Fact Sheets
Infection Control in
Health-Care Settings
Last Updated: April 2006
Introduction
All health-care settings need an infection-control program
designed to ensure prompt
- detection,
- airborne precautions, and
- treatment
of persons who have suspected or confirmed tuberculosis (TB)
disease (or prompt referral of persons who have suspected TB disease
for settings where persons with TB disease are not expected to be
encountered). In order to be effective, the primary emphasis of the
TB infection-control program should be on achieving these three
goals.
In all health-care settings, particularly those in which persons
who are at high risk for exposure to Mycobacterium tuberculosis
work or receive care, policies and procedures for TB control should
be developed, reviewed periodically, and evaluated for effectiveness
to determine the actions necessary to minimize the risk for
transmission of M. tuberculosis.
Overview of TB Infection-Control Measures
The TB infection-control program should be based on a three-level
hierarchy of control measures. The first and most important level of
the hierarchy, administrative measures, affects the largest number
of persons and is intended primarily to reduce the risk of
uninfected persons exposed to persons who have TB disease. These
measures include the following activities:
- Assigning responsibility for TB infection control in the
setting;
- Conducting a TB risk assessment of the setting;
- Developing and instituting a
written TB infection-control plan to ensure prompt detection,
airborne precautions, and treatment of persons who have
suspected or confirmed TB disease;
- Ensuring the timely availability of recommended laboratory
processing, testing, and reporting of results to the ordering
physician;
- Implementing effective work practices for the management of
patients with suspected or confirmed TB disease;
- Ensuring proper cleaning and sterilization or disinfection
of potentially contaminated equipment (e.g., bronchoscopes,
endoscopes);
- Training and educating health-care workers (HCWs) regarding
TB, with specific focus on prevention, transmission, and
symptoms;
- Screening and evaluating HCWs who are at risk for TB disease
or who might be exposed to M. tuberculosis;
- Applying epidemiologic-based prevention principles,
including the use of setting-related infection-control data;
- Using appropriate signage advising
respiratory hygiene and cough etiquette; and
- Coordinating efforts with the local or state health
department.
The second level of the hierarchy is the use of environmental
controls to prevent the spread and reduce the concentration of
infectious droplet nuclei in ambient air. Primary environmental
controls control the source of infection by using local exhaust
ventilation (hoods, tents, or booths) and dilute and remove
contaminated air by using general ventilation. Secondary
environmental controls control the airflow to prevent contamination
of air in areas adjacent to the source (airborne infection isolation
[AII] rooms) and clean the air by using high efficiency particulate
air (HEPA) filtration, or ultraviolet germicidal irradiation.
The first two control levels of the hierarchy minimize the number
of areas in the health-care setting where exposure to M.
tuberculosis may occur.
They reduce, but do not eliminate, the risk in those few areas
where exposure to M. tuberculosis can still occur (e.g., AII
rooms housing TB patients and treatment rooms in which
cough-inducing or aerosol-generating procedures are performed on TB
patients). Therefore, the third level of the hierarchy is the use of
respiratory protective equipment in situations that pose a high risk
of exposure to M. tuberculosis.
Use of respiratory protection equipment can further reduce risk
for exposure of HCWs to infectious droplet nuclei that have been
expelled into the air from a patient with infectious TB disease. The
following measures can be taken to reduce the risk for exposure:
- Implementing a respiratory protection program
- Training HCWs on respiratory protection
- Training patients on respiratory hygiene and cough etiquette
procedures.
Determining the Infectiousness of TB
Patients
In general, patients who have suspected or confirmed TB disease
should be considered infectious if (a) they are coughing, undergoing
cough-inducing procedures, or have positive sputum smear results for
acid-fast bacilli (AFB); and (b) they are not receiving adequate
antituberculosis therapy, have just started therapy, or have a poor
clinical or bacteriologic response to therapy.
For patients placed under airborne precautions because of
suspected infectious TB disease of the lungs, airway, or larynx,
airborne precautions can be discontinued when infectious TB disease
is considered unlikely and either
- Another diagnosis is made that explains the clinical
syndrome, or
- The patient produces three consecutive negative sputum
smears collected in 8- to 24-hour intervals (one should be an
early morning specimen).
Patients for whom the suspicion of infectious TB disease remains
after the collection of three negative sputum smear results should
not be released from airborne precautions until they
- Receive standard multidrug antituberculosis treatment
(minimum of 2 weeks) and
- Demonstrate clinical improvement.
For these patients, additional diagnostic approaches (e.g.,
sputum induction) and, after sufficient time on treatment,
bronchoscopy may need to be considered.
Patients who have drug-susceptible TB of the lung, airway, or
larynx, should remain under airborne precautions until they
- Produce three consecutive negative sputum smears collected
in 8- to 24-hour intervals (one should be an early morning
specimen), and
- Receive standard multidrug antituberculosis treatment
(minimum of 2 weeks), and
- Demonstrate clinical improvement.
Note
The Centers for Disease Control and Prevention (CDC) is not a
regulatory agency; CDC recommendations on infection control provide
evidence-based guidance. For regulations in your area, refer to
state and local regulations and contact your local Occupational
Safety and Health Administration (OSHA) office. A directory of OSHA
offices may be found at
www.osha-slc.gov/html/RAmap.html.
References
CDC. Guidelines for preventing
the transmission of Mycobacterium tuberculosis in health-care
settings, 2005. MMWR 2005; 54(No. RR-17).
www.cdc.gov/mmwr/pdf/rr/rr5417.pdf
Additional Information
Websites:
CDC Division of Tuberculosis Elimination:
www.cdc.gov/tb
State TB control offices:
www.cdc.gov/tb/pubs/tboffices.htm.
National Institute for Occupational Safety and Health:
www.cdc.gov/niosh/topics/tb
Occupational Safety and Health Administration:
www.osha-slc.gov/SLTC/tuberculosis/index.html
Fact Sheet:
Respiratory Protection in Health-Care Settings:
www.cdc.gov/tb/pubs/tbfactsheets/RPHCS.htm
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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