Presentation of the Dufrenoy Silver Medal to Hélène CECILIA

Congratulations to Hélène Cécilia from the DYNAMO team for receiving the Dufrenoy Silver Medal from the French Academy of Agriculture (AAF), in recognition of her thesis work entitled: "Modeling Rift Valley fever transmission dynamics: insight from micro- to macro-scale studies".

Hélène's work aimed to deepen the understanding of the transmission of Rift Valley fever (RVF), a vector-borne zoonotic viral disease primarily found in livestock such as cattle, goats, and sheep. The study focused on Senegal. The epidemic potential of RVF was mapped in the northern part of the country, highlighting a particular risk in September over three consecutive rainy seasons (2014-2016). To assess differences in infectivity among hosts, an intra-host model of viral dynamics was developed, linking the probability of vector infection. The results indicated that sheep were the most infectious species, and mosquitoes of the Aedes genus were more likely to become infected than Culex mosquitoes. This heterogeneity was integrated into a metapopulation model representing seasonal transhumance movements in northern Senegal. This allowed for the quantification of the delay between the introduction of the virus by nomadic populations and its spread among sedentary populations. Furthermore, a consistently earlier infection was observed in cattle compared to small ruminants. This thesis thus contributed to a better understanding of the transmission dynamics of a multi-host pathogen and identified avenues for the implementation of targeted and effective control strategies.

Every year, the French Academy of Agriculture (AAF) awards the Dufrenoy Silver Medal to high-quality doctoral theses dealing with a subject related to the Academy's areas of expertise. The medal ceremony for this year took place on September 20th, during which Hélène Cécilia was honored in the category of "animal production systems". From the BIOEPAR unit, we wish her the best for her career and future projects.