"Ticks: a complex and recent area of research"
In my career, I quickly became interested in ticks and their impact on health. Like mosquitoes, these arthropods are vectors that transmit various viruses, bacteria and parasites responsible for diseases in animals and humans. There are a very large number of tick species, each of which can transmit a number of these pathogens. Most of them are zoonotic, which means that they can multiply in various animal species (rodents, cattle, horses, dogs, etc.) and be transmitted to humans. One important problem with ticks is co-infection, which means that they can be infected with several micro-organisms at the same time. All these factors make ticks quite a complex subject to study compared with mosquitoes, for example, and there are still many areas to investigate.
"Increase our detection performance"
In the laboratory, my unit conducts fundamental and applied research projects to address practical problems related to the specific characteristics of ticks. We have developed a tool, for example, that can efficiently screen a large number of tick species for over 50 potential pathogens. Our studies also look at the interactions between these ticks and the pathogens they transmit, between the pathogens and tick microbiota, and between the pathogens and mammalian hosts, bearing in mind that each species of tick feeds on preferential hosts, which are occasionally humans. We also study ticks themselves, going as far as their neurophysiology, i.e. the nervous system and neurotransmitters, as well as salivary glands etc. To carry out all this research, we take samples of ticks from forests to analyse and rear for several years. We are able to artificially feed the ticks in our rearing facility through different techniques, so we have hundreds of ticks at different stages (larvae, nymphs, adults) for our experiments and are able to visualise their organs or the pathogens in these organs via the latest microscopy and fluorescence systems.
"Mapping risks and monitoring outbreaks of disease"
With the disruption of ecosystems and climate change, the geographical distribution of ticks is also in transition. They are now found, for example, at higher altitudes than in the past. It is therefore important to be able to know which tick species are found where in order to map the risks and pre-empt outbreaks of disease. For the first time in France, for example, some people recently contracted encephalitis following the consumption of raw goat's milk cheese infected with the tick-borne encephalitis virus. This type of contamination is quite rare. Investigations revealed that the goat farm was located on the edge of a forest where ticks infected with the virus were found. Until these cases, the virus was not thought to be present in this area. We are also closely monitoring the risk of the emergence of Crimean-Congo haemorrhagic fever virus in France, which can be fatal to humans. This monitoring of emerging pathogens that may appear as a result of changes in tick distribution requires close cooperation with our colleagues from different French institutes but also with the general public in order to obtain data from the field. This is why a number of citizen science projects have been launched, such as the Citique project's smartphone app for reporting bites before sending in the culprit by post, and the initiation of a project at the ANSES Laboratory in Nancy on ticks in private gardens. All these projects also allow us to interact with the public and explain what we do as scientists to better protect them.