Report on the Epidemiology of Tuberculosis in Germany - 2015

full report in German

A total of 5,865 tuberculosis (TB) cases were notified in Germany in 2015. This corresponds to an annual TB incidence of 7.3 cases per 100,000 population. There was a marked change in the numbers of tuberculosis cases in 2015, with a 29% increase compared to the previous year (2014: 4,533 cases; incidence: 5.6). This is the highest number of cases reported since 2005 (6,030 cases).

Analysis of demographic data: Tuberculosis incidence was 10.4 cases per 100,000 population, in men, and 4.2 in women (male to female ratio of 2.4). The age-specific incidence was highest in the age group 20–24 years (16.3 cases per 100,000 population; 23.6 in men and 8.7 in women). Another peak was found in the elderly over 79 years of age (incidence 8.1 cases per 100,000 population; 13.0 in men, and 5.6 in women).

Citizenship: Tuberculosis incidence in foreign nationals residing in Germany was 20 times higher than the incidence in German citizens (50.3 vs. 2.5 cases per 100,000 population). This difference between the two groups has increased compared to the previous year (factor 13). The largest difference was observed in young adults. Overall, 34.1% of all tuberculosis cases were German and 65.9% had foreign nationality. Foreign nationals affected by tuberculosis were younger than German nationals (median age: 28 vs. 60 years).

Country of birth: The proportion of patients born abroad has increased further to 72.1% (2014:
62.2%). The most frequently registered foreign countries of birth in 2015 included Somalia, Eritrea and Afghanistan.

Tuberculosis in children: A total of 196 cases were reported in children younger than 15 years of age (incidence 1.8 cases per 100,000 children). The number of cases has increased compared to 2014 (143 cases; incidence 1.3 per 100,000 children). Tuberculosis incidence was highest in the youngest age group below 5 years of age (75 cases; incidence 2.2). In children aged 5 to 9 years, incidence was 2.0 (68 cases) and in children aged 10 to 14 years it was 1.4 (53 cases). Tuberculosis incidence in children of foreign nationality was almost 37 times higher than in German children (21.4 vs. 0.6 per 100,000 population).

Case finding: The proportion of tuberculosis cases detected by active case finding has increased continuously over recent years reaching 30.3% in 2015 (1.558 cases). The increase is mostly due to active case finding for asylum seekers according to § 36 IfSG which accounted for 80.5% of cases detected by active case finding (1,255/1,558). Case numbers found through active screening of asylum seekers have almost tripled compared to 2014 (425 cases). A high proportion of childhood TB cases were detected through contact tracing (38.9%) as in previous years.

Site of disease: Pulmonary tuberculosis was diagnosed in 77.3% of cases (4,515 cases). It was found to be potentially infectious (sputum-smear or culture positive) in the majority of cases (3,429 cases, incidence 4.2 cases per 100,000 population) compared to non-infectious pulmonary tuberculosis (1,086 cases; incidence 1.3 cases per 100,000 population). Of the pulmonary cases 41.0% (1,850/4,515) were smear positive and thus highly infectious. Extra-pulmonary tuberculosis alone was diagnosed in 1,325 cases (22.7%). The most common site of extra-pulmonary involvement was lymph node tuberculosis (673/1,325; 50.8%).

Drug-resistant tuberculosis: The proportion of multidrug-resistant tuberculosis (MDR-TB) was higher with 3.3% (125 cases) in 2015 compared to 3.0% (94 cases) in 2014.

The proportion of MDR-TB cases was highest in patients born in one of the newly independent states (NIS) of the former Soviet Union (24.5% compared to 0.6% in German born patients). There were 13 extensively drug-resistant TB cases notified of whom 10 were born in a NIS country. The overall proportion of TB cases resistant to at least one of the five standard anti TB drugs (isoniazid, ethambutol, pyrazinamide, streptomycin and rifampicin) was 13.2% in 2015 and had not changed from the previous year. The proportion of »any drug resistant« tuberculosis cases was higher in patients born in a NIS country compared to those born in Germany (41.6% vs. 7.3%).

Deaths: A total of 105 patients died of tuberculosis in 2015 (2014: 109 deaths). This corresponded to a mortality of 0.13 cases per 100,000 population. The case fatality rate was 1.9% and therefore lower than in 2014 (2.5%).

Treatment outcome can only be assessed after at least 12 months of follow-up and therefore is reported here for cases notified in 2014. The completeness of treatment outcome reporting was 81.5% (3,694 of 4,533 reported cases). Among patients with available information, 76.7% (2,833 cases) were treated successfully, 14.2% (526 cases) failed treatment, 6.2% (228 cases) were still on treatment and 2.9% (107 cases) were reported as transfer out. Treatment outcome showed age-specific differences with a higher proportion (> 80%) of treatment success reported for patients younger than 50 years of age. This declined in older age groups. For patients aged 70 years or older 64.8%, and for those aged 80 years or older only 46.8% were treated successfully.

Conclusion: Tuberculosis incidence remained relatively unchanged for several years until 2013 where small increases in case numbers were observed followed by a marked increase in 2015. Available data indicates that the increasing TB case numbers are influenced by a changing demographic context and migration. Thus, the number of foreign born cases has increased steadily over recent years, while the number of German born cases has continued to decline. This increase in case numbers is predominantly due to active case-finding among asylum seekers and refugees. Many have come from countries with high TB incidence and therefore have a higher risk of disease. Active case-finding is an important tool for the early detection and treatment of cases in order to prevent the further spread of tuberculosis.

The increase of case numbers in young children requires particular attention, because of their vulnerability and also as an indicator of current transmission.
The occurrence of multidrug-resistant and extensively drug-resistant tuberculosis is a challenge to tuberculosis control and requires particular attention with a focus on ensuring successful treatment outcomes.

The German TB-surveillance system is essential for timely identification of epidemiological trends and their interpretation in the context of factors potentially influencing the epidemiological situation. However, this requires high completeness and quality of the data.

Rising case numbers, especially in the non-German population, multidrug-resistant and extensively drug-resistant tuberculosis, and a high proportion of infectious pulmonary TB indicate that tuberculosis remains a relevant public health problem with an increasing burden in high risk groups in Germany.

These developments need to be taken into consideration in the strategic approach to maintaining effective tuberculosis control. The needs of persons with a migration background should be considered. Early and thorough case finding coupled with adequate treatment and case management are essential in preventing a further increase in tuberculosis in the long term.

Furthermore, it is essential that the knowledge and experience of those working with tuberculosis is maintained and enhanced through appropriate educational opportunities both during training and in the workplace.