Tuberculosis (TB)

WHO report 2008
Global tuberculosis control


2.2 DOTS expansion and enhancement

2.2.1 DOTS coverage and numbers of patients treated

The total number of countries implementing DOTS has increased steadily from 1995, reaching 184 countries by 2006 (Table 2.1). All 22 HBCs have had DOTS programmes since 2000, many of which have been established for much longer.

DOTS coverage within countries has also increased since 1995 (Table 2.5). By the end of 2006, 93% of the world’s population lived in counties, districts, oblasts and provinces of countries that had adopted DOTS. Population coverage was reported to exceed 90% in all regions except Europe (Table 2.2). All but three HBCs (Brazil, Nigeria and the Russian Federation) reported that at least 90% of the population lived in areas where DOTS was being implemented. Population coverage in Brazil, Nigeria and the Russian Federation was 86%, 75% and 84% respectively (Table 2.5).

As reported in greater detail in Chapter 1, 4.9 million new cases of TB were notified by DOTS programmes in 2006, of which 2.5 million were new smear-positive cases. These numbers represented 98% and 99% of total TB case notifications (DOTS and non-DOTS programmes), respectively. The percentage of all estimated new cases of smear-positive TB detected by DOTS programmes – the case detection rate – was 61% globally in 2006; the case detection rate for all cases was 54%. A cumulative total of 31.8 million new and relapse cases have been treated in DOTS programmes in the 12 years from 1995 (when reliable records began) to 2006. Globally, the treatment success rate was 84.7% in the 2005 cohort, meaning that the target of 85% has almost been reached. The Western Pacific Region has reached both targets related to DOTS implementation (i.e. 70% case detection rate and 85% treatment success rate), and the South-East Asia Region and the Region of the Americas are close to doing so. The other three regions (African, European and Eastern Mediterranean regions) are much further from achieving these targets. This short summary of the data that are presented in much greater detail in Chapter 1 is useful for setting the information provided in the rest of this chapter in context.

2.2.2 Political commitment

Continued political commitment is essential for sustaining DOTS as well as for introducing and then scaling up other components of the Stop TB Strategy. Two indicators of political commitment are the existence of a national strategic plan for TB control and the share of the total funding required for TB control that is being provided from domestic sources.

A national strategic plan for TB control was reported to exist in 155 countries, including all HBCs. Among HBCs, eight increased domestic funding for TB control between 2007 and 2008: Afghanistan, Brazil, Ethiopia, Mozambique, Myanmar, the United Republic of Tanzania, Viet Nam and Zimbabwe. In a further eight HBCs (Cambodia, China, the Democratic Republic of the Congo, India, Indonesia, Kenya, the Russian Federation and South Africa), domestic funding in 2008 was maintained at a level similar to 2007. The share of the NTP budget being funded from domestic sources averages 64% across the 22 HBCs for 2008, but varies from less than 20% in Afghanistan, Kenya, Myanmar and Uganda to 30–50% in eight countries (for example, Indonesia, Mozambique, Nigeria and Pakistan) to 50–69% in four countries (for example, China and the Philippines) to over 70% in five countries (Brazil, India, the Russian Federation, South Africa and Viet Nam). There were insufficient data to make an assessment for Thailand. Full details about financing for TB control, including discussion of how domestic funding is related to a country’s income level, are provided in Chapter 3.

2.2.3 Case detection through quality-assured bacteriology

Sputum smear microscopy is being widely used for the diagnosis of TB: 85% of reporting countries (151/177) stated that it is used for all people with suspected pulmonary TB. This included 20 HBCs. Laboratory supplies are generally adequate, but six HBCs reported stock-outs at peripheral level in some units: Brazil, China, Pakistan, the Democratic Republic of the Congo, Uganda and Zimbabwe (Table 2.6). Among all countries, 20 reported some stock-outs at central level; 36 reported stock-outs at peripheral level (Table 2.6). More positively, almost all HBCs have established links with non-NTP laboratory services, including laboratories in the private sector and/or laboratory services provided by nongovernmental organizations (NGOs). This should help to expand diagnostic capacity in future, which is particularly needed in Ethiopia, Nigeria and Pakistan. In these three HBCs, the number of laboratories performing sputum smear microscopy is below the recommended benchmark of 1 per 100 000 population (Table 2.7) and case detection rates remain below the global target of 70%.

While coverage and use of sputum smear microscopy services are generally high, the availability of culture and DST remains limited in most HBCs (Table 2.7). Only seven HBCs had at least one culture laboratory for every 5 million population, which is the level recommended in the Global Plan. These were Brazil, Cambodia, China, the Russian Federation (with 34 culture laboratories for every 5 million population), South Africa, Thailand and Viet Nam. The same set of countries, plus Indonesia and Uganda, had one laboratory able to provide services for drug susceptibility testing (DST) per 10 million population. This leaves many countries with a major shortage of laboratories providing culture and DST services. Encouragingly, the need for expansion of culture and DST capacity has been widely recognized. Among the 22 HBCs, 17 have plans to establish or scale up culture and DST services.

National reference laboratories (NRLs) are essential for the expansion of quality-assured culture and DST services. Most HBCs listed increased NRL capacity and improved NRL performance as a priority activity for 2007. For this to be successful, there are several major challenges that need to be overcome. These include a shortage of adequately trained staff, insufficient funding, suboptimal biosafety standards and limited availability of sustained technical assistance.

Given the demand for improvement in diagnostic services, particularly for drug-resistant TB, the supranational reference laboratory network (SRLN) is also in the process of global expansion. Currently, there are 26 SRLs: two in the African Region, five in the Region of the Americas, 11 in the European Region, one in the Eastern Mediterranean Region, two in the South-East Asia Region and five in the Western Pacific Region (Figure 2.3). All regions have plans to expand their SRL networks, and candidate laboratories will be assessed and evaluated in the near future. This should increase coverage of quality-assured culture and DST services at both national and global levels.

2.2.4 Standardized treatment, with supervision and patient support

The vast majority of reporting countries (96%, 173/181) use standardized short-course chemotherapy, including all HBCs. Treatment with the Category I regimen for 6 months is used in 122 countries worldwide, while 31 countries use an 8-month regimen without rifampicin in the continuation phase of treatment. Among countries using the 8-month regimen, 13 (including five HBCs) have plans to switch to the 6-month regimen.

Health-facility based, community-based or home-based directly observed therapy (DOT) was used during the initial phase of treatment in 166 countries, although only 123 of these stated that it was used for all patients in all DOTS units. Among HBCs, Brazil, China, Nigeria, Pakistan and Thailand reported that DOT was available only in some units and/or only for some patients. Almost all reporting countries (96%, 170/178), including all HBCs, provided anti-TB drugs free-of-charge to all patients being treated with the Category I regimen under DOTS. Incentives and enablers are used in some countries, mostly in the European Region. Examples include food parcels, tickets for public transport and provision of psychological counselling to ensure adherence to treatment.

2.2.5 Drug supply and management system

Uninterrupted provision of quality-assured anti-TB drugs is fundamental to effective TB control. However, despite the availability of funding from the Global Fund and the Global Drug Facility (GDF), as well as the option of procurement at highly competitive prices from the GDF, drug shortages continue to occur in all regions, at both central and peripheral levels (Table 2.6). This includes shortages in two HBCs (Uganda and Zimbabwe) at central level, and in five HBCs (the Democratic Republic of the Congo, South Africa, Uganda, the United Republic of Tanzania and Zimbabwe) at peripheral level. Reported shortages were particularly common in the African Region and the Region of the Americas. Reporting on drug availability was relatively incomplete for the Region of the Americas as well the European and Western Pacific regions. This suggests that better monitoring of drug stocks is needed in some countries in these regions, for example via the revised recording and reporting forms that have been developed by WHO and other partners.

During the past year, the availability of quality-assured and affordable anti-TB drugs has improved. For example, the prequalification process for paediatric formulations of fixed-dose combinations (FDCs) has been accelerated via mechanisms including pooled procurement by the GDF, the involvement of UNITAID and provision of technical assistance from the WHO prequalification project. A total of 71 countries including 12 HBCs ordered FDCs from the GDF in 2007.

Members of the Stop TB Partnership, including WHO and Management Sciences for Health, continue to hold training workshops in drug management in collaboration with the GDF. In 2007, two workshops were held, one in Benin and the other in Cape Town.

2.2.6 Monitoring and evaluation, including impact measurement

Global targets to reduce the epidemiological burden of TB have been set for 2015 within the context of the MDGs and by the Stop TB Partnership (see Chapter 1). Measuring progress towards these targets requires routine monitoring of case notifications and treatment outcomes, as well as evaluation of the impact of TB control on incidence, prevalence and mortality using routine surveillance data (TB case notification data and TB mortality data from vital registration systems) and, in some cases, special surveys of the prevalence of disease, infection or mortality. Questions related to impact measurement were asked on the WHO data collection form for the first time in 2007.

Out of 212 countries, 184 DOTS countries and seven non-DOTS countries routinely record and report data on case notifications and treatment outcomes. In addition, 119 (of 202) reporting countries (59%) stated that they publish an annual report of NTP activities and performance. Although some countries have been publishing an annual report for more than 20 years, most countries started to produce such reports in the 1990s. Among the 22 HBCs, all published annual reports except for the Democratic Republic of the Congo, South Africa and Thailand.

Plans to assess the impact of TB control were reported by 128 out of 202 (63%) countries (Table 2.8). Among HBCs, only Afghanistan, the Democratic Republic of the Congo and Mozambique did not report having a plan for impact measurement. The proportion of countries with a plan for impact measurement was particularly high in the South-East Asia Region (9 out of 11 countries).

In-depth analysis of routine surveillance data collected by NTPs was the most frequent method by which countries intended to assess the impact of TB control (116/128, 91%). Analysis of mortality data from vital registration systems (also a form of routine surveillance data) was also reported by a large number of countries (51 out of 128 reporting countries), with numbers in absolute terms highest in the European and Western Pacific regions and the Region of the Americas. Only four countries in the African Region (Comoros, Rwanda, South Africa and Zimbabwe) reported plans to use mortality data from vital registration systems.

Surveys of the prevalence of disease were being planned by 69 countries, including 55 national and 14 sub-national surveys. Of the 44 countries that reported the year in which they were intending to start their national surveys, 8 (18%) were due to start in 2007, 17 (39%) in 2008, 7 (16%) in 2009 and the remainder in later years. Measurement of burden and impact is particularly well advanced in the Western Pacific Region, where all four HBCs have already undertaken at least one disease prevalence survey and where follow-up surveys are planned.

In December 2007, the WHO Task Force on TB Impact Measurement agreed a set of epidemiological criteria to guide the selection of countries that should undertake prevalence of disease surveys during the period up to 2015.1 These criteria were used to identify countries with all or a combination of the following characteristics: (i) weak routine reporting systems; (ii) high TB prevalence; (iii) high TB burden (number of cases); and (iv) high HIV/AIDS prevalence. The Task Force also considered whether a country already had a plan to conduct a survey within the next 10 years and whether they had done a survey since the year 2000. Of the 57 countries that met the criteria, 30 reported plans to carry out a national (n=25) or sub-national (n=5) survey. Among HBCs, 20 met the criteria, of which 17 reported plans to carry out either a national survey (n=15) or a sub-national survey (n=2, India and Pakistan). Three HBCs met the criteria but did not report having a plan to conduct a survey within the next 10 years: the Democratic Republic of the Congo, Ethiopia and Mozambique. Of the 155 countries that did not meet the criteria, 39 reported having a plan to conduct either a national (n=30) or a sub-national (n=9) survey.

The Task Force also identified a shorter list of 21 countries2 in which surveys should be prioritized in order to produce credible regional and global assessments of whether the 2015 impact targets are achieved, as well as to assess progress in the period up to 2015. This list includes 15 HBCs and six other countries.3 Among the 21 countries, 16 countries (including 12 HBCs) have reported plans to carry out national surveys and two (1 HBC) have reported plans to carry out a sub-national survey.

Most of the 52 countries that are planning prevalence of TB infection (tuberculin) surveys at national or sub-national levels also reported plans to conduct prevalence of disease surveys. It is important that these countries try to implement both surveys at the same time and in the same place.

Population-based mortality surveys (e.g. verbal autopsy studies) were being planned by only 34 countries. From the available data, it is not clear if these surveys will be limited to TB or whether they will be combined with collection of data for other diseases.


Footnotes

1 Report of the second meeting of the WHO Task Force on TB Impact Measurement. Geneva, 6–7 December 2007. Geneva, World Health Organization, 2007 (unpublished).

2 From among the longer list of 57 countries.

3 The list of 21 countries is: Bangladesh, Cambodia, China, Ghana, Indonesia, Kenya, Malawi, Mali, Mozambique, Myanmar, Nigeria, Pakistan, the Philippines, Rwanda, Sierra Leone, South Africa, Thailand, the United Republic of Tanzania, Uganda, Viet Nam and Zimbabwe.

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