Self-Study Modules on Tuberculosis
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5: Infectiousness and Infection Control
In this module, you will learn about the factors that determine
the infectiousness (contagiousness) of a person with TB disease.
This will help you and others decide whether a particular patient
should be considered infectious. You will also learn about the precautions
you should take if you come in contact with patients who are considered
infectious. These precautions, called infection control precautions,
are meant to prevent the spread of TB in hospitals, clinics, and
After working through this module, you will be able to:
- Describe the factors that determine the infectiousness of a
- Explain when a TB patient can be considered noninfectious.
- Describe the main goal of an infection control program.
- List the three types of controls in an effective infection control
- Describe how TB can be detected in a health care facility and
explain what should be done when a patient is suspected of having
- Describe the purpose and the characteristics of a TB isolation
- Describe the three types of engineering controls.
- Describe the circumstances when personal respirators should
- Describe the role of the health department in infection control.
- Describe the precautions that health care workers should take
when visiting the home of a TB patient who may be infectious.
Look for the following new terms in this module and in the glossary.
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
cough-inducing procedures – procedures that make
a patient cough, such as sputum induction, bronchoscopy, and the
administration of aerosolized pentamidine
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
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
HEPA filters – special filters that can be used
in ventilation systems to help remove droplet nuclei from the air
isolation room – a room with special characteristics
to prevent the spread of droplet nuclei expelled by a TB patient,
including negative-pressure ventilation
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
personal respirators – special masks designed
to filter out droplet nuclei; used in health care facilities and
other settings where TB may be spread
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