Skip navigation


This information is provided by the North Dakota Department of Health. It is not a substitute for advice from your doctor. 

What is tuberculosis?

Tuberculosis is a bacterial infection/disease usually affecting the lungs. Other parts of the body which can also be affected are the brain, lymph nodes, kidneys, bones, joints, larynx, intestines or eyes.  When people become infected with the TB bacteria, some will develop the disease, but most will not. 

Who gets tuberculosis?

Tuberculosis can affect people of any age.  It is commonly associated with older people who have had previous tuberculosis exposure. Individuals with weakened immune systems, including those with AIDS or those infected with the human immunodeficiency virus (HIV), are at increased risk.  Some foreign-born individuals who come from countries where TB is common may be more susceptible.

How is tuberculosis spread?

The bacteria that causes tuberculosis is spread through the air. Tuberculosis infection may result after close contact with a person who has tuberculosis disease. When a person with tuberculosis who is not taking tuberculosis medication coughs or sneezes, the bacteria get into the air. Long-term exposure to the tuberculosis bacteria is normally necessary for infection to occur.

To spread the TB bacteria, a person must have TB disease. Having TB infection is not enough to spread the bacteria. Tuberculosis may last for a lifetime as an infection, never developing into disease.  However, individuals with TB infection are at increased risk of developing TB disease, particularly during the first two years after acquiring the infection. Additionally, individuals with weakened immune system such as persons infected with HIV are at high risk of developing TB infection or TB disease. 

What are the symptoms of tuberculosis?

Symptoms include a low-grade fever, night sweats, fatigue, weight loss and a persistent cough. Some people may not have obvious symptoms.

How soon do symptoms appear?

Evidence of infection (a positive skin test) may occur from two to 10 weeks after exposure.  The most hazardous period for developing clinical disease is usually within two years after infection.  The infection can be non-active and may reactivate much later in life. 

When and for how long is a person able to spread tuberculosis?

A person with TB disease may remain contagious until he or she has been treated for several weeks.  A person with TB infection, but not disease, cannot spread the infection to others.

Does past infection with tuberculosis make a person immune?

Reinfection is rare but can occur. 

What complications can happen with tuberculosis?

If not treated, the disease is spread to others. The untreated person may become severely ill or die. 

What is the treatment for tuberculosis?

TB infection is usually treated with isoniazid (INH) alone in persons under 35. People with active TB disease must complete the prescribed course of medicine, which usually involves taking isoniazid (INH) for six to 12 months along with two or more other drugs. Treatment must be determined by a physician.

What can be done to prevent the spread of tuberculosis?

The most important way to stop the spread of tuberculosis is to cover the mouth and nose when coughing and to take the prescribed medicine as directed. Persons with disease should be excluded from school, child day care or the workplace until the disease cannot be spread. All household and close contacts of a person with TB infection or active TB disease, and all high-risk populations should be screened for evidence of infection.

All contacts with evidence of infection should be treated.