Temperature-sensitive incubation, transmissibility and risk of <i>Aedes albopictus</i> -borne chikungunya virus in Europe

Chikungunya virus (CHIKV) has been reported in over 10 European countries. Despite the temperature sensitivity of mosquito-borne viruses, there are no specific models describing the temperature-trait relationship for the extrinsic incubation period (EIP) and vector competence (VC) of CHIKV within Aedes albopictus. This limits our understanding of how temperature influences CHIKV transmission risk in Europe. We used trait data obtained from a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided literature review to model the temperature-trait relationships for EIP and VC. These relationships were then integrated into a temperature-dependent basic reproduction number, R0(T), to generate climate-based risk maps and seasonal suitability. We estimate a maximum EIP50 of 8.7 days at 18°C, a minimum of 1.7 days at 30°C. The vector competence range spans 13.8-31.8°C, peaking at 25.6°C. Moreover, CHIKV is transmissible at lower temperatures than previously recognized, suggesting plausible transmission across most of Europe in July and August, with extended suitability from May to November in southern regions. CHIKV transmission is possible across a broad thermal range, placing large parts of Europe at risk-especially southern regions. Understanding which transmission areas receive the most incursions from trade and tourism during this period can further delineate risk areas for management.