doses. Directly observed treatment is uniformly recommended for those on the latter schedule, which is often prescribed for those at high-risk of nonadherence.
Although the full course of treatment must be completed to cure the disease and limit the development of drug resistance, most individuals with active, drug-susceptible tuberculosis usually become noninfectious within 1 or 2 months of the start of treatment. Those with drug-resistant disease may remain infectious for much longer. People are considered no longer infectious when they meet three conditions: (1) they are receiving adequate therapy, (2) they have a significant clinical response to therapy, and (3) they have three consecutive negative sputum smear results for sputum collected on different days.
As noted in Chapter 1, the strategy of short-course, directly observed therapy is targeted at the prevention of drug-resistant tuberculosis arising from incomplete treatment. The earliest use of directly observed therapy in the United States dates to the 1970s, but concerns about civil rights slowed its acceptance and use (Mangura and Galanowsky, 2000). CDC recommended the strategy in 1992 (CDC, 1992c), and it is a central component of the tuberculosis control initiatives of the World Health Organization (WHO, 2000a). The recent IOM report on the elimination of tuberculosis in the United States recommended that “all states have health regulations that mandate completion of therapy (treatment to cure) for all patients with active tuberculosis” (IOM, 2000, p. 6).
For individuals not living in prisons, nursing homes, or similar settings, directly observed treatment may involve scheduled appointments that bring a patient to a physician’s office, clinic, or other site so that a nurse or other trained individual can watch the person take the required medications. In some cases, outreach workers may travel to an individual’s residence. For health care and other workers, therapy may be observed in the employee health clinic.
Even when directly observed therapy is prescribed, it does not guarantee full and complete therapy. Enhancements to the basic strategy (such as multidisciplinary case management teams or the addition of economic and other incentives) can significantly improve the results of therapy (IOM, 2000).
Today, tuberculosis is a disease that can almost always be cured if it is diagnosed promptly and treated fully in people who have well-functioning immune systems and drug-sensitive disease. Recently, treatment