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 working group on emerging viruses, “Neuroinfection and 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 pose a serious 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; these are 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 contained 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 many 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 in 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 geographical location and high urban density. The Camargue region and its wild environment, which are home to numerous migratory species, provide an ideal habitat for mosquito breeding 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, USUTU, and Chikungunya viruses, have thus been detected in Occitanie in recent years.

As warmer weather approaches, individual efforts to combat mosquitoes are becoming increasingly important in our region. Everyone should remain vigilant and follow the recommendations of the EID Méditerranée (Interdepartmental Agreement for Mosquito Control along the Mediterranean Coast), which advises, in particular, 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 outbreaks. Yannick Simonin and his team collaborate closely with the Montpellier Zoo. Zoos, in fact, serve as open-air laboratories where a wide variety of species can be found, acting as sentinels for the presence of numerous viruses in our region. His group focuses specifically 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 most at-risk regions. 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 to, in particular, 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 tip of the iceberg?