Can a TB patient infect other people in the same room?

Q: If a person is on cortisone therapy in the hospital & is in a room with a tuberculosis (TB) patient. He stays with him for about 7-9 hours talking & chatting. Can he be infected by the TB patient? Will the patient affect others in the same room?

A:There are numerous factors, which would influence the susceptibility and transmission of TB in such a circumstance. The chances of transmission would be high if the case was an open case, i.e. was shedding the TB bacilli in the respiratory secretions; had a high bacterial load of AFB in the respiratory secretions, was not on treatment or was coughing a lot. Conversely, the chances are reduced (even nil) if the patient was not an open case, had a low AFB load, had no cough and had been on treatment for one month. The susceptibility of the immunocompromised person on steroids also depends on the dose of cortisone. Such patients are also more prone to endogenous reactivation of TB.