Search

Background: Measures for containing the COVID-19 pandemic in 2020 and 2021 resulted in drastic changes in physical activity and dietary habits that also impacted body weight., Methods: The representative study German Health Update (GEDA 2021) includes self-reported information about body weight and body height for adults aged 18 years and older (n=2,985) from July to October 2021. In addition, the study asked about changes in body weight since the beginning of the COVID-19 pandemic., Results: For 59% of participants, body weight has not changed since the beginning of the COVID-19 pandemic, 26% report weight gain, and 15% report weight loss. Younger people indicate weight gain more often than older people, and individuals with obesity report weight gain more often than individuals without obesity. 1.5 years after the beginning of the COVID-19 pandemic, the average weight change within the population is approximately +0.34kg., Conclusions: The effects of restrictions in everyday life with regard to the possible negative impacts on body weight should be given greater consideration and should be monitored in the future., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Background: Overweight and obesity and their associated secondary diseases are of high public health relevance., Methods: Self-reported body weight and body height data are available in the study German Health Update (GEDA 2019/2020-EHIS). The body mass index (BMI, kg/m 2 ) was calculated and overweight (including obesity, BMI ≥25 kg/m 2 ) and obesity (BMI ≥30 kg/m 2 ) were derived., Results: According to this self-report, 53.5% of adults in Germany are overweight, men more often than women. The obesity prevalence for both sexes is 19.0%. The prevalence of overweight and obesity increases with age in both women and men. Obesity is significantly more prevalent in low education groups compared to high education groups. Compared to GEDA 2012, the prevalence of overweight is unchanged, but the obesity prevalence has continued to increase, particularly among 45- to 64-year-olds., Conclusion: The prevention potential of avoiding overweight and obesity remains high., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Health-promoting behaviours are important at any age to prevent diseases and to promote well-being. Using data from GEDA 2019/2020-EHIS, a Germany-wide, representative survey, this article describes how often the adult population in Germany reports certain types of health-promoting behaviour in their everyday lives. The behaviours considered are nonsmoking, low-risk alcohol consumption, achievement of the World Health Organization's (WHO) recommendations on aerobic physical activity, at least daily fruit and vegetable consumption, and maintaining a body weight within the normal range. This article describes the proportion of people who report these behaviours in their everyday lives by gender, age and education level, the number of health-promoting behaviours each person reports and the most common combinations in which they occur. Young adults between 18 and 29 years are most likely to achieve a health-promoting lifestyle. The proportion of people who report at least 150 minutes of physical activity per week and a normal body weight is lower in later adulthood than among 18- to 29-year-olds. The recommendation to eat fruit and vegetables daily is implemented least often of all five aspects of health behaviour under study. Finally, women are more likely to lead a health-promoting lifestyle than men., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Consuming high amounts of fast food can lead to an excessive intake of energy and subsequently promote obesity. Obesity increases a person's risk for diabetes and cardiovascular diseases. The second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017) included the Eating study as a KiGGS Module (EsKiMo II, 2015-2017) which assessed the self-reported dietary habits of children and adolescents in Germany. The analysis of the data permits an overview of the fast food consumption of 12- to 17-year-olds (n=1,353). Girls consume 57.5 grams and boys 86.3 grams of fast food per day on average (around 400 grams and 600 grams per week, respectively). Pizza is the most consumed fast food product, followed by filled pita and sausage/meat products such as curry sausage. Adolescent girls on average get 6.5% and boys 7.8% of total daily energy intake from fast food. 23% of 12- to 17-year-olds get at least 10% of their daily energy intake from fast food (high consumers). Significant differences between the proportion of high consumers exist regarding sex, age, socioeconomic status, community size, type of school and media consumption. Compared to EsKiMo I (2006), girls' daily energy intake from fast food has remained nearly constant, whereas that of boys has dropped substantially. From a nutrition physiology perspective, the aim should be to further reduce fast food consumption., Competing Interests: Conflict of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Energy drinks are soft drinks that usually contain a large content of caffeine and sugar. Excessive caffeine intake can lead to side effects such as nausea and anxiety. Up to three milligrams of caffeine per kilogram of body weight per day is considered safe for children and young people. The second Eating study as a KiGGS Module (EsKiMo II, 2015-2017) collected nationwide representative data about children's and adolescents' dietary behaviour. To collect food intake data from 12- to 17-year-olds (n=1,353), a dietary history interview was used. 8.9% of the girls and boys stated that they had consumed energy drinks during the four-week reference period, with nearly a quarter of these individuals (n=99) exceeding the limit of safe caffeine intake solely through their consumption of energy drinks. This corresponds to 2.2% of the 12- to 17-year-olds in Germany. In addition to a general warning about the high levels of sugar present in sugary drinks, awareness also needs to be raised among young people about the dangers of excessive caffeine intake resulting from the consumption of energy drinks. Regulations governing sales and advertising should also be considered., Competing Interests: Conflict of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Data from the second Eating study as a KiGGS module (EsKiMo II, 2015-2017), are used to determine the contribution of food produced by organic farming (organic food) to the diet of children aged between six and eleven years (n=1,190) in Germany. Dietary intake was assessed by food records during a total of four days. Information on the proportion of organic food intake relative to daily food intake was used to differentiate between three groups: children who did not consume organic food; children whose diet contains 8.0% or less of organic food; and children whose diet comprises more than 8.0% of organic food. The 8.0% threshold represents the mean proportion of organic food eaten by children whose diet includes any amount of organic produce. In total, 63.2% of children eat organic food. The diet of 43.0% of children contains 8.0% or less of organic food, with the diet of 20.2% comprising more than 8.0% of organic food. Vegetables and fruit are among the most commonly consumed organic products. While consumption frequency of organic food does not differ by sex or age, consumption frequency increases with higher socioeconomic status. The large proportion of children (63.2%) who eat organic food suggests that health, environmental and ethical motives play a role in the food choices made by families with children., Competing Interests: Conflict of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

This article examines educational differences in the prevalence of behavioural risk factors among adults and compares the results for Germany with the average from the European Union (EU). Data were derived from the second wave of the European Health Interview Survey, which took place between 2013 and 2015 (EHIS 2). Analyses were conducted using a regression-based calculation of relative and absolute educational differences in the prevalence of behavioural risk factors, based on self-reported data from women and men aged between 25 and 69 (n=217,215). Current smoking, obesity, physical activity lasting less than 150 minutes per week, heavy episodic drinking and non-daily fruit or vegetable intake are more prevalent among people with a low education level than those with a high education level. This applies to Germany as well as the EU average. Overall, the relative educational differences identified for these risk factors place Germany in the mid-range compared to the EU average. However, relative educational differences in current smoking and heavy episodic drinking are more manifest among women in Germany than the EU average, with the same applying to low physical activity among men. In contrast, relative educational differences in non-daily fruit or vegetable intake are less pronounced among women and men in Germany than the average across the EU. Increased efforts are needed in various policy fields to improve the structural conditions underlying health behaviour, particularly for socially disadvantaged groups, and increase health equity., Competing Interests: Conflict of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

This study examines the extent to which health inequalities among children and adolescents in Germany have developed over the past decade. The analyses are based on data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), which are representative of the 0- to 17-year-old population in Germany. The KiGGS data were collected in three waves: the KiGGS baseline study (2003-2006), KiGGS Wave 1 (2009-2012) and KiGGS Wave 2 (2014-2017). Prevalences of five health outcomes are considered: general health, mental health problems, physical activity, the consumption of sugary soft drinks, and smoking. Moreover, it defines health inequalities in relation to differences in the socioeconomic status of the family (SES), an index derived from the parents' level of education, occupation and income, and considers both absolute and relative health inequalities. In order to do so, the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were calculated using linear probability or log-binomial models. Significant inequalities were identified to the detriment of young people from families with a low SES. These inequalities were particularly pronounced in the KiGGS Wave 2 data with regard to general health and the consumption of sugary soft drinks. Additionally, evidence from trend analyses for these two outcomes suggests that relative inequalities have increased. However, absolute inequalities decreased during the same period, and this also applies to smoking. The persistently high and, in some cases, widened levels of health inequalities indicate that adolescents from families with a low SES do not benefit to the same extent from disease prevention and health promotion measures for children and adolescents as young people from families with a higher SES., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

This article focuses on selected indicators related to sports and dietary behaviour - two important factors that influence the development of obesity. The analyses are based on data collected for the second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2), which was conducted between 2014 and 2017. These data were collected, using a questionnaire, from 6,810 girls and 6,758 boys aged between 3 and 17. The analyses also compare the data collected for wave 2 with those from the KiGGS baseline study (2003-2006). More than 70% of 3- to 17-year-olds state that they participated in sports. However, boys do so significantly more often than girls, and 11- to 17-year-olds do so more frequently than 3- to 10-year-olds. In addition, there is a correlation between children's and adolescents' sports participation and those of their parents, and with an activity-friendly living environment. Younger children and girls have healthier diets than older children and boys. However, although the consumption of confectionery and sugary drinks by 3- to 17-year-olds has declined significantly since the KiGGS baseline study was conducted, 11- to 17-year-olds, in particular, eat significantly smaller amounts of vegetables than they did about ten years ago. Significantly more 3- to 10-year-olds currently eat at least five servings of fruit and vegetables per day than ten years ago, although the proportion of the children who reach this recommendation continues to remain very low at 14% overall. It is important to set an example by following a healthy lifestyle within families and other settings in early life. Furthermore, the living environments also need to be made more health-oriented to support children and adolescents in reaching the national recommendations on physical activity and healthy eating., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Consuming large amounts of sugary beverages has been related to developing obesity, diabetes mellitus type II and other chronic diseases. KiGGS Wave 2 (2014-2017) provides data on the consumption of sugary soft drinks in the 3-17 year age group in Germany. Overall, 13.7% of girls and 17.6% of boys consume one to three times a day sugary soft drinks and 3.3% of girls and 4.7% of boys four or more times. Consumption frequency increases with age and is higher among children and adolescents with low socioeconomic status (SES) than for those of the same age with high SES. The share of adolescents who drink sugary soft drinks daily has decreased since the KiGGS baseline study (2003-2006)., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Self-reported data from wave 2 of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017) provides the basis for assessing whether the levels of physical activity of children and adolescents in Germany meet the levels recommended by the World Health Organization (WHO). Merely 22.4% of girls and 29.4% of boys in the 3-17 age group are physically active for at least 60 minutes per day and therefore meet the WHO recommendations. Prevalence of recommended levels of physical activity decreases continuously with age, both for girls and boys. In KiGGS Wave 2, girls in the 3-10 age group met the levels of physical activity recommended by the World Health Organization significantly less often than in KiGGS Wave 1. Low levels of physical activity were highest amongst adolescent age girls, as well as among boys and girls of low socioeconomic status. The results indicate a great potential to promote physical activity., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Nutrition plays an important role for health, in particular of children and adolescents. In addition to the baseline German Health Interview and Examination Survey for Children and Adolescents (KiGGS, 2003-2006), the nutrition survey EsKiMo (Eating study as a KiGGS Module) assessed the dietary habits of children and adolescents aged 6 to 17 in detail. In KiGGS Wave 2 (2014-2017) the corresponding module is EsKiMo II. Between June 2015 and September 2017, specially trained nutritionists will visit EsKiMo II participants at their homes. The parents of 6-to 11-year-olds are instructed on how to complete food records on four randomly chosen days - three consecutive days, followed later by an additional day. Participants aged 12 to 17 are interviewed personally on their food intake during the past four weeks with the dietary interview programme DISHES. Further information, for example, regarding dietary supplements is also recorded. EsKiMo II will provide an up-to-date and representative overview of the current nutrition status of 6-to 17-year-olds living in Germany, and it allows analysing changes in dietary behaviour over time. EsKiMo II can identify shortcomings in the nutrition of children and adolescents and thus may contribute with important information to nutrition and health policy., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Vegetables are part of a healthy diet and can help prevent various chronic diseases. According to the GEDA 2014/2015-EHIS study, 40.4% of women and 23.9% of men eat vegetables on a daily basis. The proportion of women who eat vegetables every day increases with age: from 31.9% of 18- to 29-year-olds to 48.3% of women aged 65 and above. Around one fifth of men under the age of 65 eat vegetables daily; this increases to 35.9% of men aged 65 or above. Across all age groups, women with higher levels of education are more likely to eat vegetables on a daily basis; the same can only be said about men in the 45 to 64 age group. Finally, women and men living in Saxony are most likely to eat vegetables every day; however, the differences between the federal states are marginal., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

In GEDA 2014/2015-EHIS the prevalence of work-related physical activity was estimated based on respondents' self-reported data. 47.5% of women and 47.2% of men mostly sit or stand during work. The highest proportion of people who mostly sit or stand during work is found among 18- to 29-year-old women (55.5%) and men aged 30 to 44 (50.2%). A significantly higher proportion of men (14.8%) than women (3.2%) have jobs involving mostly heavy manual labour. For both genders, the higher a person's level of education, the more likely it is that physical activity during work is limited to sitting or standing. The results highlight great potential to promote physical activity., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Eating fruit is part of a healthy diet and can help prevent various chronic diseases. According to GEDA 2014/2015-EHIS data, 54.2% of women and 38.1% of men eat fruit daily. 38.0% of women and 25.5% of men aged 18 to 29 years eat fruit daily; and in the age group of 65 and older this figure rises to 72.6% for women and 61.1% for men. In the age groups under 65, women with higher levels of education are more likely to eat fruit every day, for men this correlation applies only to those aged between 45 and 64. In Brandenburg, Mecklenburg-West Pomerania, Saxony, Saxony-Anhalt and Thuringia, the proportion of women and men who eat fruit daily is higher than the German average, and in Bavaria and Saarland the proportion of men who eat fruit daily is lower than the German average., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Self-reported data from the GEDA 2014/2015-EHIS study was used to calculate the level of compliance among adults in Germany with the World Health Organization's (WHO) recommendations on physical activity. The WHO's recommendations distinguish between 'aerobic activity' and 'muscle-strengthening activity'. In Germany, 42.6% of women and 48.0% of men reported that they conduct at least 2.5 hours of aerobic physical activity per week, and therefore meet the WHO's recommendation on this form of activity. A higher level of education among women and men of all ages is associated with a higher frequency of meeting the WHO's recommendations on aerobic activity. In addition, 27.6% of women and 31.2% of men conduct muscle-strengthening activity at least twice a week, thereby meeting the WHO's recommendations on this form of activity. About one fifth of women (20.5%) and one quarter of men in Germany (24.7%) meet both of these recommendations. In summary, the results point to the value of encouraging people to conduct more physical activity during their leisure time. In fact, inactive people who begin to follow the WHO's recommendations can significantly reduce their long-term risk of premature mortality., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Body weight and height, as well as associated indicators like overweight and obesity, are widespread factors used to describe the health of a population. Over the past decades, the prevalence of overweight and obesity has increased worldwide and has reached significant public health relevance. According to self-reported data on body weight and body height in the GEDA 2014/2015-EHIS study, 54.0% of adults in Germany are overweight or obese (defined as having a body mass index - BMI - of 25 kg/m 2 or higher). Men are more often affected by overweight than women, with 43.3% of men having a BMI between 25 kg/m 2 and 30 kg/m 2 , compared to women (28.8%). In Germany, the prevalence of obesity (BMI greater or equal to 30 kg/m 2 ) is 18.1%; there is no significant difference between women and men. The prevalence of overweight, including obesity, is higher among women and men with increasing age. Although the prevalence of overweight, including obesity, has remained at a high level in recent years, the prevalence of obesity has increased compared to the GEDA 2010 study., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Folate is important for cell division and thus for growth and physical development. Serum folate concentrations can be used to assess a population's folate status. In Germany, the median serum folate level of adults aged 18 to 79 is 7.5 ng/ml (women: 7.9 ng/ml, and men: 7.2 ng/ml). Approximately 86% of the adult population in Germany has adequate folate levels. Higher folate concentrations are observed among older age groups and individuals with a higher socio-economic status. However, the World Health Organization recommends that women of reproductive age should, at the population level, have significantly higher folate levels in order to reduce the risk for neural tube defects. However, the majority of women in this age group do not achieve these concentrations., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

For many years, a high sodium intake has been discussed as a potential risk factor in the development of hypertension and, consequently, cardiovascular diseases. As part of the German Health Interview and Examination Survey for Adults (DEGS1), which was conducted between 2008 and 2011, sodium excretion in casual urine samples was used as a biomarker to measure sodium intake. DEGS1 observed that the median daily sodium intake of women (3.4 g) as well as men (4.0 g) exceeds the levels recommended by German and international organisations. Among other factors, men's higher sodium intake could be explained by their higher energy intake. In addition, DEGS1 demonstrates an association between women's sodium intake and age; however, no equivalent correlation was identified for men. Furthermore, although high socio-economic status is associated with lower sodium intake in men, no comparable correlation was observed among women., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

People adopt a vegetarian diet for various reasons. A largely plant-based diet not only has advantages for health, it also has positive social and environmental aspects. The aim of this analysis is to provide a description of the people in Germany who follow a predominantly vegetarian diet and to compare their food consumption with those of non-vegetarians. As part of DEGS1 (2008-2011), a validated questionnaire was used within a representative sample of 6,933 persons aged 18 to 79 to study how often and how much of 53 different food groups was consumed during a four-week period. The questionnaire also included a question about a vegetarian diet. The data were analysed descriptively and with a binary-logistical regression model. In Germany, 4.3% of the population (6.1% of women and 2.5% of men) aged 18 to 79 usually follows a vegetarian diet. The highest proportion of vegetarians is found among 18- to 29-year-olds (women 9.2% and men 5.0%) and among women aged 60 to 69 (7.3%). People with a higher level of education are more likely to usually follow a vegetarian diet. The same applies to people who live in large cities and those who conduct more than four hours of sports per week. In addition, women and men who usually follow a vegetarian diet not only consume significantly less meat compared with non-vegetarians, they also drink less energy-reduced drinks, and less beer and wine; they also drink more tea and eat more fruit and vegetables. A vegetarian lifestyle is often associated with positive socio-political impacts. It can, among others, contribute to a reduction in factory farming, which means it can help preserve the environment. A reduction in meat consumption in Germany would also be beneficial from a public health perspective, since meat consumption is currently considerably higher than the amounts recommended by the German Nutrition Society. The benefits linked to a vegetarian diet would be further strengthened, if, in addition to the relatively small group of people who completely refrain from eating meat, a larger section of the population would reduce their meat consumption., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

The growing range of ready-to-cook and ready-to-eat foods (convenience foods) and opportunities to eat outside of the home is tending to reduce the number of fresh meals that people prepare themselves. However, people continue to place great importance on preparing their own meals from fresh foods, as this provides them with greater influence over the quality and composition of the food they eat. The German Health Interview and Examination Survey for Adults (DEGS1, 2008-2011) observed that 50.8% of adults aged between 18 and 79 (61.4% of all women and 40.2% of all men) prepare their meals daily or almost daily from fresh food. Moreover, women report less often that they never cook (2.9%) than men (16.1%) and older participants report far more often to cook daily or almost daily than younger participants. Finally, among both genders is a low level of employment associated with an increased cooking frequency., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Vitamin D plays an important role in the body as part of bone metabolism. Blood serum concentrations demonstrate that 30.2% of adults (29.7% of women and 30.8% of men) have a deficient vitamin D status. In total, 38.4% of adults (38.6% of women, 38.3% of men) have an adequate status. Although there is little variation among men between the various age groups, the proportion of women with deficient vitamin D status increases with age, while the proportion of women with an adequate status decreases. Furthermore, adults with a low socio-economic status are significantly more likely to have a deficient vitamin D status than adults with a higher socio-economic status. Vitamin D status is subject to strong seasonal fluctuations. In order to ensure adequate concentrations of serum vitamin D, it is recommended to expose the face, hands and arms to the sun two to three times a week between March and October without using sun protection; however, sunburn should be strictly avoided., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)

Harmful alcohol consumption is one of the five essential risk factors for disease, impairments and premature death around the world. It is considered to be a contributory cause for more than 200 diseases and is co-responsible for causing many intentional and unintentional injuries. In order to reduce harmful alcohol consumption, the health target "Reduce alcohol consumption" has been currently elaborated in Germany and focuses on a policy mix of behavioural and situational preventive measures to include as far as possible all relevant players for the development of overarching objectives. The data from the recurrent health surveys by the Robert Koch Institute (RKI) allow an evaluation of trends of harmful alcohol consumption in the population aged 25 to 69 between 1990/1992, 1997/1999, and 2008/2011. Harmful alcohol consumption is defined as a daily consumption of pure alcohol of more than 10g for women and more than 20g for men. For the years 2008-2011 harmful alcohol consumption for the age group 18 to 79 years is calculated based on the "German Health Interview and Examination Survey for Adults" (DEGS1) and examined in connection with socio-demographic and health-related factors. The results of DEGS1 show that 13.1% of women and 18.5% of men consume alcohol in harmful quantities. For men harmful alcohol consumption rises with the age; for women the lowest prevalence is found in those aged 30-39 years and the highest in the age group 50-59 years. Women with a high socio-economic status drink a harmful quantity of alcohol to a higher extent than women from medium or low status groups. For men there are no corresponding differences. Mainly smoking is associated with harmful alcohol consumption. Between 1990 and 1992 as well as between 2008 and 2011 harmful alcohol consumption has strongly declined, for women from 50.9% to 13.6%, for men from 52.6% to 18.3% (age group 25 to 69 years). Even if harmful alcohol consumption in the population has strongly declined, the per capita consumption of pure alcohol is above the average of the EU Member States in Germany. For that reason, preventive measures for specific target groups are required., Competing Interests: Conflicts of interest The authors declared no conflicts of interest., (© Robert Koch Institute. All rights reserved unless explicitly granted.)