Section 4: Preventing Exposure to Tuberculosis

For Students
Infectious Disease Prevention Educational Module
Section 4: Preventing Exposure to Tuberculosis

Section 4 Learning Objectives
This section is designed to help you:

- Describe the risks of tuberculosis exposure for health care workers.
- Describe the fit-tested mask requirements for students who rotate through areas at high risk for tuberculosis.

Preventing Exposure to Tuberculosis
Health care workers in a health care environment who are at risk for bloodborne pathogen exposure may also be at risk for exposure to tuberculosis.

Tuberculosis (TB) is a disease caused by a bacterium, Mycobacterium tuberculosis.  TB is spread primarily by airborne droplets that are coughed up from the lungs of persons with active disease.  Once inhaled, the organisms establish infection in the lungs and then disseminate throughout the body before the immune response brings the primary infection under control.  Most infected persons have no symptoms of the disease.  Following infection, a small percentage of individuals will develop symptoms.  About ten percent of persons who become infected will develop an active case of TB during their lifetime.

The risk of developing active disease is enhanced by a number of factors that include: HIV infection, pharmacologic immunosuppression, steroids, underlying medical conditions such as diabetes mellitus, and sudden weight loss.  For decades, the prevalence of tuberculosis in the United States was declining.  However, since the mid-1980s, the number of tuberculosis cases has increased.  Here are a few facts:

- According to the Minnesota State Department of Health, the total number of cases and incidence of tuberculosis for the state of Minnesota in 2001 was 239 or 4.9 per 100,000 population.  Of these, 140 cases were from Hennepin County and 42 from Ramsey County.
- The risk increases when an uninfected person shares space with an infected person for long periods of time.
- At this time, the TB surveillance information from the Minnesota Department of Health is indicating an increase in the rates of TB for foreign-born persons in Minnesota.  The increase in drug-resistant TB in Minnesota creates the need for health professionals to be diligent with their Mantoux testing.

Properly fitted face masks offer protection against inhalation of airborne pathogens.  Place a mask before entering a room where there is a risk of respiratory exposure.  In the hospital, an isolation card posted at the doorway lists protective clothing and other precautions to prevent exposure to a patient's disease.

Health care workers are required to follow OSHA regulations in caring for persons with active tuberculosis.  As a student, you will not be allowed to care for a patient with tuberculosis without proper mask fit testing.  Your individual rotation site will provide you with instructions in how to handle this specific situation when it arises.  If you have completed mask-fit testing, you should carry documentation of testing and the mask requirements during rotations.

Proceed to Section 5: Protocol for Responding to an Exposure to Bloodborne Pathogens.