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Case Investigation Process

When an individual is diagnosed with active tuberculosis, there is a systematic process that is followed to identify people at risk of becoming infected. It is a process with many steps and often is very lengthy for specific reasons.

Initially, people such as family members and close friends who have had ongoing, close, prolonged contact with the individual are identified and tested. It can take up to eight weeks after becoming infected for a person to test positive for TB, so it is generally not urgent to test every potential exposure immediately. Sometimes individuals need to be tested twice, and the final results of testing are not available for several months.

If any individuals have become infected, they generally have what is called “latent TB” where the TB bacteria is present in the body but is contained and not contagious. Persons with latent TB are not sick, not infectious, and cannot pass it on to other people (see more on this below). TB is very different from something like the flu. With tuberculosis, when someone becomes infected, they generally are not immediately sick and can NOT pass it on to others as occurs with a flu outbreak.

As an investigation of an active TB case proceeds, if a number of the closest contacts test positive for TB, the list of individuals expands to include those who had less exposure to the active TB case. It is a systematic process to make sure that individuals who are at high risk are tested and any infections related to the active case can be identified.

Additional information is provided below about the process of following up on possible exposures.

Tuberculosis (TB) FAQ

What is TB?

Tuberculosis (TB) is a disease caused by the Mycobacterium tuberculosis bacteria. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body.

How is TB spread?

TB is spread through the air from one person to another. TB is spread through close, prolonged contact with a person with active TB when they cough, sneeze, sing or speak. TB is not spread by shaking someone’s hand, sharing food or drink, sharing toothbrushes, or coming into contact with their clothes.

Does TB make you sick?

There are two main types of tuberculosis: latent tuberculosis infection and active tuberculosis disease.

Most people infected with the TB bacteria have latent tuberculosis infections and do not become sick. These people do not have symptoms, and cannot spread TB to others. They are NOT contagious or infectious. A small portion of people with latent TB infection can go on to develop active TB at some point in their lives. (see below).

Only individuals with active TB disease are sick and may be able to spread TB to others.

Can TB be treated?

Yes. People with active TB disease can be treated with medications. After a period of treatment, they are no longer contagious and usually make a full recovery.
Individuals with latent TB infection can take preventative medicine to greatly decrease their risk of getting sick with active TB in the future.

Is there a vaccine for TB?

Yes, there is a vaccine for TB called Bacille Calmette-Guerin (BCG), but it is not recommended in the U.S. and not used widely because it has a limited overall effectiveness for preventing TB. It is used in some countries to prevent severe forms of TB in children.

What is being done to address the active TB case at MU?

The student with active TB left campus, is on home isolation and being treated. The Columbia/Boone County Department of Public Health and Human Services is working closely with the student to identify close contacts the student may have had. Those individuals are being notified that they need TB testing.

Why aren’t you recommending that everyone on campus be tested for TB?

We are following CDC guidelines in determining who should be tested.

The Centers for Disease Control and Prevention (CDC) recommends that testing for TB be targeted to only those individuals who are identified as high risk. The test is most accurate in this group. If everyone on campus were tested, the vast majority of the individuals tested would be at very low risk of having been exposed to tuberculosis. Testing individuals at low risk for exposure can lead to positive test results that may not be related to the current active TB case, may not be related to true TB exposures, and could cause confusion with the current active TB contact investigation. Additionally it subjects those who have positive tests for other reasons to undergo x-ray testing and take unnecessary medication.

Will the student with active TB be allowed to return to campus and if so, when?

People with active TB are allowed to return to normal activities when it has been determined they are no longer infectious (contagious).

What do you mean by “high-risk” contacts?

People at highest risk for TB infection are those who are in close, prolonged contact with someone that has active TB. The longer the period of time spent, and the smaller the physical space, the higher the risk of infection. People with active TB disease are most likely to spread it to people they spend time with every day.

What should I do if I think I am “high risk?”

If you think you are high risk, please call Megan Huddleston, RN, MU Student Health Center, at 573-884-9937 for further guidance.

Why can’t specific details about the student be shared?

The student’s privacy and health information is protected by law under the Health Insurance Portability and Accountability Act (HIPAA).

Should I get tested?

TB testing in people without concerning symptoms is only recommended for certain groups at higher risk for being infected with TB bacteria including:

  • People who are considered “high-risk contacts” of someone  with active TB disease
  • People who live or work in high-risk settings (correctional facilities, long-term care facilities, nursing homes, homeless shelters)
  • Health-care workers who care for patients at increased risk for TB disease
  • People from a country where active TB disease is common
  • Infants, children and adolescents exposed to adults who are at increased risk for latent TB infection or active TB disease (from CDC)

Additionally, TB testing is recommended for individuals with certain medical conditions or taking certain medications that cause an individual to be immunocompromised (meaning it is hard for these individuals to fight off infections). If you think this applies to you, you can discuss this with your health care provider.

Can I get tested?

You can get a TB test if you want one, although it is strongly discouraged unless you are at higher risk (see higher risk categories above).

Will everyone in the student’s classes be tested?

At this time, it is not recommended to do mass testing of all students that attended the same classes as the student with active TB. After testing the student’s closest contacts, if it is determined that testing of all classmates is warranted, students will be notified that they need to be tested.

Can I make other people sick if I was around the student with active TB?

In most people who are infected with TB, the body is able to fight the bacteria to stop them from growing. The bacteria become inactive, but they remain alive in the body and can become active later. This inactive infection is called “latent” TB.  People with latent TB infection can’t spread TB bacteria to others. People who have latent TB infection can be treated to make it unlikely that they will develop active TB disease. Without treatment, about 5 to 10 out of one hundred people with latent TB will develop active TB disease themselves.