Report on the Epidemiology of Tuberculosis in Germany - 2012

full report in German

In Germany for 2012, a total of 4,220 tuberculosis (TB) cases were notified. The TB incidence rate was 5.2 cases per 100,000 population, a slightly decrease from the rate of 5.3 cases per 100,000 (4,317 cases) reported for 2011.

Analysis of demographic data: Tuberculosis incidence in males was 6.4 cases per 100,000 population while it was only 3.9 in females (men to women ratio of 1.7). This sex-specific difference 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 (7.4 cases per 100,000 population; 10.7 in men and 5.1 in women). Another peak was found in young adults (age group 25–29 years; incidence 7.1 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 22.2 cases per 100,000 population being almost 7 times higher than the incidence in German citizens (3.2 cases per 100,000 population), reflecting a markedly increased risk of TB in non-nationals. The greatest difference was observed in children and young adults. Overall 59.4% were German and 40.6% had foreign nationality. Patients of foreign nationality had a younger age structure than German nationals (median age: 36 vs. 57 years).

Country of birth: The proportion of patients born abroad has slightly increased to 50.0%. Patients are originating predominantly from Turkey and the Newly Independent States of the former Soviet Union (NIS). These data confirm 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 178 cases were reported in children younger than 15 years of age (incidence 1.6 cases per 100,000 children). Compared with 2011 (177 cases; incidence 1.6 cases per 100,000 children) the number of cases has been almost unchanged. Tuberculosis rates were the highest in the youngest age group below 5 years of age (88 cases; 2.6 cases per 100,000 children). In children aged 5 to 9 years incidence was unchanged at 1.5 (51 cases) and in the group of children aged 10 to 14 years at 1.0 (39 cases). The tuberculosis incidence in non-national children was about 7.2 times as high as in German children (incidence 1.1 vs. 8.0 cases per 100,000 children).

Site of disease: 3,159 cases (77.3%) had pulmonary tuberculosis. Potentially infectious (sputumsmear or culture positive) pulmonary tuberculosis was markedly more frequent (2,485 cases, incidence 3.0 cases per 100,000 population) than non-infectious pulmonary tuberculosis (674 cases, incidence 0.8 cases per 100,000 population). More than one third of the pulmonary cases (1,144/3,159; 36.2%) were smear positive and thus highly infectious. Extra-pulmonary tuberculosis alone was diagnosed in 926 cases (22.7%). The most common site of extra-pulmonary involvement was lymph nodes (453/926; 48.9%).

Drug-resistant tuberculosis: The proportion of multidrug-resistant tuberculosis (MDR-TB) increased from 1.8% (54 cases) in 2011 to 2.3% (65 cases) in 2012. The proportion of strains resistant to at least one of the first-line drugs (isoniazid, ethambutol, pyrazinamide, streptomycin, and rifampicin), increased from 12.1% in 2011 to 12.7% in 2012. The proportion of drug resistant tuberculosis cases was higher among foreign-born patients originated from one of the NIS countries than in German-born patients (33.0% vs. 9.0%).

Deaths: A total of 146 patients have died of tuberculosis in 2012 compared to 144 patients who died in the previous year. This corresponds to a mortality of 0.2 cases per 100,000 population. Case fatality rate was 3.5% and thus was nearly the same than in 2011 (3.4%).

Treatment outcome can only be assessed after at least 12 months of follow-up and therefore is reported for cases notified in 2011. The completeness of treatment outcome reporting was 87.1% (3,758 of 4,317 reported cases). Among patients with available information, 80.3% (3,019 cases) were successfully treated (defined as treatment completed or cured), 16.2% (609 cases) failed treatment for different reasons, 3.3% (124 cases) were still on treatment and 6 cases were reported as transfer out. We identified some important agespecific differences in treatment outcomes. Pa-tients younger than 30 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 64.1%. 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 (63.0% vs. 81.7%).

Conclusion: In Germany, case numbers in 2012 are still falling, although tuberculosis incidence has markedly less decreased in recent than in previous years. The increase in tuberculosis incidence rates in young children observed since 2009 fortunately did not continue in 2012, however a decrease could neither be observed. Therefore, because of their vulnerability and also as an indicator of current transmission this group needs still increased attention.

Since 2007 the proportion of foreign-born patients has increased and now accounts for half of all registered TB patients in Germany. However, the proportion of German-born tuberculosis patients is high compared to other low incidence countries in the European Union.

The current growth in drug resistance needs more attention. High rates of drug resistant tuberculosis in foreign-born patients reflect epidemiology of tuberculosis in their countries of origin and confirm the relevance of collected demographic data.

We can conclude that TB-surveillance is essential for timely identification of epidemiological trends and their interpretation in the context of factors potentially influencing the epidemiological situation in Germany.

The decreasing success in the reduction of case-numbers and in addition the increasing trends in resistant and multidrug-resistant tuberculosis indicates that tuberculosis still remains a relevant public health problem and that efforts for an effective disease control need to be maintained in Germany.