Tuberculosis (TB)

Home » Tuberculosis (TB) » TB Infection

TB Infection

When a person has been infected with Mycobacterium tuberculosis they have a tuberuclosis infection, which is different than having tuberculosis. Tuberculosis infection is asymptomatic and is confirmed by a positive purified protein derivative (PPD) skin test.

The PPD is derived from a protein found in the tuberculosis bacteria. The protein stimulates a response (localized swelling) in a person whose immune system has been exposed to the bacteria. A certain size swelling indicates a reaction in the PPD.

This test may produce false positives and false negatives. Because a false positive result may lead to unneeded therapy that carries its own risks, skin testing generally is performed only in those who are at risk for TB infections. Those at risk include, but are not limited to, people who have the following:

• Signs, symptoms, and/or laboratory findings suggesting active TB
• Recent contact with someone who has or may have active TB
• HIV infection or AIDS
• Abnormal chest x-ray compatible with past TB


Advertising Disclaimer
• Silicosis (respiratory disease caused by the inhalation of dust containing silica)
• IV (intravenous) drug abuse habit
• Diabetes mellitus
• Long-term corticosteroid therapy
• Immunosuppressive therapy (e.g., organ transplant recipients, cancer patients)
• Endstage renal disease (kidney failure)
• Clinical conditions associated with rapid weight loss
• Hematologic (blood) and/or reticuloendothelial (affecting macrophages and liver, spleen, and bone marrow cells) diseases
• Emigrated from Asia, Africa, Latin America, or Oceania (areas with prevalence of TB)
• Inadequate health care (i.e., Third World populations, prison populations, nursing home residents, mental illness facility residents)

© 1998-2009 Healthcommunities.com, Inc. All Rights Reserved.

Tuberculosis (TB) Resources

	Questions to Ask Your Pulmonary Care Team The more knowledge you have, the easier it is to make decisions about your lung condition. Print this free handout to take with you on your next office visit.	Advertising Disclaimer
	Join Our Tuberculosis Forum Do you have a question, want to share medical advice, or just need to discuss your situation with someone else having a similar experience? The healthchannels forum is a resource for everyone to share and discuss their health and medical needs with others.
	Living with...Share your story Do you have a personal health story that you would like to share with others? As a source of free patient education, our goal is to provide our users with trustworthy information and support from others. That's why we've started our "Living with..." sections.
	Our "Living With..." support pages are a place to share experiences about living with a certain condition, disease, disorder, or illness and for loved ones of those dealing with health-related issues. Many people, especially when newly diagnosed, find comfort in knowing that others are having a similar experience. Help others by sharing your story. View stories already submitted.
	Stay Updated Sign up for our newsletter and receive important updates on the medical conditions that are most important to you.
To quickly access health information from your website's browser, download Healthcommunities.com's healthchannels toolbar. Advertising Disclaimer