In cooperation between the Academy for Public Health in Düsseldorf and the National Research Platform for Zoonoses, numerous representatives from science and the public health service (ÖGD) met again in Düsseldorf on 14 February 2017. The topic of this event was tuberculosis.
In contrast to other regions of the world, the spread of tuberculosis in Germany has declined sharply in recent decades. The newly emerging challenges posed by resistant tuberculosis strains and global networking therefore require not only an exchange between human and veterinary medicine and between science and the ÖGD, but also an exchange between old and young, since knowledge of many examination techniques and diagnostics in both medical fields also seems to have disappeared with the decline of tuberculosis in Germany. Therefore, the workshop brought together people from the clinic, the ÖGD and science up to European epidemiology.
Dr. Ute Teichert, head of the Academy for Public Health in Düsseldorf, opened the event. Afterwards, Prof. Dr. Christian Menge also gave introductory words of welcome on behalf of the Zoonoses Platform and introduced the National Research Platform for Zoonoses. As head of the Institute for Molecular Pathogenesis at the Friedrich-Loeffler-Institute, which is home to the National Reference Laboratory for Bovine Tuberculosis, he also gave a technical introduction to tuberculosis and described planned changes in the Bovine Tuberculosis Ordinance. According to this, the cooperation between veterinary and health authorities is to be strengthened in the field of tuberculosis, which will result in corresponding adjustments in the Infection Protection Act and the Animal Health Act. Following his presentation, a first, detailed discussion began on the role of cats and other pets as vectors for mycobacteria in nursing and old people's homes and on the communication and distribution of responsibilities between veterinary and health authorities.
Dr. Oswinde Bock-Hensely of the Tuberculosis Museum in Heidelberg discussed the relevance of tuberculosis for health in Europe until the middle of the 20th century. She highlighted the museum and the historical significance of tuberculosis and established references to works by important artists who had been strongly influenced by tuberculosis. Tuberculosis had represented a very great threat to human health in Germany until the 1950s, which today hardly anyone can imagine.
Epidemiology of tuberculosis in Europe - figures not complete
Dr. Vahur Hollo from the European Centre for Disease Prevention and Control (ECDC) in Stockholm spoke about the epidemiology of tuberculosis in Germany, Europe and the world. Despite patchy figures for Europe, it can be said that there has been a decline in tuberculosis in Europe since 1995, although the decline has been much slower since 2006 and there has even been a slight increase in tuberculosis cases in individual countries since 2014. The proportion of Mycobacterium bovis is low among laboratory-confirmed cases, although data on this are incomplete. The incidence of tuberculosis in the population varies widely within Europe. In Western Europe, tuberculosis is more common among immigrants, while in Eastern Europe tuberculosis is more common among the native population. In Eastern Europe, multidrug-resistant tuberculosis pathogens also play a particularly important role. Mr Hollo went on to point out the link between HIV and tuberculosis. There are certain overlaps here. The figures presented on the success of the treatment caused discussion, as some participants felt that they did not correspond with the experiences of the health authorities. There also seems to be an underreporting on the topic of zoonotic tuberculosis. Both phenomena can be partly explained by the different official responsibilities that are divided between human and veterinary medicine and between the countries.
Tuberculosis in animals - raw milk as source of infection
Dr. Karin Schwaiger from the LMU in Munich described the situation in veterinary medicine. Until the eradication of bovine tuberculosis, about one third of all human cases in animals had been infected, among other things through food. Since 1997, the Federal Republic of Germany has been considered officially free of bovine tuberculosis. Since 2008, however, there has again been a conspicuous increase in bovine tuberculosis in the Alpine region. Recent studies of cattle and wildlife ruminants - especially red deer - showed a prevalence of Mycobacterium caprae in almost 5% of the red deer in this region in Germany and almost 20% in Austria. More detailed examinations of the carcasses and se and excretions identified different manifestations of tuberculosis in red deer, which are often not clinically manifest. However, according to Mrs. Schwaiger, certain forms of tuberculosis can be overlooked in the examinations of slaughtered and killed game. The infectious form of tuberculosis, the so-called open tuberculosis, is however very rare and can be recognized by the trained examiner if it is present. Deer are currently considered the reservoir for bovine tuberculosis in the Alpine chain, although the transmission routes are unclear. Research projects on the transmissibility of bovine tuberculosis are currently underway in order to take preventive action and prevent transmission between deer and cattle and humans. The aim is to maintain the bovine tuberculosis-free status and to reduce the risk of infection for wild animals, farm animals and humans. She stressed that pasteurising milk makes it edible, even if it contains mycobacteria. A transmission of mycobacteria via raw milk or raw milk cheese, however, is possible. When selling raw milk, it was therefore necessary to point out that the milk should be heated before consumption. People who consume raw milk unheated because they expect health or taste benefits from it are taking a risk.
In the following discussion, the possibility of treatment in animals is addressed. For cattle, the Bovine Tuberculosis Ordinance prohibits therapy, which means that an infected cattle must be killed and the meat or milk must never be marketed as food. Pets may theoretically be treated, but in case of imminent danger, the killing of these animals can be ordered. In the course of outbreaks on farms, the official veterinarian will decide individually on the basis of risk assessment. However, diagnostic methods for tuberculosis are often species-specific and therefore not equally applicable to all animals.
Class instead of mass - individualized therapy approaches in human medicine
Dr. Barbara Kalsdorf from the Borstel Research Centre reported on the challenges of tuberculosis research in human medicine. She presented the current situation with regard to vaccines (in Germany, vaccination is no longer recommended due to the benefit-risk assessment), diagnostics and therapy options. In diagnostics, the challenge is not only to find infected patients but also to determine resistance in order to be able to treat them accordingly. In therapy, on the other hand, it is essential to treat for a sufficiently long time to prevent the development and spread of resistance. Within the framework of new approaches to personalized medicine, individually adapted diagnostic and therapeutic approaches are used. From their point of view, special challenges are therefore, in addition to a rapid start of therapy, among other things, optimized drug monitoring, individualized drug combinations and a biomarker-controlled, individualized therapy duration.
Tuberculosis the unknown disease
After the lunch break, Dr. Peter Witte reported on the daily work with tuberculosis in the health office of the Minden-Lübbecke district. He explained that the tuberculosis prevalence among refugees in Germany was significantly higher than among the locals. However, after decades of declining tuberculosis infection in Germany, doctors in private practice would have problems correctly diagnosing tuberculosis on the basis of clinical symptoms. Laboratory findings and other diagnostic methods would therefore be particularly important. It would happen that migrants with suitable symptoms and knowledge of the occurrence of tuberculosis in their home countries would themselves formulate a suspicion of tuberculosis to the doctor and a tuberculosis infection would nevertheless remain undiscovered. Meanwhile, in the Health Office of Minden-Lübbecke , every tuberculosis patient is examined in detail, accompanied and receives a closely monitored therapy. This also includes the allocation of a place of residence so that the implementation of the therapy is secured and is not interrupted by relocation. In addition to challenges and prospects of success in the therapy, Mr. Witte spoke about problems in the discharge of patients from the clinic, as unfortunately some of the accompanying doctor's letters were incorrect with regard to the treatment to be continued.
Tuberculosis in Allgäu - interaction between wild and farm animals
Dr. Dr. Markus Schick from the Bavarian State Office for Health and Food Safety supplemented this lecture with a view from the Veterinary Office. He described the wide range of tasks of the veterinary offices and went into the history of tuberculosis. Until bovine tuberculosis was effectively combated, the proportion of people infected with Mycobacterium bovis was still very high, with one third of all tuberculosis cases. By fighting the disease in animals and pasteurising milk, it was possible to reduce the number of cases. Tuberculosis in cattle is still a notifiable animal disease. Since Germany is considered to be free of bovine tuberculosis, nationwide surveillance was abolished in 1997 and reduced to meat inspection at slaughterhouses. The outbreak in the Allgäu in 2012/ 2013 posed a number of challenges for the authorities. Tuberculosis positive animals had to be killed and their milk had to be disposed of, which was a logistical challenge. In addition, many young veterinarians had to learn how to handle the now unusual methods, such as tuberculinisation. In addition, there were farmers who were not cooperative in the official examination of their animals and blaming between hunters and farmers. In the meantime, the outbreak situation in cattle in the Allgäu region has been brought back under control and the status of bovine tuberculosis-free status is not in danger. However, it turned out that part of the red deer population in this area is infected. It is now considered certain that the outbreaks in deer and cattle in the Alpine region are related. The summer grazing of alpine pastures seems to play a role in this. M. caprae was detected in all animals. Investigations in sick people in Austria showed that in two cases M. caprae was transmitted from the animal population to humans.
Tuberculosis among migrants from Africa and Eastern Europe
Finally, Dr. Nicolas Schönfeld from the German Central Committee for the Fight against Tuberculosis reported. He also described that the number of tuberculosis cases in Germany is currently increasing due to the wave of migration. At the same time, the proportion of resistant tuberculosis strains among migrants from Africa was significantly lower than among migrants from Eastern Europe. Depending on the origin of the patients, different tuberculosis strains with different characteristics are therefore to be expected, with the consequence that different treatments are necessary for these patient groups. In his opinion, certain examinations are also not effective and must be supplemented by modern methods such as computer tomography in order to be able to make reliable statements. For explanation and illustration, he presented numerous case reports including diagnostic problems and therapeutic approaches. In his view, it is necessary to treat for a very long time - considerably longer than the 6 months sometimes practiced - to prevent the development of resistance. He also described that there are regions with special challenges and that the clinical examination of children is also of great importance. As a summary of his key messages, he provides an article in Pneumonews: "Tuberculosis in Fugitives - What you should be aware of", which is available for download below this report.
Interdisciplinary exchange in the discussion
The presentations were followed seamlessly by a detailed final discussion. Here, the consumption of raw milk was once again discussed, although this is currently not playing a role in tuberculosis infection in Germany. This led directly to the zoonotic risk of tuberculosis. In view of the current situation in diagnostics in humans and animals and the special challenges in detecting tuberculosis, everyone was of the opinion that, in view of the infected deer population in the Alps and the changed infection situation in humans as a result of migration, it was important to look closely and thoroughly investigate suspected cases. In the current phase, it was important to quickly identify the beginnings of outbreaks in humans and animals so that the current good situation could not come to a head unnoticed. Both veterinary and human medicine are called for here. It is particularly important, he said, to provide more capacity in the health authorities to detect and diagnose rising tuberculosis numbers in good time and to monitor them in the patients' environment. For this purpose, a sufficient number of specialised tuberculosis doctors must again be trained and educated. From the point of view of the discussants, however, this new requirement would not be achievable with the current financial and personnel resources of the offices.
The next important point discussed was the role of pets and domestic animals. As mentioned at the beginning, they play a role both on affected farms and in old people's and nursing homes. For these animal species there are hardly or no suitable live tests for tuberculosis, which means that there is usually a residual suspicion. The Infection Protection Act and the Animal Health Act provide the legal framework for this. There is a separate regulation only for cattle. The research community was told that there is a lack of knowledge about tuberculosis in small pets and that there is an urgent need for information on diagnostics and treatment options.
There is also a great need for research on tuberculosis and food. In the opinion of those present, there is insufficient research into whether and how often mycobacteria are present on food. Milk is not tested for tuberculosis because of pasteurisation. At the slaughterhouse, the official veterinarians carry out post-mortem examinations, and laboratory tests must be carried out if there is any suspicion. The auditorium missed the proof of the absence of mycobacteria, but considers it necessary, especially in the present time.
Finally, it was emphasised that tuberculosis in particular is an example where the knowledge from research and practice of human and veterinary doctors in isolation is not sufficient, but where cooperation brings great added value and is essential for the protection of people and animals.
Tuberculosis today. Where do we stand in Germany, Europe and globally?
Dr. Vahur Hollo, European Center of Disease Prevention and Control
Tuberculosis in veterinary medicine
PD Dr. Karin Schwaiger, Ludwig-Maximilians-Universität München
Challenges in tuberculosis research: Quo Vadis?
Dr. Barbara Kalsdorf, Forschungszentrum Borstel
What are the most relevant challenges in the daily practice of the health authority?
Dr. Peter Witte, Gesundheitsamt Kreis Minden Lübbecke
What are the most relevant challenges in the daily practice of the veterinary office?
Dr. Dr. Markus Schick, Bayerische Landesamt für Gesundheit und Lebensmittelsicherheit
Research initiatives: What is there and what is needed to combat tuberculosis adequately in the future?
Dr. Nicolas Schönfeld, Deutsches Zentralkomitee zur Bekämpfung der Tuberkulose
March 24 is World Tuberculosis Day
RKI press release on the occasion of World Tuberculosis Day
Participants of the workshop in the rooms of the Academy for Public Health in Düsseldorf