All are features of yellow fever except ?
Ans. is 'd' i.e., Validity of vaccination begins immediately after vaccination Yellow fever Yellow fever is a zoonotic disease caused by ar abro-virus. It affects principally monkeys. Agent - Flavivirus fibricus a group B arbovirus of togavirus family. Vector - Aedes aegypti mosquito. Reservoir - Monkeys and forest mosquitoes. Transavarian transmission of the virus in mosquitoes has been shown to occur in adverse conditions (e.g., during extended dry seasons), in the absence of susceptible hosts. o There is no evidence that yellow fever has ever been present in Asia. Environmental factor for yellow fever. A temprature of 24degC or more is required for the multiplication of the virus in the mosquito. It should be accompnied by a relative humidity of over 60% for the mosquitoes to live long. Urbanization is leading to extension of yellow fever in Africa. Measures designed to restrict the spread of yellow fever are specified in the "International health regulation" of WHO. These are implemented by the Govt of India through stringent aerial and maritime traffic regulations. Broadly these comprise : - i. Travellers All travellers (including infants) exposed to yellow fever or passing through endemic zones of yellow fever must posses a valid international ceificate fo vaccination against yellow fever before they are allowed to enter yellow fever receptive areas like India. The validity of the ceificate begins 10 days after the date of vaccination and extends up to 10 years. Revaccination performed before the end of the validity of ceicicate renders the ceificate valid for a fuher period of 10 years staing on the day of revaccination. If no such ceificate fo vaccination is available, the travellar is placed on quarantine for 6 days from the date of leaving an infected area. ii. Mosquitoes The aircraft and ships arriving from endemic areas are subjected to aerosol spraying with prescribed insecticides. Airpos and Seapos are kept free from the breeding of insect vectors over an area extending at least 400 metres around their perimeters. The "aedes aegypti index" is kept below 1.
IP 3-6 days
1 attack gives life long immunity
Caused by vector aedes
Validity of vaccination begins immediately after vaccination