Global Tuberculosis Report -- 2012.pdf

FIGURE 2.16 Progress in global coverage of data on drug resistance, 1994–2011Year of most recentrepresentative dataon anti-TB drugsurveillance1995–19992000–20042005–20092010–2011Ongoing 2012No dataSubnational data onlyNot applicablecorrective actions need to be identified and implemented.Inventory studies have been implemented in very fewcountries to date. Examples include the UK, the Netherlandsand several countries in the Eastern MediterraneanRegion (Egypt, Iraq, Yemen and, most recently, Pakistan).To facilitate and encourage inventory studies in morecountries, WHO and its partners (notably the Centers forDisease Control and Prevention in the USA and the UK’sHealth Protection Agency) initiated the development of aguide on how to design, implement, analyse and reporton inventory studies in 2011. As this report went to press,the guide was due to be published before the end of 2012.Electronic recording and reporting of dataAssessment of various aspects of data quality is the firstand most basic of the three major components of theTask Force’s framework for assessing surveillance data(Figure 2.2) and several of the standards in the TB surveillancechecklist are about data quality. In all of theregional and country workshops held between 2009 and2012, it was evident that it is much easier to assess thequality of TB surveillance data in countries with casebasedelectronic recording and reporting. In 2011, WHOand its partners produced a guide on electronic recordingand reporting for TB care and control, which was widelydisseminated in April 2012 (Box 2.5).2.5.2 Surveys of the prevalence of TB diseaseNationwide population-based surveys of the prevalenceof TB disease provide a direct measurement of the numberof TB cases; repeat surveys conducted several yearsapart can allow direct measurement of trends in diseaseburden. Surveys are most relevant in countries where theburden of TB is high (otherwise sample sizes and associatedcosts and logistics become prohibitive) and surveillancesystems are thought (or known) to miss a largefraction of cases.Before 2007, few countries had implemented prevalencesurveys (Figure 2.9, Figure 2.17). In the 1990s,national surveys were confined to China, Myanmar, thePhilippines and the Republic of Korea. Before 2009 andwith the exception of Eritrea in 2005, the last nationalsurveys in the African Region were undertaken between1957 and 1961. From 2002 to 2008, there was typicallyone survey per year. In 2007, WHO’s Global Task Forceon TB Impact Measurement identified 53 countries thatmet epidemiological and other criteria for implementing asurvey. A set of 22 global focus countries were selected toreceive particular support in the years leading up to 2015.Following five years of substantial efforts by countries,supported by the Task Force (Box 2.6), enormousprogress has been achieved (Figure 2.17). If surveys areimplemented according to schedule, around 20 surveyswill be implemented during 2011–2013, with a majorpeak in activity in 2012 and 2013. The number of surveysbeing implemented at the same time in 2012, at five,GLOBAL TUBERCULOSIS REPORT 2012 25