About Active TB Disease and Latent TB Infection (LTBI)
Active Tuberculosis (TB) Disease
Tuberculosis, or TB, is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria can attack any part of the body, but usually attack the lungs. People who are infected with TB do not always feel sick.
Latent Tuberculosis Infection (LTBI)
People with latent TB do not have any symptoms and cannot spread TB. If they do not get treatment, however, they may develop active TB disease in the future, spread the disease to others, and feel quite ill.
People with active TB disease can be treated and cured if they get medical help. Even better, people who have latent TB infection, but are not yet sick, can take medicine so they will never develop active TB disease.
TB is spread from one person to another.
The bacteria that cause TB are spread through the air when a person with active TB disease of the lungs or throat:
When this happens, people nearby may breathe in these bacteria and become infected with TB. Only those with active TB disease can spread the bacteria to others. A person who has been infected with the bacteria may develop active TB disease weeks or years after infection depending on their immune system. Many people with latent TB infection never develop active TB disease.
TB is not spread by:
- Touching an object that someone infected with TB has touched
- Shaking someone's hand
- Sharing food or drink
- Sharing toothbrushes
Signs and symptoms of active TB disease depend on where in the body the bacteria are growing. TB bacteria most often grow in the lungs.
Signs and symptoms of active TB disease in the lungs include:
- A bad cough, lasting three weeks or longer
- Pain in the chest
- Coughing up blood or phlegm from deep inside the lungs (sputum)
- Weakness or fatigue
- Weight loss
- No appetite
- Fever, chills, sweating at night
People with latent TB infection will not feel sick and will not have these signs and symptoms.
If you believe you may have been exposed to someone with active TB disease, contact your doctor or local health department. They will help you get a TB skin test or a TB blood test. A person who has been exposed to TB bacteria may become infected. A person with latent TB infection (LTBI) cannot spread the bacteria to others right away. Only those who develop active TB disease can spread the bacteria to others.
Bovine TB is a chronic disease of animals caused by bacteria Mycobacterium bovis, which is closely related to the bacteria that causes human TB. People may get bovine TBs after close contact with infected animals or after eating unpasteurized dairy products from infected animals. See the Department of Agriculture, Trade, and Consumer Protection (DATCP) for more information about bovine TB in Wisconsin. View recommendations on safe handling of animal carcasses from herds with infected animals.
Department of Health Services Resources
- Active Tuberculosis Disease Fact Sheet, P-42099 – A fact sheet with information on TB infection and TB disease, how TB spreads, signs and symptoms, prevention, and treatment, available in English, Hmong, and Spanish.
- Latent Tuberculosis Infection Fact Sheet, P-42099b – A fact sheet with information on TB infection, medicine, testing, prevention, and treatment, available in English, Hmong, and Spanish.
- How can I prevent tuberculosis (TB)? P-02504 – An infographic outlining steps people can take to prevent TB.
- Wisconsin TB cases by local public health regions and county, P-00438 – A fact sheet with number of active TB disease cases by region and county.
- Local Public Health in Wisconsin – A link to local public health departments in Wisconsin.
- Biosafety Recommendations for Individuals Handling Carcasses from Animals Known or Suspected to Have Tuberculosis, P-00295 – A fact sheet with information for safe management of animal carcasses.
- Bureau of Communicable Disease Archived Webinar page – A link to archived webinars on different communicable disease topics, including TB.
Centers for Disease Control and Prevention (CDC) Resources
- CDC Basic TB Facts – CDC TB basic facts page with links to information on how TB spreads, prevention, exposure, and more.
- TB Personal Stories – Watch videos from TB survivors about their treatment experience.
- Patient and General Public Materials – Fact sheets and posters from CDC with general TB information, available in English, Spanish, Tagalog, and Vietnamese.
- What You Need to Know About Your Medicine for Latent TB Infection - Isoniazid (PDF) – Information on the TB medication Isoniazid.
- What You Need to Know About Your Medicine for Latent TB Infection - Rifampin (PDF) – Information on the TB medication Rifampin.
- What You Need to Know About Your Medicine for Latent TB Infection - Isoniazid and Rifapentine (PDF) – Information on the TB medications Isoniazid and Rifapentine.
- Resources for the Community, California Department of Health – A website providing patient education on active TB disease and LTBI, with videos and promotional infographics in English, Tagalog, Cantonese, Vietnamese, and Spanish. It includes patient information on TB treatment for pregnant women and new mothers.
- Key Messages for TB and Diabetes, Virginia Department of Health – A educational tool for patients and health care workers on TB and diabetes, available in English, Spanish, Arabic, Vietnamese, Tagalog, and Korean.
- Multilingual Educational Materials, NSW Multicultural Health Communication Services – A website providing basic fact sheets on TB disease, available in 15 languages.
- Tuberculosis, Germs, and Medicine, Public Health Madison & Dane County – An educational video on TB disease in Hmong with English subtitles.
Questions about TB? Contact Us!
Phone: 608-261-6319 ǀ Fax: 608-266-0049