Transmission
Chikungunya is an alphavirus spread by Aedes aegypti and Aedes albopictus mosquitoes that bite during daytime hours. Repellent, long sleeves and accommodation with screens reduce exposure.
Geography
Outbreaks across the Caribbean, Central and South America, sub-Saharan Africa, Southeast Asia and Indian Ocean islands. Major recent outbreaks have included Réunion, Brazil and Paraguay. Risk is highest in rainy season.
Immunity
A single dose of IXCHIQ (live-attenuated) gives strong protection from around 28 days post-injection. Long-term durability is being studied — current data suggest persistent immunity, but boosters may be recommended in future.