Differences Immense Between Typical and Atypical TB

Q:  The husband of a woman I know recently died from a combination of emphysema and an atypical form of tuberculosis. She is convinced that the form of TB from which he died is not contagious. I know that emphysema is not contagious, but find it difficult to believe that the same is true of TB. The idea that TB is not contagious is difficult for me to accept. Please help me to understand.

A:  Although I don’t know the age of this questioner, I suspect that she has some recollection of how tuberculosis afflicted so many Americans in the past. Many died as a result of TB and others spent years in sanitariums subject to a variety of treatments that yielded a cure, but often at the expense of extensive scarring of the lungs and a diminished respiratory capacity.

For the purposes of this discussion, think of tuberculosis in two classes, atypical and mycobacterium tuberculosis (typical TB). Typical TB is a contagious and potentially life-threatening form of TB that has made a bit of a comeback lately due to the increase in numbers of people with immune deficiencies. Consequently, anyone with an active immune deficiency needs to have regular surveillance for this form of TB, especially if symptoms develop. The same is true for their close contacts, including health care workers.

Atypical TB is a threat only for those with immuno-deficiencies and those with chronic respiratory problems, especially emphysema. Often, people with chronic respiratory ailments are treated with steroid medications (although inhalers with steroids are generally safe), which can increase susceptibility to atypical TB. Healthy people with no chronic respiratory problems, no immune deficiencies and not on chemotherapy are not at risk.

A simple TB skin test is the best way to address any concerns about infections. The test is only sensitive for mycobacterium tuberculosis. A positive test is usually followed by a chest x-ray to look for evidence of infections in the lungs. Depending on the patient’s age and the x-ray findings, treatment with anti-tuberculosis medications may be necessary.

Do not shun or isolate those with atypical forms of TB. Most people with active diagnosed TB can be well cared for with medications and isolation in special hospital rooms, but can still have visitors as long as a mask is worn.

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