What is Tuberculosis?
How is it spread?
Screening of IUPUI, University and Riley Hospital clinical pre-placement candidates
Screening of candidates with documentation of positive TST and negative chest x-ray
Screening of current employees/students with Tuberculin skin tests (TST)
Tuberculin Skin Test (TST) also known as a PPD or Mantoux skin test
Conversion of a reactive but not positive TST
TST conversion from a negative to a positive reaction
Latent TB Infections (LTBI)
Signs and symptoms of active disease
Active disease
Treatment
Multidrug resistance
BCG Vaccine
Fit testing
Caring for patients with TB
What is Tuberculosis?
Tuberculosis (TB) is an infectious disease that has infected humans for
centuries. It is caused by the organism Mycobacterium
tuberculosis. It
affects mainly the respiratory system but may affect the bones, kidneys,
and brain. TB that occurs in the lungs (pulmonary TB) or the
larynx (voice box) is most concerning as disease in those locations is
infectious to others.
Until the discovery of antibiotics, many people died from TB. People still die from TB, but not as many. Up until the early 1970s, special units and even institutions existed to house people with TB. The BellFlower clinic, at 10th and Wilson Street on the IUPUI campus, used to be a TB sanitarium.
How is it spread?
Droplets containing the organism enter the air when someone with pulmonary
or laryngeal TB sneezes, coughs, laughs or sings. A person must
inhale the organism and it must reach the small airways of the lungs
to cause pulmonary disease. It takes several hours of close contact
with a person with TB to spread the disease or infection. TB is
usually acquired by members of the same household, close friends or coworkers. A
healthcare worker (HCW) who spends a lot of time with a patient with TB is at risk also. Most
cases of TB in the United States are due to immigration from areas where
TB is common. Some of these areas include Mexico, Latin America, Asia,
Africa, Russia, and Eastern Europe. U. S. cities or areas with
large populations including: high rates of homeless, migrant workers,
prisons, and immigrants have the most cases. Children, the elderly,
and others with decreased immune system function are most susceptible.
Screening of IUPUI, University and Riley Hospital clinical pre-placement candidates
IUPUI Health Services screens IUPUI and Clarian Health Partner pre-placement
candidates who will work at IUPUI, University Hospital or Riley Hospital
with patient contact. Tuberculin Skin Tests (TST-also known
as a PPD) are used to screen for infection and disease in individuals without
a documented history of a positive TST. New hires with patient
contact receive a 2-step TST. A 2-step means 2 TST are placed at
least a week apart. One is placed and read prior to receiving clearance
to work and the second is done a week or so later. The second TST
boosts the immune system into a reaction if an infection occurred in the
distant past. The immune system may not respond to the first injection,
but the second injection stimulates the immune system’s “memory” and
causes a reaction if the person was infected after an exposure, even if
it was 20 years ago.
If the TST is positive, the candidate will be sent to University Hospital for a chest-x-ray to determine is active disease is present. A mask must be worn until told by IUPUI Health Services staff that it can be removed. The mask is worn to protect the general public until the individual with a positive TST is no longer suspected of having active disease.
If the chest x-ray is indeterminate (can’t exclude TB), the individual will be referred to their primary care provider for a repeat chest x-ray or a CT scan (CT scan if recommended by the radiologist). Neither IUPUI nor Clarian pays for the additional evaluation to determine if the candidate has active TB.
Screening of candidates with documentation of positive TST and negative chest x-ray
If a candidate brings paperwork from a healthcare provider or healthcare
institution that documents a positive TST and a negative chest x-ray taken
within the last 2 years, the individual will not be given a TST or another
chest x-ray. The chest x-ray must have been done in the U.S. A
questionnaire that screens for specific symptoms is to be completed annually
in place of the skin test.
Screening of current employees/students with Tuberculin skin tests (TST)
Current employees and students with patient contact at IUPUI and Clarian
Health Partners (University and Riley Hospital) are required to be screened
annually for TB. TST (also called a PPD) are used to screen for
infection and disease.
Tuberculin Skin Test (TST) also known as a PPD or Mantoux skin test
A Tuberculin Skin Test is an injection of a specific amount of solution
(Tubersol or Aplisol) into the forearm of an individual. The injection
solution contains a dead protein found in the TB organism. If your
immune system recognizes that protein, a hard knot (induration) forms
at the site of the injection. The immune system recognizes the
protein if the person has been infected with the TB organism. If
the person has not been infected with the organism, the hard knot does
not form. The TST cannot give you TB. A new blood test (QuantiFERON
TB Gold test) has been developed and approved for TB screening and may
become more widely used in the near future.
The TST is placed onto the forearm (usually the left, 1-2 inches below the inner elbow crease). The TST is “read” or interpreted 48-72 hours later. TST are not placed on Thursdays at IUPUI Health Services because the clinic is not open to read the test 48-72 hours later. If an individual does not have the test read within the time limit, an IUPUI employee or student will be charged a fee for having another test placed. Clarian employees are not charged for repeated tests. The form may be taken with the employee to allow a TB certified person, LPN, RN or MD to read the test. The completed form MUST be returned to the clinic or the test will have to be repeated.
If a TST reacts, it is measured in millimeters (mm) to determine the size of the reaction. Redness is not a reliable sign of a positive TST. Induration is measured to determine the size of the reaction. Induration is a feeling of hardness under the skin at the site of the TST.
Positive TST:
5mm or more of induration for HIV + individuals,
10mm or more of induration for healthcare workers
15mm or more of induration for someone with no risk factors.
Once the TST becomes positive, the individual should no longer receive a TST. Instead, a TB questionnaire is substituted on an annual basis for the TST. The questionnaire lists common symptoms of active disease and asks the employee if they are present. If any of the symptoms on the questionnaire are reported, the individual will be assessed for signs/symptoms of active disease. If disease is suspected, a chest x-ray will be ordered.
Conversion of a reactive but not positive TST
A TST conversion is >10 mm increase in the size of the TST induration
during a 2-year period in 1) an HCW with a documented negative (<10
mm) baseline two-step TST result or 2) a person who is not an HCW with
a negative (<10 mm) TST result within 2 years.
TST conversion from a negative to a positive
reaction
Approximately 2-12 weeks after exposure or infection, the TST will become
positive.
Latent TB Infections (LTBI)
Latent TB infection occurs when an individual develops a positive TST but
has no signs or symptoms of the disease. The person does not feel
sick. A chest x-ray will show no sign of TB disease. It is
presumed that the individual has been exposed to Tuberculosis but the immune
system has kept the organism contained in the body and the organism is
not able to multiply. It remains dormant (but still alive) as long
as the immune system is able to contain it.
A person with latent infection is not infectious to others. Chronic disease, such as diabetes, cancer, leukemia, kidney disease and use of steroids or other immunosuppressants, reduces the ability of the immune system to contain the organism.
It is thought that an individual with latent TB has a 10% risk of developing active disease within 2 years of the time the TST first becomes positive. That risk can be decreased with prophylactic medication use. See treatment.
Signs and symptoms of active disease
Cough of over 2 week duration
Cough that produces blood
Fever
Night sweats
Weight loss
Loss of appetite
Malaise-general feeling of not being well.
Pleuritic chest pain
Sputum samples that test positive for acid fast bacilli
Active disease
A person with active disease will not be able to work until 3 consecutive
sputum samples are negative for acid-fast bacilli.
Treatment
Medication used to treat active disease or latent infection can cause significant
side effects. The individual undergoing treatment must be monitored
regularly for side effects. Monitoring includes laboratory tests
to check liver function and completion of a questionnaire that asks whether
specific symptoms are present.
Initial treatment for active disease involves taking up to 4 antibiotics over several months. Treatment for occupationally-acquired active TB is provided by the employer. Treatment of a pre-placement candidate with active disease is provided by the county health department in which the individual resides, or the personal healthcare provider. The employer does not provide treatment for pre-employment candidates.
Latent infection is treated with daily isoniazid (INH) for 9 months. Treatment for latent infection will be provided by the employer for current employees. It can also be obtained from the local health department or personal healthcare provider. Treatment for a pre-placement candidate with latent infection is provided by the local health department or personal healthcare provider. Treatment for latent infection is recommended to decrease the risk of developing active disease in the future, but is the choice of the individual.
Public health department workers can be assigned to watch an individual take the medication to ensure compliance. Individuals who refuse to take treatment for active disease may be incarcerated. Active TB is a threat to public health and is taken very seriously.
Multidrug resistance
If antibiotics prescribed to treat TB are stopped too soon or are not taken
as prescribed, the organism frequently becomes resistant to one or more
of the antibiotics. The resistant strain of the organism may be
transmitted to other individuals. It is very important to take
the medication as prescribed to prevent resistance.
BCG Vaccine
There is controversy as to whether a vaccine (BCG) used in many foreign
countries causes induration, or if induration is due to past exposure
to the TB organism. The CDC and IUPUI Health Services takes the
position that induration is probably due to past exposure to the organism
and not due to the vaccine. If the BCG vaccine was given in the
past 2 years, it might be considered as a cause for the reaction. The
size of the reaction determines the next step in assessment for infection
or disease. Redness sometimes occurs at the site of the TST, some
people are sensitive to preservatives in the solution. Redness
is not an indication for determining a positive reaction.
Fit testing
Fit testing with N-95 HEPA filter masks is done to protect the employee
or student from inhaling harmful particles, especially Tuberculosis organisms. The
mask will be provided by your employer after passing a fit-test. Medical
conditions and physical characteristics are taken into consideration
before a fit test is done.
If an individual is not able to be fitted with a N-95 mask, a PAPR may be used instead. A PAPR is a Personal Air Purifying Respirator. It consists of a hood that covers the head, which connects to an air hose, filter and battery pack. Hoods are to be used by only one person (personal), but several people may share the other equipment.
Caring for patients with TB
Correct use of a PAPR or N-95 mask greatly decreases the risk of caring
for a patient with active or suspected TB. Patients with active
disease or who are suspected of having TB should be placed in isolation
as soon as TB is suspected. Isolation rooms for TB patients have
special air systems which prevent the organism from being circulated
to other areas.
Patients may have spent time in the hospital before TB is diagnosed or suspected. HCW who have cared for the patient diagnosed with TB are identified by administration and names are sent to Infection Control. Employees who have been exposed to TB are screened in IUPUI Health Services with TST as soon as possible and again in 3 months.
Screening and assessing for TB is an ongoing process. Cases among healthcare workers occur infrequently but regularly. TB is an infectious disease and we must be vigilant in screening for it. Annual completion of questionnaires and TST placements are important infection control measures.
