According to International Health Regulations, there is no risk of spread of yellow Fever if the Aedes aegypti index remains below

International Health Regulations (IHRs) of WHO covers 7 diseases: – Cholera – Plague – Yellow Fever – Smallpox – Wild Polio Virus – Human Influenza – SARS International measures to restrict the spread of Yellow Fever (IHRs): – Travellers: - Must possess a valid International certificate of vaccination (validity 10days – 10yrs) against YF before they enter ‘YF receptive areas’ - If no such certificate available: Quarantine for 6 days (Max I.P of YF) from date of leaving an infected area - If traveller arrives before certificate becomes valid (10 days after vaccination): Isolate till it becomes valid Mosquitoes: - Aircrafts/ships arriving from endemic areas: Aerosol spray to kill insect vectors - Airports/ seaports kept free from vector breeding: at least 400 meters around boundary - Aedes aegypti index: kept below 1%