Report on the Epidemiology of Tuberculosis in Germany - 2013

full report in German

In Germany for 2013, a total of 4.318 tuberculosis (TB) cases were notified corresponding to a TB incidence rate of 5.3 cases per 100,000 population. Case numbers are about 2.4% higher than in the previous year (2012: 4,217 cases; incidence: 5.2) and comparable to those from 2011 (4,307 cases, incidence 5.3). Thus, after many years of declining numbers, a plateau was reached.

Analysis of demographic data: Tuberculosis incidence in males was 6.6 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 80 years of age or older (9.2 cases per 100,000 population; 15.0 in men and 6.3 in women). Another peak was found in young adults (age group 25–29 years; incidence 7.6 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 26.5 cases per 100,000 population being more than 9 times higher than the incidence in German citizens (2.8 cases per 100,000 population), reflecting a markedly increased risk of TB in non-nationals. Compared to the previous year this discrepancy has been further increased (factor 7). The greatest difference was observed in children and young adults. Overall 51.6% were German and 48.4% had foreign nationality. Patients of foreign nationality had a younger age structure than German nationals (median age: 35 vs. 59 years).

Country of birth: The proportion of patients born abroad has increased to 56.6%. The most frequent foreign countries of birth include 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 169 cases were reported in children younger than 15 years of age (incidence 1.6 cases per 100,000 children). Compared with 2012 (173 cases; incidence 1.6 ) the number of cases has been almost unchanged. Tu-berculosis rates were the highest in the youngest age group below 5 years of age (76 cases; incidence 2.2). In children aged 5 to 9 years incidence was unchanged at 1.5 (52 cases) and in the group of children aged 10 to 14 years at 1.0 (41 cases). The tuberculosis incidence in non-national children was about 13 times as high as in German children (incidence 10.9 vs. 0.8).

Site of disease: 3,298 cases (76.9%) had pulmonary tuberculosis. Potentially infectious (sputum-smear or culture positive) pulmonary tuberculosis was markedly more frequent (2,624 cases, incidence 3.2 cases per 100,000 population) than non-infectious pulmonary tuberculosis (674 cases, incidence 0.8). More than one third of the pulmonary cases (1,181/3,298; 35.8%) were smear positive and thus highly infectious. Extra-pulmonary tuberculosis alone was diagnosed in 989 cases (23.1%). The most common site of extra-pulmonary involvement was lymph nodes (500/989; 50.6%).

Drug-resistant tuberculosis: The proportion of multidrug-resistant tuberculosis (MDR-TB) markedly increased from 2.1% (64 cases) in 2012 to 3.4% (102 cases) in 2013. Among patients born in the NIS, the proportion of MDR-TB was highest (18.2% vs. 0.7% in German-born patients). The proportion of strains resistant to at least one of the standard drugs (isoniazid, ethambutol, pyrazinamide, streptomycin, and rifampicin), increased from 12.7% in 2011 to 14.3% in 2013. The proportion of drug resistant tuberculosis cases was higher among foreign-born patients originated from one of the NIS countries than in Germanborn patients (36.3% vs. 9.4%). For the first time three extensively drug resistant tuberculosis cases were reported in 2013.

Deaths: A total of 146 patients have died of tuberculosis in 2013. This corresponds to a mortality of 0.2 cases per 100,000 population. Case fatality rate was 3.4%. The highest case fatality rate was found in the age group of 80 years or older (10.6%). In children and young adults under 20 years, no death was recorded.

Treatment outcome can only be assessed after at least 12 months of follow-up and therefore is reported for cases notified in 2012. The completeness of treatment outcome reporting was 91.8% (3,873 of 4,217 reported cases). Among patients with available information, 79.3% (3,073 cases) were successfully treated (defined as treatment completed or cured), 16.0% (618 cases) failed treatment for different reasons, 3.8% (148 cases) were still on treatment and 34 cases (0.9%) were reported as transfer out. We identified some important age-specific differences in treatment outcomes. Patients younger than 40 years of age had higher treatment success rates (> 85%), than the older age groups. Among patients aged 70 years or older the treatment success was 67.4%, among those aged 80 years or older only a proportion of
55.8% successful treatment.

Conclusion: After the continuous decline in the number of tuberculosis cases has already slowed since 2009 case numbers stagnate now – as in some other industrialized nations.

The increase in tuberculosis incidence rates in young children observed since 2009 fortunately did not continue in 2012 and 2013, 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 more than half of all registered TB patients in Germany. However, the proportion of German-born tuber-culosis patients is high compared to other low incidence countries in the European Union.

The current growth in drug resistance needs special 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 high proportion of drug resistant and multidrug-resistant tuberculosis as well as the high proportion of infectious pulmonary TB indicates that tuberculosis still remains a relevant public health problem and efforts for an effective disease control need to be maintained in Germany.
For a successful and sustainable progress in tuberculosis control, the consistent implementation of existing recommendations for contact investigation and for the prevention and treatment of tuberculosis is essential. Moreover, it is important that the knowledge and practical experience are retained in dealing with this disease. Thus, appropriate education and training in study and work should be promoted.