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"How contagious is TB?"

ZocdocAnswersHow contagious is TB?


I was babysitting a child for the last 2 days and I found out she was possibly exposed to TB the day before she came over. I have a 2 yr old myself. How concerned should I be?


Sorry to hear about your concerns, and it is easy to understand why you are worried. You should definitely discuss your concern with a doctor soon. Tuberculosis is a serious medical condition that we may all have to worry about more in the future as strains of the infection become more resistant to antibiotics. In the US, we have been fortunate to have some success against this condition with proper measures of treatment and also the judicious use of measures aimed at decreasing tumor spread. Most commonly, the disease is spread via the air and aerosolized particles. Most agree that the infection is minimally contagious, if at all, once it has left the air. For that reason, it is unlikely that your child is at any great risk if the story is as you describe and there was no additional exposure in the past to the other child. The reason is that there is an incubation period, in which a person contracts the disease but doesn't have signs of the disease. Without a cough or sneeze to aerosolize the infectious particles, they can't easily infect your daughter (ie, sharing toys is not likely to cause an infection). It is important to realize that there are exceptions, and you will definitely need to discuss this with a doctor soon. Please speak to your doctor.

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