Download MULTIDRUG-RESISTANT TUBERCULOSIS: What Nurses Should

MULTIDRUG-RESISTANT
TUBERCULOSIS: What Nurses Should
Know
Felissa R. Lashley, RN, PhD, FAAN, FACMG
Professor, College of Nursing, and
Interim Director, Nursing Center for Bioterrorism and Infectious
Disease Preparedness, College of Nursing
Rutgers, The State University of New Jersey
This module is designed to highlight important information about multidrug resistant
tuberculosis (MDR-TB). MDR-TB is also considered to be a potential agent for bioterrorism
and is considered as a possible Category C bioterrorism agent by the Centers for Disease
Control and Prevention (CDC). This module was supported in part by USDHHS, HRSA
Grant No. T01HP01407.
Multidrug-Resistant Tuberculosis
(MDR-TB)
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MDR-TB is considered as a Category-C biological
agent in regard to its potential for use in
bioterrorism by the CDC.
These agents are considered as possible
emerging public health threats and are
considered as such in the module on Biological
Weapons: Essential Information on Category C
Agents.
XDR-TB (extensively resistant tuberculosis) refers
to cases of TB that are resistant to isonazid ,
rifampin, the second line drugs, the
fluoroquinolones, and at least one of three
injectable drugs. i.e. amikacin.
Objectives
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Describe the signs and symptoms
commonly associated with pulmonary TB.
Identify persons at high risk for MDR-TB.
Describe reasons for development of drug
resistance in the treatment of TB.
Identify possible clinical outcomes after
acquisition of Mycobacterium tuberculosis.
Identify appropriate infection control for
persons with MDR-TB.
Definition
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MDR-TB is defined as a case of TB
caused by a strain of M. tuberculosis
that is resistant to two or more
antituberculosis drugs. Some define
MDR-TB as a case of TB caused by a
strain of M. tuberculosis that is
resistant to isoniazid and rifampin.
Etiology
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Both tuberculosis infection and tuberculosis (TB)
are due to the tubercle bacilli.
The most common in the US is Mycobacterium
tuberculosis.
M. tuberculosis is a nonmotile, non-spore forming
rod shaped bacillus with no capsule.
It does not produce toxin.
It is known as acid fast because of staining
characteristics.
It can survive for long periods under adverse
conditions.
Description
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Infection with M. tuberculosis can
be pulmonary or extrapulmonary.
Pulmonary TB is the most common
form in developed countries.
In extrapulmonary TB, signs and symptoms
depend on the affected organ system as well as
systemic symptoms.
Major concerns about MDR-TB arose in the early
1990s when nosocomial outbreaks occurred.
Concerns about XDR-TB arose in about 2000,
and appears most prevalent in South Africa,
parts of Asia especially South Korea and Eastern
Europe.
Epidemiology
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MDR-TB is particularly common in:
 Resource
poor areas
 Global "hot spots" such as some areas
in the former Soviet Union, India, the
Dominican Republic, Ivory Coast, and
others
 Congregate settings such as prisons or
long-term care facilities
Epidemiology cont.-2
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In practice, MDR-TB develops either
because the person is infected
initially with a:
 Drug-resistant
strain (primary), or
 Susceptible strain that becomes
resistant (secondary)
 Primary resistance would be most likely
in regard to bioterrorism use.
Epidemiology cont.-3
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Reasons for secondary resistance are
numerous and complex:
 Wrong
drugs used in an improper way
 Failure to assess drug susceptibility
patterns of the organism
 A large bacterial load, especially in the
case of cavitation
 Poor adherence to the treatment
regimen
Epidemiology cont.-4
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TB (including MDR-TB) and HIV co-infections are
relatively common globally and each condition
adversely affects the other.
In the US in 2007, the overall number of TB
cases reported in the U.S. was 13, 293.
In the U.S. between 1993 and 2006, 49 cases of
XDR-TB were reported, and in 2006, 116 cases of
MDR-TB were reported.
The overall case rate was 4.4 cases per 100,000
population. U.S. born blacks and foreign born
persons account for a disproportionate number of
cases.
Epidemiology cont.-5
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TB remains a major global problem.
Each year about 2 million people die
of TB each year worldwide. In 2006,
WHO reported 9.2 million new cases
of TB.
In the U.S., 49 cases of XDR-TB
were reported between 1993 and
2006.
Transmission
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Person-to-person through inhalation of droplet
nucleii
Infected person usually coughs or sneezes and
projected infected droplet nucleii into the air
Ingestion of contaminated food or water (rare in
US)
Direct inoculation is rare although infection
through transplants has occurred.
Outcomes of Contact with M.
tuberculosis
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Many factors determine outcome
such as:
 Host
susceptibility, such as genetic
factors and immune status
 Organism characteristics, such as
virulence
 Environment, such as length of time
and proximity of contact between the
susceptible person and the person with
TB
Sequence of Events in Brief:
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After M. tuberculosis enters the
body, possible events include:
 No
infection
 Tuberculous infection
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Remains dormant in latent form (90%)
Progression to clinical disease (10%)
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Within a year or two (5%)
Years later (5%)
Thus, persons may have:
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Latent TB infection in which persons are infected
with tubercle bacilli but are not infectious to
others nor show clinical symptoms but do usually
have a positive reaction to the tuberculin skin
test but usually negative chest radiograph. They
may be candidates for preventive drug therapy,
OR
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Active TB in which they are infected with tubercle
bacilli, usually have positive sputum smears and
cultures, usually have a positive reaction to the
tuberculin skin test, usually have clinical
symptoms, and may be infectious to others
before treatment is effective.
Clinical Manifestations
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MDR-TB are or are not clinically
distinguishable from drug-susceptible
TB at the outset.
Signs, symptoms, and radiological
findings are similar initially to drugsusceptible TB.
In the non-bioterrorist setting, reasons to
suspect drug resistance are:
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A history of previously treated TB in a person
presenting with active TB
High community rates of drug resistant TB
Positive HIV status
High likelihood of exposure to nosocomial, prison
or community sources of MDR-TB
The infected person is from a country with a high
MDR-TB rates
Contacts with persons with MDR-TB
Infected person has received inadequate
treatment regimens for >2 weeks
Smears or cultures remain positive despite 2
months of treatment for TB
Symptoms of Pulmonary TB
include:
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Cough (usually
productive and maybe
bloody)
Low-grade fever
Sweating
Chills at night
Fatigue
Malaise
Anorexia
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Weight loss
Dull, aching chest pain
or tightness
Symptoms of
extrapulmonary TB
depend on the organ
system involved but
may include systemic
symptoms such as
malaise
Diagnosis generally consists of:
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Medical history,
Clinical signs and symptoms,
Chest x-ray for pulmonary TB,
Sputum smear and/or culture for
acid-fast bacilli, and possibly
A tuberculin skin test.
Diagnosis notes
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Tuberculin skin test with purified protein
derivative as screen; anergy may be seen in
elderly and the immunosuppressed.
Chest x-ray or radiograph of extrapulmonary site
shows characteristic findings of abnormalities in
apical or posterior segments of upper lobe or
superior segments of lower lobe but is not used
to confirm diagnosis of pulmonary TB.
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Appearance may be unusual in HIV-positive persons
Sputum smears and cultures for tubercle bacilli.
Treatment
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Initial non-MDR-TB therapy in drugsusceptible disease calls for 8 weeks
of therapy with isoniazid, rifampin,
pyrazinamide, and ethambutol
followed by a continuation regimen
of isoniazid and rifampin for 18 more
weeks as the most frequent option.
Aggressive treatment is suggested.
Treatment cont.-2
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Usually the initial regimen for MDRTB will consist of at least 3 TB drugs
the patient has not used before (a
single drug should never be added)
and as many as 6 drugs.
There are detailed dosages and
possible options available depending
on many factors. Newer guidelines
should always be consulted.
Treatment cont.-3
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MDR-TB treatment depends on the
drug resistance pattern present:
 It
may include directly observed therapy
 Occasionally, surgical resection may be
used in treatment
 Detailed information about management
options are given in the references (see
CDC reference in particular)
Prevention
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MDR-TB may be prevented by
clinicians:
 Choosing
the appropriate therapeutic
regimen based on clinical,
microbiological, pathological,
radiological and epidemiological
information, and
 Assuring a regimen with the highest
likelihood of adherence to therapy.
Management, including Infection
Control
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Teaching the patient and family about
preventing transmission, especially
etiquette and hygiene, use of masks
where indicated, and handwashing.
Isolation precautions are usually needed
until there have been 3 negative sputum
cultures.
Ascertaining likelihood of adherence and
using measures to enhance adherence.
Promptly isolate persons suspected or
known to have TB.
Use appropriate infection control.
MDR-TB
For sputum positive pulmonary MDR-TB, appropriate
infection control includes: infection control
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Special airborne precautions, including isolation
in a negative pressure isolation room, and
appropriate air handling.
Staff should wear appropriate personal protection
devices, and close door behind them.
Staff should remove personal protection devices
before exiting anteroom and sanitize hands after
leaving room. See infection control module
details, and CDC, (2005). Guidelines for
preventing the transmission of My cobacterium,
2005.
Murphy, R.A. (2008) The emerging crisis of drug-resistant tuberculosis in
South Africa: Lessons from New York City. Clinical Infectious Diseases 46,
1729-1732
For sputum positive pulmonary MDR-TB,
appropriate infection control includes:
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Special airborne precautions, including
isolation in a negative pressure isolation
room.
Staff should wear powered-air purifying
respirators (PAPRs), and close door behind
them.
Staff should remove PAPR before exiting
anteroom and sanitize hands after leaving
room. See infection control module for
details or CDC (2005).
MDR-TB References
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CDC. (2003). Treatment of TB. American Thoracic Society,
Centers for Disease Control and Prevention, and Infectious
Disease Society of America. MMWR, 52 (RR-11),1-88.
Lashley, F.R., & Durham, J.D. (Eds.). (2007). Emerging
infectious diseases: Trends and issues. 2nd edition. New
York: Springer Publishing Co.
Mukherjee, J.S., Rich, M.L., Socci, A. R. et al. (2004).
Programers and principles in treatment of multidrugresistant tuberculosis. Lancet, 363, 474-481.
CDC (2008). Trends in tuberculosis- United States, 2007.
MMWR 57, 281-285.
CDC (2005) Guidelines for preventing the transmission of
tuberculosis; healthcare settings, 2005. MMWR,54,1-141.
Yew, W.W. and Leung, C.C. (2008) Management of
multidrug-resistant tuberculosis: Update 2007. Respirology,
13, 21-46.