ABSTRACT
Preventive therapy refers to the treatment of patients who are known, or are likely, to be infected with tubercle bacilli, but without active disease with a simple regimen (usually isoniazid), with the intention of preventing tuberculosis (TB) in the future. In TB control, the term ‘‘preventive therapy’’ may be misleading in that it implies primary prevention of infection rather than its actual use for ‘‘early treatment’’ or ‘‘secondary prevention’’ in patients who have an established infection of Mycobacterium tuberculosis. Hence, the terminology ‘‘treatment of latent tuberculosis infection’’ (LTBI) has been adopted rather than ‘‘preventive therapy’’ to more accurately describe this strategy (1). Both terms will be used in the text that follows.
