Isoniazid preventive therapy for tuberculosis. Are we losing our enthusiasm?

Contact investigation activities of the Tennessee Department of Health and Environment (TDHE) Tuberculosis (TB) Control Program from 1979 to 1985 were reviewed. Out of 32,722 identified contacts, 6,030 (20.1 percent) were infected (positive purified protein derivative [PPD]). Only 2,731 (45 percent) of the infected contacts were started on preventive therapy. Both the absolute number and the relative percentage of infected contacts starting on INH prevention therapy have gradually declined over the years. While 569 (67 percent) of the infected contacts were started on preventive treatment in 1979, only 296 (37.5 percent) received isoniazid (INH) preventive therapy in 1985. Although an increasing percentage of those starting preventive therapy completed the prescribed course, the enthusiasm for recommending preventive therapy has declined for the infected individuals above the age of 15. More enthusiasm and efforts are needed from physicians in initiating and maintaining INH preventive therapy to accomplish tuberculosis eradication.