Eurosurveillance - Volume 13, Issue 12, 18 March 2008

World Tuberculosis Day on 24 March commemorates the date in 1882 when Robert Koch presented his findings on the causing agent of tuberculosis (TB) - Mycobacterium tuberculosis. This celebration provides a good opportunity to take stock of the achievements in controlling the disease so far - and the remaining challenges at global, regional, national and local level.

Overview of the epidemiological situation in 2006. The latest available information from countries in the World Health Organization (WHO) European Region carries important signals about the tuberculosis (TB) situation in this part of the world [1]. The total number of TB cases reported in the Region was slightly lower in 2006 than in 2005 (422,830 versus 426,457), reflecting a decrease in three-fourths of the reporting countries. Most TB cases in 2006 (73%) were reported by 12 former Soviet Union republics in the East, 21% by the European Union and West (EU and West) and 6% by the remaining countries in the Balkans (Table 1; for the composition of geographical areas see Box). National TB notification rates ranged from 4 to 282 per 100,000 population. The total TB notification rate for the whole Region has increased very slightly between 2002 and 2006, from 46 to 48 cases per 100,000, although rates of previously untreated TB cases appear to be on the decrease in both the East and West (Figure 1). We describe the main epidemiological features of TB cases notified in each of the abovementioned areas using surveillance data reported by the countries themselves.

Many European Union (EU) Member States show a decline in tuberculosis (TB) incidence and many have low incidence rates (15 countries reported less than 10 cases per 100,000 population in 2006). However, despite the progress in curbing the TB epidemic, the disease remains a public health threat in the EU. The epidemiological patterns are still very diverse between countries and control efforts are challenged by problems such as multidrug-resistant (MDR TB) and extensively drug-resistant tuberculosis (XDR TB), TB/HIV co-infection and the concentration of cases within vulnerable groups.

In 2005, 426,457 tuberculosis (TB) cases were notified in the World Health Organization (WHO) European Region, with a wide variation and an incremental west-to-east gradient in notification rates also reflected in TB mortality rates. In the enlarged European Union ('EU-27') and other western countries - where 19% of cases were of foreign origin in 2005 (>50% in 13 countries) - overall TB notification rates decreased by 2.4% yearly between 2000 and 2005, compared to 1.6% in 1995-2000, reflecting a declining incidence in all age groups and in most countries. Half the cases notified by the 12 ex-republics of the former Soviet Union in the East in 2005 were reported by the Russian Federation. In the East, the mean annual increase in 1995-2000 (10.0%) was higher than in 2000-2005 (3.9%), and in recent years the number of new cases stabilised while previously treated cases have increased. Efforts are still needed to improve and standardise TB surveillance across the Region. The collection of additional data on risk factors of TB may be useful for surveillance and control. .

National reference laboratories (NRL) and other laboratories are the cornerstones of well-functioning tuberculosis programmes and surveillance activities. However, the scope and activity of NRL services for mycobacterial identification and drug susceptibility testing (DST) has not been examined in detail across the European Union (EU), nor has the added value of cooperation and networking at the European level been explored with regard to strengthening laboratory services. Therefore, the European Centre for Disease Prevention and Control (ECDC) has commissioned a survey to explore these issues and to identify areas of work that could bring added value by supporting networking activities of tuberculosis (TB) reference laboratories in the EU. Structured questionnaires were sent to TB reference laboratory experts in the EU and European Economic Area (EEA) countries, and in three additional countries selected on the basis of their networking activities with EU projects and other initiatives (Switzerland, Croatia and Israel). The compiled results describe the activities and structure of 32 NRLs (29 countries replied, a response rate of 91%). The analysis of the survey led to the following recommendations for strengthening TB laboratory services: (1) implementing of the published European standards for TB laboratory services with respect to infrastructure, national reference functions, biosafety, human resources, quality assurance, operational research (including evaluation of new medical diagnostics), accuracy and speed, appropriately trained staff; (2) ensuring that laboratories only perform activities for which they have demonstrated proficiency; (3) implement validated and standardised second-line drug susceptibility testing (DST), including drugs used to define extensively drug-resistant tuberculosis (XDR TB); (4) aiming to identify Mycobacterium tuberculosis complex (MTBC) and rifampicin (RIF) resistance in over 90% of cultures and cases from smear-positive sputum directly within one to two working days. To realise some of the above recommendations and to strengthen links of TB surveillance and microbiology activities in the EU, a list of suggested generic areas of activities for an EU network of reference laboratories is presented. Such a network would build on and link to existing networks and initiatives at the European and global level.

On 26 February 2008, the World Health Organization (WHO) published its fourth report on the global situation regarding drug resistance in tuberculosis (TB). The report, based on information collected between 2002 and 2006 on 90,000 TB patients in 81 countries, found that 5.3% of the nine million new cases of TB each year are multidrug-resistant (MDR). This is the highest rate yet recorded.