preventing tuberculosis in the work place a computer-based training module 2012

Preventing Tuberculosis in the Work Place

A Computer-based Training Module2012

Tulane University-Office of Environmental Health & Safety

Course Objectives• Briefly describe the history of TB• Discuss the transmission and pathogenesis of TB• Explain the difference between TB infection and TB

disease• Tuberculin Skin Testing• Sites of TB Disease• List risk factors for the development of TB disease• Personal Protective Equipment (PPE); Preventing

the transmission of TB


Who Should Take the TB Tutorial?• Any employee whose job requires contact with

hospital, clinic, or research study patients• Anyone who works with children in Tulane Day

Care• Anyone who works with individuals in homeless

shelters or prisons• Anyone working with tuberculosis infected

animals or non-human primates• Anyone working in a research laboratory where

tuberculosis research is performed


How long will the tutorial take?

It will take approximately 35 to 40 minutes to navigate through the tutorial and take the quiz located at the end. Once the quiz is complete, and you have passed with at least an 80%, you will be allowed to print out a copy of the “Certificate of Completion” to keep with your records.


How will I receive credit for taking the tutorial?

Before beginning this tutorial, you will enter your Tulane username and Tulane email password. Once provided, you will be able to take the tutorial, and then take a quiz to demonstrate mastery of the material covered. Your responses will be automatically recorded in a database accessible only to the Office of Environmental Health and Safety.


A Brief History of Tuberculosis

Tuberculosis, also known as consumption, white plague, and wasting disease, has affected humans for centuries. Until the 1800’s, it was widely considered to be a hereditary disease, and its victims were sent to sanatoriums to undergo special regimens designed to rid their bodies of the deadly disease.


A Brief History of Tuberculosis (cont.)

It was not until the year 1882 that a German scientist, Robert Koch, discovered the bacteria responsible for causing the disease, Mycobacterium tuberculosis. Even though Koch discovered M. tuberculosis, it was not until 1943 that an American scientist, Selman Waksman, discovered Streptomycin, a drug capable of killing TB bacteria.


A Brief History of Tuberculosis (cont.)

Following the discovery, many people with TB were cured, and the death rate began to drop dramatically. During the years between 1943 and the mid-1980’s, more drugs were discovered for the treatment of TB. However, during the 1980’s the number of TB cases was again on the rise due to a number of individual factors. One of these reasons was MDR-TB.


Multi-Drug Resistant TB

In some parts of the world, there are TB strains which are resistant to standard medical treatments. These strains are known as MDR-TB (multi-drug resistant TB), and a few cases even exist here in Louisiana. The good news is that protection from exposure to MDR-TB is the same as that required to protect against regular TB! We will discuss engineering and work practice controls later in the tutorial.


Transmission of Mycobacterium tuberculosis

Mycobacterium tuberculosis, the bacteria responsible for causing TB, is spread from person to person via air.


Transmission of Mycobacterium tuberculosis (cont.)

When an individual with infectious TB disease coughs, sneezes, sings, or speaks, minute particles containing M. tuberculosis may be expelled into the air. These particles, or droplet nuclei, range in size from 1-5 microns in diameter. Because of their extremely small size, these droplet nuclei may remain airborne for hours, given the proper conditions.


Transmission of Mycobacterium tuberculosis (cont.)

When another person inhales the previously exhaled droplet nuclei, transmission may occur. However, not everyone who is exposed to an infectious TB patient will become infected with M. tuberculosis. The probability of transmission is dependent on three factors:


Factors determining transmission of M. tuberculosis

• Contagiousness of the TB patient • The environment the exposure occurred in • Length of exposure


Pathogenesis of Mycobacterium tuberculosis

When a person inhales air that contains droplet nuclei, most of the larger droplets will become lodged in the upper respiratory tract, where infection is unlikely to develop. Should the droplet nuclei reach the small air sacs of the lung (alveoli) however, infection will begin.


Sites of TB Disease

Pulmonary TB- Pulmonary, or laryngeal TB occurs in the lungs. About 85% of TB cases are pulmonary. Most patients with pulmonary TB have a cough and an abnormal chest x-ray, and are considered infectious until certain criteria are met.


Sites of TB Disease (cont.)

Extrapulmonary TB: Extrapulmonary Tb occurs in places other than the lungs, such as the larynx or lymph nodes, brain, kidneys, bones, or joints. It occurs more often in people with HIV. Most types of extrapulmonary TB are not considered infectious.


Sites of TB Disease (cont.)

Miliary TB: Miliary TB occurs when tubercle bacilli enter the bloodstream and are carried to all parts of the body, where they grow and cause disease in multiple sites. This condition is rare, but extremely serious, and gains its name from the chest x-rays that contain what appears to be millet seeds scattered throughout the lungs.


Risk Factors for the Development of TB Disease

• Infection with HIV• Injection of illicit drugs• TB infection within the

last two years• Chest x-rays suggestive

of previous TB• Diabetes mellitus• Silicosis

• Prolonged corticosteroid therapy

• Immunosuppressive therapy

• Certain types of cancer• Severe kidney disease• Certain intestinal

conditions


Preventing the Spread of TB• In the Hospital

Patients suspected of having TB based on signs, symptoms, and chest film should be admitted to a special isolation room with a dedicated air filtration system. Any employee who is required to have contact with a TB patient, regardless of job classification, must be trained to wear the N95 TB respirator. We will discuss the N95 in greater detail later.


Preventing the Spread of TB (cont.)

• In the Outpatient Clinic

Since most outpatient clinics do not have special isolation facilities, the risk of spreading TB is minimized by having patients wear a mask and isolating them from other patients. Also, patients should be asked to cover their mouths and noses when coughing or sneezing. Just as in the hospital setting, any employee who is required to have contact with a TB patient, regardless of job classification, must be trained to wear the N95 TB respirator.


Preventing the Spread of TB (cont.)

• In the CommunityNo universally effective means of preventing TB in a community setting exists at this time, but the spread of TB in the community can be slowed or prevented by:

1.) Covering mouths and noses when sneezing or coughing.

2.) Identifying individuals in the community who have contracted TB


Engineering & Work Practice Controls to Reduce TB

Transmission

In hospital and clinic areas, ventilation systems which exhaust air to the outside have been shown to reduce TB transmission. Ventilation is effective if it has been properly installed and its operation is monitored by trained technicians.


Engineering & Work Practice Controls to Reduce TB Transmission (cont.)

Special rooms for TB patients require a minimum of 12 air changes/hour for new facilities, as well as air filtration units. These rooms must be kept under negative pressure.



Biological safety cabinets which filter air through HEPA filters are used in many laboratory situations where exposure to TB is likely. These cabinets are certified annually by the Office of Environmental Health & Safety to ensure their proper operation.



Although ventilation, filtration, and negative pressure rooms help, they do not completely protect individuals from acquiring TB infection. Personal Protective Equipment (PPE) must also be worn. For a more in depth description of PPE, view the following slides.


The Differences Between TB Infection and TB Disease

TB infection means that there are M. tuberculosis bacteria present in the body, but the immune system of that body is controlling the proliferation of the bacteria. This is accomplished by the production of specialized cells that surround the tubercle bacilli and then encapsulate them in a hard shell.


The Differences Between TB Infection and TB Disease (cont.)

TB infection is determined by the Mantaux PPD skin test. Individuals with TB infection are not contagious and therefore cannot spread the disease to others. They will usually have normal chest x-rays, sputum smears and cultures will remain negative, they will be asymptomatic, and are NOT contagious.


The Differences Between TB Infection and TB Disease (cont)

When an individual has TB disease, their x-rays will usually appear abnormal, and sputum smears and cultures will return positive. In addition, they will exhibit symptoms such as cough, fever, and weight loss, and they ARE contagious at this point.


TB Infection vs. TB Disease TB Infection TB Disease

Tubercle bacilli present in the body

tuberculin skin test reaction usually positive

Chest x-ray- Usually normal Chest x-ray- Usually abnormal

Sputum smears and cultures-negative

Sputum smears and cultures- positive

Symptoms-Asymptomatic Symptoms- cough, fever, weight loss, etc.

Infectiousness-Not infectious

Infectiousness- Infectious

Not a case of TB A case of TB


Personal Protective Equipment (PPE) for Preventing TB

A respirator must be worn at all times by all employees entering a TB patient’s room or other area with high TB exposure potential in order to prevent contact with airborne droplet nuclei containing the TB organism. The N95 respirator (mask) is the PPE used by employees to protect themselves from getting TB.


Personal Protective Equipment (PPE) for Preventing TB (cont.)

The N95 respirator is intended to be worn by employees, not by patients with active TB!!!



The N95 respirator is not a standard paper mask like those worn by surgeons in the OR. Although paper masks and some other masks may provide a certain level of protection, these masks do not provide a tight enough fit to bar the inhalation of TB droplet nuclei.



Not only do the N95 respirators provide a tighter fit around the mouth and nose, they are made of a thicker material that is designed to prevent the passage of TB droplet nuclei. Because this type of respirator is more durable than regular surgical masks, they may be used more than once by an employee, provided they are kept clean and dry, and no harm has come to the filter material.



When not in use, the N95 respirator should be kept in a plastic bag, and stored in a locker or coat pocket.


Obtaining an N95 Respirator

The location of respirators will vary depending on your position at the University. In clinics and at the hospital, respirators will be a stock item. At other sites, the respirators must be ordered. Ordering information may be obtained through the Office of Environmental Health & Safety (504) 988-5486.


Steps to Obtaining and Using an N95 TB Respirator

• Employees must receive a medical evaluation• Employees must be trained and fit tested in order

to properly don the N95 (Contact Kim Chapital: (504)988-2870)

• Employees must follow Tulane’s Respiratory Protection Policy


Respirator Fit-Testing

To obtain a schedule of respirator fit testing, please contact the office of Environmental Health and Safety at (504)988-5486.


Tuberculin Skin Testing (TST)

To definitively determine exposure to TB, a tuberculin skin test, or Purified Protein Derivative (PPD), is performed. The test involves injecting a small amount of killed, purified proteins under the skin.


Tuberculin Skin Testing (cont.)

72 hours after the injection, an exposed individual will demonstrate a raised bump at the site of injection. This raised area must be measured by the nurse or physician that administered the test. It is the size of the reaction that will determine whether the reaction is positive or negative.



It is important to note that a positive skin test is a marker of infection with TB, but does not necessarily imply active TB disease!!!



Who Needs PPD Testing? Health care workers in contact with patients Medical students Social workers Receptionists in clinics Respiratory therapists Etc.



How Often Must Tuberculin Skin Testing Be Done?

Annually for those in contact with patients At least annually for those whose jobs place them

at increased risk for TB, such as those working with TB patients or in a laboratory that handles TB.



What Does a Positive TST Mean?

A positive Tuberculin Skin Test (TST) means that you have been exposed to the organism responsible for causing TB, but does not necessarily mean that you will develop active TB. Most healthy people will never develop the symptoms of active TB.



In fact, persons with a positive TST are not even contagious unless they have the signs or symptoms of active TB, so a positive TST test will not interfere with your ability to work.



Does a Positive TST Require Medical Treatment?

An employee with a positive TST may be monitored on an annual basis for the development of signs or symptoms of active TB. Not everyone with a positive TST will require treatment.



The decision to medicate a person with a positive TST that lacks signs or symptoms of TB depends on such findings as:

Radiologic findings on chest films Age of the individual Risk factors underlying the development of active

TB



Where Can I Get a Tuberculin Skin Test?Contact your department head. Each department is

responsible for accepting charges associated with the Tuberculin Skin Testing for high-risk employees for that work area. The employee may get the skin test from any healthcare provider with the charges being sent to the employee’s department or the employee may file for reimbursement.

Students may report to the Student Health Center for their TST.


Tulane Medical Surveillance Program

In the event of an exposure incident at Tulane, he employee must notify the supervisor and the Employee Report of Occupational Injury or Disease must be completed. The employee must take the completed form to a medical provider so the individual will receive medical management and follow-up treatment, and will be counseled on the benefits and risks of TB prophylaxis. OEHS will follow-up with the employee as necessary.

Students should similarly complete the Student First Report of Injury form and report to the Student Health Center for medical evaluation.


Course Credit

You have completed the slide presentation. Please click the link below to enter into the test area to receive credit for course completion.

https://audubon.tulane.edu/ehs/enterssn.cfm?testnum=133

Proceed to Quiz

https://audubon.tulane.edu/ehs/enterssn.cfm?testnum=133

http://audubon.tulane.edu/ehs/enterssn.cfm?testnum=133

preventing tuberculosis in the work place a computer-based training module 2012

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