Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get StartedRisk factors
By Mayo Clinic staffAnyone can get tuberculosis, but certain factors increase your risk of the disease. These factors include:
- Lowered immunity. A healthy immune system can often successfully fight TB bacteria, but your body can't mount an effective defense if your resistance is low. A number of factors can weaken your immune system. Having a disease that suppresses immunity, such as HIV/AIDS, diabetes, end-stage kidney disease, certain cancers or the lung disease silicosis, can reduce your body's ability to protect itself. Your risk is also higher if you take corticosteroids, certain arthritis medications, chemotherapy drugs or other drugs that suppress the immune system.
- Close contact with someone with infectious TB. In general, you must spend an extended period of time with someone with untreated, active TB to become infected yourself. You're more likely to catch the disease from a family member, roommate, friend or close co-worker.
- Country of origin. People from regions with high rates of TB — especially sub-Saharan Africa, India, China, the islands of Southeast Asia and Micronesia, and parts of the former Soviet Union — are more likely to develop TB. In the United States, more than half the people with TB were born in a different country. Among these, the most common countries of origin were Mexico, the Philippines, India and Vietnam.
- Age. Older adults are at greater risk of TB because normal aging or illness may weaken their immune systems. They're also more likely to live in nursing homes, where outbreaks of TB can occur.
- Substance abuse. Long-term drug or alcohol use weakens your immune system and makes you more vulnerable to TB.
- Malnutrition. A poor diet or one too low in calories puts you at greater risk of TB.
- Lack of medical care. If you are on a low or fixed income, live in a remote area, have recently immigrated to the United States or are homeless, you may lack access to the medical care needed to diagnose and treat TB.
- Living or working in a residential care facility. People who live or work in prisons, immigration centers or nursing homes are all at risk of TB. That's because the risk of the disease is higher anywhere there is overcrowding and poor ventilation.
- Living in a refugee camp or shelter. Weakened by poor nutrition and ill health and living in crowded, unsanitary conditions, refugees are at especially high risk of TB infection.
- Health care work. Regular contact with people who are ill increases your chances of exposure to TB bacteria. Wearing a mask and frequent hand washing greatly reduce your risk.
- International travel. As people migrate and travel widely, they may expose others or be exposed to TB bacteria.
References
- Riley LW. Microbiology and pathogenesis of tuberculosis. http://www.uptodate.com/home/index.html. Accessed Dec. 22, 2008.
- Pezzella AT, et al. Surgical aspects of thoracic tuberculosis: A contemporary review - Part 1. Current Problems in Surgery. 2008;45:675.
- Summary. In: WHO Report 2008: Global tuberculosis control - Surveillance, planning, financing. World Health Organization. Accessed Dec. 20, 2008. http://www.who.int/tb/publications/global_report/2008/summary/en/index.html.
- Bass JB Jr. Patient information: Tuberculosis. http://www.uptodate.com/home/index.html. Accessed Dec. 20, 2008.
- Tuberculosis (TB). National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/TBdefinitions.htm. Accessed Dec. 20, 2008.
- Tuberculosis. American Lung Association. http://www.lungusa.org/site/apps/nlnet/content3.aspx?c=dvLUK9O0E&b=4294229&ct=5320855. Accessed Dec. 20, 2008.
- Tuberculosis fact sheet. American Lung Association. http://www.lungusa.org/site/apps/nlnet/content3.aspx?c=dvLUK9O0E&b=4294229&ct=3052619. Accessed Dec. 20, 2008.
- The difference between latent TB infection and active TB disease. Centers for Disease Control and Prevention. http://www.cdc.gov/tb/pubs/tbfactsheets/LTBIandActiveTB.htm. Accessed Dec. 20, 2008.
- Tuberculosis (TB): Symptoms. National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/symptoms.htm. Accessed Dec. 20, 2008.
- Tuberculosis: General information. Centers for Disease Control and Prevention. http://www.cdc.gov/tb/pubs/tbfactsheets/tb.htm. Accessed Dec. 20, 2008.
- Bass JB Jr. Risk factors for tuberculosis. http://www.uptodate.com/home/index.html. Accessed Dec. 22, 2008.
- Maartens G, et al. Tuberculosis. The Lancet. 2007;370:2030.
- Key points. In: WHO Report 2008: Global tuberculosis control - Surveillance, planning, financing. World Health Organization. http://www.who.int/tb/publications/global_report/2008/key_points/en/index.html. Accessed Dec. 20, 2008.
- Tuberculosis (TB): TB and HIV infection. National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/tbHIV.htm. Accessed Dec. 20, 2008.
- Madariaga MG, et al. Extensively drug-resistant tuberculosis. American Journal of Medicine. 2008;121:835.
- Lew W, et al. Initial drug resistance and tuberculosis treatment outcomes: Systematic review and meta-analysis. Annals of Internal Medicine. 2008;149:123.
- Fauci AS, et al. Multidrug-resistant and extensively drug-resistant tuberculosis: The National Institute of Allergy and Infectious Diseases research agenda and recommendations for priority research. Journal of Infectious Diseases. 2008;197:1493.
- Tuberculosis (TB): TB definitions. National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/TBdefinitions.htm. Accessed Dec. 20, 2008.
- Grant A, et al. Clinical review: Managing drug resistant tuberculosis. BMJ. 2008;337:a1110.
- Jeong YJ, et al. Pulmonary tuberculosis: Up-to-date imaging and management. American Journal of Radiology. 2008;191:834.
- Pediatric tuberculosis fact sheet. American Lung Association. http://www.lungusa.org/site/apps/nlnet/content3.aspx?c=dvLUK9O0E&b=4294229&ct=3052619. Accessed Dec. 20, 2008.
- Diagnosis of tuberculosis disease. Centers for Disease Control and Prevention. http://www.cdc.gov/tb/pubs/tbfactsheets/diagnosis.htm. Accessed Dec. 20, 2008.
- Catanzaro A. Rapid diagnostic tests for tuberculosis. http://www.uptodate.com/home/index.html. Accessed Dec. 22, 2008.
- Tuberculosis skin test fact sheet. American Lung Association. http://www.lungusa.org/site/apps/nl/content3.asp?c=dvLUK9O0E&b=2060731&content_id={E017092A-511A-4871-8EAE-17988C696509}¬oc=1. Accessed Dec. 20, 2008.
- Tuberculosis (TB): Diagnosis. National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/diagnosis.htm. Accessed Dec. 20, 2008.
- TB skin test. Lab Tests Online. http://www.labtestsonline.org/understanding/analytes/tb_skin/. Accessed Dec. 22, 2008.
- Zhang Y. Advances in the treatment of tuberculosis. Clinical Pharmacology & Therapeutics. 2007;82:595.
- Menzies D, et al. Adverse events with 4 months of rifampin therapy or 9 months of isoniazid therapy for latent tuberculosis infection. Annals of Internal Medicine. 2008;149:689.
- HIV and tuberculosis fact sheet. American Lung Association. http://www.lungusa.org/site/apps/nl/content3.asp?c=dvLUK9O0E&b=2060731&content_id=%7bA3132347-3F7C-4ED7-AB4C-34FBEE5B0D4C%7d¬oc=1.
- Tuberculosis and pregnancy. Centers for Disease Control and Prevention. http://www.cdc.gov/tb/pubs/tbfactsheets/pregnancy. Accessed Dec. 20, 2008.
- Tuberculosis (TB): Prevention. National Institute of Allergy and Infectious Diseases. http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/prevention.htm. Accessed Dec. 20, 2008.