TB control and prospects for reducing TB incidence, prevalence, and deaths globally

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The technology to control TB has long existed, but it remains underutilized. Initially, the term "DOTS" (Directly Observed Treatment, Short-course) referred specifically to directly observed treatment combined with short-course chemotherapy. However, DOTS has evolved into a broader public health strategy with five principal elements:

  1. Political commitment.
  2. Case detection by sputum smear microscopy, primarily among symptomatic, self-referring patients.
  3. Standard short-course chemotherapy with supportive patient management, including DOT.
  4. A reliable system for regular drug supply.
  5. A standard recording and reporting system, including the evaluation of treatment outcomes.

The MDG framework for TB control includes two measures aimed at DOTS implementation (case detection and treatment success) and three impact measures (incidence, prevalence, and deaths) relevant to all TB control methods. This second set of measures not only promotes epidemiological evaluation beyond implementation but also enables a more comprehensive TB control approach, going beyond DOTS. An inclusive approach might involve preventive methods and improved patient care through collaboration with public and private clinicians, particularly for patients co-infected with HIV or drug-resistant TB. It might also incorporate new technologies and make better use of existing tools.

TB incidence rates are seldom measured directly; they are estimated from population-based surveys on the prevalence of Mycobacterium tuberculosis infection or TB disease, or through independent assessments, often qualitative, of surveillance system performance. The accuracy of these estimates is limited, as incidence cannot be reliably calculated from prevalence without precise measures of illness duration.

In regions such as Africa and Eastern Europe, managing TB is complicated by the links between HIV/AIDS and drug resistance, necessitating region-specific solutions. By 2003, DOTS had nearly reached the limits of public notification systems, which rely on data from government-run health clinics and hospitals. The next phase of DOTS expansion must adapt this basic care package to work beyond these limits, linking DOTS programs with nonparticipating public clinics and hospitals, as seen in Indonesia. All medical practitioners should be encouraged to adopt at least the basic care package. More challenging still, DOTS programs must contribute to expanding health services in areas lacking professional healthcare.

In TB control discussions, it is crucial to remember that incidence and death rates are influenced by more than drug treatment. Cofactors such as nutritional status, tobacco and alcohol use, other infections, and genetic susceptibility also impact TB dynamics and require further study. Ideally, TB death statistics would come from reliable vital registration systems; however, many of the poorest countries do not systematically or accurately record deaths by cause.

Source:
Dye, C., Watt, C.J., Bleed, D.M., Hosseini, S.M. and Raviglione, M.C., 2005. Evolution of tuberculosis control and prospects for reducing tuberculosis incidence, prevalence, and deaths globally. Jama, 293(22), pp.2767-2775.

 

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