Mycobacterium Tuberculosis

Decline� During 2000, a total of 16,377 cases of

tuberculosis (TB) (5.8 cases per 100,000 of population) were reported to CDC from the 50 states and the District of Columbia, representing a 7% decrease from 1999 and a 39% decrease from 1990. In 1992 there was a resurgence of TB in the United States.

Reported Cases Ethnicity

Source: CDC

Rate per Population

Source: CDC

Mycobacterium Tuberculosis (TB)

� A slow growing bacteria that primarily affects the respiratory tract of humans.

� Other areas that can be affected:

TB Growth

� What happens after the bacteria have entered the body?They begin to grow in the alveoli (small air

sacs) of the lungs and then spread throughout the lung and body.

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Lung Anatomy

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Source: CDC

1

Incubation

� What is the usual incubation period?2-10 weeks for TB infectionUp to 2 years for TB disease (highest risk)

� TB infected, Latent TB:Positive Skin Test-not contagious

� TB disease/active:Showing symptoms and is highly

contagious

Treatment

� Multidrug resistantThey are trying many new different drug

combinations to combat the drug-resistant strains.

� DOTDirectly Observed Therapy

Directly Observed Therapy

� DOTDirectly Observed Therapy

Source: CDC

Testing

� Two major screenings available to the general population: Tine Test (3 prong)PPD (Purified Protein Derivative)

PPD Testing

Source: CDC

Transmission

� Inhalation of infectious particles:Infectious particles are carried in the air

after an active TB individual speaks, coughs, sneezes, or certain medical procedures are performed.

� These particles are called droplet nuclei.

� 1-5 microns/ 1/5000 of an inch in size

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Infected Person

Transmitting Droplets Inhalation of Droplets

Cough-Sneeze-Talking

Respirator

� A respirator is a personal protective device that removes air contaminants such as dust, mists, and aerosols from the ambient air.

� The ones used to protect against TB, filter out material down to 0.3 microns at 95% efficiency (N95).NIOSH approved

Respirator

Respirator

N 95 NIOSHApproved

Must be fit tested

AFB Isolation

� Acid Fast Bacilli (AFB) isolation room:Warning signsMust be maintained under negative

pressure. Exhaust air from the isolation room away

from air intakes for the building, usually on the roof.

Filters

� High Efficiency Particulate Air filter (HEPA):Used to filter air for recirculation in an AFB

isolation room at 0.3 microns at 99.97% efficiency.

Settings at Risk

� High Risk Settings:Health care settingsCorrectional institutionsHomeless sheltersLong-term care facilities for the elderlyDrug treatment centers

Where are your risks?