"Carrion flies are very good DNA collectors"

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.

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.

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 cereus biovar 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.

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.