How Tuberculosis Disease is Spread

Tuberculosis (TB) can be spread when a person with active tuberculosis disease in their lungs coughs, sneezes or talks. It is usually only moderately infectious and usually requires prolonged exposure in an enclosed space to spread. TB is also usually treatable and curable with modern antibiotics.

 Latent TB Infection and Active TB Disease

When TB germs enter the body, they usually lie dormant for months or years. This is called latent TB infection. A person with a latent TB infection is not sick, does not have symptoms of tuberculosis, and cannot spread it to others. Therefore, it is not necessary for people with only a positive skin test and no TB disease symptoms to be excluded from school or work. A chest x-ray will be performed to be certain that these individuals do not have active TB. A person with latent TB infection has a 10 percent chance of developing active TB disease later in their lifetime. However, with treatment for latent TB this risk can be almost completely eliminated.

The most common symptoms of active TB disease include coughing, night sweats and unexplained weight loss. Additional symptoms include coughing up blood, fever, loss of appetite and chest pain. A person must have the active form of TB disease in order to spread it to other people.

How a TB contact investigation works

Controlling the spread of tuberculosis and protecting the public health depends on finding people who have been exposed. Further evaluation determines whether these exposed individuals have no TB infection, a latent noninfectious TB infection, or an active TB infection that could be spread to others. Those individuals identified as possibly having active TB are advised to begin treatment and are required to stay home until it can be shown they cannot spread the disease to others.

Therefore, the most effective procedure is to begin testing with those who have close contact with a person with active TB. The results of initial investigations lead to continued investigations until all those identified as being at risk are evaluated.

What a Positive TB Skin Test Means

 A positive skin test means that there is a possibility that an individual has been infected with TB. Further evaluation and testing will determine whether the infection is the latent noncontagious form or the active form. The vast majority of those with positive skin tests will be determined to have the latent noncontagious form.

Treatment for TB

While tuberculosis can be a serious illness, it can usually be treated and cured by taking a course of medication (antibiotics).

If active TB disease is suspected, public health professionals would take the patient’s history, collect three sputum samples, begin the patient on a course of four medications by directly observed therapy (patients are supervised while medications are given) for at least six months to eliminate the disease, begin a new contact investigation, and require the person be excluded from school or work for a period of time until they are considered non-contagious. 

For those with latent TB infection, DSHS strongly recommends a course of preventive medication therapy with one drug, usually lasting nine months to ensure that the TB bacteria won’t activate later on and cause active TB in the future. People who do not take preventive treatment may develop active disease in the future, infect other people, and result in the future spread of TB in the community and among family members.

People with either latent TB infection or active TB disease should take medication completely, as directed by a doctor, to ensure the medication will treat the infection without recurrence and the bacteria won’t become resistant. Treatment is carefully monitored to be certain it is done correctly and to watch for medication side effects.

TB and Football and Other Sporting Events

It is not necessary to cancel football games or limit the participation of people who are not sick in order to prevent the spread of tuberculosis. In fact, the open air setting of football games acts to prevent the transmission of TB. Additionally, someone who is capable of spreading the disease is almost always sick and would have symptoms that make them unable to participate in athletic events. People who have been diagnosed with latent TB infection cannot spread the infection to others, so they may participate fully in all activities.