Report on the Epidemiology of Tuberculosis in Germany - 2021

full report in German

In 2021, a total of 3.896 tuberculosis (TB) cases were notified in Germany. This corresponds to an annual TB incidence of 4.7 cases per 100,000 population.

After the number of cases had increased significantly in 2015 and 2016 to almost 6,000 cases each, lower numbers were registered in 2017 and 2018 with around 5,500 cases. Another significant decrease of more than 12% each was observed in 2019 (4,811 cases) and 2020 (4,159 cases). The current case numbers continue to fall, but with a decrease of around 6% in 2021, half as high as in the past two years.

Analysis of demographic data: Tuberculosis incidence was 6.1 cases per 100,000 population in men and 3.3 in women (male to female ratio of 1.9). The age-specific incidence was highest in young adults (age group 20 – 24 years: 10.1; age group 25 – 29 years: 10.3).

Citizenship: Tuberculosis incidence in foreign nationals residing in Germany was almost 15 times higher than the incidence in German citizens (23.5 vs. 1.6 cases per 100,000 population, respectively). The largest difference was observed in young adults. Overall, Germans comprised of 31.8% of all tuberculosis cases, whereas the remaining 68.2% 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 (74.0%) of all patients. The most frequently registered foreign countries of birth in 2021 included Romania, India, Somalia and Eritrea.

Tuberculosis in children: A total of 153 cases were reported in children younger than 15 years of age (incidence 1.3 cases per 100,000 children). There was a slight decrease compared to 2020 (168 cases; incidence 1.5 per 100,000 children), in particular in children below five years. Overall, tuberculosis incidence was highest in the youngest age group below five years of age (69 cases; incidence 1.7). In children aged 5 to 9 years, the incidence of TB was 0.7 (27 cases), while in children aged 10 to 14 years, it was 1.5 (57 cases). Tuberculosis incidence in children of foreign nationality was around 11 times higher in comparison to German children (5.8 vs. 0.5 per 100,000 population). The majority of children had a migration background.

Case finding: As in previous years, most cases (2,970; 87.8%) were detected by passive case finding, including 11 cases (0.3 %) as part of a postmortem examination. The proportion of tuberculosis cases detected by active case finding was 12.2% in 2021 (414 cases) – in particular due to mandatory screening of asylum seekers and refugees (5.1%, 171 cases) and contact tracing (4.8%, 162 cases).

Site of disease: Pulmonary tuberculosis was diagnosed in 71.3% of cases (2,760 cases; incidence 3.3 per 100,000 population) and was potentially infectious (sputum-smear or culture positive) in the majority of cases (2,325 cases, incidence 2.8) in comparison to non-infectious pulmonary tuberculosis (435 cases; incidence 0.5). Out off the pulmonary TB cases, 50.4% (1,391 cases) were smear-positive and, thus, were the most infectious cases. Extra-pulmonary tuberculosis solely was diagnosed in 1,109 cases (28.7%; incidence 1.3). In about half of these extra-pulmonary cases, the main affected site were the lymph nodes (579 cases; 52.2%). Foreign nationals were more frequently affected by extra-pulmonary tuberculosis than German nationals (Incidence 7.7 vs. 0.3).

Drug-resistant tuberculosis: The proportion of multidrug-resistant tuberculosis (MDR-TB) was 2.8% (77 cases) in 2021, and is therefore unchanged compared to the previous year (2020: 2.8%, 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 (17.3% compared to 2.0% in German born patients). According to the new WHO case definition that has been implemented since 2021, one case of extensively drug-resistant TB (XDR-TB) was notified in 2021.

The overall proportion of TB cases resistant to at least one of the four standard anti-TB drugs (isoniazid, rifampicin, ethambutol, pyrazinamide [HREZ] was 10.2% (2020: 10.0%). This proportion was higher among patients born in a NIS country in comparison to those born in Germany (24.1% vs. 7.4%, respectively).

Deaths: A total of 112 patients died of tuberculosis in 2021. This corresponded to a mortality rate of 0.13 cases per 100,000 population. The case fatality rate was 2.9%, which was slightly lower than in the previous year (2020: 3.0%, 125 deaths).

Treatment outcome can only be assessed after at least 12 months of follow-up and is, therefore, reported here for cases notified in 2020. The completeness of treatment outcome reporting was 82.2% (3,420 of 4,159 reported cases). Of these 3,420 cases 78.6% (2,687 cases) were treated successfully, 14.0% (479 cases) experienced an unsuccessful treatment outcome for different reasons, 3.0% (102 cases) were still on treatment, and 4.4% (152 cases) were reported as having transferred out. Treatment outcome showed age-specific differences with a higher proportion (> 90%) 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 48% completed treatment successfully.

Conclusion: After the high increase in TB cases in 2015 and 2016 followed by consistently lower numbers in 2017 and 2018, in 2019 and 2020 a significant decrease in the number of cases of more than 12% compared to the previous years could be observed. In 2021, the numbers are still declining, but with a decrease of 6%, the decline was only about half as high as in the past two years.

With a total of 3,896 cases and an incidence of 4.7 cases per 100,000 population, in 2021 the lowest numbers were registered since the implementation of the German Infection Protection Act (IfSG) in 2001.

The extent to which the COVID-19 pandemic has had an impact on the development of the case numbers in the last two years is difficult to assess, since the epidemiological TB-situation is influenced by several different factors.

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. It remains to be seen how the trend will develop in the coming years. The current epidemiological situation is complex and mainly affected by demographic trends and global mobility – for example from high-burden countries or from areas with a high proportion of MDR- TB, such as currently from Ukraine.

The high proportion of infectious pulmonary tuberculosis illustrates the importance of contact tracing in order to diagnose and treat disease early and effectively prevent further transmission. 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. Tuberculosis retains its importance in the differential diagnosis, regardless of age and origin.

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 treatment outcomes are also of relevance, which remain below the treatment target of 90% set by the WHO – especially in older people. Furthermore, testing for resistance to antituberculosis drugs, regardless of country of birth, is of particular importance.

Even in times of the COVID-19 pandemic, which poses enormous challenges for the health authorities, ensuring early diagnosis and a complete therapy according to guidelines is crucial for tuberculosis control. This also applies with regard to the people currently fleeing from the war in Ukraine and are seeking protection.

The implementation of the necessary measures and strategies in Germany requires coordinated cooperation between all those involved in the healthcare system. Multi-, pre-extensively and extensively drug 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.

Tuberculosis in Germany still remains an important publichealth disease – especially as a differential diagnosis in the COVID-19 pandemic and also in relation to international migration.