Self-Study Modules on Tuberculosis
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Glossary
This glossary contains the new terms listed at the beginning of
Modules 1-5.
acid-fast bacilli (AFB) - mycobacteria
that stay stained even after they have been washed in an acid solution;
may be detected under a microscope in a stained smear
adherence to treatment - following the recommended
course of treatment by taking all the prescribed medications for
the entire length of time necessary
administrative controls - guidelines for promptly
detecting patients who have TB, placing them in an area away from
other patients, giving them a diagnostic evaluation as soon as possible,
and treating them if they are likely to have TB disease
adverse reaction - negative side effect resulting
from the use of a drug (for example, hepatitis, nausea, headache)
AIDS - acquired immunodeficiency syndrome, a disease
in which the immune system is weakened and therefore less able to
fight certain infections and diseases; AIDS is caused by infection
with the human immunodeficiency virus (HIV)
alveoli - the small air sacs of the lung that
are at the end of the airway; when droplet nuclei reach these air
sacs, TB infection begins
anergy - the inability to react to a skin test
because of a weakened immune system, often caused by HIV infection
or severe illness (see anergy testing)
anergy testing - giving
skin tests using two substances other than tuberculin; done to determine
whether a person is anergic. People who do not react to any of the
substances, including tuberculin, after 48 to 72 hours (that is,
people who have less than 3 millimeters of induration to all of
the skin tests), are considered anergic.
bacteriologic examination - tests
done in a mycobacteriology laboratory to diagnose TB disease; includes
examining a specimen under a microscope, culturing the specimen,
and doing drug susceptibility testing
baseline skin test - the tuberculin skin test
given to employees or residents in certain facilities when they
start their job or enter the facility (see TB
screening program and two-step
testing)
BCG - bacille Calmette-Guérin
(BCG), a vaccine for TB disease that is used in many countries but
rarely used in the United States; may cause a false-positive reaction
to the tuberculin skin test
boosted reaction - a positive reaction to a tuberculin
skin test, due to a boosted immune response from a skin test given
up to a year earlier; occurs in people who were infected a long
time ago and whose ability to react to tuberculin had lessened.
Two-step testing is used in TB screening programs to tell the difference
between boosted reactions and reactions caused by recent infection
(see booster phenomenon
and two-step testing)
booster phenomenon
- a phenomenon in which people (especially older adults) who are
skin tested many years after becoming infected with M. tuberculosis
may have a negative reaction to an initial skin test, followed by
a positive reaction to a skin test given up to a year later; this
happens because the first skin test boosts the immune response.
Two-step testing is used in TB screening programs to tell the difference
between boosted reactions and reactions caused by recent infection
(see two-step testing)
bronchoscopy - a procedure used to obtain pulmonary
secretions or lung tissue with an instrument called a bronchoscope;
used only when patients cannot cough up sputum on their own and
an induced specimen cannot be obtained
case rate - the number of cases
that occur during a certain time period, divided by the size of
the population during that time period; the case rate is often expressed
in terms of a population size of 100,000 persons
case reporting - informing the state or local
health department when a new case (an occurrence) of TB disease
has been diagnosed or is suspected
cavity - a hollow space within the lung, visible
on a chest x-ray, that may contain many tubercle bacilli; often
occurs in people with severe pulmonary TB disease
clinical evaluation - an evaluation done to find
out whether a patient has symptoms of TB disease or is responding
to treatment; also done to check for adverse reactions to TB medications
clinician - a physician, physician assistant,
or nurse
close contacts - people who spend time with someone
who has infectious TB disease
colonies - groups of mycobacteria that have grown
in a culture
contact investigation - a procedure for interviewing
a person who has TB disease to determine who may have been exposed
to TB. People who have been exposed to TB are screened for TB infection
and disease.
continuation phase - the period after the first
8 weeks of treatment, during which tubercle bacilli that remain
after the initial phase are killed
corticosteroid - a type of steroid, either natural
or man-made, often used to treat arthritis or certain allergies
cough-inducing procedures - procedures that make
a patient cough, such as sputum induction, bronchoscopy, and the
administration of aerosolized pentamidine
culture - organisms grown on media (substances
containing nutrients) so that they can be identified; a positive
culture for M. tuberculosis contains tubercle bacilli,
whereas a negative culture contains no detectable tubercle bacilli
daily regimen - a treatment schedule
in which the patient takes a dose of each prescribed medication
every day
diabetes mellitus - a disease in which the body's
ability to use sugar is weakened
diagnostic evaluation - an evaluation used to
diagnose TB disease; includes a medical history, a chest x-ray,
the collection of specimens for bacteriologic examination, and possibly
a tuberculin skin test
directly observed therapy (DOT) - a strategy devised
to help patients adhere to treatment; means that a health care worker
or another designated person watches the TB patient swallow each
dose of the prescribed drugs
droplet nuclei - very small droplets (1 to 5 microns
in diameter) that may be expelled when a person who has infectious
TB coughs or sneezes; they can remain suspended in the air for several
hours, depending on the environment
drug injection - using a needle
and syringe to inject drugs into the body
drug susceptibility pattern - the list of drugs
to which the strain of tubercle bacilli is susceptible and to which
it is resistant
engineering controls - engineering
systems used to prevent the transmission of TB in health care facilities,
including ventilation, high-efficiency particulate air (HEPA) filtration,
and ultraviolet germicidal irradiation
epidemiology - the study of the distribution and
causes of disease and other health problems in different groups
of people
erythema - redness around the site of the injection
when a Mantoux skin test is done; erythema is not considered when
the reaction size is measured, because redness does not indicate
that a person has TB infection
ethambutol - a drug used to treat TB disease;
may cause vision problems. Ethambutol should not be given to children
who are too young to be monitored for changes in their vision.
exposure to TB - time spent with someone who has
infectious TB disease
extrapulmonary TB - TB disease
that occurs in places other than the lungs, such as the lymph nodes,
the pleura, the brain, the kidneys, or the bones; most types of
extrapulmonary TB are not infectious
false-negative reaction - a negative
reaction to the tuberculin skin test in a person who has TB infection;
may be caused by anergy, recent infection (within the past 10 weeks),
or very young age (younger than 6 months old)
false-positive reaction - a positive reaction
to the tuberculin skin test in a person who does not have TB infection;
may be caused by infection with nontuberculous mycobacteria or by
vaccination with BCG
foreign-born persons - people
born outside of the United States; foreign-born persons from areas
of the world where TB is common (for example, Asia, Africa, Latin
America, and the Caribbean) are more likely to become exposed to
and infected with TB
gastric washing - a procedure
done by inserting a tube through the patient's nose and passing
it into the stomach; may be useful for obtaining sputum from children,
who produce little or no sputum when they cough
health care facilities - places
where people receive health care, such as hospitals or clinics
HEPA filters - special filters that can be used
in ventilation systems to help remove droplet nuclei from the air
hepatitis - damage to the liver, causing symptoms
such as nausea, vomiting, abdominal pain, fatigue, and dark urine;
hepatitis can be caused by several drugs used to treat TB infection
or disease
HIV - human immunodeficiency virus, the virus
that causes AIDS
immune system - cells and tissues
in the body that protect the body from foreign substances
immunosuppressive therapy - therapy that suppresses,
or weakens, the immune system
induced sputum - sputum that is obtained by having
the patient inhale a saline (salt water) mist, causing the patient
to cough deeply; this procedure is used to help patients cough up
sputum if they cannot do so on their own
induration - swelling that can be felt around
the site of injection after a Mantoux skin test is done; the reaction
size is the diameter of the indurated area (excluding any redness),
measured across the forearm
infection control procedures - measures to prevent
the spread of TB
infectious - capable of spreading infection; a
person who has infectious TB disease expels droplets containing
M. tuberculosis into the air when he or she coughs or sneezes
infiltrate - a collection of fluid and cells in
the tissues of the lung; visible on a chest x-ray in people with
pulmonary TB disease
initial phase - the first 8 weeks of treatment,
during which most of the tubercle bacilli are killed
intermittent regimen - a treatment schedule in
which the patient takes each prescribed medication two or three
times weekly at the appropriate dosage
isolate - a group of organisms isolated, or separated,
from a specimen; in an M. tuberculosis isolate, the organisms
have been identified as M. tuberculosis (a positive culture
for M. tuberculosis)
isolation room - a room with special characteristics
to prevent the spread of droplet nuclei expelled by a TB patient,
including negative-pressure ventilation
isoniazid - the drug that is most often used for
preventive therapy and also used to treat TB disease; although relatively
safe, it may cause hepatitis and other adverse reactions in some
patients
liver function tests - tests done
to detect damage to the liver
malaise - a feeling of general
discomfort or illness
Mantoux tuberculin skin test
- the preferred method of testing for TB infection; done by using
a needle and syringe to inject 0.1 ml of 5 tuberculin units of liquid
tuberculin between the layers of the skin (intradermally), usually
on the forearm; the reaction to this test, usually a small swollen
area (induration), is measured 48 to 72 hours after the injection
and is classified as positive or negative depending on the size
of the reaction and the patient's risk factors for TB
media - substances containing special nutrients
for growing cultures of bacteria found in specimens
medical history - the part of a patient's life
history that is important for diagnosing and treating TB infection
or disease, including history of exposure, symptoms, diagnosis of
TB infection or disease, and risk factors for TB disease
miliary TB - TB disease that
occurs when tubercle bacilli enter the bloodstream and are carried
to all parts of the body, where they grow and cause disease in multiple
sites; the chest x-ray of patients with miliary TB often looks like
millet seeds scattered throughout the lung
multidrug-resistant TB (MDR TB) - TB that is resistant
to isoniazid and rifampin; more difficult to treat than drug-susceptible
TB
multiple-puncture test
- tuberculin skin test done by puncturing the skin of the forearm
with a set of short prongs or tines to inject tuberculin (for example,
Tine test); although easy to give and convenient, these tests are
not accurate and should not be used to determine whether a person
has TB infection
mycobacteria - a kind of bacteria; mycobacteria
can cause a variety of diseases
mycobacteriology laboratory - a laboratory that
deals specifically with M. tuberculosis and other mycobacteria
Mycobacterium africanum -
a type of tuberculous mycobacteria, closely related to M. tuberculosis,
that can cause a disease similar to TB in humans; it is very rare
in the United States
Mycobacterium avium complex - a common
type of nontuberculous mycobacteria that can cause disease in humans
Mycobacterium bovis - a type
of tuberculous mycobacteria that can cause a disease similar to
TB in cows. Before the pasteurization of milk became common practice,
these mycobacteria were often spread to humans through contaminated
milk; in the United States today, M. bovis rarely affects
humans
Mycobacterium tuberculosis - the
organism that causes TB and is sometimes called the tubercle bacillus;
belongs to a group of bacteria called mycobacteria
negative pressure - a ventilation
system designed so that air flows from the corridors into an isolation
room, ensuring that contaminated air cannot escape from the isolation
room to other parts of the facility
nontuberculous mycobacteria - mycobacteria that
do not cause TB disease and are not usually spread from person to
person; one example is M. avium complex
pathogenesis - how an infection
or disease develops in the body
peripheral neuropathy - damage to the sensory
nerves of the hands and feet, causing a tingling sensation or a
weakened sense of touch in the hands and feet
personal respirators - special masks designed
to filter out droplet nuclei; used in health care facilities and
other settings where TB may be spread
PPD skin test - a tuberculin skin test (see purified
protein derivative [PPD])
preventive therapy - medication that is given
to people who have TB infection to prevent them from developing
TB disease
pulmonary TB - TB disease that occurs in the lungs
(about 85% of all U.S. cases), typically causing a cough and an
abnormal chest x-ray; pulmonary TB is usually infectious if untreated
purified protein derivative
(PPD) - the type of tuberculin used in the Mantoux skin
test
pyrazinamide - a drug used to treat TB disease,
usually during the initial phase of treatment; should not be given
to pregnant women
relapse - the return of a disease
after a partial recovery from the disease
residential facilities - institutions where people
live, such as nursing homes, correctional facilities, or homeless
shelters
resistant - able to grow in the
presence of a particular drug
rifampin - a drug used to treat TB disease; also
used for preventive therapy in people with a positive skin test
reaction who have been exposed to isoniazid-resistant TB. Rifampin
has several possible side effects (for example, hepatitis, turning
body fluids orange, drug interactions).
silicosis - a lung disease caused
by inhaling silica dust, which is used in the production of glass
and ceramics; occurs most often in mining and foundry workers
skin test conversion - a change
in a skin test reaction from negative to positive between screening
intervals
smear - a specimen that has been smeared onto
a glass slide, stained, washed in an acid solution, and then placed
under the microscope for examination; used to detect acid-fast bacilli
in a specimen
sputum - phlegm from deep in the lungs, collected
in a sterile container for processing and examination
streptomycin - an injectable drug used to treat
TB disease; may cause hearing problems. Streptomycin should not
be given to pregnant women.
susceptible - able to be killed by a particular
drug
symptoms of TB disease - conditions caused by
TB disease. The symptoms of pulmonary TB disease include coughing,
pain in the chest when breathing or coughing, and coughing up sputum
or blood. The general symptoms of TB disease (pulmonary or extrapulmonary)
include weight loss, fatigue, malaise, fever, and night sweats.
The symptoms of extrapulmonary TB disease depend on the part of
the body that is affected by the disease
TB screening
program - a program in which employees and residents of
a facility are periodically given tuberculin skin tests; done to
identify people who have TB infection and possibly TB disease and
to determine whether TB is being transmitted in the facility
transmission - the spread of an organism, such
as M. tuberculosis, from one person to another; depends
on the contagiousness of the patient, the type of environment, and
the length of exposure
tubercle bacilli - another name for Mycobacterium
tuberculosis organisms, which cause TB disease
tuberculin - protein derived from tubercle bacilli
that have been killed by heating; used to determine whether a person
has TB infection. Tuberculin is not a vaccine.
tuberculin skin test - a test used to detect TB
infection (see Mantoux tuberculin skin
test or multiple-puncture
test)
tuberculin unit - a standard strength of tuberculin
used in the United States and Canada; a strength of 5 tuberculin
units is used for the Mantoux tuberculin skin test
tuberculous mycobacteria - mycobacteria that can
cause TB disease or other diseases very similar to TB; the tuberculous
mycobacteria are M. tuberculosis, M. bovis, and
M. africanum
two-step testing
- a strategy used in TB screening programs to distinguish a boosted
reaction (caused by TB infection that occurred many years before
the skin test) from a reaction caused by recent infection. If a
person has a negative reaction to an initial skin test, a second
test is given 1 to 3 weeks later; a positive reaction to the second
test probably represents a boosted reaction, not recent infection.
Two-step testing is used in many TB screening programs for skin
testing employees when they start their job.
ultraviolet germicidal irradiation
- the use of special lamps that give off ultraviolet light, which
kills the tubercle bacilli contained in droplet nuclei
ventilation systems - air systems
designed to maintain negative pressure and to exhaust the air properly;
designed to minimize the spread of TB in a health care facility
Last Reviewed: 05/18/2008 Content Source: Division of Tuberculosis Elimination
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
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