Veterinarian Dr. Fee Zimmermann collects long-term data on human, animal and environmental health in the African tropics and on her doorstep - in Mecklenburg-Western Pomerania. She heads a research group at the Helmholtz Institute for One Health (HIOH) in Greifswald. In this interview, she talks about the importance of the tropics for future disease outbreaks and about animal helpers in data collection.
Dr. Zimmermann, you head the One Health Surveillance Core Unit at the HIOH. Sounds complicated, what exactly is it and what is your group working on?
One Health research is about always considering the health of humans, animals and the environment together and that they cannot be separated from each other. Especially when you are researching antimicrobial resistance or zoonoses, i.e. diseases that spread from animals to humans, you have to consider all sides. The Core Unit aims to set up long-term One Health studies in various indicator regions and collect comprehensive long-term data, which will then serve as a basis for the various research departments at the HIOH and for our partner institutions. What is also particularly important to us is the responsible use of resources. It often makes sense to carry out different analyses with the same sample or to use the same infrastructure for different analyses so that not everyone does everything twice.
Fee Zimmermann is head of the One Health Surveillance Core Unit at the Helmholtz Institute for One Health (HIOH) in Greifswald.
You mentioned indicator regions. Where exactly are they located and what does your work there look like?
Our study areas are relatively small, very precisely defined regions. On the one hand in the African tropics, but also here in Germany. We look at which pathogens are circulating and what actually leads to disease in humans. We have also ensured wildlife monitoring at our two indicator regions in the tropics - the Taï National Park in the Republic of Côte d'Ivoire and the Dzanga Sangha Protected Areas in the Central African Republic - for a long time. We carry out autopsies on wild animals that are found dead in the forest, which gives us an idea of which diseases are relevant in wildlife.
What we are still setting up are cohort studies at our two field sites in Africa, where we will regularly collect health data from the population, but also look at the health of domestic and farm animals and which pathogens are present in people’s homes. We also look at rodents, bats and mosquitoes and collect climate and biodiversity data. All together and at the same location, so that we can better understand complex interrelationships. The tropics in particular are a very relevant area for us because they have a high level of biodiversity. Deforestation and human encroachment into remote areas can lead to transmission of new pathogens to humans and - in combination with the unfortunately often poor health infrastructure - lead to outbreaks.
What exactly do these cohort studies look like?
In Africa, we are working with eight to nine villages in both countries that lie directly on the borders of the national park. We would like to recruit around 2,000 people for the cohorts and carry out various clinical examinations and distribute questionnaires every two to three years in order to gain information on the state of health in the population. We are currently developing the study design for this together with the Department of Epidemiology at the HZI. As these cohorts are to be true One Health cohorts, the extensive data already mentioned above will be collected at the same time.
How willing is the population to participate?
In both countries, people were very interested and very open. We tend to come from the field of wildlife research, and the locals think it's great that we are now also doing something in the villages and for the local population. In Germany, there tends to be cohort fatigue, which we absolutely cannot confirm for Africa.
If you derive behavioral measures from your findings that affect the population: How do people react to them?
Since the major Ebola outbreak in Africa in 2014/15, awareness and interest in such recommendations have been really high. In Central Africa, for example, we are also working with the local radio station to disseminate our findings. One focus at the HIOH is on research on the emergence of infectious diseases. As we take a long-term approach, the great thing is that we see the effects of natural and man-made interventions, such as climate change. We can see how biodiversity is changing and what effect this has on human health. And we can also see the effects of measures to combat climate change, such as reforestation.
Do you have an example of an effect of climate change?
My colleague Lorenzo Lagostina has been looking at the composition of rodent populations from villages to forests every year for some time now and can clearly see, for example, that biodiversity has decreased in recent years. Mainly generalists are spreading, i.e. species that can cope in all habitats. For example, the composition of bat species can change, which in turn can lead to a change in the number of mosquitoes present and thus in exposure to disease.
HIOH researchers also determine the composition of bat species.
How do you monitor biodiversity? That must be very difficult, especially in the rainforest.
We catch the bats in the traditional way with nets in the forest and identify the species. But we also work with environmental DNA, which my colleague Jan Gogarten collects from leaf swabs or carrion flies. He uses genome analyses to see which animals are present in the forest. Great apes and bats are key for us, as the great apes are so closely related to us. In Taï National Park, for example, we discovered a new anthrax pathogen years ago, Bacillus cereusbiovar anthracis. It causes 40 percent of wild animal deaths there, especially among chimpanzees. A study has shown that there is a seroprevalence in the population around the park, meaning that people have antibodies against the pathogen and must therefore have come into contact with it. However, we still do not know whether this also leads to cases of disease in humans and hope to be able to clarify this aspect soon.
HIOH scientist Ariane Düx tested mosquito traps in Taï National Park in April 2024. Mosquitoes are also to be monitored as vectors, i.e. carriers of pathogens, as part of One Health Surveillance.
Let's go to another region. What are the investigations underway in Mecklenburg-Western Pomerania?
We are currently working on site with the University of Greifswald, the University Medicine Greifswald and the Friedrich Loeffler Institute. We have six seed grant projects together with the various founding partners to set up the study design for our One Health Surveillance. In one of these projects, for example, we want to improve and standardize wildlife monitoring in Western Pomerania. Wildlife samples are usually tested for parasites in cooperation with hunters, but we want to extend this to bacteria, viruses and antimicrobial resistance. In a joint project with the Department of Epidemiology at the HZI, we are looking at which cohort studies already exist in northeast Germany and how we can expand these to turn them into real One Health cohorts. For example, there is already the SHIP study (short for "Study of Health in Pomerania"). It has a One Health module in which the study participants are asked whether they have pets. If so, their dogs, cats and chickens are also examined.
The HIOH is also running a citizen science project called CiFly. What is its aim?
Our CiFly team works together with schools. The pupils develop their own study protocols and catch carrion flies, which they use to determine local biodiversity. Carrion flies are very good DNA collectors as they feed on feces and carcasses. By studying carrion flies, it is possible to gain an overview of mammal biodiversity and also of circulating antimicrobial resistance. For example, the children thought about comparing biodiversity in their gardens with the city center or investigating if they could find more antimicrobial resistance around the sewage treatment plant. They had some really great ideas. Introducing children to science and getting them excited about it is the most important effect for us - because the HIOH also needs young talent.
Interview: Dr. Benjamin Blank
This text was published in the HZI magazine InFact in the issue Autumn 2024.
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