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%
5%
1%
10%
8%