24. Proportion of tuberculosis cases detected and cured under directly-observed treatment short courses (DOTS)

 

Definition

The tuberculosis detection rate is the percentage of estimated new infectious tuberculosis cases detected under the directly observed treatment, short course (DOTS) case detection and treatment strategy. The cure rate is the percentage of new, registered smear-positive (infectious) cases that were cured or in which a full course of DOTS was completed. A tuberculosis case is defined as a patient in whom tuberculosis has been bateriologically confirmed or diagnosed by a clinician.

 

Goal/target addressed

Goal 6. Combat HIV/AIDS, malaria and other diseases.

Target 8. Have halted by 2015 and begun to reverse the incidence of malaria and other major diseases.

 

Rationale

Since tuberculosis is an airborne contagious disease, primary control is effected through finding and treating infectious cases and thus limiting the risk of acquiring infection. The recommended approach to primary control is the DOTS strategy, an inexpensive strategy that could prevent millions of tuberculosis cases and deaths over the coming decade.

 

DOTS is a proven system based on accurate diagnosis and consistent treatment with a full course of a cocktail of anti-tuberculosis drugs (isoniazid, rifampicin, pyrazinamide, streptomycin and ethambutol). DOTS requires government commitment, careful detection, consistent treatment, uninterrupted supply of anti-tuberculosis drugs and a monitoring and reporting system to evaluate treatment outcomes for each patient.

 

Method of computation

The case detection rate is the ratio of smear-positive case notifications in a given year to the estimated number of new smear-positive cases arising in that year. For some countries, there is a margin of uncertainty in the estimation of the denominator of this ratio.

 

The treatment success rates is the ratio of new, registered smear-positive (infectious) cases that were cured or completed a full course of DOTS to the total number of new, registered cases. Treatment success rates can be monitored directly and accurately in cohorts of patients treated under the DOTS strategy. Systematic evaluation of patient progress and treatment outcomes provides the numerator.

 

Data collection and source

Data on both the detection rate and the treatment success rate are derived from World Health Organization DOTS programmes, which monitor and report cases detected, treatment progress and programme performance.

 

References

World Health Organization, www3.who.int/whosis and www.who.int/gtb/dots.

Global Tuberculosis Control 2002: Surveillance, Planning, Finance, 2002, World Health Organization (www.who.int/gtb/publications).

World Health Organization Yearbook, annual, World Health Organization [Canít find this book. Should it be World Health Report?]

Stop TB Partnership, www.stoptb.org.

 

Periodicity of measurement

Administrative data are, in principle, available annually. Household survey are generally available annually. Household surveys are generally available every three to five years. Data from DOTS programmes, though incomplete, are updated frequently.

 

Gender issues

At younger ages, the prevalence of infection is similar in boys and girls. At older ages, a higher prevalence has been found in men; in most of the world, more men than women are diagnosed with tuberculosis and die from it. However, recent analyses comparing infection and disease rates suggest that the propensity to develop the disease after infection with mycobacterium tuberculosis (the progression rate) may be greater among women of reproductive age than among men of the same age. A recent review of socioeconomic and cultural factors relating to these suggested differences called for further research to clarify such differences in the epidemiology of tuberculosis.

 

Tuberculosis is nevertheless a leading cause of death from infectious disease among women. Because tuberculosis affects women mainly in their economically and reproductively active years, the impact of the disease is also strongly felt by their children and families.

 

International data comparisons

World Health Organization, www3.who.int/whosis and www.who.int/gtb/dots.

Stop TB Partnership, www.stoptb.org.

 

Comments and limitations

Tuberculosis cases reported by ministries in developing countries are usually only a fraction of the number of cases in the population. It is estimated that in 2000 only 27 percent of new cases were notified under DOTS and only about 19 percent of cases were successfully treated.

 

Agencies   

Ministries of health.

World Health Organization.