Tuberculosis: TB Test

Tuberculosis / TB Test

What is it?

Tuberculosis is an infection caused by slow-growing bacteria that festers in areas of the body containing an abundant amount of blood and oxygen. Tuberculosis found in the lungs is known as pulmonary TB and tuberculosis that spreads to other organs is called extrapulmonary TB. This condition is highly contagious, but treatment is often effective and can take between six to nine months to treat, or in severe cases, can take up to two years to treat an infected patient.

Tuberculosis is a disease that is spread through the air from one person to another. When someone who is sick coughs, speaks, laughs, sings, or sneezes, people nearby may breathe the bacteria into their lungs. Tuberculosis usually attacks the lungs, but can also attack other parts of the body, such as the brain, spine, or kidneys. Many strains of tuberculosis are resistant to drugs used in treatment. People with active tuberculosis infections need to take several types of medication for months to eradicate the disease and prevent further development of antibiotic resistance.

Tuberculosis in people over the age of 65 constitutes a large proportion of TB cases in the United States. Many of these individuals have a latent TB infection; however, with aging these individuals’ immune function starts to decline, placing them at increased risk of developing the active TB disease. These seniors and employees in long-term care facilities are at a higher risk of complications from this disease.

TB Test Costs

Employer: Ask if the cost of testing is covered by your employer or potential employer

Health Insurance: Testing may be included in your health coverage

Out of Pocket: Locations like Walgreens start TB testing costs at $10

Colleges: Some on-site health labs offer student discounts

Health Department Clinics: If you meet certain income requirements these can be free

Cost Study 

How Much is It 


Tuberculosis (TB) screening and testing of health care personnel is recommended as part of a TB Infection Control Plan and might be required by state regulations. State Regulations 

CDC / US Center for Disease Control: All U.S. health care personnel should be screened for TB upon hire.

Healthcare workers (HCWs) are at high risk of Mycobacterium tuberculosis infection due to occupational exposure.

You must have had two consecutive negative tuberculin skin tests using purified protein derivative (PPD).

Annual TB rates in the United States have declined substantially during the past nearly three decades, according to CDC data, with the 2017 rate dipping to 2.8 per 100,000 population — a 73% decrease from 1991, when the rate was 10.4 per 100,000, and a 42% dip from 2005’s rate of 4.8 per 100,000.

In all health care settings, particularly those in which people are at high risk for exposure to TB, policies and procedures for TB control should be developed, reviewed periodically, and evaluated for effectiveness to determine the actions necessary to minimize the risk for transmission of TB.

Infection with Mycobacterium tuberculosis (TB) poses a health risk to patients, health care workers, visitors, and volunteers in long term care facilities (e.g., hospices and skilled and unskilled nursing facilities).

Sample State Regulations

State of California

HHA – Home Health Agency

All agencies shall require health assessments and maintain health records for employees with direct patient contact.

The written health assessment report shall:

Provide for a tuberculosis screening which shall be administered to all new employees who have direct patient contact and annually thereafter using a test for tuberculosis infection that is recommended by the federal Centers for Disease Control and Prevention (CDC) and licensed by the federal Food and Drug Administration (FDA).

The tuberculosis test shall be administered by a licensed health care professional who is specifically trained for the procedure.

Employees who present evidence of a previous positive tuberculosis test or that he or she has previously been treated for tuberculosis infection or disease shall be excluded from the tuberculosis screening testing.

An employee shall not be required to undergo the annual tuberculosis screening requirements of (c)(4) if the local health officer certifies in writing that less frequent testing may be conducted, and the rationale for less frequent testing is in accordance with applicable federal, state, and local requirements and established professional standards


Tuberculin Skin Test (TST) / Mantoux Tuberculin Test – 2 STEPS:
A tuberculin skin test is done to see if you have ever been exposed to tuberculosis (TB). This is a 2 step test and is done by putting a small amount of TB protein (antigens) under the top layer of skin on your inner forearm.

Step 1: Using a small needle, a health care provider injects a liquid into the skin of the lower part of the arm. When injected, a small, pale bump will appear.

Review result

⦁ Positive — consider TB infected, no second TST needed; evaluate for TB disease.
⦁ Negative — a second TST is needed. Retest in 1 to 3 weeks after first TST result is read.

Step 2: The person given the TST must return within 2 or 3 days to have a trained health care worker look for a reaction on the arm where the liquid was injected. The health care worker will look for a raised, hard area or swelling, and if present, measure its size using a ruler. Redness by itself is not considered part of the reaction.

Review results

⦁ Positive — consider TB infected and evaluate for TB disease.
⦁ Negative — consider person not infected.


TB Blood Tests

An IGRA is a blood test that can determine if a person has been infected with TB bacteria. An IGRA measures how strong a person’s immune system reacts to TB bacteria by testing the person’s blood in a laboratory. Two IGRAs are approved by the U.S. Food and Drug Administration (FDA) and are available in the United States:

⦁ QuantiFERON®–TB Gold In-Tube test (QFT–GIT)
⦁ T–SPOT®.TB test (T–Spot)

Blood is collected into special tubes using a needle. The blood is delivered to a laboratory as directed by the IGRA test instructions. The laboratory runs the test and reports the results to the health care provider.

Positive TB Blood Tests:

If a person is found to be infected with TB bacteria, other tests are needed to see if the person has the TB disease. TB disease can be diagnosed by medical history, physical examination, chest x-ray, and other laboratory tests. TB disease is treated by taking several drugs as recommended by a health care provider.

If a person does not have TB disease, but has TB bacteria in the body, then latent TB infection is diagnosed. The decision about taking treatment for latent TB infection will be based on a person’s chances of developing TB disease.

How is TB Disease Treated?

TB disease can be treated by taking several drugs for 6 to 12 months. It is very important that people who have TB disease finish the full amount of medicine, and take the drugs exactly as prescribed. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the germs that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat. In some situations, staff of the local health department meet regularly with patients who have TB to watch them take their medications. This is called directly observed therapy (DOT). DOT helps the patient complete treatment in the least amount of time.