Report on the Epidemiology of Tuberculosis in Germany - 2011

full report in German

In Germany for 2011, a total of 4,317 tuberculosis (TB) cases were notifi ed. The TB incidence rate was 5.3 cases per 100,000 population, a further decrease from the rate of 5.4 cases per 100,000 (4,388 cases) reported for 2010. The observed reduction in TB cases in the last two years was smaller than in previous years.

Analysis of demographic data: tuberculosis incidence in males was 6.3 cases per 100,000 population while it was only 4.2 in females (men to women ratio of 1.5). This sex-specific diff erence was particularly pronounced in adults of 40 years of age or older. The age-specific incidence was the highest in persons 70 years of age or older (7.9 cases per 100,000 population; 11.0 in men and 5.7 in women). Another peak was found in young adults (age group 25 – 29 years; incidence 6.6 cases per 100,000 population), which was mainly attributed to the population of non-nationals.

Citizenship: tuberculosis incidence in foreign nationals residing in Germany was 22.1 cases per 100,000 population being 6.5 times higher than the incidence in German citizens (3.4 cases per 100,000 population), refl ecting a markedly increased risk of TB in non-nationals. The greatest diff erence was observed in children and young adults. Overall 60.5% were German and 39.5% had foreign nationality. Patients of foreign nationality had a younger age structure than German nationals (median age: 37 vs. 58 years).

Country of birth: approximately half (50.9%) of all patients were born in Germany, while 49.1% of cases were reported among immigrant population coming predominantly from Turkey and the Newly Independent States of the former Soviet Union (NIS). These data confi rm that analysis of citizenship information alone (see above) may lead to underestimation of the proportion of TB patients having a migration background.

Tuberculosis in children: a total of 179 cases were reported in children younger than 15 years of age (incidence 1.7 cases per 100,000 children) compared with 160 cases reported in 2010 (incidence 1.5 cases per 100,000 children). Tuberculosis rates were the highest (2.7 cases per 100,000 children) in the youngest age group (< 5 years old) had the highest increase in case numbers (74 cases in 2010 to 92 cases in 2011). Also in children aged 5 to 9 years (incidence 1.5) a slight increase from 48 to 52 reported cases was observed while in children aged 10 to 14 years (incidence 1.0) a slight decrease in case-numbers were found (38 to 35 cases). The tuberculosis incidence in non-national children was about ten times as high as in German children (incidence 10.0 vs. 1.0 cases per 100,000 children).

Site of disease: 3,346 cases (79.6%) had pulmonary tuberculosis. Potentially infectious (sputum-smear or culture positive) pulmonary tuberculosis was markedly more frequent (2,586 cases, incidence 3.2 cases per 100,000 population) than non-infectious pulmonary tuberculosis (760 cases, incidence 0.9 cases per 100,000 population). Around one third of the pulmonary cases (1,133/3,346; 33.9%) were smear positive and thus highly infectious. Extrapulmonary tuberculosis alone was diagnosed in 856 cases (20.4%). The most common site of extrapulmonary involvement was lymph nodes (431/856; 50.4%).

Drug-resistant tuberculosis: the proportion of multidrug-resistant tuberculosis (MDR-TB) slightly increased from 1.7% (52 cases) in 2010 to 2.1% (56 cases) in 2011. All in all, the proportion of MDR-TB remains stable at around 2%. The proportion of strains resistant to at least one of the fi rst-line drugs (isoniazid, ethambutol, pyrazinamide, streptomycin, and rifampicin), decreased from 12.8% in 2010 to 11.9% in 2011. The proportion of drug resistant tuberculosis cases was higher among foreign-born than in German-born patients (32.7% vs. 7.2%).

Deaths: a total of 162 patients have died of tuberculosis in 2011 compared to 161 patients who died in the previous year. This corresponds to a mortality of 0.2 cases per 100,000 population. Case fatality rate was 3.8% and thus was nearly the same than in 2010 (3.7%).

Treatment outcomes can only be assessed after at least 12 months of follow-up and therefore is reported for cases notifi ed in 2010. The completeness of treatment outcome reporting was 91.6% (4,021 of 4,388 reported cases). Among patients with available information, 81.2% (3,262 cases) were successfully treated (defi ned as treatment completed or cured), 16.1% (648 cases) failed treatment for diff erent reasons, 2.6% (105 cases) were still on treatment and 6 cases were reported as transfer out. We identifi ed some im portant agespecifi c diff erences in treatment outcomes. Patients younger than 40 years of age had higher treatment success rates (> 90%), than the older age group. With increasing age (70 or older years of age), the treatment success rate declined to 63.3%. Lower treatment success rates in elderly can be explained by increased case fatality of tuberculosis and due to other causes. Treatment success was less frequently achieved among MDR-TB patients compared to patients with drug susceptible tuberculosis (52.5% vs. 82.5%).

Conclusion: Epidemiology of tuberculosis in Germany in 2011 mirrors the situation in Germany presented in former reports. However, the tuberculosis incidence in the last years has markedly less decreased than in previous years. Hence, one can assume that Germany is approaching a steady state – similarly to other Western European regions. The increase in tuberculosis incidence rates in young children observed since 2009 further continues also in 2011. This might be a sign of a changing trend, as paediatric tuberculosis (which is usually primary tuberculosis) indicates recent infection. High rates of drug resistant tuberculosis in foreign-born patients refl ect epidemiology of tuber culosis in their countries of origin and confirm the relevance of collected demographic data.

We can conclude that TB-surveillance is essential for timely identifi cation of epidemiological trends and their interpretation in the context of factors potentially infl uencing the epidemiological situation.

The decreasing success in the reduction of case-numbers indicates that tuberculosis still remains a relevant public health problem in Germany. Joint eff orts are essential for continuing an optimized tuberculosis control tailored to the specific needs of Germany.