Book traversal links for Definitions
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 WHOrecommended 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 (DR-TB): TB disease caused by a strain of Mycobacterium 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 tuberculosis (EPTB) (classification): any bacteriologically confirmed or clinically diagnosed case of TB involving organs other than the lungs (e.g. pleura, peripheral lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges).
High TB transmission setting: a setting with a high frequency of individuals with undetected or undiagnosed active TB, 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.
Household contact: a person who shared the same enclosed living space as the index case for one or more nights or for frequent or extended daytime periods during the 3 months before the start of current treatment.
HIV-associated TB: the disease state due to M. tuberculosis in an individual who is living with HIV.
Index patient (index case) of TB: The initially identified person of any age with new or recurrent TB in a specific household or other comparable setting in which others may have been exposed. An index patient is the person on which a contact investigation is centred but is not necessarily the source case.
Inpatient health-care setting: a health-care 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: integrated health services are 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.
Multidrug-resistant TB (MDR-TB): TB caused by a strain of M. tuberculosis that is resistant to rifampicin and isoniazid.
Number needed to screen (NNS): the number of persons that need to undergo screening in order to diagnose one person with TB disease.
Outpatient health-care setting: a health-care 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 substances such as tobacco or alcoholic and caffeinecontaining beverages and foods.
Presumptive tuberculosis (TB): presumptive TB refers to a patient who presents with symptoms or signs suggestive of TB (prfeviously known as a TB suspect).
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.
Tuberculosis (TB) disease: the disease state due to M. tuberculosis, commonly referred to as TB.
Tuberculosis (TB) infection: a state of persistent immune response to stimulation by M. tuberculosis antigens with no evidence of clinically manifest active TB. There is no gold standard test for direct identification of M. tuberculosis infection in humans. Most infected people have no signs or symptoms of TB but are at risk of active TB disease.
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.
WHO-recommended rapid diagnostic test: A test approved by WHO that employs molecular (e.g. Xpert Ultra®) or biomarker-based techniques (e.g. urinary lipoarabinomannan assays (U-LAM)) for the diagnosis of TB. Throughout this publication, the term “WRD” refers to molecular WRDs unless otherwise specified.
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.