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TB exposure



A Mexican patient came into our office with a cough X`s 3 weeks. He tested Positive.  We have no circulation in our office and he had not covered his mouth.  I have not had a PPD yet and I was wondering if I can infect my pregnant daughter? My husband also has Crohn`s and should I worry about him?


In answering this question, I am assuming the patient tested "positive" means that he was diagnosed with active TB disease of the lung.

It is unlikely that through your limited exposure that you have developed "active" TB which is infectious, therefore you are highly unlikely to "infect" your daughter or your husband. However, you are at risk for developing "latent TB infection."

When a healthy person inhales TB bacteria, one of three things can occur: No infection, latent TB infection, or active TB disease. The most common outcome is "latent TB infection". This occurs when the body's immune system is able to fight the bacteria and stop it from growing. It remains inactive in your body and there are no symptoms of "active" TB disease such as fever, night sweats, cough or weight loss and importantly you are not infectious to others. About 10% of the people with latent TB infection can develop active TB sometime in their lifetime especially in the first two years after the exposure. Development of active TB disease after exposure usually occurs in individuals with a very weak immune system such as in an HIV-infected individual or those taking medications that decrease one's immune system.

Only people with active TB disease of the lung can infect others by spreading the TB germ in the air when they speak, cough, sing, or sneeze and create aerosols. Any persons who have been exposed to someone with active TB should contact their doctors to be evaluated for latent TB infection and active TB disease (get a baseline PPD and a repeat in 3 months). Persons with latent TB infection can receive treatment to prevent them from developing active TB disease.

For more information:

Go to the Tuberculosis health topic, where you can:

Response by:

Shu-Hua   Wang, MD, MPH&TM Shu-Hua Wang, MD, MPH&TM
Clinical Assistant Professor of Infectious Diseases
Clinical Assistant Professor of The Division of Epidemiology
College of Medicine
The Ohio State University

Larry S Schlesinger, MD Larry S Schlesinger, MD
Molecular Virology, Immunology and Medical Genetics
Microbiology Administration
Environmental Health Sciences
College of Medicine
The Ohio State University