Facts About Tuberculosis

Tuberculosis Remains A Global Health Threat

Screening and Treatment are the Key to Control

What is Tuberculosis (TB)?

TB is a contagious, infectious disease caused by bacteria (Mycobacterium tuberculosis). TB bacteria usually attack the lungs, but can affect other parts of the body such as the kidney, bones, and brain. TB is a serious disease which kills 1.5 million people each year worldwide. However, if the disease is recognized early on, and treated appropriately, the chances of recovery are good.

  • At least two billion people are thought to be infected with TB bacteria.
    • At least one person becomes infected every second.
  • Each year, approximately nine million people around the world become sick with TB disease.
  • 1.5 million TB-related deaths occur worldwide each year.
    • TB takes one life every 21 seconds.
  • TB is the leading cause of death of people who are HIV-infected.
  • There were an estimated 480,000 cases of multi-drug resistant (MDR) TB in 2013.

Who is at risk for TB?

  • People living with HIV are 21-34 times more likely to develop TB than people without HIV due to their suppressed immune systems
  • Diabetics are also more likely to develop TB disease. The co-infection of diabetes and active TB is difficult to treat, resulting in poorer outcomes - including treatment failure, and death
  • People taking immunosuppressant drugs for diseases like rheumatoid arthritis and psoriasis, are at a higher risk.
  • Healthcare workers are at a higher risk due to contact with possibly infected patients
  • People who come from a country with a high prevalence of TB are at risk. Of the 9 million people who become sick with TB each year, more than half are from South East Asia and the Western Pacific.
  • Certain other communities remain at higher risk. These groups include the elderly, immigrants, homeless, inmates, and people with a weakened immune system, and of course anyone  who comes into contact with these individuals.

How is TB spread?

TB bacteria are spread through the air when a person with TB disease of the lungs or throat coughs, sneezes, speaks, or sings, which may cause people in close proximity to become infected.

What is the difference between TB infection (latent TB) and active TB?

  • Not everyone who becomes infected with TB bacteria develops TB disease. A person who is infected with the bacterium that causes TB, but who shows no symptoms and is not sick with the disease, is regarded as having latent TB infection (LTBI).
    • Approximately 1 in every 10 persons infected with TB bacteria will go on to develop active TB disease.
  • Individuals with LTBI and a compromised immune system are more likely to progress to active TB.
  • Active TB occurs when the TB bacteria overcome a person’s immune system and symptoms (e.g., cough, night sweats and weight loss) appear. A person who has active pulmonary TB is contagious.

How is TB Treated?

TB therapy is a well-studied but still imperfect discipline. The course of treatment can take as long as 2 years, depending on how the TB bacteria respond to the daily dose of medication. Adherence to this treatment  regime is difficult for most people, and quitting therapy early has led to  drug resistant strains of TB developing.   

How can TB be Prevented?

Treatment of LTBI prevents most cases of active TB from developing. Treatment of an individual with LTBI is significantly cheaper and easier than treating an individual with contagious, active TB. This strategy breaks the cycle of TB transmission, and has been recommended  by the World Health Organization in their LTBI guidelines (2014)

TB May Be Resistant to Treatment Options

  • Of particular concern to TB control are people who develop TB in a form that resists treatment with two or more of the best-known, first-line, anti-TB drugs. This is known as multidrug-resistant TB (MDR-TB).
    • 3.5 percent of new TB cases,  are MDR-TB cases.
  • In addition, though rarer, extensively drug-resistant TB (XDR-TB) has become an increasingly challenging and important issue. An estimated 9% of patients with drug resistant TB have XDR-TB. The strains of bacteria at work in this form of the disease are resistant to both first-line and second-line treatments. In such cases, doctors are left with treatment options that are much less effective, putting the lives of their patients in danger.
    • An estimated 480,000 new cases of MDR/XDR-TB emerge annually.

Where to get a TB blood test

If you are at risk for TB, you will want to get tested as soon as possible. Ask your health care provider for the most accurate TB blood test, QuantiFERON-TB Gold. For more information about the test, read What is QuantiFERON-TB Gold?