indexed at, Google Scholar, Cross Ref

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