TB Key Terms

What are key terms related to TB and human rights?

A variety of terms is used in TB and human rights work. All definitions are adapted from the WHO unless otherwise indicated.


Active TB
Tuberculosis disease associated with symptoms or signs, including findings on physical examination.

Active, voluntary and collaborative involvement of the patient in a mutually acceptable course of behavior (including taking the prescribed dose of a particular medicine at the recommended time) to produce the desired therapeutic results.

Adherence support
Adherence support refers to medical, social and economic initiatives to help patients who face barriers to accessing TB treatment and care. Examples include providing travel vouchers or transportation to health care facilities, food packages, peer support, education and follow-up, and engaging community health workers to accompany patients as they access health care.1

Anti-retroviral therapy (ART)
Anti-retroviral drugs inhibit various phases of the life-cycle of the human immunodeficiency virus (HIV), thus reducing HIV-related symptoms and prolonging life expectancy of people living with HIV.


BCG (Bacille-Calmette-Guérin) vaccin
A live vaccine against TB derived from an attenuated strain of Mycobacterium bovis. The vaccine protects against severe forms of TB in children (TB meningitis and miliary TB), but its efficacy in preventing pulmonary TB in adults is highly variable.


Community-based care
Activities conducted outside of formal health facilities (hospitals, health centres and clinics) using community-based structures (such as schools, places of worship and congregate settings, homes). Care is often provided by trained lay and community health workers in patients’ homes.

Test to determine whether there are TB bacteria in a person’s phlegm or other body fluids. This involves growing organisms on or in media (liquid or solid substances containing nutrients) so that they can be identified. Results can take 2 to 4 weeks in most laboratories.2


Directly observed therapy (DOT)
An adherence-enhancing strategy in which a healthcare worker or other trained person watches a patient swallow each dose of medication and is accountable to the public health system. DOT is the preferred method of care for all patients with TB disease and is a preferred option for patients under treatment for latent infection.3

Drug-resistant TB
TB disease caused by Mycobacterium tuberculosis organisms that are resistant to at least one first-line anti-tuberculosis drug.

Drug-susceptibility test (DST)
A laboratory determination to assess whether an M. tuberculosis complex isolate is susceptible or resistant to anti-TB drugs that are added to mycobacterial growth medium. The results predict whether a specific drug is likely to be effective in treating TB disease caused by that isolate.4 


Extensively drug-resistant TB (XDR TB)
A form of TB caused by bacteria resistant to all the most effective drugs (i.e. MDR-TB plus resistance to any fluoroquinolone and any of the second-line anti-TB injectable drugs: amikacin, kanamycin or capreomycin).

Extrapulmonary TB
Patient with tuberculosis of organs other than the lungs (e.g. pleura, lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges).


Harm reduction
Refers to a set of interventions designed to diminish the individual and societal harms associated with drug use, including the risk of HIV infection, without requiring the cessation of drug use. In practice, harm reduction programs include syringe exchange, drug substitution or replacement therapy using substances such as methadone, health and drug education, HIV and sexually transmitted disease screening, psychological counseling, and medical care.

High burden country
One of the 22 countries which together account for approximately 80% of all new TB cases arising each year. The WHO also identifies another 27 high MDR-TB burden countries that concentrate more than 85% of MDR-TB cases emerging globally.5

HIV infection
Infection with the human immunodeficiency virus (HIV) the virus that causes AIDS (acquired immunodeficiency syndrome). A person with both latent TB infection and HIV infection is at very high risk for developing TB disease.6


Infectious TB
Active TB that is transmissible to others, i.e. contagious, usually determined by a positive sputum smear in case of pulmonary or laryngeal disease.

Isoniazid or INH
A medicine used to prevent TB disease in people who have latent TB infection. INH is also one of the four medicines often used to treat TB disease. It is a first-line agent for treatment of all forms of TB.7

A state of separation between persons or groups to prevent the spread of disease. Isolation measures can be undertaken in hospitals or homes, as well as in alternative facilities. Once the diagnosis is made and treatment begun, isolation is usually neither necessary nor appropriate for patients who are willing to undergo treatment. Isolation has a very limited role to play in patients in whom treatment has failed.


Latent TB infection
Infection where M. tuberculosis bacilli are present in the body but the disease is not clinically active. Not everyone who is infected with tuberculosis bacteria develops the disease. People who are infected may not feel ill and may have no symptoms. The infection can last for a lifetime, but the infected person may never develop the disease itself. People who are infected but who do not develop the disease do not spread the infection to others.


Mycobacterium tuberculosis
The bacterium of the M. tuberculosis complex that is the most common causative infectious agent of TB disease in humans. The M. tuberculosis complex also includes M. bovis and five other related species.

Multidrug-resistant TB (MDR TB)
A form of TB that does not respond to the standard six month regimen using first line-drugs (i.e. resistant to isoniazid and rifampicin). It can take two years to treat with drugs that are more toxic, and 100 times more expensive. If the drugs to treat MDR-TB are mismanaged, further resistance can occur.


Preventive therapy
The treatment of subclinical, latent infection with M. tuberculosis to prevent progression to active TB disease, usually based on 6–9 months of oral isoniazid.

Development of active tuberculosis disease from a state of latency.

Pulmonary TB
Patient with tuberculosis disease involving the lung parenchyma.


The detention, isolation or distancing of healthy individuals who may have been exposed to an infectious disease for a given period to slow transmission of the disease.


Relapse case
Patient previously declared cured but with a new episode of bacteriologically positive (sputum smear or culture) TB.

Rifampin or RIF
One of the four medicines often used to treat TB disease. It is considered a first-line drug.8


Test to determine whether there are TB bacteria in phlegm. To perform this test, lab workers smear the phlegm on a glass slide, stain the slide with a special stain, and look for any TB bacteria on the slide. It usually takes a day to get the results.9

Sputum smear examination
A laboratory technique in which sputum is smeared on glass slides and stained with an acid-fast stain. Slides are subsequently examined by microscopy for the presence of acid-fast bacilli.

Phlegm coughed up from deep inside the lungs. Sputum is examined for TB bacteria using a smear; part of the sputum can also be used to do a culture.10 

Stop TB Strategy
The Stop TB Strategy aims to dramatically reduce the global burden of TB by 2015, and has six components: (1) pursue high-quality DOTS expansion and enhancement; (2) address TB-HIV, MDR-TB, and the needs of poor and vulnerable populations; (3) contribute to health system strengthening based on primary health care; (4) engage all care providers; (5) empower people with TB, and communities through partnership; and (6) enable and promote research.


Purified protein derivative (PPD) – a mixture of antigens from a culture filtrate extract of M. tuberculosis that is used for skin testing; many of its antigens are non-species specific.

Tuberculin skin test
Cutaneous (intradermal) injection of tuberculin to identify people who have been sensitized to mycobacterial antigens by infection with M. tuberculosis, non-tuberculous mycobacteria or vaccination with BCG.

Tuberculosis (TB)
Active disease attributable to Mycobacterium tuberculosis complex, typically affecting the lungs and airways in which case it is directly transmissible through droplet.11 TB spreads rapidly, especially in areas where people are living in crowded conditions, have poor access to health care, and are malnourished. People of all ages can contract tuberculosis. But the risk of developing TB is highest in children younger than three years old, in older people, and people with weakened immune systems (for example, people with HIV).


A test that employs automated real-time nucleic acid amplification technology for rapid and simultaneous detection of TB and rifampicin resistance.12


1 WHO, Global Tuberculosis Control 2012 (2012).

2 CDC, Core Curriculum on Tuberculosis: What the Clinician Should Know (2013). www.cdc.gov/tb/education/corecurr/pdf/corecurr_all.pdf.

3 National Tuberculosis Curriculum Consortium (NTCC), “Tuberculosis Glossary”. http://ntcc.ucsd.edu/NTCC_glossary.pdf.

4 NTCC, “Tuberculosis Glossary”. http://ntcc.ucsd.edu/NTCC_glossary.pdf.

5 Centers for Disease Control and Prevention, Core Curriculum on Tuberculosis: What the Clinician Should Know (2013).


6 TB CARE I, Guidelines to Measure the Prevalence of Active TB Disease Among Health Care Workers, USAID (2012). www.tbcare1.org/publications/toolbox/tools/hss/HCW_TB_Prevalence_Measuring_Guidelines.pdf.

8 Ibid.

9 Ibid.

10 Ibid.

11 TB CARE I, Guidelines to Measure the Prevalence of Active TB Disease Among Health Care Workers, USAID (2012).

12 Ibid.