Eurosurveillance - Volume 14, Issue 11, 19 March 2009

World TB day on 24 March commemorates this event and is an opportunity for a critical appraisal of the TB situation, for raising awareness and for joining forces in order to control the disease.

Since 1 January 2008, the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization Regional Office for Europe (WHO/Europe) jointly coordinate the tuberculosis (TB) surveillance activities in Europe. The data collected provides an opportunity for a comprehensive analysis of the TB situation. We aimed at analysing the EU and EEA/EFTA data to identify general TB trends and to provoke some discussion regarding the challenges and needs for monitoring the epidemic.

In Germany, since the enactment of the Protection Against Infection Act (IfSG) in 2001, notification of cases of salmonellosis is based on a stable case definition [1], facilitating comparability of data. The annual incidence of notified cases of salmonellosis has declined from over 90 per 100,000 population in 2001 to 60-70 per 100,000 in 2004 through 2007. After very little change from 2005 through 2007, a marked decrease of the number of notified cases (22.6% compared to 2007) was observed in 2008. This drop, as well as the overall decline since 2001 was almost entirely due to the dwindling number of notifications of infections with Salmonella enterica subsp. enterica of serotype Enteritidis (SE) (Figure 1).

Overall numbers of multidrug-resistant (MDR) tuberculosis (TB) rose sharply in the United Kingdom and Scotland in 2007. Risk factors associated with MDR TB in the United Kingdom have been identified but there has been no previous report on risk factors associated with MDR TB in Scotland. Enhanced Surveillance of Mycobacterial Infections (ESMI) data were used to examine demographic and clinical characteristics and treatment outcome of MDR TB cases notified in Scotland between 2000-7. There was a total of 11 culture-positive cases of MDR TB, five of which were notified in 2007. The majority of patients were female, 15-44 years old and unemployed. All were born outside the United Kingdom and most had arrived within the past year from or frequently travelled to their home countries in China, the Indian subcontinent or Africa. Except for one individual, our patients did not self report a history of previous diagnosis of TB which was previously identified as a risk factor for MDR TB in the United Kingdom. Only three patients received directly observed treatment (DOT). Only two patients had completed treatment at 12 months, partially due to the inadequate length of follow-up under the current ESMI system. Our results suggest that most patients had primary resistance due to transmission of MDR TB in high incidence countries and thus point to the importance of international efforts to control MDR TB in these countries. In Scotland, national efforts should be made to increase the number of MDR TB patients receiving DOT and to extend follow-up to improve monitoring of treatment outcome. It is important to identify high risk groups for MDR TB infection in order to deliver effective community-based disease control measures.

In order to estimate the reliability of the officially reported national tuberculosis (TB) incidence rates we performed a retrospective review of data collected in regional and national public health framework. TB notifications for the period 2000-2003 were obtained from two major hospitals and three relevant Public Health Departments (PHDs) in the region of West Greece, and subsequently compared with the data reported to the Hellenic Centre for Diseases Control (KEELPNO). During the four-year study period a total of 161 cases of TB were reported to the PHDs in West Greece; 70% of these cases were reported to the KEELPNO. Furthermore only 72 (38.7%) out of the 186 cases of TB identified in the two hospitals were notified to the PHDs. Assuming that the degree of undernotification observed for the two hospitals is the same throughout the region, we estimated that the case detection rate was 14 cases per 100,000 persons per year, i.e. 3.7 times higher than the rate officially reported for the period 2000-2003. Male predominance (2.1, male/female ratio) and an increased incidence in the elders (older than 60 years) and adolescents (10-14 years old) were also evident. The study demonstrated a substantial underestimation of TB burden in West Greece. In the face of the massive influx of immigrants and refugees coming from regions with high TB incidence and the increase of the number of drug-resistant cases a reliable and complete notification of TB is crucial in the planning of programs and development of appropriate control policies.

A literature review was performed to assess the effectiveness of tuberculosis (TB) contact tracing among migrants and the foreign-born population with emphasis on the European Union. Effectiveness of contact tracing was assessed using the following indicators: coverage, proportion of contacts with TB (TB yield), proportion of contacts with latent tuberculosis infection (LTBI yield) and number of investigated contacts per index case (contacts/index case ratio). The key findings from the literature review were: Among foreign-born contacts, a higher median LTBI yield was found compared with contacts born in the country, when exposed to the same foreign-born index cases. No clear differences were observed between TB and LTBI yield among contacts of foreign-born index cases compared with contacts of index cases from the general population (including the foreign-born) due to the large variation seen between the studies. The included non-European studies screened more contacts per foreign-born index case, used lower cut-off values to define a positive tuberculosis skin test and found higher LTBI yields among contacts. Although the high heterogeneity across the studies made the comparison challenging, several conclusions are made regarding contact tracing among migrants.