Chikungunya Virus Detection in Semen

Chikungunya is an arboviral disease transmitted by Aedes mosquitoes, present in intertropical zones and Europe. In August 2024, autochthonous cases appeared on Réunion, followed by a large epidemic. In March 2025, the incidence surpassed 2,000 cases per week. Due to a lack of data, the Haut Comité de Santé Publique issued an unfavorable opinion on using substances of human origin during the epidemic. Although the presence of Chikungunya virus genome in semen has been reported in 7 men, the incidence of viral excretion is unknown. This raises concerns about the risk of sexual transmission and infectivity, especially in assisted reproductive technologies. Previous studies on other arboviruses (Zika, dengue) have explored genital excretion. The goal of this prospective pilot study is to investigate Chikungunya virus presence and infectivity in semen, as well as to evaluate the effectiveness of sperm preparation methods in obtaining virus-free gametes. Fifteen patients with acute Chikungunya virus infection will provide blood, urine, and semen samples at different time points (7, 15, 30, 60, 90, and 180 days post-symptom onset). Seminal plasma, native sperm cells, and prepared sperm fractions will be tested for Chikungunya virus RNA at the University Hospital of La Réunion and Toulouse. This study will provide insights into viral excretion patterns and help improve the safety of medically assisted reproduction in epidemic situations.