Tuberculosis Fact Sheet

March 2013

Tuberculosis is an airborne infectious disease caused by the bacterium Mycobacterium tuberculosis that usually affects the lungs, although other organs and tissues such as the kidney, spine and brain can be affected as well. TB can be spread by coughing, sneezing, laughing or singing.1 Repeated exposure to someone with TB disease is generally necessary for infection to take place.

  • 2011 data shows the total number of new cases of tuberculosis in the United States (10,528) decreased for the ninth consecutive year, resulting in the lowest rate for reported TB cases (3.4 p per 100,000) since national surveillance began in 1953.2
  • In 2011, non-Hispanic Asians had the highest TB case rate (20.9 per 100,000) followed by non-Hispanic Native Hawaiians/Pacific Islanders (15.9 per 100,000), non-Hispanic Blacks (6.3 per 100,000), Hispanics (5.8 per 100,000), American Indian/Alaska Natives (5.6 per 100,000) and non-Hispanic Whites (0.8 per 100,000).3
  • For the tenth consecutive year, over half of new TB cases (62%) were in foreign-born persons. The case rate among foreign-born persons was 11.5 times higher than among U.S. born persons (17.2 vs. 1.5 per 100,000). In 2011, four countries accounted for approximately half (50%) of all foreign-born cases: Mexico, the Philippines, India and Vietnam.4
  • In 2009, 529 people died of tuberculosis, a decrease from the 590 deaths in 2008.5
  • The World Health Organization (WHO) estimated that that 8.7 million people fell ill with TB and approximately 1.4 million deaths resulted from TB in 2011 worldwide.6
  • It is important to understand that there is a difference between being infected with TB and having TB disease. Someone who is infected with TB has the TB germs, or bacteria, in their body. The body's defenses, though, are protecting them from the germs, and they are not sick. This is called latent tuberculosis. A person with symptoms of TB disease or evidence of infection needs to be seen by a physician.
  • Several symptoms are associated with TB disease, including prolonged coughing (sometimes including coughing up of blood), repeated night sweats, unexplained weight loss, loss of appetite, fever, chills, and general lethargy. Because these signs may be indicative of other diseases as well, a person must consult a physician to determine the cause of these symptoms.
  • The simplest way to find out if you have a TB infection is to get either a TB skin or blood test, widely available at clinics or at a doctors’ office. If either is significant, then you probably have TB infection and the doctor will run more tests, such as a chest x-ray, to determine whether you have active TB disease. 
    • The preferred skin test is the Mantoux test, in which a small amount of testing material is injected under the very top layers of skin on the forearm. In 48 to 72 hours the test is read by a trained person, usually a nurse or doctor. The skin test may be significant because of previous vaccination against TB. In some groups, such as the elderly or those with impaired immunity, the skin test may not be significant in the presence of TB infection.7
    • There are two blood tests available in the U.S. that the FDA has approved for the detection of active and latent TB. Blood is drawn and sent to a lab where the strength of the immune system’s response to the TB bacteria is measured to determine infection. Blood tests for TB may be preferred over the skin test for those vaccinated against TB or unable to return for a skin test reading.8
  • TB screening programs should be targeted to each community's high risk groups. It is extremely important that these screening programs undergo regular evaluation of their usefulness.
  • TB skin or blood testing is recommended for diagnostic screening among the following high-risk groups: 
    • persons with signs, symptoms, and/ or laboratory abnormalities suggestive of clinically active TB
    • people who interact with persons with active TB disease
    • poor and medically under-served people
    • homeless people
    • those who come from countries with high TB incidence rates
    • nursing home residents
    • alcoholics and intravenous drug users
    • people with HIV or AIDS, or who are otherwise immune-suppressed
    • people in jail or prison
    • health care workers and others such as prison guards who work with high-risk populations.9
    • teachers who come in contact with high-risk populations, although this decision is made by local health authorities
    • people with certain other medical conditions which increases the risk for TB
  • Most TB can be cured. There are drugs that can kill the germs that cause TB, but a person must continually take the prescribed medication for at least six months and possibly up to a year or more for successful treatment.10
  • If a person stops taking the medicine before completing treatment, the germs may come back more resilient than before. Surviving bacteria may become resistant to the drugs used to treat TB, causing multi-drug resistant tuberculosis (MDR TB), or in some cases, extensively-drug resistant tuberculosis (XDR TB), which is a strain of TB with extensive resistance to second-line drugs. XDR TB has emerged worldwide as a threat to public health and TB control, raising concerns of a future epidemic of virtually untreatable TB or TB which is difficult to treat and too expensive for poor countries. During 1993-2002, patients with XDR TB were 64% more likely to die or have treatment failure.11 In the United States,XDR TB cases peaked in 1993, with six or fewer every year since:12

Number of XDR Cases by Year

  • Because it is difficult for some people to successfully complete their tuberculosis treatment, several innovations have been developed. One of these is the use of incentives and enablers, which may be transportation, tokens or food coupons that are given to patients each time they appear at the clinic or doctor's office for treatment. Incentives and enablers are combined with the use of directly observed therapy (DOT). DOT is a system of treatment in which the patient is administered his or her medication by a nurse or health worker and is observed taking the medication.13

For more information on tuberculosis, please review the Tuberculosis Morbidity and Mortality Trend Report in the Data and Statistics section of our website at www.lung.org or call the American Lung Association at 1-800-LUNG-USA (1-800-586-4872).

For further information on drug resistant tuberculosis please review our separate fact sheets on MDR TB and XDR TB.

 

Sources:
1. Centers for Disease Control and Prevention. Division of Tuberculosis Elimination.
Fact Sheets: Tuberculosis: General Information. October 28, 2011.
2. Centers for Disease Control and Prevention. Reported Tuberculosis in the United States, 2011. October 2012.
3. Ibid.

4. Ibid.
5. Ibid.
6.  World Health Organization. Tuberculosis Fact Sheet No 104. Reviewed February 2013.
7. American Thoracic Society and Centers for Disease Control and Prevention. Targeted Tuberculin Testing  and Treatment of Latent Tuberculosis Infection. Morbidity and Mortality Weekly Report. June 9, 2000; 49(RR06):1-54.
8. Centers for Disease Control and Prevention. Division of Tuberculosis Elimination. Testing for Tuberculosis (TB). April 27, 2012.
9. Ibid.
10. Centers for Disease Control and Prevention. Division of Tuberculosis Elimination. Fact Sheets: TB Can Be Treated. June 6, 2012.

11. Centers for Disease Control and Prevention. Emergence of Mycobacterium tuberculosis with Extensive Resistance to Second-Line Drugs—Worldwide, 2000-2004. Morbidity and Mortality Weekly Report. March 26, 2006; 55(11):301-5.
13. Centers for Disease Control and Prevention. Tuberculosis in the United States: National Tuberculosis Surveillance System Highlights from 2011.
14. American Thoracic Society, Centers for Disease Control and Preventionand Infectious Disease Society of America. Treatment of Tuberculosis. Morbidity and Mortality Weekly Report. June 20, 2003; 52(RR-11):1-77.