Spotlight: Yannick Simonin – Associate Professor and Director of the “Infection Biology” Master’s Program

Yannick Simonin is an associate professor and director of the “Infection Biology” master’s program at the Faculty of Sciences in Montpellier; he leads the “Neuroinfection and EmeRging VirusEs” working group on emerging viruses at INSERM PCCEI.

 As part of the ARBOSUD–MUSE program, his research group is studying the surveillance and circulation of zoonotic viruses, particularly those transmitted by insect vectors in the Montpellier region, as well as in certain African countries, notably Burkina Faso.

Zoonoses are diseases that are initially transmitted to humans by animals. It is estimated that more than 75% of emerging diseases are of zoonotic origin. They therefore represent a real public health problem, as is currently the case with the COVID-19 pandemic, whose causative virus, SARS-CoV-2, most likely originated in bats, which are believed to be its natural reservoir.

Among zoonoses, vector-borne diseases are particularly noteworthy; that is, diseases transmitted by blood-feeding arthropods (insects that feed on the blood of vertebrate hosts, such as ticks or mosquitoes). These diseases are called arboviruses, and the viruses responsible are arboviruses. This includes, in particular, the viruses that cause dengue, chikungunya, and Zika.

“A vector-borne disease is transmitted by a vector, often a blood-feeding arthropod, such as a mosquito. By biting an infected person or animal, it ingests the parasites, viruses, or bacteria present in the blood. After an incubation period of a few days, the infected insect can transmit the pathogen to a healthy person through another bite.”

There can be multiple reasons for the introduction of a new vector-borne disease. For some of them, such asWest Nile virus and its cousin, theUsutu virus, migratory birds are responsible for bringing these viruses from Africa. Humans, as well as certain pets such as dogs and horses (particularly those from the Camargue), can become infected through mosquitoes that have become contaminated by biting sick birds. The Occitanie region is particularly vulnerable to the spread of vector-borne diseases due to its geographic location and high urban density. The Camargue region and its wilderness, which are home to many migratory species, provide an ideal environment for mosquitoes to thrive and, consequently, increase the risk of vector-borne diseases. These diseases are on the rise in the region, as well as more broadly in southern France and Europe, hence the need to establish local surveillance networks. Cases of infections with the dengue virus, as well as West Nile virus, USUTU, and chikungunya, have thus been detected in Occitanie in recent years.

Individual efforts to combat mosquitoes are particularly important in our region as warmer weather approaches. Everyone should remain vigilant and follow the recommendations of the EID Méditerranée (Interdepartmental Agreement for Mosquito Control along the Mediterranean Coast), which advises, among other things, avoiding standing water near one’s home.

Monitoring the circulation of these arboviruses would make it possible to anticipate—or even limit—the emergence of new epidemics. Yannick Simonin and his team are collaborating in particular with the Montpellier Zoo. Zoos, in fact, serve as open-air laboratories where a diverse range of species can be found, acting as sentinels for the presence of numerous viruses in our region. His group focuses in particular on monitoring two emerging arboviruses:West Nile virus andUsutu virus. These two viruses can affect the human nervous system by reaching the brain and causing potentially severe inflammation. It is therefore important to better understand their circulation in the regions most at risk. In collaboration with CIRAD, his team has just published a study monitoring the presence of these viruses in our region, not only in humans but also in mosquito vectors and various animals (dogs, horses, birds). This is known as the “One Health” concept, which involves implementing a collaborative, multisectoral, and transdisciplinary approach, particularly to anticipate the risk of new diseases emerging—a subject of utmost importance in light of recent events….

Since the COVID pandemic, the surveillance reflex has been triggered… What if COVID were just the tree that hides the forest?