Stephan Zientara, age 56, is a veterinary surgeon and virologist. His role at ANSES is to study infectious animal diseases, zoonoses and vector-borne diseases. General Inspector of veterinary public health – Director of the ANSES/INRAE/ENVA joint research unit – Deputy Director of the ANSES Laboratory for Animal Health at the Maisons-Alfort site
“Human intrusion into nature is making it easier for viruses to emerge”
After training as a vet, I decided to move into research in order to better understand and prevent animal disease. Over the past thirty years, I’ve been working with my colleagues from the unit on the viruses affecting different species, such as cats and dogs, horses and cattle. Some of these viruses, such as the ones causing foot-and-mouth disease in ruminants or African horse sickness in horses, are responsible for the major animal diseases, making them a real threat not only for farms but also for public health in general. My work places particular emphasis on vector-borne illnesses such as bluetongue, which primarily affects sheep and is transmitted by midges. Some of these diseases do not affect animals alone: West Nile virus, for example, is mosquito-borne and can cause neurological disorders or even death in both horses and humans. Man’s intrusion into nature is leading to more frequent contact with wild animals. New viruses are emerging and circulating more freely between species. Insect vectors are multiplying due to a climate that is more favourable to their proliferation and also due to the growth of transport. Today, we can travel around the world in just a few hours!
“A specialist at the cutting edge of a subject and also in phase with real life”
These viruses are highly complex to study and our work as a team gives us a clearer understanding of how they can infect a horse, a mosquito or a human, and why they don’t infect other species. To better understand these phenomena with regard to the crossing of the species barrier, we are pursuing fundamental research projects in order to study the way in which a virus interacts with the cells of the infected host, i.e. how it infects the cells, how it interacts with cellular components and how it evades the response of the host. To be able to detect viruses rapidly, we’re developing a number of tests including, for example, a serological test to detect the antibodies produced by an infected animal, and which will subsequently be used by vets. This is known as applied research. It’s highly stimulating to be both a specialist at the cutting edge of a subject and, at the same time, to be liaising with professionals in the field. My work brings me into contact with people from the farming world as well as with fellow academics at scientific conferences. It's hugely rewarding to be able to make discoveries, to prevent disease more effectively and ultimately to see the impact of our achievements in real life. We need research in order to have the data. At the same time, I think it’s important to have this scientific perspective in order to remain in phase with the realities of the field.
“Provide support during crises such as COVID-19”
With my colleagues, my role is also to support control measures and the decisions made by the authorities. The laboratory holds reference mandates for most animal diseases. This means that we develop the methods that are used to carry out official analyses in order to identify the presence of a virus in an animal. We try to determine the emergence of a virus rapidly in order to stop it spreading. As part of this activity, we coordinate a number of networks bringing together professional people and organisations in order to maintain a continuous watch. I have experienced a number of crises in which fast action is essential in order to isolate the virus and confirm its identification. In this current COVID-19 epidemic, one of the teams from the unit (led by Professor Sophie Le Poder) detected the first cat in France to be infected with SARS-CoV-2. We knew that cats could be susceptible to this virus. We put in place a system of vigilance and activated a number of networks, including the network of veterinary surgeons, to make sure that we would be informed as soon as anybody reported any suspicious symptoms in a cat. In this way, we were able to identify the sick cat and carry out analyses in order to confirm the strain of the SARS-CoV-2 virus. A scientific paper was written about this discovery and published in the database of PubMed, the reference website for medicine and biology.