Report on the Epidemiology of Tuberculosis in Germany - 2020

full report in German

In 2020, a total of 4,127 tuberculosis (TB) cases were notified in Germany. This corresponds to an annual TB incidence of 5.0 cases per 100,000 population. After a significant increase in case numbers in 2015, the numbers have decreased in 2017 and remained stable in 2018. Compared to 2019, when the incidence decreased by 12.8 % compared to the previous year, this was even more pronounced in 2020 with a decrease of 14.2 %. The question, whether this epidemiological development has been influenced by the COVID-19 pandemic, cannot be suffiviently answered by surveillance data alone.

Analysis of demographic data: Tuberculosis incidence was 6.5 cases per 100,000 population in men and 3.5 in women (male to female ratio of 1.9). The age-specific incidence was highest in the age group 20 – 24 years (11.4 cases per 100,000 population; 14.9 in men and 7.5 in women).

Citizenship: Tuberculosis incidence in foreign nationals residing in Germany was 13.7 times higher than the incidence in German citizens (24.6 vs. 1.8 cases per 100,000 population, respectively). The largest difference was observed in young adults. Overall, Germans comprised of 33.9% of all tuberculosis cases, whereas the remaining 66.1 % of all cases were foreign nationals. Foreign nationals affected by tuberculosis were younger than German nationals (median age: 31 vs. 61 years).

The analysis by country of birth showed that the proportion of foreign-born patients – as in the previous years – accounts for almost three-quarters (71.3 %) of all patients. The most frequently registered foreign countries of birth in 2020 included Somalia, Romania and Eritrea.

Tuberculosis in children: A total of 163 cases were reported in children younger than 15 years of age (incidence 1.4 cases per 100,000 children). There was a slight decrease compared to 2019 (195 cases; incidence 1.7 per 100,000 children). Tuberculosis incidence was highest in the youngest age group below five years of age (84 cases; incidence 2.1 per 100,000). In children aged 5 to 9 years, the incidence of TB was 0.8 per 100,000 (30 cases), while in children aged 10 to 14 years, it was 1.3 per 100,000 (49 cases). Tuberculosis incidence in children of foreign nationality was around 12 times higher in comparison to German children (6.6 vs. 0.5 per 100,000 population).

Case finding: As in previous years, most cases (3,087; 88.4 %) were detected by passive case finding. The proportion of tuberculosis cases detected by active case finding was 11.6 % in 2020 (405 cases) – in particular due to contact tracing (5.4 %, 187 cases) and the mandatory screening of asylum seekers and refugees (3.8 %, 133 cases).

Site of disease: Pulmonary tuberculosis was diagnosed in 71.4 % of cases (2,903 cases; incidence 3.5 per 100,000) and was potentially infectious (sputum-smear or culture positive) in the majority of cases (2,495 cases, incidence 3.0) in comparison to non-infectious pulmonary tuberculosis (408 cases; incidence 0.5). Out off the pulmonary TB cases, 50.3 % (1,460 cases) were smear-positive and, thus, were the most infectious cases. Extra-pulmonary tuberculosis solely was diagnosed in 1,161 cases (28.6 %). In about half of these extra-pulmonary cases, the main affected site was the lymph node (601 cases; 51.8 %). Foreign nationals are more frequently affected by extrapulmonary tuberculosis than German nationals (Incidence 7.8 vs. 0.4).

Drug-resistant tuberculosis: The proportion of multidrug-resistant tuberculosis (MDR-TB) was 2.7 % (79 cases) in 2020, and it is thus slightly higher than in the previous year (2019: 2.5 %, 88 cases), although the absolute number of cases has decreased.

The proportion of MDR-TB was highest in patients born in one of the newly independent states (NIS) of the former Soviet Union (15.8 % compared to 1.3 % in German born patients). Four extensively drug-resistant TB cases were notified in 2020.

The overall proportion of TB cases resistant to at least one of the five standard anti-TB drugs (isoniazid, rifampicin, ethambutol, pyrazinamide, and streptomycin) was 10.6 % in (2019:11.4 %). The proportion of any drug-resistant TB cases was higher among patients born in a NIS country in comparison to those born in Germany (29.7 % vs. 8.7 %, respectively).

Deaths: A total of 108 patients died of tuberculosis in 2020. This corresponded to a mortality rate of 0.13 cases per 100,000 population. The case fatality rate was 2.7 %, which was slightly lower than in the previous year (2019: 2.9 %, 138 deaths).

Treatment outcome can only be assessed after at least 12 months of follow-up and is, therefore, reported here for cases notified in 2019. The completeness of treatment outcome reporting was 85.6 % (4,117 of 4,812 reported cases). Among patients with available information, 78.4 % (3,226 cases) were treated successfully, 12.5 % (516 cases) experienced an unsuccessful treatment for different reasons, 3.8 % (158 cases) were still on treatment, and 5.3 % (217 cases) were reported as having transferred out. Treatment outcome showed age-specific differences with a higher proportion (> 85 %) of treatment success reported for children and younger patients; this proportion declined in older age groups. For patients aged 80 years or older, only about 50 % completed treatment successfully.

Conclusion: Following the significant increase in tuberculosis in 2015 and 2016 followed by consistently lower numbers in 2017 and 2018, as in 2019 a significant decrease in the number of cases of currently more than 14 % compared to the previous year could be observed in 2020.

In order to achieve the goal set by the World Health Organization (WHO), which for low incidence countries like Germany expects the incidence to be reduced to less than one case per 100,000 inhabitants by 2035, an annual incidence decrease of at least 10 % would be required. The current decline would therefore have to continue. It remains to be seen how the trend will develop in the coming years. The current epidemiological situation is mainly influenced by migration and demographic trends in the population.

The high proportion of infectious pulmonary tuberculosis illustrates the importance of contact tracing. In addition, the screening of refugees and asylum seekers when they are admitted to a shared accommodation facility remains an important measure in active case finding. However, most cases are discovered by passive case finding.

The majority of the patients were born abroad. Nevertheless, around a quarter of tuberculosis patients were born in Germany. Most of them are older people who became infected with TB in the war or post-war years and did not develop active tuberculosis until later in life. Naturally, the size of these birth cohorts is getting smaller. Still, the importance of maintaining continued vigilance against TB and the consideration for differential diagnosis, irrespective of age or origin, needs to be highlighted.

Children are a particularly vulnerable group and often develop a serious clinical picture. Despite declining and small case numbers, tuberculosis among young children requires still particular attention, not only because of their vulnerability, but also as an indicator of current transmission among the population.

Efforts to further improve the treatment outcome are also of relevance. High case numbers in the non-German population, multidrug-resistant and extensively drug-resistant TB, and a high proportion of infectious pulmonary TB indicate that TB remains a significant public health issue in Germany, mainly affecting risk groups.

Ensuring an early diagnosis and a complete therapy according to guidelines is crucial for tuberculosis control and requires coordinated cooperation between all those involved in the healthcare system. Multi- and extensively resistant tuberculosis in particular require competent case management by well-trained and experienced doctors and an adequately equipped public health sector.
Finally, a well-established TB-surveillance system is essential for timely identification of epidemiological trends and their interpretation.