How can a person becoming infected with XDR-TB?
The majority of healthy people with normal immunity may never become ill with TB, unless they are heavily exposed to infectious cases who are not treated or who have been on treatment for less than about one week. Even then, 90% of people infected with TB bacteria never develop TB disease. This applies to XDR-TB as well as to “ordinary” TB. People with HIV infection, however, in close contact with a TB patient, are more likely to catch TB and fall ill. The TB patients whom they meet should be encouraged to follow good cough hygiene, for example, covering their mouths with a handkerchief when they cough, or even, in the early stages of treatment, using a surgical mask, especially in closed environments with poor ventilation. The risk of becoming infected with TB is very low outdoors in the open air. Overall, the chances of being infected with XDR-TB are even lower than with ordinary TB because cases of XDR-TB are still very rare.
