The trend of declining tuberculosis case numbers in Germany continues
On December 8, 2021, the Robert Koch Institute published its report on the epidemiology of tuberculosis (TB) in Germany for 2020 [1]. With a total of 4127 registered TB cases in 2020, the trend of declining case numbers continues. With 5.0 registered new cases per 100,000 inhabitants, the lowest incidence of TB since the introduction of the Infection Protection Act (IfSG) was recorded in 2020. Following a temporary increase in the number of cases in 2015 and 2016, this downward trend has already been observed for five years and continued in 2019 with a decrease in cases of -14% compared to the previous year. Whether and to what extent the effects of the Covid-19 pandemic have had an impact on this development cannot yet be assessed due to the multifactorial background.
A demographic analysis of the reporting data revealed that young men continue to have the highest risk of contracting TB. At 6.5 cases per 100,000 inhabitants, the incidence among men was almost twice as high as among women. The most frequently affected age group was 20 to 24-year-olds, with an incidence of 11.4 cases per 100,000 inhabitants. The majority of TB sufferers also had a migrant background: Almost three quarters (71%) were born outside Germany. The number of TB cases among children and adolescents under the age of 15 also declined, with 163 cases (incidence 1.4 per 100,000 children). Nevertheless, children continue to represent a particularly vulnerable group among TB sufferers.
The majority of TB cases (88%) were recorded through passive case detection - however, active case detection as part of environmental examinations and screening measures in accordance with Section 36 of the Infection Protection Act (Infektionsschutzgesetz) is of great importance with 320 cases detected. Pulmonary tuberculosis was the most common form of manifestation, accounting for 71% of cases. The majority (86%) were registered as open and therefore infectious, of which half (50%) were microscopically positive, which indicates a higher infectivity. Of the total of 1161 extrapulmonary tuberculoses (28%), the lymph nodes were most frequently affected.
The relative proportion of multi-resistant TB pathogen strains is roughly unchanged compared to the previous year at 2.7%, while the absolute number of cases (79 cases in total) has decreased in line with the overall epidemiological trend.
In 2020, a mortality rate of 0.13% per 100,000 inhabitants was recorded with 108 TB-related deaths. Based on the treatment results available to date, TB treatment was successfully completed in 78% of cases. Differences were found in the analysis by federal state. At around 50%, treatment success is significantly lower in older patients - age-related causes of death are more common in this cohort and are included in the mortality assessment. Overall, however, Germany remains well below the WHO's declared target of 90% successful completion of TB treatment, as factors such as treatment discontinuation and unsuccessful follow-up (e.g. due to transfer to unknown) are included in the analysis in addition to mortality.
In summary, there is a continuing downward trend in the number of tuberculosis cases in Germany. The reasons for this are multifactorial; in addition to reduced migration from countries with a higher TB incidence to Germany, underdiagnosis due to the conditions of the SARS-CoV-2 pandemic cannot be ruled out. TB mortality has increased worldwide and the number of cases is expected to rise(WHO 2021) [2]. The further development of TB case numbers must also be awaited in Germany. Treatment successes continue to fall short of expectations for a low-incidence country with a highly developed healthcare system and could be improved by strengthening treatment structures. The new S2k guideline on the treatment of TB, which will be published in the coming months, can make a contribution to this.
Literature:
- Robert Koch Institute. Report on the epidemiology of tuberculosis in Germany for 2020. Berlin. Robert Koch Institute; 2021.
- World Health Organization. Global Tuberculosis Report. Geneva: World Health Organization; 2021.
