FeedbackNote: The definitions listed below apply to the terms as used in these guidelines. They may have different meanings in other contexts.
Adolescent: a person aged 10–19 years.
Adult: a person over 19 years of age.
Advanced HIV disease: for adults, adolescents, and children aged 5 years or more, “advanced HIV disease” is defined as a CD4 cell count of less than 200 cells/mm3 or a WHO clinical stage 3 or 4 event at presentation for care. All children with HIV aged under 5 years should be considered as having advanced disease at presentation.
Bacteriologically confirmed TB: a person from whom a biological specimen is positive by a WHO-recommended rapid diagnostic test, culture or smear microscopy.
Child: a person under 10 years of age.
Clinically diagnosed: when a person who does not fulfil the criteria for bacteriological confirmation has been diagnosed with TB disease by a medical practitioner who has decided to give the person a full course of TB treatment.
Computer-aided detection (CAD): the use of specialized software to interpret abnormalities on chest radiographs that are suggestive of TB. The results are expressed as abnormality scores. CAD may be used for screening or triage.
Drug-resistant TB: TB disease caused by a strain of Mycobacterium tuberculosis (M. tuberculosis) complex that is resistant to any TB medicines.
Drug-susceptibility testing (DST): in vitro testing using either molecular or genotypic techniques to detect resistance-conferring mutations, or phenotypic methods to determine susceptibility to a medicine.
Extensively drug-resistant TB (XDR-TB): TB disease caused by a strain of M. tuberculosis complex that is resistant to rifampicin (and may also be resistant to isoniazid), and that is also resistant to at least one fluoroquinolone (levofloxacin or moxifloxacin) and to at least one other “Group A” drug (bedaquiline or linezolid).
Extrapulmonary TB (EPTB) (classification): any bacteriologically confirmed or clinically diagnosed episode of TB involving organs other than the lungs (e.g. pleura, peripheral lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges).
Inpatient healthcare setting: a healthcare facility where patients are admitted and assigned a bed while undergoing diagnosis and receiving treatment and care, for at least one overnight stay.
Integrated services: health services that are managed and delivered in a way that ensures that people receive a continuum of health promotion, disease prevention, diagnosis, treatment, disease management, rehabilitation and palliative care services at the different levels and sites of care within the health system and according to their needs throughout the life-course.
High TB transmission setting: a setting with a high frequency of individuals with undetected or undiagnosed TB disease, or where infectious TB patients are present and there is a high risk of TB transmission. People with TB are most infectious when they are untreated or inadequately treated. Spread is increased by aerosol-generating procedures and by the presence of highly susceptible individuals.
HIV-associated TB: the disease state due to M. tuberculosis in an individual who is living with HIV.
Household contact: a person who shared the same enclosed living space as the individual diagnosed with TB for one or more nights or for frequent or extended daytime periods during the three months before the start of current treatment.
Multidrug-resistant TB (MDR-TB): TB caused by M. tuberculosis strains that are resistant to at least both rifampicin and isoniazid.
Outpatient healthcare setting: a healthcare facility where patients are undergoing diagnosis and receiving treatment and care but are not admitted for an overnight stay (e.g. an ambulatory clinic or a dispensary).
People-centred services: a human rights-based approach to care that consciously adopts individuals’, carers’, families’ and communities’ perspectives as participants in, and beneficiaries of, trusted health systems that are organized around the comprehensive needs of people rather than individual diseases, and respects social preferences.
People who use drugs: people who use psychoactive substances through any route of administration, including injection, oral, inhalation, transmucosal or transdermal. For the purposes of this document this definition does not include the use of widely used substances such as tobacco or alcoholic and caffeine-containing beverages and foods.
Person with presumptive TB: a person with symptoms or signs suggestive of TB disease (previously known as a TB suspect).
TB disease: the disease state due to M. tuberculosis. In this document, it is commonly referred to as TB “disease” (or “active” TB) in order to distinguish it from TB infection.
TB infection: a state of persistent immune response to stimulation by M. tuberculosis antigens with no evidence of clinically manifest active TB disease. Most infected people have no signs or symptoms of TB but are at risk for TB disease. This was previously referred to as latent TB infection (LTBI) but given that infection cannot always be considered latent the term TB infection (TBI) is being used instead. There is no gold standard test for direct identification of M. tuberculosis infection in humans.
TB preventive treatment (TPT): treatment offered to individuals who are considered at risk of TB disease in order to reduce that risk. Also referred to as treatment of TB infection, LTBI treatment or TB preventive therapy.
Universal health coverage: under universal health coverage, individuals and communities have access to high-quality promotive, preventive, curative, rehabilitative and palliative essential health services without experiencing financial hardship.
Women (breastfeeding, pregnant, postpartum): the terms breastfeeding, pregnant or postpartum women are used here given that the majority of data are disaggregated by sex and do not specify gender identity. However, the term “woman” is intended to be inclusive of all those who identify as women and/or who give birth. While the majority of persons who are or can give birth are cisgender women (who were born and identify as female), WHO acknowledges the importance of the experiences of transgender men and other gender diverse people who have the reproductive capacity to give birth.
